Science word of the day: Abiotic

Pronunciation: Ay-bye-AH'-tik

What it means: Abiotic means "without living organisms." Scientists typically use the term when referring to nonliving aspects of an ecosystem that affect organisms' growth or reproduction. Some abiotic factors might be light, water, fertilizer, nutrients or chemical elements, such as oxygen or sulfur. Others include the tides or rain. Sometimes, "abiotic" is used to describe the origin of a particular chemical. Abiotic methane, for example, comes from chemical reactions between rocks and water in Earth's crust, unlike biotic methane, which comes from decaying organic matter as well as microbes living in your gut.

How to use it in a sentence: A new "gold rush" of exploration is on for abiotic hydrogen, which forms when rocks react with water deep underground and could be a renewable, carbon-free fuel of the future.

Can you crack our science word of the day puzzle, Chain Word?

Unlike humans, frogs and other amphibians don't need to rely on their lungs to breathe; their unique skin helps them exchange oxygen and drink. But how do frogs breathe and drink through their skin?

Frog skin is complex: It's thin, covered in glands that produce mucus to keep the skin moist, and porous enough to allow air molecules to permeate.

"[Their skin] is designed to allow both oxygen to get into the skin, and water to be absorbed," Christopher Raxworthy, a curator and herpetologist at the American Museum of Natural History in New York, told Live Science.

A network of small blood vessels right underneath the skin absorbs oxygen directly from water or the air, and also allows carbon dioxide to be driven out of the body in a process called cutaneous respiration, explained Kurt Schwenk, an evolutionary biologist at the University of Connecticut who has studied the breathing mechanisms of frogs and tadpoles. "It's really almost identical to a lung system," Raxworthy added.

Although frogs can also breathe through their lungs and the lining of their mouth, cutaneous respiration allows frogs to survive underwater and through long hibernations. "Almost without trying, just having skin that's moist, and having some blood vessels in it, they're going to exchange gas and water through their skin, whether they like it or not," Schwenk said, although not all frogs depend on cutaneous respiration equally.

Meanwhile, tadpoles don't have developed gills yet, so they need to breathe in air from the surface to survive. But when they're hatchlings, they're too small to break water's surface tension. Instead, they create their own air bubbles. In a 2020 study, Schwenk and his colleague observed the tadpoles swim right below the surface, where they quickly suck in air, forming a bubble. Then, they push the air bubble into their lungs.

Related: Can turtles really breathe through their butts?

Frogs' porous skin is also how they drink. "That water is getting into all those spaces in the skin, and is then being absorbed across cell membranes into cells and into the bloodstream," Schwenk added. Many frogs even have a highly vascularized area on their skin called a "drinking patch," through which they can absorb a large amount of water.

Some frogs found in arid areas — like the trilling frog and the water-holding frogs living in Australian deserts — are especially adept at absorbing water during rainy seasons. "They store it, and then they go into burrows, into the ground, and sometimes they might even put an extra layer of mucus around them, and then they can survive on that water that they stored internally for months or even years until the next rains come," Raxworthy explained.

Although it's a handy tool, their skin's permeability also means frogs and other amphibians are especially vulnerable to pollutants and climate change, Schwenk said. Studies have shown that the permeability of frog skin routinely exposes the animals to commercial chemical products and microplastics. And because frogs need to keep their skin moist to survive, the increased droughts and warmer weather scientists predict from climate change could shrink frog habitats, especially in the Amazon rainforest and the Atlantic rainforest in Brazil, Argentina and Paraguay.

"Amphibians tend to be some of the first groups that you start seeing declining or disappearing, and that usually is an indication of a problem within the environment," Raxworthy said. Losing frogs, in turn, changes the balance of an ecosystem because of their position on the food chain: They keep insect populations under control and are prey for snakes and birds.

Time will tell if some frog species will adapt to a changing climate. "A question that runs through all climate change biology is whether any particular species is subject to climate change, which is all of us, can adapt fast enough," Schwenk said. "In most cases, climate change is happening much faster than animals can adapt."

Animal quiz: Test yourself on these fun animal trivia questions

This striking astronaut photo shows a unique chain of three atolls lined up side-by-side off the coast of Australia. The oval islands were once part of a colossal coral system that rivaled the Great Barrier Reef.

The trio of islands makes up Rowley Shoals, an uninhabited Australian territory located in the Timor Sea around 180 miles (290 kilometers) off the coast of Western Australia. From southwest to northeast (left to right), the islands are named Imperieuse Reef, Clerke Reef and Mermaid Reef.

The egg-shaped structures are all atolls — rings of land built from fringing coral reefs that once circled an island that has subsequently sunk beneath the waves. These atolls are evenly spaced out into a near-perfect straight line spanning roughly 60 miles (100 km) from end to end, according to NASA's Earth Observatory.

Each island has a surface area of around 30 square miles (80 square km). Only Imperieuse Reef and Clerke Reef have white sandy islets, or cays, that remain above water. Imperieuse Reef also has the only permanent human-made structure in Rowley Shoals — a lighthouse.

The atolls sit on one of the largest continental shelves on Earth. Around 10 million years ago, this area was home to a massive barrier reef system spanning more than 1,250 miles (2,000 km), which later fell into the sea due to tectonic subduction.

The atolls are believed to be some of the last remnants of this lost ecosystem, along with Ningaloo Reef, the Ashmore and Cartier Islands and the Scott and Seringapatam Reefs, according to a study published in February 2025.

Related: See all the best images of Earth from space

The collective ecosystems of Rowley Shoals experienced a massive decline in the 1970s when the islands became popular with tourists and started hosting deep-sea fishing expeditions.

As a result, the area is now protected by two marine reserves: Rowley Shoals Marine Park, which contains Imperieuse Reef and Clerke Reef; and Mermaid Reef Marine Park, which protects Mermaid Reef and its surrounding waters. This has helped the respective ecosystems to recover to pre-tourism levels.

Today, the atolls are home to a wide variety of marine life, including sea turtles, reef sharks and giant clams, as well as around 900 other species of fish, mollusks and corals, according to the Atlas of Living Australia.

Rowley Shoals is currently listed as one of the best places to go scuba diving in Australia, outside of the Great Barrier Reef, according to the Professional Association of Diving Instructors (PADI). However, the atolls' diving season is limited to between September and December to help minimize the impacts of these visitors.

More than half of all known animal species on Earth are insects — critters with a hard external skeleton, three pairs of jointed legs, antennae and a body divided into three segments (the head, thorax and abdomen). There are about 1.4 billion insects for every human on the planet, and their combined weight is 70 times that of all people. Insects are found on every continent and in almost every habitat type, including hot deserts, salty coastal waters and frigid mountain streams. While 97% of insects live on land, some thrive in fresh water and seawater.

5 fast facts about insects

• More than 1 million insect species have been described so far, but scientists estimate there could be up to 30 million we haven't discovered yet.
• Insects are the only invertebrates (creatures without a backbone) to have wings. Most insects have two pairs of wings, but some — including fleas, ants and lice — have no wings.
• Parasites can transform insects into real-life zombies. Infected insects do what the parasite wants, which can be to go up to a predator to be eaten or jump into a pool of water where the insect will drown.
• Many insects are cannibals. For example, female praying mantises may attack and eat males during or after they mate.
• Bees and moths pollinate plants, which helps give us food. But harmful pesticides are leading to large declines in these insects' numbers.

Everything you need to know about insects

Insect pictures

Discover more about insects

• These insects keep evolving to look like sticks. Why?
• How do insects know which flowers have pollen?
• Why are insects attracted to artificial lights?

Further reading

• "Rise of the Zombie Bugs: The Surprising Science of Parasitic Mind-Control"
• "The Jewel Box: How Moths Illuminate Nature's Hidden Rules"
• Discover fun facts about insects at the Smithsonian Institution and learn more from the Australian Museum about how scientists categorize insects.

A gigantic iceberg that broke off of an Antarctic glacier has revealed a thriving never-before-seen ecosystem in the depths beneath.

The iceberg A-84, which is roughly the size of Chicago, calved from Antarctica's George VI Ice Shelf on Jan. 13, 2025.

After receiving news of the iceberg’s movement from satellite imagery, scientists aboard the Schmidt Ocean Institute's research vessel Falkor quickly hurried to the site. Just 12 days later, they arrived to find a never-before-seen ecosystem filled with giant sponges, fish, enormous sea spiders and octopuses exposed to the open air for the first time.

"We seized upon the moment, changed our expedition plan, and went for it so we could look at what was happening in the depths below," expedition co-chief scientist Patricia Esquete, a marine biologist at the University of Aveiro in Portugal, said in a statement. "We didn't expect to find such a beautiful, thriving ecosystem. Based on the size of the animals, the communities we observed have been there for decades, maybe even hundreds of years."

What lies beneath Antarctica's roughly 500 feet (150 meters) of ice is scarcely known, but scientists have suspected that it is filled with a gigantic network of rivers, lakes and estuaries. Yet it wasn't until very recently that scientists discovered that this hidden underworld harbored life.

Related: Scientists create new map showing ice-free Antarctica in more detail than ever before

Without sunlight or nutrients raining down from above, this life is likely sustained by deep-sea ocean currents that slip beneath the surface of the shelf, although scientists are unsure if this is the only mechanism at play.

To investigate the once-hidden biome, the scientists deployed a remotely operated submarine (named SuBastian), which — due to the thick ice blocking off GPS signals — navigated using sound waves to arrive at the ocean floor.

Once there, the submarine collected biological and geological samples from among the region's coral and sea sponges. Some of these creatures' enormous sizes suggested they'd been growing for centuries. The researchers also deployed other autonomous vehicles to study how meltwater is affecting the region.

"The science team was originally in this remote region to study the seafloor and ecosystem at the interface between ice and sea," Jyotika Virmani, executive director of the Schmidt Ocean Institute, said in the statement. "Being right there when this iceberg calved from the ice shelf presented a rare scientific opportunity. Serendipitous moments are part of the excitement of research at sea — they offer the chance to be the first to witness the untouched beauty of our world."

Antarctica quiz: Test your knowledge on Earth's frozen continent

A Buddhist ritual has created an all-you-can-eat buffet for otters living near rivers on the Tibetan Plateau, new research suggests.

"Fangsheng," meaning life release, is the religious practice of saving and releasing animals that were destined to be slaughtered. Buddhist texts recommend the ritual as a way of "paying back debt," "erasing bad luck… healing illness" and "extending one's life," among other benefits, according to a 2020 study in the International Journal of Interreligious and Intercultural Studies.

In accordance with this practice, Buddhists living on the Tibetan Plateau in southwestern China have been releasing fish they buy from markets into local rivers since at least the 1990s, a study published June 21 in the journal Current Zoology has found — and otters have acquired a taste for the newly freed fish.

"Religious fish release may provide additional food resources for otters," researchers wrote in the study. Released fish are usually exotic, non-native species, such as crucian carp (Carassius carassius) and common carp (C. carpio), that could spread diseases or compete with native species for resources. Local authorities banned releasing non-native fish into the wild in 2019, but residents were largely unaware of this, the study noted.

Related: Alaskan sea otters were brought back from the brink of extinction. Now wolves are hunting them.

Despite thousands of fish being released every year, researchers found only a handful swimming in local rivers, including just two crucian carp in samples taken during spring and autumn 2019. This species has successfully invaded and established populations elsewhere on the Tibetan Plateau, according to the study.

'Adventurous consumers'

Eurasian otters (Lutra lutra) are top predators and "adventurous consumers" that don't shy away from new food options, the researchers said. To find out whether otters are feasting on ritual fish, the team analyzed otter fecal samples on the banks of the rivers where the fish are released

The researchers found that, despite making up a tiny proportion of the fish available, non-native fish species made up 20% of the prey detected in otter poop, suggesting they seek out the ritual fish over naturally occurring species. "Eurasian otters showed a preference for released fish," the study authors said. The researchers propose that by hunting exotic fish, the otters may mitigate the impact of Fangsheng and prevent non-native species from colonizing the river ecosystem.

Otters probably aren't choosing released fish for their taste but because they are easy to catch. 

The cold, low-oxygen conditions on the Tibetan Plateau are harsh for exotic species transported from lower elevations. Rising 14,800 feet (4,500 meters) above sea level, the plateau is often referred to as the "roof of the world," according to NASA's Earth Observatory. As a result, released fish may not swim as fast as native species, the researchers suggested.

"Another reason may be that non-native fish have higher nutrition and/or energy, which needs to be studied further in the future," the authors wrote. The team hopes to continue investigating the role of otters in removing released fish by excluding the predators from a stretch of river.

Thirty years after Pablo Escobar's death in 1993, the notorious cartel leader's "cocaine hippos" are still wreaking havoc in one of the world's most biodiverse countries. 

A new study of the invasive mammals' population in Colombia revealed there could be double the number experts previously estimated, Nature reported. A study in 2021 estimated that there were around 98 individuals, but the more recent census, published in April,  puts the population at between 181 and 215. 

These hippos are descended from just four adults that were illegally imported by Escobar in 1991 from Africa to his private zoo at Hacienda Nápoles. Although many of the zoo's other exotic animals — such as giraffes and zebras — were transferred to sanctuaries after Escobar's death, the three female hippos and the one male remained in place due to the challenges of removing them. However, they escaped the abandoned estate and have been living, and rapidly reproducing, in the Magdalena River system ever since. 

Researchers calculated the revised population estimate after conducting surveys in 2021 and 2022. As well as counting hippos in person, they used drones to spot hippos in difficult-to-reach locations, as well as other tracking methods such as using footprints. 

Related: Burmese pythons are helping rats take over Florida's Everglades — and that could help spread disease

Although popular with tourists and some locals, Colombia’s hippos (Hippopotamus amphibius) are an invasive species and pose a multitude of problems. Hippos are ecosystem engineers, so they are drastically changing the ecosystem around them by eating vast quantities of vegetation and filling the Magdalena River system with excrement. While excrement provides a natural source of fertilizer and nutrients for aquatic life, too much of it can have an adverse effect. A 2018 study in the journal Biological Conservation compared pools in central Tanzania that had high and low densities of hippos, and found that the former had lower oxygen content and lower diversities of invertebrates and fishes because of  the high levels of excrement.

Hippos are also dangerous and kill around 500 people every year in Africa. They are territorial, aggressive, fast — both on land and in water — and very strong. There have been at least two hippo attacks on people in Colombia since 2019. 

The Colombian government has grappled with its hippo problem for a number of years. Although culling them might seem like a solution and is endorsed by some conservationists, according to Nature, there was an outcry when a dead hippo was photographed alongside a group of posing soldiers, which put paid to plans for future culls, according to the Guardian. 

Wildlife officials have attempted to administer contraceptives to female hippos via darts and sterilise males, but these initiatives are proving costly and challenging. A study published in April 2023 in the journal Scientific Reports looked at contraceptives and found that it would cost between $1 million to $2 million to "sufficiently decrease hippo population growth to achieve long-term removal." However, this was based on a hippo population of 91 individuals, so this is potentially a huge underestimate of the costs. 

According to the Guardian, plans have been underway to transfer 70 of the hippos to sanctuaries abroad, in northern Mexico and in India, which could cost $3.5 million. But this would still leave between 111 and 145 hippos roaming the river system, the new population estimate suggests. 

Burmese pythons are inadvertently helping rats dominate parts of the Everglades in Florida by wiping out their traditional predators, researchers have found. The rise in rodents could further disrupt an already fragile ecosystem and increase the risk of disease to humans. 

The first Burmese python (Python bivittatus) was found in Everglades National Park in 1979, and numbers skyrocketed throughout the 1980s and 1990s. There are now tens of thousands of the snakes living in the Everglades, and over the last 40 years they have decimated native populations, including bobcats, rabbits and foxes. 

But some smaller mammals appear unaffected by the presence of Burmese pythons, including the cotton rat (Sigmodon hispidus). To find out what impact pythons are having on this species, researchers caught 115 rats and fitted them with transmitters — 34 were in an area known to have a low population of pythons, while 81 were in an area with a high python population. 

They tracked the rats every 48 hours, and recorded the predator involved when any were found dead. In cases where the corpses had likely been swallowed, the team analyzed scat and regurgitated remains for rat DNA. 

Related: Gruesome video reveals the moment a 5-foot alligator corpse was cut from the gut of a dead python

The team’s findings, published May 17 in the Journal of Mammalogy, showed that rat death rates were similar in both areas. Though pythons killed six of the tagged cotton rats in the high python population area, they did not have a significant impact on the overall rat population.

But because pythons have had a devastating effect on the populations of other, larger mammals, such as bobcats and foxes, this has left an ecosystem opening for the rats to take over.

As a result, in areas where pythons are pervasive, cotton rats "now dominate the community," study author Robert A McCleery, an associate professor of wildlife ecology and conservation at the University of Florida, told Live Science in an email. 

The collapse of large and medium-sized mammal populations in the Everglades has impacted important ecosystem processes, such as nutrient cycling and scavenging. Rabbits, for example, acted as a keystone species for seed dispersal. 

Rats, the authors said, are unlikely to be able to fulfill the roles that the lost mammals played. 

Their dominance also has the potential to spread diseases to people. Cotton rats are reservoirs for viruses that can pass to humans, including the Everglades virus (EVEV) and hantaviruses. And in a 2017 study in Biology Letters, researchers found that in the absence of other mammals, mosquitoes in some parts of the Everglades are now mainly feasting on cotton rats. Diseases carried by the rats can then be passed through mosquito bites to humans. 

The study focused on a species of mosquito — Culex cedecei  — that tends to stay away from urban areas, but another species, Culex panocossa, has also been found in Florida — and this species survives in cities. 

Nathan Burkett-Cadena, the study’s lead author and associate professor of entomology at the University of Florida,  said C. panocossa has now come into contact with cotton rats, and this could lead to "increased risk of arbovirus [viruses spread by insect vectors] infection for people living in south Florida," he told Live Science. EVEV is one of these viruses, symptoms for which include fever, severe headache, muscle pain and in rare cases, brain swelling. 

More than 5,000 undescribed animal species have been discovered in the depths of a massive "pristine wilderness" in the Pacific Ocean, a new study shows. But researchers warn they could soon be wiped out by deep-sea mining.

The Clarion-Clipperton Zone (CCZ) is a fracture zone — a large scar of deformed seafloor created by tectonic plate movements — that stretches from Mexico to Hawaii and covers around 2.3 million square miles (6 million square kilometers), which is around 3.5 times the area of Alaska. 

The  CCZ seafloor, which ranges from around 2.5 to 3.7 miles (4 to 6 kilometers) below the ocean surface, is covered with potato-size spherical nodules that are rich in highly desired metals such as manganese, cobalt and nickel, as well as small concentrations of extremely valuable rare earth elements , which has made it prime real estate for deep-sea mining companies.

In the study, published Thursday (May 25) in the journal Current Biology, researchers compiled the first comprehensive list of animal species found in the region using data from more than 100,000 records collected during research trips. The new database, known as the CCZ checklist, contains 5,580 animal species, of which only 438 are officially named. But the researchers estimate there may actually be between 6,000 and 8,000 animal species living in the CCZ and that between 88% and 92% of them could be unidentified.

"There are so many wonderful species in the CCZ," study lead author Muriel Rabone, a deep-sea ecologist at the Natural History Museum in London, said in a statement. "With the possibility of mining looming, it's doubly important that we know more about these really understudied habitats."

Related: 10 bizarre deep sea creatures found in 2022

The biodiversity within the CCZ is very high. The species in the checklist belong to 27 phyla that can be further divided into 49 classes, 163 orders, 501 families and 1,119 genera. 

The most abundant phylum is arthropods — invertebrates with an exoskeleton such as sea spiders, barnacles and crustaceans — which makes up 27% of the database; followed by annelids, or segmented worms, which makes up 18% of the list; and nematodes, or non-segmented worms, which makes up 16% of the species listed. Other groups include cnidarians, a phylum including jellyfish and corals; poriferans, or sponges; mollusks, which include nudibranchs, bivalves and cephalopods; and the nearly indestructible tardigrades. 

Of the named species listed in the CCZ checklist, only six have been recorded living outside the CCZ, which suggests that a majority of the unidentified species listed are also endemic to the region. 

The entire CCZ is beyond the national jurisdiction of any country, and as a result it is managed by the United Nations' International Seabed Authority (ISA). Deep-sea mining in areas beyond national jurisdiction is currently prohibited. But the ISA can grant contracts to mining companies to explore potential deep-sea mining sites. So far, the ISA has granted 17 contracts in the CCZ, covering 463,000 square miles (1.2 million square km). 

The impacts of these exploratory surveys are currently limited. But the ISA could start granting full mining contracts as soon as July 2023 following the deadline for member nations to agree on new mining regulations. If no agreement is reached, companies can start applying for contracts based on draft regulations, which offer very limited environmental protections, New Scientist reported.

Deep-sea mining could potentially impact marine life in a number of ways, including seabed destruction, noise pollution, light pollution and sediment plumes that dump mining waste products directly into the water column, according to the Deep Sea Conservation Coalition — a group made up of more than 100 non-government organizations.

The study researchers say that follow-up studies into the unnamed species listed in the CCZ checklist must be carried out as soon as possible, so that mining companies can develop ways of minimizing their impacts on the marine environment. 

"We share this planet with all this amazing biodiversity," Rabone said, "and we have a responsibility to understand it and protect it."

A strange underwater mountain towering above the seafloor "like a Bundt cake" has been discovered off the coast of California by an uncrewed sailing ship mapping the North Pacific, according to the mission team.

The unnamed, 3,200 foot (975 meter) tall formation falls just short of the required size for a seamount — at least 3,300 feet (1,000 m) above the surrounding seafloor, according to the National Oceanic and Atmospheric Administration (NOAA). Nonetheless, oceanographers have referred to the feature as such because, like other seamounts, it is an underwater mountain with steep sides rising from the seafloor and the remnant of an extinct volcano. 

Underwater mountains formed by volcanic activity sometimes poke through the ocean surface and give rise to islands, such as Hawaii. But this one is entirely submerged, with a crowning crater still visible 1,200 feet (366 m) below sea level.

Apart from its crater, this strange seamount looks nothing like a volcano. "Typically seamounts have sloped sides, like Mount Fuji," Aurora Elmore, program manager for NOAA's Ocean Exploration Cooperative Institute, told SFGATE. "But what's interesting about this one is that it's really steep. It rises from the bottom of the seafloor with a tower shape."

The Saildrone Surveyor — the world's largest uncrewed ocean mapping vehicle — detected the bizarrely shaped mountain 200 miles (322 kilometers) off the coast of northern California. It stands outside the area where seamounts are usually found near the coast, which means the discovery "expands the range" of seamounts, Elmore said. 

Related: Nuclear-powered US submarine collided with a hidden underwater mountain, Navy reveals 

When they first saw the seamount on multibeam sonar images, "the immediate reaction from the team was that it looked like a Bundt cake," Neah Baechler, a hydrographer with the Ocean Exploration Trust and lead surveyor for Saildrone, told The Sacramento Bee. "It's very round and with steep sides and a curved top that slopes into a crater at the center."

The tall doughnut shape may be the result of intense and rapid volcanic activity or a pileup of marine detritus — "millennia of fish poop" — that sharpened the slopes, Elmore said. While this type of formation exists elsewhere on the ocean floor, it is rare to find one (almost) big enough to qualify as a seamount.

"The fact that we can still find these things is really exciting," Jon Copley, a professor of deep-sea ecology and ocean exploration at the University of Southampton in England, told Live Science. "The majority of seamounts around the world — and there are many thousands of them — are formed as undersea volcanoes. This one looks like it would have formed as an underwater volcano because it has a crater."

Seamounts are crucial habitats for marine life because they provide hard, rocky surfaces for creatures to attach to, Copley explained. These are hard to come by in the deep sea, which is mostly covered in loose, muddy sediment. "Seamounts can be too steep for mud to stick to, and some animals really thrive on the sides," Copley said. "When one sticks up, it creates strong currents for filter feeders to grow up into the water and catch food, and you get deep-sea coral and sponge gardens growing there." 

Whether the Bundt cake-shaped mountain will officially qualify as a seamount will probably be up to the committee that names underwater features — the General Bathymetric Chart of the Oceans' Sub-Committee on Undersea Feature Names, which operates under the International Hydrographic Organization and the Intergovernmental Oceanographic Commission (of UNESCO) — Copley said.

The Saildrone Surveyor discovered the feature in February, but the vessel's journey through the North Pacific began in July 2022. The ship first mapped the unknown contours of the seafloor around Alaska's Aleutian Islands before cruising down along the coast of California, according to a statement. 

An idyllic beach in Australia turned into a nightmare scene earlier this week, when locals discovered an enormous, beheaded crocodile rotting in the sand.

Some residents think the mutilation could have been an act of vengeance following a recent spate of crocodile attacks against humans along the Queensland coast between Port Douglas and Cooktown, according to news.com.au. But it's still unclear how the 13-foot-long (4 meters; including the head) giant died, according to the Queensland Department for Environment and Science (DES).

The carcass was in such a state of decay that staff were unable to conduct a necropsy, the government agency said. "Due to the state of decomposition, it cannot be determined if there has been any human interference," the DES told Live Science in a prepared statement. "It may be that the crocodile was decapitated (pre- or post-mortem) due to natural predation."

Some locals, however, doubt that another crocodile decapitated the enormous animal and suspect that it was slaughtered in a trophy killing.

"The DES claim is absolutely ridiculous," Tom Chalmers Hayes, a crocodile photographer and conservationist who went to the scene following reports of the dead animal, told Live Science in a message on social media. "I was with the body for three hours and there is absolutely no marking to suggest a crocodile has killed this male and torn it up, very clear machete marks are on the body and around the neck area where the head has been removed."

Related: Giant 14-foot-long crocodile found with human remains in stomach 

The headless crocodile was found on Cow Bay Beach, north of the Daintree River. Based on its size, the large male is considered an "icon" crocodile under Queensland's conservation laws, which means that it is more strictly protected than smaller individuals. Herpetologists estimate it was at least 30 to 40 years old and a top predator.

The loss of a gigantic male like this one could unsettle the social order of other crocodiles in the area. "As we're only beginning to understand the social system of crocodiles, it is difficult to predict how the removal of a single large male crocodile will impact the remaining crocodiles in the area," Cameron Baker, a postdoctoral researcher at Charles Darwin University in Australia who is not involved in the beheading investigation, told Live Science in an email. "However, it will likely represent a period of social unrest and change in the population as individuals try to determine where they sit in the new social hierarchy resulting from this large male's loss."

Conflict could arise between several males vying to replace the dead individual, although crocodiles may not be as territorial as scientists once thought, Baker said.

The killing could also have a ripple effect on the coastal ecosystem. "As top predators, crocodiles potentially play several crucial roles in their environment," Baker explained. "For instance, by limiting the population density and behavior of their prey species, crocodiles inadvertently enhance the survival of their prey's prey. As such, the removal of crocodiles through hunting may unintentionally alter the composition of the ecosystem, reducing its overall health and productivity."

Crocodiles in Queensland have come back from the brink of extinction since the 1970s, when hunters killed them for their skins, according to a 2020 DES report. But they are still listed as a vulnerable species by the DES under the state's Nature Conservation Act 1992.

The beheading follows three serious but non-fatal crocodile attacks on people in the area since February. The last incident occurred on April 8, when a nearly 15-foot-long (4.5 m) croc repeatedly bit a man and nearly drowned him at Archer Point, south of Cooktown. The man managed to escape by sticking his fingers in the animal's eyes.

Scientists have discovered never-before-seen viruses that thrive in sunlit oceans from pole to pole and infect plankton. They dubbed the newfound microbes "mirusviruses" — "mirus" meaning "strange" in Latin.

The researchers concluded that mirusviruses belong to a large group of viruses called Duplodnaviria, which includes the herpesviruses that infect animals and humans, based on shared genes that encode the shell, or "particle" enclosing their DNA. But the strange, newfound viruses also share a staggering number of genes with a group of giant viruses, called Varidnaviria.

This suggests that mirusviruses are a bizarre hybrid between two distantly related viral lineages, the scientists concluded.

"They seem to be an extremely unusual group of viruses," Tom Delmont, a researcher at the French National Centre for Scientific Research (CNRS) who participated in the discovery, told Live Science. "This is why we consider them as being chimeric, because they are a mix of two different groups of viruses — on one side the herpesviruses, based on the particle genes, and on the other side the giant viruses, based on many more genes."

The team described the strange, newfound viruses in a study published Wednesday (April 19) in the journal Nature. The discovery highlights how little we know about the viruses lurking in Earth's oceans.

Related: Scientists discover viruses that secretly rule the world's oceans

To find the viruses, the team pored over data from the Tara Ocean expedition, which collected nearly 35,000 ocean water samples containing viruses, algae and plankton between 2009 and 2013. The researchers then searched for evolutionary clues in millions of microbes' genes.

"Working on this data is like surveying a huge area of sand with a metal detector, looking for a treasure," Delmont said. "We found an evolutionary treasure."

In combing through this data trove, the scientists detected a previously undescribed lineage of double-stranded DNA viruses, the mirusviruses, that can be found in the sunlit surface waters of polar, temperate and tropical oceans. These abundant viruses infect plankton, which are tiny organisms that drift on ocean currents and can produce spectacular blooms visible from space, according to the National Ocean Service. 

By invading the plankton's cells, mirusviruses likely help regulate the microorganisms' activity and thus the flow of carbon and nutrients through the ocean.

"Viruses are a very natural component of plankton at the surface of the ocean," Delmont said. "They are going to destroy many, many cells every day and this is going to release nutrients, particles inside the cells that are going to be used by other cells to be active and healthy."

Mirusviruses may be the key to resolving the enigmatic origin of herpes viruses, Delmont said. The genes encoding the protective shell around viral DNA are strikingly similar in both groups, suggesting that they are related.

"This means that there is a shared evolutionary history between herpes, that infect only animals, and the mirusviruses that are everywhere in the ocean, where they infect unicellular organisms," Delmont said. "All of this is pointing to a planktonic origin for herpes."

These unusual viruses represent a new front for research into microbial life in our oceans and there are many more discoveries in store, Delmont said.

"We will be trying to isolate mirusviruses in the coming year," co-author Hiroyuki Ogata, a professor at the Institute for Chemical Research at Kyoto University, told Live Science in an email. "Isolation is now essential to uncover the mystery of this new viral [group]."

Scientists have discovered tiny fragments of 2 million-year-old DNA trapped within frozen layers of Arctic sediment. The ancient genetic material, which is the oldest ever discovered, has provided a glimpse of a previously unknown ecosystem.

Since 2006, researchers have uncovered 41 samples of DNA within a 328-foot-deep (100 meters) slab of sediment at the Kap København Formation in northern Greenland. The genetic fragments, known as environmental DNA, were left by plants, animals and microbes that once lived in the area and have been perfectly preserved by permafrost and ice. 

The previous oldest DNA sample ever found, which was revealed to the world in 2021, was retrieved from a 1.2 million-year-old mammoth bone in Siberia, researchers wrote in a statement.

In a new study, published Dec. 7 in the journal Nature, researchers isolated and analyzed the ancient DNA samples and compared them with known genome sequences to reveal what creatures left the DNA. The results paint a picture of an incredibly diverse ecosystem that included birds, reindeer, hares and, most surprisingly, mastodons, an extinct group of elephant relatives that were not previously known to have lived that far north.

"A new chapter spanning one million extra years of history has finally been opened and for the first time we can look directly at the DNA of a past ecosystem that far back in time," study lead author Eske Willerslev, an evolutionary ecologist at the University of Cambridge in the U.K., said in the statement.

Related: Scientists discover 1 million-year-old DNA sample lurking beneath Antarctic seafloor 

The DNA fragments were incredibly difficult to study. Each scrap of genetic material was only "a few millionths of a millimeter long," which made it hard to isolate the fragments from the sediment layer without completely breaking them, the researchers wrote in the statement. The collection of the sediment began in 2006, but before attempting to extract the DNA, the researchers decided to wait until more advanced technology was available.  

"It wasn't until a new generation of DNA extraction and sequencing equipment was developed that we've been able to locate and identify extremely small and damaged fragments of DNA in the sediment samples," study co-author Kurt Kjær, a paleogeologist and geneticist at the University of Copenhagen in Denmark, said in the statement.

As well as a variety of animals, the DNA also revealed the presence of several species of trees, bacteria and fungi. Not all of the DNA samples could be matched with known species, suggesting that some could be new to science. However, almost all were identified to at least the correct genus. 

The sediment layer excavated by the researchers accumulated during a 20,000-year period around 2 million years ago. During this time, the area was between 18 and 31 degrees Fahrenheit (10 to 17 degrees Celsius) warmer than Greenland is today, the researchers wrote in the statement. This shows that entire ecosystems can rise and fall because of climatic changes, they added. 

Related: World's oldest human DNA found in 800,000-year-old tooth of a cannibal 

"The data suggests that more species can evolve and adapt to wildly varying temperatures than previously thought," study co-author Mikkel Pedersen, an evolutionary geneticist at the University of Copenhagen, said in the statement. "But, crucially, these results show they need time to do this." Therefore, species at threat from current human-driven climate change are unlikely to be as successful because they will have much less time to adapt, he added.

The researchers will now try to build a more in-depth picture of the Kap København ecosystem by working out how the various species might have interacted with one another, according to the statement. The new findings could also shed more light on if and how DNA has changed over the last 2 million years, the team added.

Being able to locate, isolate and sequence such ancient DNA also provides hope that similarly ancient, or even older, genetic samples could be unearthed elsewhere around the globe.

"If we can begin to explore ancient DNA we may be able to gather ground-breaking information about the origin of many different species — perhaps even new knowledge about the first humans and their ancestors," Willerslev said. "The possibilities are endless."

A bizarre-looking translucent, gelatinous fish with an unusual suction cup on its belly made a surprise appearance for a group of scientists who were studying the deep sea near Alaska. 

The odd animal is a blotched snailfish (Crystallichthys cyclospilus), a seafloor-dwelling creature that lives exclusively in the North Pacific and can survive more than 2,723 feet (830 meters) below the ocean surface. Researchers from the National Oceanic and Atmospheric Administration (NOAA) stumbled upon this squishy weirdo while trawling off the coast of the Aleutian Islands in Alaska as part of a routine survey of the deep sea ecosystem there. On June 19, NOAA scientist and expedition crew member Sarah Friedman shared a photo of the blotched snailfish on Twitter.

The fish's body is "very gelatinous" and felt like "holding a lump of Jell-O," Friedman told Live Science in an email. "This is thought to be an adaptation to maintain neutral buoyancy and efficiently swim while coping with the crushing pressure of the deep sea," she added.

The team was excited to show off the peculiar specimen online so that more people could see the fish for themselves. "They live in relatively remote locations and at deeper depths, so the average person will never encounter this species," Friedman said. But although such fish are uncommon, the researchers did find "four or five" different blotched snailfish specimens during the trip, she added.

Related: Translucent jellyfish, with fish trapped inside it, washes up on UK beach 

Blotched snailfish have bodies that are almost entirely see-through — apart from their eyes, stomachs and dark spots on their skin. This adaptation helps them to stay hidden from predators. "Many animals that live at deeper oceanic depths are translucent," Friedman said. It enables them to "blend in with the dark background in a habitat with limited light availability and few structures to hide behind."

Like several other species of snailfish, blotched snailfish have modified fins on their bellies that form a suction cup. "This allows them to easily attach to rocks and corals on the ocean floor and avoid expending the energy to constantly swim around, particularly in strong currents," Friedman said.

Overall, little is known about what these snailfish get up to in the deep ocean. "Snailfish are an incredibly enigmatic and diverse group of fishes, with species that inhabit a wide range of environments, from tidepools to the deepest trenches of the ocean," Friedman said. "But not much is known about the ecology of deeper snailfish species," although scientists do know that they prey on small invertebrates that crawl along the seafloor, she added. (There are more than 400 species of snailfish globally.)

The team also found a number of other interesting marine specimens during the trip, including a giant sea spider (which isn't actually a true spider); an anglerfish with massive pointed teeth and a luminous barb for luring prey; and a barreleye fish, which can swivel its eyes to peer through the top of its translucent head.

However, the main goal of these trawls is not to find rare species. Rather, the surveys are carried out to assess the overall health of the ecosystem, particularly regarding the populations of commercially targeted species. "This research is essential to sustainably manage fish and crab species that support commercial, recreational and subsistence fisheries and Alaska coastal communities," Friedman said.

Originally published on Live Science.

One of the world’s most dangerous prehistoric ecosystems just added another huge predator to its lineup. In the Bahariya Formation, a famous fossil site in Egypt’s Sahara Desert, a team of Egyptian and American paleontologists recently uncovered a huge fossil vertebra belonging to a newly described species of meat-eating abelisaurid dinosaur — a bipedal, carnivorous group that lived during the Cretaceous period (145 million to 66 million years ago). 

Like other abelisaurids, the newfound dinosaur had a shortened, bulldog-like face. And despite its ferocious appearance, this carnivore probably wasn’t the biggest, baddest boss to roam its stomping grounds.

"We’re about 99% sure that, unlike some of its relatives from other times and places, this particular abelisaurid was not at the top of its food chain," Matthew Lamanna, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh and one of the researchers who discovered the dinosaur, told Live Science in an email.

Related: Crocodile-faced dinosaur may have been Europe's largest ever predator

Though Lamanna and his fellow scientists found only a single bone, they were able to identify the fossil as an abelisaurid vertebra almost immediately, based on distinctive structures called epipophyses. "That’s a multisyllabic word that basically means 'sticky-outy bits on the top left and top right of the vertebra,'" Lamanna said. This abelisaurid is the first dinosaur of its kind to be discovered at the Bahariya Formation site. After running a computer-based analysis of the bone’s morphology, the team concluded that it belonged to a previously unknown species, which has yet to be given a scientific name. They published their findings June 8 in the journal Royal Society Open Science. 

An abelisaurid somewhat resembled a heavy-set Tyrannosaurus rex, only with even stubbier arms, Smithsonian Magazine reported. They roamed the Southern Hemisphere from the middle of the Jurassic period, about 170 million years ago, right up until the Chicxulub asteroid brought the Cretaceous to a screeching halt. Perhaps the most famous abelisaurid is the horned Carnotaurus, a Patagonian predator that reached 25 feet (7.6 meters) long, according to London's Natural History Museum. Its name is taken from the Latin words for "flesh" and "bull," and animated versions of this fearsome carnivore have appeared in Apple TV's "Prehistoric Planet" and in the "Jurassic Park" franchise (though, its portrayals display varying degrees of scientific accuracy). 

The researchers suspect that the newly discovered abelisaurid was smaller than Carnotaurus, likely reaching just 16 to 20 feet (5 to 6 meters) in length. And compared to the predators who shared its native habitat 98 million years ago, the newfound abelisaurid would have been a relative pipsqueak.

The Bahariya Formation was previously home to a uniquely predator-rich slice of prehistoric life. This once-vast mangrove swamp hosted numerous species of fish, turtles, snakes and dinosaurs. The newfound abelisaurid would have rubbed elbows (metaphorically speaking) with a T. rex lookalike known as Carcharodontosaurus; a mysterious giant therapod (bipedal, three-toed dinosaurs) called Bahariasaurus; the monstrous Spinosaurus, which had long and slender crocodilelike jaws and a sail growing from its back; and giant predatory fish and crocodilians.

Finding so many large predators living together in a single ecosystem is rare,  Lamanna said. "How this 98-million-year-old environment managed to support not one but four massive predatory dinosaurs remains a puzzle," he added.

The newly described fossil is now stored in the permanent collection of Mansoura University's Vertebrate Paleontology Center in Egypt. In the future, Lamanna and his coauthors plan to return to the Bahariya Formation and search for more bones from their abelisaurid — and maybe even give it a name.

"Hopefully more of this Bahariya beast will turn up sooner or later," Lamanna said. 

Originally published on Live Science.

A never-before-seen ecosystem lurks in an underground river deep below the icy surface in Antarctica. Researchers recently brought this "hidden world" into the light, revealing a dark and jagged cavern filled with swarms of tiny, shrimplike creatures.    

The scientists found the secret subterranean habitat tucked away beneath the Larsen Ice Shelf — a massive, floating sheet of ice attached to the eastern coast of the Antarctic peninsula that famously birthed the world's largest iceberg in 2021. Satellite photos showed an unusual groove in the ice shelf close to where it met with the land, and researchers identified the peculiar feature as a subsurface river, which they described in a statement. The team drilled down around 1,640 feet (500 meters) below the ice's surface using a powerful hot-water hose to reach the underground chamber. 

When the researchers sent a camera down through the icy tunnel and into the cavern, hundreds of tiny, blurry flecks in the water obscured the video feed. Initially, the team thought their equipment was faulty. But after refocusing the camera, they realized that the lens was being swarmed by tiny crustaceans known as amphipods. This caught the team off guard, as they had not expected to find any type of life this far below the icy surface. 

"Having all those animals swimming around our camera means there’s clearly an important ecosystem process happening there," Craig Stevens, a physical oceanographer at the National Institute of Water and Atmospheric Research (NIWA) in Auckland, New Zealand, said in the statement. The discovery of the secret shrimp-infested structure had the team "jumping up and down for joy," Stevens added.

Related: Alarming heat waves hit Arctic and Antarctica at the same time 

Experts have long suspected that there is a vast network of rivers, lakes and estuaries underneath Antarctica, but until now these features have been poorly studied. It was previously unknown if they harbored life, which makes the new finding even more important. "Getting to observe and sample this river was like being the first to enter a hidden world," lead researcher Huw Horgan, a glaciologist at Te Herenga Waka – Victoria University of Wellington in New Zealand, told The Guardian.

Horgan first spotted hints of the subsurface structure in 2020 while looking at a satellite photo of the area. It was visible as a long depression, or groove, stretching across the ice — a hallmark of an underground river. However, despite being prominent in the satellite images, the groove initially eluded surface detection, Stevens said. "But then we found this tiny, gentle slope and guessed we’d got the right spot."

After sending the camera down into the river, the team was surprised to learn that the cavern looked drastically different from what they had predicted. The researchers had expected that the roof of the chamber would be smooth and flat. But instead, they found that the roof was very uneven and had lots of steep undulations. The cavern was also much wider nearer the roof. "It looked like a loaf of bread, with a bulge at the top and narrow slope at the bottom," Stevens said. 

The researchers also unexpectedly discovered that the water column underground split into four or five distinct layers of water flowing in opposite directions. "This changes our current understanding and models of these environments," Stevens said. "We’re going to have our work cut out understanding what this means."

The team arrived above the buried river just in time to make another interesting observation. The researchers set up camp a couple of days before the record-shattering eruption of the Hunga Tonga-Hunga Ha’apai volcano in Tonga on Jan. 15. The massive explosion caused pressure waves that rang Earth's atmosphere like a bell, and sensors the researchers had placed on the ice's surface  recorded similar pressure waves moving through the underground chamber. "Seeing the effect of the Tongan volcano, which erupted thousands of kilometres away, was quite remarkable," Stevens said. "It is a reminder about just how connected our whole planet is." 

The scientists will continue to study the newfound subsurface ecosystem and hope to learn more about how the nutrients in the water are cycled through Antarctica's underground water networks to support the abundance of life that lives there. 

However, the researchers also worry that even hidden ecosystems like this one may be at risk from rapidly warming temperatures caused by climate change. "The climate is changing, and some key focal points are yet to be understood by science," Steven said. "But what is clear is that great changes are afoot."

Originally published on Live Science.

Hypnotic drone footage shows a swarm of reef sharks ripping apart the floating remains of a dead humpback whale along the Australian coastline. During the feeding frenzy, at least 60 sharks can be seen swirling in a spiral around the blubbery carcass, but eyewitnesses say there may have been more than 100 sharks taking advantage of the whale buffet. 

Tourists John Cloke and Indy Crimmins captured video of the gruesome aquatic feast in waters off Norman's Beach near Albany in Western Australia. After returning from a morning fishing trip, Cloke saw "this big thing bobbing in the water with birds around it" and sent his drone to investigate, according to ABC News. 

The resulting footage, which was shared on the pair's Instagram page on May 16, showed dozens of sharks circling a floating humpback whale (Megaptera novaeangliae) that appeared to be around 49 feet (15 meters) long. As the drone's camera zoomed out, more sharks emerged on the perimeter of  a mesmerizing vortex, waiting for an opportunity to dart in and grab a bite. "At one point there's probably about 100 sharks around the carcass," Cloke told ABC News. "We couldn’t count them all." 

Such detailed views of sharks and other scavengers feeding on dead whales at the ocean surface are rare. But experts say that the event itself is actually quite common.

"As someone who works in the area of shark research, it's very interesting footage but not that unusual," Steve Taylor, a shark researcher at the Department of Primary Industries and Regional Development in Australia, told ABC News. However, the footage in the new video is "beautiful," he added.

 Related: Dead whale in the Mediterranean probably 'one of the largest' ever found 

In August 2021, a team of marine biologists unexpectedly discovered eight great white sharks (Carcharodon carcharias) viciously tearing apart a dead humpback whale off the Massachusetts coast. In 2017, a sequence from the BBC's Blue Planet II series also showed a number of different sharks scavenging the remains of whale that was killed by a ship. 

Most cetaceans float on the surface after they die because their bodies fill up with gases as they decompose. A 2020 study, published in the journal Frontiers in Marine Science, found that the amount of gas produced plays a big role in determining if a whale or dolphin carcass will be washed ashore. Larger, blubber-rich cetacean species, such as humpback whales, float for longer periods of time — sometimes more than a week — which makes them ideal targets for scavengers like sharks and seabirds.

In the recent footage of the feeding frenzy in Australia, it is unclear which shark species were involved, but they were probably smaller reef sharks, likely including bronze whalers (Carcharhinus brachyurus), Taylor told ABC News. 

"A whale carcass is a good feeding opportunity for many different species of sharks in our coastal waters," he said.

However, a sea surface feeding frenzy is just the first step in a long process of decomposition that feeds dozens of marine species dwelling at different ocean depths. After a whale carcass eventually sinks, drifting beyond the reach of surface-swimming sharks, it reaches the seafloor and becomes what is known as a "whale fall." 

At the sea bottom, the whale's remaining flesh is stripped from the bones by diverse seafloor scavengers, including octopuses, eels, crabs and deep-sea sharks, according to the Ocean Conservancy. Even after the whale has been reduced to a skeleton, its bones are then slowly devoured by chemical-munching microbes and worms, in a process that can take more than a decade, according to the National Oceanic and Atmospheric Administration.

Originally published on Live Science.

Scientists have uncovered the origin of a mysterious landlocked mangrove forest in the heart of Mexico's Yucatán Peninsula.

Normally, trees of this species — known as red mangroves, or Rhizophora mangle — grow only in salt water, along tropical coastlines. But this forest is located near the San Pedro River in the state of Tabasco, more than 125 miles (200 kilometers) from the nearest ocean. Somehow, these mangroves have adapted to live exclusively in this freshwater environment in southeast Mexico. 

Exactly how this ecological enigma came about has baffled scientists. But now, an international, multidisciplinary team of researchers has revealed that this out-of-place ecosystem began growing around 125,000 years ago, when sea levels were much higher and the ocean covered most of the region.

Related: 10 out-of-this-world images of Earth taken by Landsat satellites

"The most amazing part of this study is that we were able to examine a mangrove ecosystem that has been trapped in time for more than 100,000 years," lead author Octavio Aburto-Oropeza, a marine ecologist at the Scripps Institution of Oceanography at the University of California, San Diego, said in a statement. It was like putting together a "lost world," he added. 

How did it get there?

Researchers began studying the San Pedro mangrove system only recently, but local people have enjoyed the unique ecosystem for generations.  

"I used to fish here and play on these mangroves as a kid, but we never knew precisely how they got there," co-author Carlos Burelo, a botanist at the Juárez Autonomous University of Tabasco in Mexico who grew up near the forest, said in the statement. "That was the driving question that brought the team together."

To find out how this coastal ecosystem ended up marooned so many miles from the coast in an alien environment, the researchers analyzed the DNA in the mangrove trees to see how different they were from other mangrove populations. 

The mangroves' "genomes accumulate mutations every generation at a rate of about one in every 300 million letters of the genetic code, which will be passed on to future generations," Richard Nichols, an evolutionary geneticist at Queen Mary University of London who was not involved with the study, told Live Science.  "By counting up the number of differences between two genomes it is possible to estimate the number of generations since those two genomes shared an ancestor."

This is one of the most accurate ways to date when two populations became isolated. "If two populations have become isolated from each other, the most recent common ancestors of the individuals from different populations must pre-date the period of isolation," Nichols said.

Based on the number of genetic mutations accumulated in the mangroves' DNA, the team determined that the mangroves have been isolated from the geographically closest coastal mangroves for around 125,000 years.  Because global sea levels were much higher 125,000 years ago due to warmer atmospheric temperatures, the researchers suspect that the area was once a coastline. 

Therefore, the mangrove forest likely took root while the ocean was higher and managed to survive after it receded to modern-day levels, leaving the coastal ecosystem trapped inland and forcing it to adapt to the freshwater conditions provided by the San Pedro River. 

Changing sea levels 

Global sea levels have risen and fallen many times throughout Earth's history, due, in part, to subtle changes in Earth's orbit around the sun that cause the planet to receive more or less solar radiation, according to the National Oceanic and Atmospheric Administration (NOAA).

During periods in which Earth receives the least amount of radiation, known as glacial maximums or ice ages, the atmospheric temperature drops and ice sheets cover much larger areas in polar regions. When the planet receives the most amount of radiation, known as an interglacial period, the temperature rises and ice sheets melt, releasing more water into the oceans.

The last interglacial period ended around 120,000 years ago, according to NOAA, which lines up with the researchers' theory about the mangrove forest and rising sea levels. 

However, previous models did not predict that sea levels at that time would be high enough to cover the mangrove forest — which is currently 30 feet (9 meters) above sea level. 

The region surrounding the forest lies so low that a relatively small change in sea level can produce dramatic effects inland, so even though previous models only slightly underestimated the sea level rise, they massively underestimated how much of the region would have been submerged, according to the statement. 

Researchers hope that findings could help predict how the region may be impacted by climate change induced sea level rises in the future."Studying these past adaptations will be very important for us to better understand future conditions in a changing climate," Aburto-Oropeza said. 

Ancient relict 

The researchers described the San Pedro River mangrove forest as a "relict," an ecosystem that has survived from an earlier time period. And it wasn't just the mangroves that managed to survive — so did around 100 other species that thrived in or near the ancient ocean, including fish, turtles and plants, according to the statement.

"This discovery is extraordinary," co-author Felipe Zapata, a geneticist at the University of California, Los Angeles, said in the statement. "Not only are the red mangroves here with their origins printed in their DNA, but the whole coastal lagoon ecosystem of the last interglacial has found refuge here."

The researchers are not sure exactly how the mangroves and species that live among them were able to adapt to freshwater conditions, but other researchers can now use the site to investigate these questions. "There is certainly more to discover about how the many species in this ecosystem adapted throughout different environmental conditions over the past 100,000 years," Aburto-Oropeza said.

However, without protected status, the forest could be in danger. In the 1970s, a misguided development plan led large parts of the region to be affected by deforestation, and the mangroves only narrowly avoided destruction.  But the forest is still very vulnerable to a similar situation in the future. 

"We hope our results convince the government of Tabasco and Mexico's environmental administration of the need to protect this ecosystem," the researchers wrote in their paper. "The story of Pleistocene glacial cycles is written in the DNA of its plants, waiting for scientists to decipher it."

The study was published Oct. 4 in the journal Proceedings of the National Academy of Sciences.

Originally published on Live Science.

The residents of a gated community in Argentina are struggling to get along with some unruly new neighbors: hundreds of the world's largest rodents.

The capybaras (Hydrochoerus hydrochaeris), also known as carpinchos, have been running rampant for weeks inside Nordelta, an affluent neighborhood north of Buenos Aires that is home to around 40,000 people. Local residents have reported that the robust rodents, which can reach over 4 feet (1.2 meters) long and weigh up to 174 pounds (79 kilograms), have been pooping in gardens, destroying flower beds, causing traffic accidents and allegedly biting pet dogs, although capybaras are not known to be aggressive toward humans or pets, according to Argentine newspaper La Nacion.

However, environmentalists say the capybaras are not invading Nordelta but rather taking back their home from the multimillion-dollar development, which, in the late 1990s, was built on top of ecologically important wetlands surrounding the banks of the Paraná River, the second-largest river in South America.

Related: 15 of the largest animals of their kind on Earth

"It's the other way round: Nordelta invaded the ecosystem of the carpinchos," Enrique Viale, a prominent Argentine environmental lawyer, told The Guardian. "Wealthy real-estate developers with government backing have to destroy nature in order to sell clients the dream of living in the wild," he added, "because the people who buy those homes want nature, but without the mosquitoes, snakes or carpinchos." 

Capybaras never completely disappeared from Nordelta after the community was completed, but their population plummeted due to the loss of habitat and disturbance caused by construction. Now, after decades without any natural predators, such as jaguars, their population is rising again, with a 17% increase in the past year. Currently, around 400 capybaras roam Nordelta, but experts think that, at the current rate, the population could eventually reach around 3,000, according to La Nacion.

Nordelta residents want officials to remove capybaras from the development and introduce new measures to stop the rodents from freely wandering around the 3,000-acre (1,214 hectare) community — for instance, by adding reinforced hedgerows and fencing, according to La Nacion. Some locals have also threatened to shoot the capybaras, although so far, none have been killed, according to The Guardian.

In response, environmental activists have been protesting within Nordelta over the past week, many wearing mascot-like cardboard capybara headpieces, to call for the government to protect the capybaras and allow them to remain within their once-natural habitat, according to La Nacion. 

The capybaras have also become popular among the Argentine public, particularly within Buenos Aires, with many poorer people seeing them as a symbol of a class war against the city's elite, who have destroyed an important ecosystem to separate themselves from the poorer communities, according to The Guardian.  

For example, Nordelta has changed the natural drainage systems provided by the wetlands and regularly causes flooding in the surrounding communities. "When there are extreme weather events, it is the poorer surrounding neighborhoods that end up flooded," Viale told The Guardian. "As always, it is the poor who end [up] paying the price.”

Some experts believe that, because of the backlash from environmentalists and poorer communities, Nordelta residents will have to get used to their new neighbors rather than remove them.

"Nordelta is an exceptionally rich wetland that should never have been touched," Sebastian di Martino, a biologist and conservation director at the Rewilding Argentina Foundation, told French news agency AFP. "Now that the damage has been done, the residents need to reach a certain level of coexistence with the carpinchos."

Originally published on Live Science.

If you're taking a day trip to the Sahara Desert in North Africa, you're going to want to bring a lot of water and plenty of sunscreen. But if you're planning to stay the night, then you better bring a snug sleeping bag, too. 

That's because temperatures in the Sahara can plummet once the sun sets, from an average high of 100 degrees Fahrenheit (38 degrees Celsius) during the day to an average low of 25 degrees Fahrenheit (minus 4 degrees Celsius) during the night, according to NASA.

So, why does this dramatic temperature shift happen in arid deserts like the Sahara? And how do native animals and plants deal with such wild extremes? 

Related: Could the Sahara ever be green again?

Heat and humidity

The reason that arid deserts — dry regions covering about 35% of Earth's land — get so hot, and subsequently so cold, is a combination of two key factors: sand and humidity.

Unlike a thermos, sand doesn't retain heat very well. When heat and light from the sun hit a sandy desert, sand grains in the desert's top layer absorb and also release heat back into the air, according to a 2008 report from NASA's Jet Propulsion Laboratory in Pasadena, California. During the day, sand's radiation of the sun's energy superheats the air and causes temperatures to soar. But, at night most of the heat in the sand quickly radiates into the air and there is no sunlight to reheat it, leaving the sand and its surroundings colder than before.

However, this phenomenon alone doesn't account for such a drastic drop in temperature. After all, when the sun goes down on a tropical beach, you don't need to don a winter coat.

The main reason for the stark temperature change is that desert air is extremely dry. In arid deserts like the Sahara and the Atacama Desert in Chile, the humidity — the amount of water vapor in the air — is practically zero, and unlike sand, water has a huge capacity to store heat.

Water vapor in the air traps heat close to the ground like a giant invisible blanket and stops it from dissipating into the atmosphere, according to World Atlas. Air with high humidity also requires more energy to heat up, meaning it also takes more time for that energy to dissipate and for the surroundings to cool down. Therefore, a lack of humidity in deserts allows these arid places to quickly heat up but also rapidly cool. 

Adapting to extreme temperatures 

Despite these rapid temperature swings, desert animals are well adapted for the desert's extreme temperature changes. 

"It tends to be a relatively small problem for them," said Dale DeNardo, an environmental physiologist at Arizona State University who specializes in desert animals. "The bigger challenge is getting enough food and water to survive."

Reptiles, the most abundant and diverse animal group in the desert, are well adapted to extreme temperature variation because they are cold blooded, or ectothermic, which means they do not need to invest energy in maintaining a constant body temperature. In other words, reptiles can use this energy elsewhere, like hunting. Many reptiles also benefit from being small, which allows them to find shady nooks during the day or warmer rocks at night. "There's a lot of different places to go to be warmer or cooler, especially when you're small," DeNardo told Live Science.

Related: How do lizards cool off?

However, large warm blooded, or endothermic mammals, like camels, are too big to hide away from the sun and can't let their body temperature drop. Rather, camels survive by maintaining a constant body temperature in both hot and cold conditions. They do this by having lots of insulation in the form of fat and thick fur, which prevents them from gaining too much heat during the day and losing too much at night, DeNardo said.

In contrast, desert birds use evaporative cooling — where they use water to transfer heat away from their bodies, like how humans sweat and dogs pant — through a range of different methods (some vultures urinate on their legs to cool down). But their ability to fly long distances between water sources or to scavenge food, means they don't have to worry as much about conserving water like other desert animals. "I call it cheating because they don't really experience the limitations of a desert," DeNardo said.

Plants, on the other hand, are more vulnerable to extreme temperatures. "They face a much bigger challenge because they don't get to move," DeNardo said. That's why iconic desert plants, like cactuses, have developed a range of defenses, such as spikes and toxins, to protect their precious water from predators. However, freezing temperatures at night can be deadly for plants because water freezes and expands within their tissues, which can cause irreversible damage. Therefore, plants  grow only in areas where the air temperature does not fall below freezing for more than a couple of hours each night, known as the freezeline.

Changing climate

Researchers are still figuring out how climate change may affect arid places and organisms, but "we're definitely going to see changes," DeNardo said. "For most deserts, we are predicting an average rise in temperature of 3 to 4 degrees Fahrenheit [1.7 to 2.2 C]." 

However, research indicates that "Nights are going to be warmer, but that's not as bad as warmer days," DeNardo noted.

Instead, the real problem is that climate change may impact the amount of annual precipitation that desert creatures rely on. "It will become less consistent, you will have relatively wet years and relatively dry years," DeNardo said. "But even if most are wet enough, it will only take one really dry year to cause big problems."

This story was updated at 5:00 AM ET on Feb. 22 to fix a Fahrenheit to Celsius conversion.

Originally published on Live Science.

Sometime in the late 1600s, in the lush forests of Mauritius, the very last dodo took its last breath. After centuries of untroubled ferreting in the tropical undergrowth, this species met its untimely end at the hands of humans, who had arrived on the island less than 100 years before. With their penchant for hunting, habitat destruction and the release of invasive species, humans undid millions of years of evolution, and swiftly removed this bird from the face of the Earth.

Since then, the dodo has nestled itself in our conscience as the first prominent example of human-driven extinction. We've also used the dodo to assuage our own guilt: the creature was fat, lazy and unintelligent — and as popular story goes, those traits sealed its inevitable fate.

But in fact, we couldn't be more wrong, said Julian Hume, a paleontologist and research associate with the National History Museum in the United Kingdom. He studies the fossils of extinct species, and has devoted a portion of his career to correcting the dodo's dismal reputation. By digitally modelling the remains of a dodo’s skeleton, he's produced a 3D digital reconstruction that draws an altogether different picture of a bird that was faster, more athletic and far brainier than popular culture has led us to believe. "It was nothing like this big, fat, bulgy thing that was just waddling around. This bird was super adapted to the environment of Mauritius," Hume told Live Science. Instead, humans' unrelenting exploitation was the real culprit behind the dodo's untimely death. 

Related: What could drive humans to extinction?

But that's not all we've gotten wrong. Despite the commonly held belief, the dodo actually wasn't the first creature that humans drove to extinction — not by a long shot. In fact, humanity was wiping out the world's fauna thousands of years before we set eyes on the dodo. "There was certainly a lot more going on before and after that event," said Hume.

So, if the iconic dodo wasn't the first species we drove to the brink, then which animal gets this disheartening title, instead?

Humans on the move

We've grown accustomed to thinking about human-driven species extinction as a relatively recent trend in our history. Yet, researchers have found convincing palaeontological evidence that dismantles that idea.

"The real problem started when we, as humans, started migrating," Hume said. That starting point is still debated, but most recent estimates suggest that migrations that led to lasting populations of humans spread across the globe began with the movement of hominids — Neanderthals and other ancient human relatives, as well Homo sapiens — out of Africa and southeast Asia, roughly 125,000 years ago. This is where the evidence gets interesting. As humans left their ancestral homes, and over the following tens of thousands of years went on to colonize Eurasia, Oceania, North and South America, the fossil record shows a parallel uptick in the extinction in large-bodied animals — also known as megafauna — across those continents. 

"As [hominids] migrated out of Africa, you see this incredibly regular pattern of extinction," said Felisa Smith, a professor of ecology and evolutionary biology at the University of New Mexico, who studies how animals' body sizes have changed over the course of history. As she and her colleagues explained in a 2018 study published in the journal Science, each time our ancestors set foot in new places, fossil records show that large-bodied species — the humongous prehistoric relatives of elephants, bears, antelope and other creatures — started going extinct within a few hundred to 1,000 years, at most. Such rapid extinction timescales don't occur at any other point in the last several million years (not since the non-avian dinosaurs were wiped out by an asteroid about 65 million years ago.) "The only time you see it is when humans are involved, which is really striking," Smith said. 

Some of those early lost species would seem like fantastical beasts if they roamed Earth today. For example, "There was an armadillo-like thing called the glyptodon, which was the size of a Volkswagen bus," Smith told Live Science. Glyptodons, many equipped with vicious-looking spiked tails, disappeared from the Americas at the end of the last ice age, roughly 12,000 years ago — which is probably connected to the earlier arrival of humans there. The number of gigantic Eurasian cave bears, several hundred pounds heavier than grizzly bears today, went into a steep decline about 40,000 years ago, around the same time that humans began to spread across their habitat. South America was once home to lumbering giant ground sloths — and humans were also the most likely candidate in their demise, about 11,000 years ago. 

Related: How often do ice ages happen?

What made large animals, in particular, so susceptible to humanity's spread? Megafauna likely represented food, or a threat, to incoming humans. What's more, animals that had never encountered humans before were probably unwary of these strange newcomers migrating into their unspoiled lands, which might have increased their vulnerability to attack. Unlike other smaller animals that breed more rapidly, megafauna also reproduce more slowly and so have smaller populations compared with other species, Hume explained: "So if you take out a big section of [a population] they cannot reproduce quickly enough to build up numbers again."

It wasn't just hunting that posed a threat — but also the spread of human-caused fires that would have destroyed swathes of habitat, and increasing competition from humans for food. For instance, it's thought that by preying heavily on the same herbivores, growing numbers of hungry humans helped drive the extinction of the short-faced bear, a gigantic South American species that once stood at over 10 feet (3 meters) tall, and died out roughly 11,000 years ago. Climate change, paired with human impacts like hunting, also proved to be a lethal combination for some megafauna — most famously, mammoths, which went extinct about 10,500 years ago (except for the dwarf woolly mammoth, which survived until about 4,000 years ago on an island off northern Russia). "If you combine climate change with a negative human impact, it's a disaster," said Hume.

An answer?

All of this is to say that humans have systematically wiped out the species around us from almost the beginning of our history. Our migration prompted "a disaster across the world," said Hume. "We weren't very pleasant." Unfortunately, we've continued our ancestors' legacy, with, among thousands of other species, the eradication of Madagascan hippos 1,000 years ago, the loss of moa birds in New Zealand 600 years ago, and the decimation of passenger pigeons 106 years ago. We are also responsible for ongoing extinctions today.

But this still hasn't answered the question of what species went extinct first. And here's the catch: the data on human-driven extinction across the planet is only reliable as far back as about 125,000 years— but that doesn't mean we weren't driving animals to extinction before that in Africa, too. In fact, there's compelling evidence to suggest that before humans migrated out, they unleashed their hunting instincts on species there as well. 

Related: When did humans discover how to use fire?

Smith's research has revealed that the average body size of African animals 125,000 years ago was only half that of species that were present on other continents around the world. "Africa is one of the largest continents, so it should have had a mean body size similar to that of the Americas and Eurasia where it was roughly about 100 kilograms [220 lbs.]," Smith said. "The fact that it didn't suggests that there had already been an effect of hominids on megafauna in Africa, prior to 125,000 years ago." 

In essence, because the rest of history tells us that humans are good at dispatching the largest creatures in an ecosystem, we can make a fairly safe assumption that hominids in Africa at the time could have been responsible for extinctions going even further back in time.

Still, there's no way to know for sure what that 'first' species would have been — though Smith takes a wild guess: "It was probably some species in the elephant family. But whether that's palaeomastodon, or stegodon" — the latter being a behemoth with tusks that measured 10 feet (3 meters) long - "I couldn't tell you."

Clues for the future

We may not have a clear answer to that original question - but perhaps the more important one to ask is what humanity's legacy of extinction can teach us about conservation, going into the future. 

Past extinctions have revealed that when animals — especially megafauna — disappear, there are profound ecological consequences. Whole landscapes are transformed in the absence of their shaping effects, with changes to vegetation and species diversity. Smith has even published research showing that the decline of global megafauna in past millennia led to dips in the amount of methane they burped out — with potentially transformative consequences for global climate. What's more, when animals disappear, whole rafts of dependent species go down with them. The iconic dodo presents one such cautionary tale: when the birds died out, so did a Mauritian dung beetle that relied on dodo feces to survive.

Understanding human-driven extinctions of the past can help us figure out what the environmental consequences have been, explained Smith, and how we can limit those in the future by protecting the species that remain. Even the dodo's extinction provides clues that are helping us preserve ecosystems today. Hume is working on a project to catalog pollen spores present in the sediments around dodo fossils, to build up a detailed picture of the lush, palm-fringed forests they once roamed. That's helping conservationists to rewild the island with vegetation that was once there. "We're actually reconstructing the exact species of plants and trees from the environment the dodo was living in, before humans arrived," Hume said. 

A bit of paradise was lost when we drove the dodo to extinction — not to mention the thousands of species whose demise came before that. But perhaps with hindsight, and the willingness to learn from our mistakes, some of that can be reclaimed.  

Originally published on Live Science. 

Species appear and disappear in the blink of a geologic eye; that's a rule of life. There have been five mass extinctions in Earth's past, when changes to the climate, the emergence of new adaptations and even cosmic interventions caused many unique life-forms to die off. A sixth mass extinction is currently underway, and the only thing that distinguishes it from its predecessors is the cause: humans.

Why are so many of Earth's species going extinct? The reasons are myriad and include loss of habitat, overhunting and competition with non-native species that were introduced by people. But how did we get to this point, so soon after an era in which the world's bounty seemed endless, with flocks of passenger pigeons so large that they covered the sun and herds of bison that numbered in the thousands?

Some would explain that these sudden declines in the past century stem from modern overconsumption. But we must look back even further, to the period of European colonization that began in the 1500s and ended 400 years later. [10 Species You Can Kiss Goodbye]

In fact, many of the European nations that are even now forcing conservation measures on countries across the world are to blame for the current conservation crisis.

Tigers, for example, are the darlings of conservation efforts worldwide. An estimated 80,000 tigers were slaughtered in India between 1875 and 1925, when the country was under British rule; currently, the global tiger population is less than 4,000 individuals, according to the International Union for the Conservation of Nature and Natural Resources.

American bison, on the other hand, represent a modern conservation success story — or so it would seem. Federal protections saved bison from extinction in the mid-1900s, but the iconic animals were brought to the brink of extinction by European colonizers. Driven largely by a desire to destroy a much-needed indigenous resource, colonizers' widespread slaughter reduced bison populations from over 30 million animals to fewer than 100 individuals in less than a century, the U.S. Fish and Wildlife Service reported.

Indigenous traditions

Conserving and managing natural resources isn't a modern concept; indigenous peoples across the world have practiced it for generations. They might not have had the statistical models and the technology available today, but they had experience-based knowledge, traditions, rituals.

In pre-colonial Zimbabwe, it was taboo to cut the muhacha tree, also known as the Mobola plum tree, as it was nutritionally and culturally important. It was also forbidden to kill certain rare animals like the pangolin without permission from the local chief, researchers reported in 2018, in the journal Scientifica. In Guatemala, the mythical status of the resplendent quetzal, a brilliantly colored bird, helped promote its conservation, according to a study published in 2003 in the journal Ecology and Society.

Totemic relationships limited or outright banned the hunting of certain species such as elephants among ethnic groups like the Ikoma in Tanzania, while Inuits saw themselves not as land owners, but as land inhabitants, playing a part in a larger cycle that helped to sustain them.

It was through these mores that indigenous peoples conserved and sustainably used their natural resources.

In most cases, the poachers and small-time loggers in the news stories are local individuals: a Congolese man with a rusted axe in the forest, or a Vietnamese boy setting snares, for example. However, a look back in history reveals that the people who have historically dealt the most devastating damage to forests and wildlife worldwide were European colonizers.

European colonization brought not only a clash of cultures, but also an almost total decimation of those traditions that kept order within indigenous societies and helped to conserve natural resources, according to the Scientifica study . Europeans saw that Africa, the Americas and Asia were rich in fur and feather, skin and wood, gold and ivory; using a mixture of religious supremacy and scientific racism, colonizers gave themselves permission to carve up those continents like so much meat, descending upon exotic so-called Edens like locusts.

Forests were cut down. Precious metals were dug up. Wild animals were killed. All of this natural wealth was stolen from indigenous peoples and used to enrich what is now called the "developed" world. [Photos: Wild Animals of the Serengeti]

Too little, too late

Decades after white colonialists ravaged the world’s natural resources, concerns arose — locally and globally — about conserving what little of those precious resources remained. And indigenous people, as they had before, paid the price then, and are still paying today. From Virunga to Rajasthan, Yellowstone to Kruger, indigenous people were barred from areas declared protected by someone hundreds of miles away, and were forced to relocate from lands they had occupied for generations.

Horrific acts are committed in the name of conservation: kidnapping suspected poachers in the dead of night, beatings for imagined infractions, sexual assaults and even murder. In 2017, Newsweek reported that an estimated 500 men were shot in 2016 while in or near Gorongosa National Park in Mozambique, on suspicion of poaching. National Geographic also reported accounts of suspected poachers who were tortured or raped by military officers in Tanzania.

Today, on social media, millions across the world sit in judgment on reports of poaching, ready to favorite, retweet, share or call for blood in the comments, and throw money at a problem they're sure they understand based on one-sided conservation narratives.

As in most stories, conservation has heroes and villains. The villains — poachers — are indigenous people across the world who have historically been defrauded, violated, murdered and displaced. Though they may no longer be under colonial rule, they are still criminalized in the name of conservation, even when their own survival is at stake.

Meanwhile, so-called conservation heroes act as gatekeepers to resources that were never theirs to begin with, regulating what little remains from the people who have already lost the most.

In past centuries, colonialism perpetrated great crimes that affected millions; the lasting impact of that legacy is carried by those still living and will be shouldered by those who have yet to be born. According to a United Nations report published online May 9, thousands and thousands of species are currently faced with extinction, and humanity’s ability to live in the only home we have (and most likely ever will know) is swiftly eroding.

The nations that built empires across the world — and in doing so, fueled today's conservation emergencies — will be cushioned against the worst of the fallout as ecosystems collapse worldwide. And yet, the most ethical action would be to voluntarily relinquish the wealth and resources that protect them, extending that protection to everyone. We who benefit from colonialism’s violent past must acknowledge our role in causing the crises that face humanity, and seek to recompense those who have been wronged.

• 10 Easy Ways to Help Wildlife, Every Day (Photos)
• Species Success Stories: 10 Animals Back from the Brink
• Wipe Out: History's Most Mysterious Extinctions

Originally published on Live Science.

While the U.S. government was partially shut down for 35 days, the country's national parks suffered damage that could last generations. Now, as volunteers and conservationists assess the environmental and economic damage around the country, it seems that Joshua Tree National Park — a wonderland of spiky trees and surreal, time-sculpted rocks in Southern California — has experienced some of the worst damage.

"What's happened to our park in the last 34 days is irreparable for the next 200 to 300 years," Curt Sauer, a former superintendent of the park, said at a rally on Saturday (Jan. 26).

However, that estimate might be a bit overstated, according to one expert Live Science spoke to. While it's true that the survival of the park's Joshua trees has downstream impacts on the desert birds, insects, mammals and reptiles that rely on them for shelter and sustenance, the loss of a few individual trees is unlikely to have long-lasting effects on the park's 800,000-acre (324,000 hectares) ecosystem, Cameron Barrows, an associate research ecologist at the University of California Riverside's Center for Conservation Biology, told Live Science in an email.

Short shutdown, long-term damage

Reduced to a handful of essential staff during the shutdown, the park was unable to perform basic maintenance functions like emptying the trash or making sure the toilets didn't overflow with human waste. Meanwhile, only eight law-enforcement rangers were tasked with protecting the entire park's 1,238-square- mile-grounds (3,207 square kilometers) grounds — an expanse of land about the size of Delaware, Live Science previously reported.

During that time the security lapse, park gates were toppled and locks smashed. Rocks were defaced with graffiti, illegal campfires and vehicle traffic destroyed vegetation at some of the park's most iconic sites, and at least three of the park's ancient Joshua trees were chopped down in order to make way for illegal off-road paths. According to the National Park Service website, the average joshua tree in the park is age of the park's iconic trees is estimated to be about 150 years old.

But that doesn't necessarily mean damage to the park will take centuries to repair, Barrows said.

"Certainly, replacing one destroyed Joshua tree to the same age and condition could take [centuries]," Barrows said. "But I would be hard pressed to say the park is at greater risk of ecological damage by the loss of one tree. If it was, say, 100 acres or greater, then we are probably at a scale where ecosystem integrity is compromised." (Barrows noted that he has not been back to the park since the shutdown to see the full scale of the damage.)

More harmful to the ecosystem may be the many miles of fresh tire marks pummeled into the park's soil by off-road vehicles. That desert soil isn't just dirt or sand — it's also a complex community of vegetation and microbes that can help support every plant and animal that interacts with it.

"Vehicles creating improvised roads are a significant issue," Marinna Wagner, Masters in Landscape Architecture, told Live Science in an email. "Not only does such activity destroy existing vegetation, but the resultant soil compaction reduces soil moisture, increases runoff, causes erosion and sedimentation, and prevents seedling germination, thus slowing down the rate of ecosystem recovery even further."

National Park Service spokesperson Mike Litterst told Vice.com that soil damage like this can last for decades. So far, crews have helped repair about 20 miles (32 km) of tire tracks left during the shutdown, Vice reported, with many more to go.

These and other repairs may stress the park financially as it reckons with considerable financial losses from the shutdown. According to Sauer, the park relied on more than $300,000 in entrance fees to stay open during the shutdown, dipping into money that was meant to be used on park maintenance and the construction of a new visitors' center. In total, Sauer estimated that Joshua Tree lost about $800,000 in revenue during the shutdown.

Editor’s Note: This story was updated to add comment from Marinna Wagner.

• Yellowstone and Yosemite: Two of the World's Oldest National Parks ...
• Happy 100th Birthday! US National Parks in Photos
• Giant Sequoias and Redwoods: The Largest and Tallest Trees

Originally published on Live Science.

David Steen received his Ph.D. in Biological Sciences from Auburn University and is now a Research Ecologist at the Georgia Sea Turtle Center on Jekyll Island. Steen has published dozens of scientific papers about wildlife ecology and conservation biology and is also an award-winning science communicator known for his wide-ranging outreach efforts (find him on Twitter, Instagram and Facebook. Finally, Steen is Executive Director of The Alongside Wildlife Foundation, a nonprofit he founded to promote science-based solutions to living alongside wildlife in perpetuity. Steen contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

Species are rapidly disappearing all around us; indeed, you and I are living through Earth's sixth great extinction. Most reasonable people agree that losing species is a problem. However, as a conservation biologist and a science communicator, I am used to hearing the occasional argument from radicals about why we need not be especially concerned about that loss. Imagine my horror to see these arguments compiled into a Perspectives piece published in The Washington Post, and written by a professor of biology no less! I cannot believe that it is 2018 and I have to explain why extinction is actually a bad thing, but here we are.

The piece works hard to make the case that we need not be particularly distressed about the loss of biodiversity by arguing, if you will humor me some loose paraphrasing, that we are going to lose species no matter what and extinction does not make much of a difference anyway because new species might evolve in the future. But for this line of reasoning to make sense one must ignore decades of conservation science and centuries of art, literature and philosophy, not to mention millions of years of evolution. Although there have already been many responses to the article — nearly unanimous in their disapproval — I feel compelled to go on record as well and explain why the article was so aggravating to me, as someone who puts a lot of time and effort into helping people appreciate and value biodiversity.

Mainly, the author should have known better.

As an accomplished evolutionary biologist, the author must recognize how silly it is to describe the gradual change of evolutionary lineages over millions of years, and argue this process is synonymous — biologically and ethically — to our ongoing and rapid extinction crisis. Today, our actions are actually ending lineages, and in only a few scant years too, while simultaneously destroying the evolutionary stage, the animals' habitats.

One of the foundations of a graduate education is learning how to appreciate and understand a subject before critically evaluating it. A few moments spent talking to any conservation biologist would have revealed to the author why so many scientists and environmentalists are concerned about the issues he callously tosses aside.

For example, the author questions why invasive species — animals that are not native to a habitat — are perceived as negative, despite the fact that they often increase the number of species in a given area. There is a pretty simple answer. Conservation biologists do not view conservation as a game, in which the goal is to create areas with the highest species counts. Rather, our priorities are based on the preservation of native ecosystems and their communities of unique species.

Although the article frames conservation as a field attempting to save species in isolation, it has been nearly 70 years since the philosopher and scientist Aldo Leopold emphasized the importance and complexity of ecological interactions in natural communities, and how these communities begin to fall apart when their member species are lost. He noted that keeping "every cog and wheel is the first precaution of intelligent tinkering." Consequently, he would not likely subscribe to the worldview espoused in the Washington Post article, nor would the generations of scientists that came after him.

Finally, when the author argues that extinctions will not significantly change our way of life, to whom is he referring? Who is part of the "developed society" that the author sees in our shared future? Does "we" include all of the world's different cultures and their unique relationships with nature, or is he actually just envisioning a future world like his own?

I could go on. The piece is littered with mischaracterizations and oversights all seemingly in service to nihilistic proclamations about biodiversity loss; the article is not a robust scholarly work so I will not treat it as such. It is a shame that the article did not reflect much familiarity with the work of scientists and philosophers who have built their careers studying and communicating conservation issues.

After the article's publication and in the face of mounting criticism, the author seemed to backtrack considerably from the points he made in the article while responding to critics on the Facebook page I use for science outreach and in a longer piece that he posted on his own Facebook page. Specifically, he claimed that he values conservation efforts but was not able to effectively communicate this in the article because of, among other things, restrictive word limits. Frankly, I feel that this explanation rings hollow, given he used 247 words to make the case in one paragraph of the original article that biodiversity — both the pinnacle and foundation of life on Earth — can actually be bad.

Why do I care so much about a single article? I care because I worry that it provides the public with a distorted view of how biologists view our ongoing extinction crisis while also providing ammunition to those who wish to unsustainably exploit our natural resources.

But perhaps I fear most of all that the piece will demoralize those who care about conservation and biodiversity.

In truth, we are surrounded by conservation successes; we have brought iconic species like the American alligator and the bald eagle back from the brink of extinction because we recognized their value and we fought for them. We can and will do it again for other imperiled species. For me, extinctions caused by our actions will never be spiritually or culturally acceptable.

And I know I am not alone.

Original article on Live Science.

Climate change may be leading to shifts in the communities of sea life beneath an Antarctic ice shelf, researchers say.

Scientists diving beneath sea ice at the edge of Antarctica's Ross Ice Shelf have discovered unexpected changes in the seafloor ecosystem compared to previous studies of the same area, and they think the thinning of the ice shelf caused by climate change may be to blame.

"Surprisingly big changes in the coastal seafloor communities have occurred in only a few years," Patrick Degerman, one of three researchers from Finland on the expedition along with six from New Zealand, wrote in a dispatch from the team's camp on the ice shelf near New Harbour in the Ross Sea.

"Two days ago, [two of the researchers] did the first dive of the year under the ice in crystal clear water, and much to everyone's surprise, the animal community on the seafloor had changed dramatically since the last visit in 2009," he wrote in the first week of November on the expedition's Facebook page, "Science Under the Ice." [See Photos of the Big Changes Beneath the Antarctic Ice Shelf] 

For the duration of the six-week expedition, the team members from Finland are regularly updating the page with posts, photographs and videos of their work above and below the ice.

"The first diver observations show that the changes can be unexpectedly rapid, even in Antarctica, where everything is expected to happen very slowly due to the low temperature," Degerman wrote.

The seafloor beneath Antarctica's ice shelves is usually in complete darkness and lacks most of the "marine snow" of phytoplankton and other biological material that rains down from the sunlit levels of other parts of the ocean.

Although the depth of the dive sites beneath the ice shelf is only about 66 feet (20 meters), the sparse animal life found there is similar to that found in the very deepest parts of the oceans, and consists mainly of organisms like deep-sea sponges, sea stars, brittle stars and sea cucumbers.

"What used to be a very stable, sparse and food-deprived animal community on the seafloor under the thick ice in New Harbour is now much richer, with more species and higher densities of animals," Degerman wrote. "Some species rarely observed at this site now appear to be relatively common."

Changing climate

The researchers are spending six weeks at two camp sites on the Ross Ice Shelf, the largest and southernmost ice shelf on the Antarctic continent. Both sites have been studied by previous diving expeditions, so the researchers can make a scientific comparison of any changes that have occurred over time.

"The aim of this expedition is to explore how climate change will affect the marine biodiversity in Antarctica," Degerman wrote. "Almost all of the biodiversity in Antarctica is found in the oceans. A unique combination of species and isolation has provided a place to treasure, largely unaffected by human activity."

The researchers think the changes in the seafloor ecosystem seen at the New Harbour site are probably the result of thinning sea ice that permits more light to filter through, and occasionally breaks up in the Antarctic summer months.

"New Harbour sea ice can go for years without breaking [up], and this multiyear ice can grow up to 4.5 meters [15 feet] thick. When the ice is thick, very little light can penetrate the ice to fuel primary production (for example, algae), and thus food supply to the animals on the seafloor is limited," Degerman wrote.

"The rich community now observed is most likely a rapid response to the sea ice breaking out two years in a row, resulting in more light and higher productivity in the ecosystem," he added. "The ice is currently about 3 meters [10 feet] thick."

In addition to conducting scientific research, the Finnish researchers are also recording the work of the expedition using five 360-degree video cameras. It's the first time an entire scientific expedition has been documented in virtual reality.

The 360-degree video will be available early next year after being processed in Finland, but until then, the researchers are regularly sharing photographs and videos of their work above and below the ice shelf, including aerial drone footage and underwater video from the dive site at New Harbour, some of which was posted to YouTube on Nov. 8.

Moving on

During the last stage of their stay at the New Harbour camp and dive sites, the researchers conducted "closed chamber" experiments on the seafloor to examine how much food is consumed by animal species that are common in the ecosystem, such as brittle stars (Ophionotus victoriae). [Weird Wildlife: The Real Animals of Antarctica]

The closed-chamber experiments would "analyse the food webs (who eats who) to compare with previous analyses conducted in 2001, 2002 and 2009, when sea ice conditions were very different, to reveal how food webs have changed over the last 15 years and what this will imply for the future of these unique ecosystems," Degerman posted to the expedition Facebook page early last week.

"The aim is to investigate how the seafloor ecosystem will work differently as a result of climate change,"  University of Helsinki marine biologist Joanna Norkko wrote in a Nov. 6 update.

"In addition to warmer temperatures, climate change is expected to lead to increased food availability to the animals on the seafloor. This is because the sea ice is predicted to get thinner, which means that more light will penetrate the ice, which, in turn, means that there will be more algae growing on the underside of the ice (so-called ice algae)," Norkko explained. "These algae are the main food source for many of the animals on the seafloor."

In their most recent posts from the ice, the researchers reported that they've now struck their camp at New Harbour and have returned briefly to the New Zealand Antarctic headquarters at Scott Base. Next, they will head to their second camp on the Ross Ice Shelf, near Cape Evans on Ross Island.

"[We] spent two days packing up the whole camp to go back to Scott Base for a day to repack (and have a shower) before heading out to our second site at Cape Evans for a few days of diving," reads the latest update, posted Tuesday (Nov. 14).

"But, as is quite common in Antarctica, the weather had its own way, and snow and increasing wind forced us to wait until the late evening before we could start driving back to Scott Base in the two Hägglunds [tracked snow vehicles], towing all of our gear on big sleds," they wrote in the update. "It was a beautiful night though! Thanks to the Scott Base staff for driving all through the night!"

Editor's Note: This article was updated to clarify that the scientists were diving beneath sea ice at the edge of the Ross Ice Shelf, not beneath the shelf itself.

Original article on Live Science.

And now, data gathered by a fleet of satellites circling Earth since 1997 have been visualized as a breathtaking time-lapse video of our dynamic planet, capturing the most complete view to date of biology on a global scale, spanning two decades.

During warm months in each hemisphere, sea-ice cover near the poles declines and the lush green colors of emerging plant life spread in undulating waves over land, as more plants take up carbon dioxide and produce oxygen. In the oceans, microscopic phytoplankton swirl to form growing and shrinking clouds, likewise following seasonal cycles of growth that are visible to NASA satellites as subtle color changes in the water. [Earth Pictures: Iconic Images of Earth from Space]

"That's the Earth — that is it breathing every single day, changing with the seasons, responding to the sun, to the changing winds, ocean currents and temperatures," Gene Carl Feldman, an oceanographer at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a statement.

"These are incredibly evocative visualizations of our living planet," Feldman said.

There's no question that the time-lapse video is mesmerizing to watch, but it also shows researchers something unprecedented, revealing the behavior of oceans and land simultaneously and through time, over decades.

"We've never had data like these before," Compton Tucker, an Earth scientist with NASA, said in a video statement.

"Half of our photosynthesis occurs in the oceans and the other half on land. And having these data to show both [sites of photosynthesis] at the same time — day after day, month after month, year after year for 20 years — is a great tool to study life on Earth," Tucker added.

NASA experts compiled all this data from space to tell the fascinating visual story of the changes that happen on land and sea from season to season, creating a map that enables researchers to monitor ocean and forest health, and track conditions in fisheries and agriculture. As years tick by, larger-scale changes reveal how these cycles may be shifting in response to human activities that are reshaping the planet and its climate.

"You can see greening of the Arctic. You can see earlier summers, later winters," NASA oceanographer Jeremy Werdell said in a video statement.

"The view from space has opened our eyes to so many different things," Werdell said.

Continuous, global viewing of Earth's oceans began with the launch of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite in 1997, and scientists were just in time to observe the transition from El Niño to La Niña — when tropical ocean temperatures in the Pacific shift from being warmer than average to being cooler than average.

That transition had a dramatic impact on phytoplankton growth, with plankton blooming in ocean regions where hardly any signs of planktonic life had been spied by satellites before.

"And we watched it happen in real time," Feldman said in the statement.

"For me, that was the first demonstration of the power of this kind of observation, to see how the ocean responds to one of the most significant environmental perturbations it could experience, over the course of just a few weeks," he said.

Certain patterns can also be observed over land, on a regional level. In the United States, for example, the recent impacts of drought in Texas, California and the Pacific Northwest are visible, while the southeastern part of the country has been spared extremes of dryness and flood. Consolidating this data from Earth-orbiting satellites helps scientists to better understand the interconnectedness of all these processes — in the oceans and on land, Fedldman said.

The fact that the time-lapse is beautiful and fascinating doesn't hurt either, Werdell added.

"The ability to expand your senses into space; compress time; watch visualizations like these; see how the ecosystems of land, sea, atmosphere, ice all interact; and then to be able to rewind it and watch it again and again — it's amazing," he said.

Original article on Live Science.

Every year, thousands of wildebeests tumultuously drown while trying to cross the Mara River in eastern Africa, but there is a silver lining to their deaths: The wildebeest remains provide essential nutrients to wild animals throughout the Serengeti food web, according to a new study.

About 1.2 million wildebeests, also known as gnus (Connochaetes taurinus), take part in the largest terrestrial migration in the world, traveling from the dry plains to the lush savanna in search of food and water every year, the researchers said.

But an average of 6,250 wildebeests — or 1,100 tons (1,000 metric tons) of biomass — never make it across the Mara. Rather, their bodies decompose, contributing the "equivalent biomass of 10 blue whale carcasses per year to this moderately sized river," the researchers wrote in the study. [Camera Trapped: Elusive Wildlife Caught in Photos]

There were at least 13 mass drownings between 2001 and 2015, according to historical reports and field surveys, the researchers said. These mass drownings typically happen from early June to late July, when the wildebeests make their annual migration across the Mara, a river that pours into Lake Victoria and provides water for the greater Serengeti Mara ecosystem of Kenya and Tanzania.

Once the wildebeests meet their untimely ends, it isn't long before scavengers — including vultures, some flying more than 60 miles (100 kilometers) to dine — show up with hearty appetites. These scroungers include Nile crocodiles, Marabou storks, white-backed vultures, Rüppell's vultures and hooded vultures, the researchers said.

The scavengers aren't the only beneficiaries: The wildebeests' soft tissues take between two and 10 weeks to decompose, and then provide as much as 50 percent of the food that supports fish populations in the Mara, the researchers found. Moreover, maggots — a favorite meal of the mongoose — flourish on the wildebeests' dead bodies, the researchers noted.

The wildebeests' bones take more than seven years to decompose, providing much-needed phosphorus to the river, which, in turn, supports algae, insects and fish, the researchers said.

"Rotting animal flesh spikes the aquatic ecosystem with nutrients," study co-researcher Emma Rosi, an aquatic ecologist at the Cary Institute of Ecosystem Studies in Millbrook, New York, an environmental research organization, said in a statement."But once carcasses disappear, bones — which make up nearly half of biomass inputs — continue to feed the river."

Moreover, these nutrients travel throughout the river basin, as they are either carried downstream by the river or taken inland by scavengers, the researchers found.

"The frequency and scale of these events suggest that mass drownings may have played an important role in other rivers historically, when large migrations and unimpacted rivers were more common features of the landscape," lead researcher Amanda Subalusky, a postdoctoral associate at the Cary Institute, said in a statement.

Subalusky worked on the study as a graduate student in the Department of Ecology and Evolutionary Biology at Yale University. The research was published online June 19 in the journal Proceedings of the National Academy of Sciences.

Original article on Live Science.

Sponges may be simple creatures, but they basically ruled the world some 445 million years ago, after the Ordovician mass extinction, a new study finds.

Roughly 85 percent of all species died in the Ordovician mass extinction, the first of the world's five known mass extinctions. (The other mass extinctions are the Late Devonian, End Permian, End Triassic and End Cretaceous.) However, while the Ordovician mass extinction wiped out many of these ancient creatures, one group actually prospered: sponges.

"We think the sponges thrived because they can tolerate changes in temperature and low oxygen levels, while their food source (organic particles in the water) would have been increased enormously by the death and destruction all around them," lead study author Joe Botting, a paleontologist at Nanjing Institute of Geology and Palaeontology in China, said in a statement.

Chinese and British researchers discovered the fossils of some of these sponges in the newfound Anji Biota, a fossil deposit in the bamboo forests of Zhejiang province, in eastern China. The scientists uncovered nearly 100 species during their first excavation at Anji, and 75 of these species were sponges, many with preserved soft tissues, they said. [Wipe Out: History's Most Mysterious Extinctions]

The diversity of sponges is impressive given that the end-Ordovician event is the second-largest mass extinction on record, the researchers said.

The extinction occurred when a sudden, intense ice age was followed by an equally rapid warming period, which changed the ocean's chemistry and circulation, the researchers said. Earlier studies show that plankton quickly recovered after the extinction, but there are few fossils from that time period that show how other organisms fared, they said. In fact, until the discovery of the Anji Biota, the only known, well-preserved fossil deposit from that era was South Africa's Soom Shale.

Usually, mass extinctions decimate animal life, with the surviving ecosystems holding only small, stunted species that somehow managed to survive. In contrast, thousands of fossils indicate that the sponges in the Anji Biota were large and complex. Moreover, while some sponge species lived only in certain areas, others were so plentiful, they formed forests on the seafloor, the fossils show.

In addition, the researchers uncovered several mollusks known as nautiloids, as well as a rare find: a single fossil sea scorpion that still had its legs.

It's possible that the vast abundance of sponges in ancient China helped the post-extinction ecosystem recover "by stabilizing the sediment surface [and] allowing sessile [immobile] suspension feeders such as brachiopods, corals and bryozoans to recover rapidly," the researchers wrote in the study.

What's more, other scientists have discovered numerous sponge remains dating to periods following other mass extinction events, suggesting that it's not uncommon for sponges to take over following a major ecological collapse, the researchers said.

The findings were published online Feb. 9 in the journal Current Biology.

Original article on Live Science.

MARINE CORPS BASE HAWAII — Whether it's the noxious gases rising from the Kilauea volcano, or the lively coral reefs that sprawl across the seafloor around the island chain, Hawaii's ecosystems are under some serious scientific scrutiny this month.

Researchers are here gathering data using NASA's high-altitude airplanes, outfitted with cameras that capture visible light as well as infrared radiation. One airplane, the ER-2, can soar to 67,000 feet, or "the edge of space," as NASA systems engineer Michael Mercury put it. From that height, on daily flights over the islands, the cameras snap images that the scientists then stitch together and analyze, Mercury said, explaining the project at a media briefing that the space agency held here on Wednesday (Feb. 8). [Earth Pictures: Iconic Images of Earth from Space]

The goal of this current work in Hawaii is to find the best ways to use these measurements to gain new insights into volcanic activity and coral reef health. For example, scientists studying Hawaii's active volcano are trying to refine their models that predict exactly how and when the "vog," or volcanic smog that forms from Kilauea's gases, will blanket Hawaiian cities instead of blowing out over the Pacific. Other researchers, who study coral reef ecosystems, are using the images from the high-altitude flights to better understand what aspects of water quality make the difference between a thriving reef and one that is overgrown with algae.

But there is a larger goal, too. NASA has plans to launch an Earth-observing satellite into low-Earth orbit in 2022. That project, called the HyspIRI mission (or Hyperspectral Infrared Imager), will provide researchers with images of Earth's surface that are similar to those being gathered now in Hawaii, and from ecosystems all over the world.

The current project in Hawaii will help the researchers to figure out exactly which instruments and equipment are most useful for their work, and should be the ones that are loaded up onto that satellite.

Eventually, the satellite could be used to gather data not only on volcanoes and corals, but also on many other features that change the Earth's surface over time, such as wildfires that destroy vegetation, thinning glacial ice or changes in the health of croplands.

Once the HyspIRI satellite is in place, researchers plan to use it in conjunction with aircraft- or ground-based instruments. "The satellite might see something new, [and] point us to new places to go with the airplane," Randy Albertson, deputy director of the NASA Airborne Science Program, told Live Science. [Colorful Creations: Incredible Coral Photos]

In the meantime, the Hawaii projects are in full swing. In the coral project, the images taken by the instruments aboard the aircraft can help the researchers spot changes in the color of a reef, said Steven Ackleson, an oceanographer with the Naval Research Laboratory in Washington, D.C., who is in Hawaii to work on the project. 

"Reef pigments come from both the zooxanthellae and from the corals themselves," Ackleson told Live Science, using the scientific term for the algae-like organisms that live in symbiosis with the coral polyps. "Colors indicate health," he said.

The researchers want to figure out the best ways to draw information from the images to determine coral health, he said. For example, the scientists are hoping to learn more about why some types of zooxanthellae tolerate warming waters better than others. The answer may involve differences in the chloroplasts between the different types of zooxanthellae, he said.

The researchers who are working on the volcano project are using the images to better study the composition of the gas plume that arises from Kilauea, and how it changes as the plume spreads out, said Vincent Realmuto, a geoscience researcher at NASA's Jet Propulsion Laboratory.

A key part of the project is looking at how the plumes affect Hawaii's air quality, Realmuto said.

For example, one question the volcano researchers are trying to answer with the new data is exactly how quickly the sulfur dioxide gas that the volcano emits becomes aerosolized, meaning it combines with other compounds to form particulate matter, which can be harmful to human health.

The current estimate is that process takes 10 hours, Realmuto said. But that estimate is very rough. "The local temperature, the humidity, the topography – all of these impact the conversion rate," he said. The new data will help the scientists to create better models to predict the formation and movements of the particulate matter, which could lead to better forecasts of the vog. [The 10 Biggest Volcanic Eruptions in History]

Albertson noted that even when it launches, the new satellite won't eliminate the need for gathering data from instruments aboard aircraft and on the ground. Ground-based instruments can gather measurements on a much finer scale than the satellite will. But the satellite's capacity to get images from the entire Earth in a short amount of time will be a huge advantage for researchers.

To put this in perspective, Mercury said, the current six-week effort will capture images, using the visible-light camera, for most of Hawaii. If that camera were on a satellite, for the same amount of time, the researchers would be able to capture the same level of imaging for the entire Earth's surface, four times over, he said.

Originally published on Live Science.

Wilderness areas around the world have experienced catastrophic declines over the last two decades, with one-tenth of global wilderness lost since the 1990s, according to a new study.

Since 1993, researchers found that a cumulative wilderness area twice the size of Alaska and half the size of the Amazon has been stripped and destroyed.

The shrinking wilderness is due, in part, to human activity such as mining, logging, agriculture, and oil and gas exploration. The researchers said theirfindings underscore the need for international policies to recognize the value of wilderness and to protect wilderness areas from the threats they face. [In Images: One-of-a-Kind Places On Earth]

"Globally important wilderness areas — despite being strongholds for endangered biodiversity, for buffering and regulating local climates, and for supporting many of the world's most politically and economically marginalized communities — are completely ignored in environmental policy," study lead author James Watson, an associate professor in the School of Geography Planning and Environmental Management at the University of Queensland, in Australia, said in a statement.

"Without any policies to protect these areas, they are falling victim to widespread development. We probably have one to two decades to turn this around," said Watson, who is also director of the Science and Research Initiative at the Wildlife Conservation Society.

Central Africa and the Amazon saw the most wilderness decline, the researchers found. Of the roughly 1.27 million square miles (3.3 million square kilometers) of global wilderness lost, the Amazon accounted for nearly one-third, and 14 percent of the world's wilderness was lost from Central Africa, according to the study.

The researchers determined that only 11.6 million square miles (30.1 million square km) of wilderness is left, which equates to just 20 percent of the Earth's total land mass.

"The amount of wilderness loss in just two decades is staggering," study co-author Oscar Venter, an associate professor of ecosystem science and management at the University of Northern British Columbia, said in the statement. "We need to recognize that wilderness areas, which we've foolishly considered to be de-facto protected due to their remoteness, is actually being dramatically lost around the world."

The researchers defined wilderness as "biologically and ecologically intact landscapes that are mostly free of human disturbance." In their new study, the scientists mapped these areas around the world to assess how their ecosystems have changed over the years. The researchers noted that wilderness areas do not exclude people, but rather have lower levels of human impact that results in biophysical disturbance to natural habitats.

Once wilderness is gone, it cannot be restored because the ecological processes that underpin the ecosystems are destroyed, the researchers said. The only option, they said, is to proactively protect what is left.

"If we don't act soon, there will only be tiny remnants of wilderness around the planet, and this is a disaster for conservation, for climate change, and for some of the most vulnerable human communities on the planet," Watson said. "We have a duty to act for our children and their children."

The study was published online Thursday (Sept. 8) in the journal Current Biology.

Original article on Live Science.

Getting peed on is a good thing, at least for coral reefs, scientists have found.

When fish let loose, they release phosphorus into the water. This, combined with nitrogen excreted from their gills, is crucial for coral reef survival and growth, according to recent studies.

Now, new research shows just how much this "fishy waste" matters. When scientists studied areas with heavy fishing, they found that almost half of the key nutrients needed to maintain a healthy reef ecosystem were missing. [How Much of the Ocean Is Whale Pee (and Worse)?]

That's right — large, predator fish are needed to mist the reefs with their pee, study lead author Jacob Allgeier, a postdoctoral researcher at the University of Washington's School of Aquatic and Fishery Sciences, said in a statement.

"Fish hold a large proportion, if not most, of the nutrients in a coral reef in their tissue, and they're also in charge of recycling them," Allgeier said. "If you take the big fish out, you're removing all of those nutrients from the ecosystem."

To study the impact of these nutrients, researchers surveyed 143 fish species at 110 sites across 43 Caribbean coral reefs. Some reefs had few fish because of commercial fishing, whereas others were marine preserves with fishing bans.

Reefs with many large, predator fish had the healthiest levels of nutrients, the researchers found. Meanwhile, reefs with few large fish had about 50 percent fewer nutrients, including phosphorous and nitrogen, which are essential to their survival, the researchers said.

"This study is useful to understand alternative ways fishing is affecting coral reef ecosystems," Allgeier said.

Big fish

When fishers target big fish — such as grouper, snapper and barracuda — the fish, and their pee, disappear, the researchers said.

Normally, fish take shelter in coral reefs during the day, whiling away the time as they relieve themselves. At night, they typically forage for food within the reef communities.

Researchers have known about this behavior for decades. A 1983 study published in the journal Science found that schools of fish did this peeing-during-the-day routine within coral communities, and that corals with these schools grew more than twice as fast as reefs without schools.

Allgeier said the results of the 1983 study inspired him to conduct his new research. He knew that coral reefs operate on a "tight" nutrient cycle, meaning they need an efficient transfer of nutrients in order to grow. Fish help regulate this cycle with their pee and gill excretions, he said.

So Allgeier spent four years measuring how many nutrients fish released, which allowed him to build a giant data set of fish size and nutrient output. He did this by catching hundreds of live fish, putting them in plastic bags for 30 minutes, and measuring the nutrients of the water before and after, he said.

The results showed that nitrogen output was related to fish size, and that carnivorous fish peed more phosphorus than small herbivorous fish.

What's more, models created by Allgeier and his colleagues will help researchers estimate how much waste specific species and sizes of fish release, he said. "It's remarkable how robust the models are just from knowing fish size and species," he said.

The study was published online Aug. 16 in the journal Nature Communications.

Original article on Live Science.

A predator's bark may indeed be worse than its bite, new research suggests.

Simply hearing a recording of wild dogs barking can keep wild raccoons from foraging along a shoreline of several small islands, according a new study.

That, in turn, fuels a population rebound in the raccoons' prey, such as crabs and fish. The findings could have implications for other ecosystems, where animals lower in the food chain quiver at the mere mention other top predators.

"When it comes to conserving biodiversity and maintaining healthy ecosystems, fear has its uses. By inspiring fear, the very existence of large carnivores on the landscape, in and of itself, can provide a critical ecosystem service human actions cannot fully replace, making it essential to maintain or restore large carnivores for conservation purposes on this basis alone," the researchers wrote in the paper, which was published today (Feb. 23) in the journal Nature Communications. [Video: Watch Raccoons Cower At the Sound of Dogs Barking]

Web of fear

Past studies had shown that even spiders with disabled mouthpieces, which could scare, but not physically harm, grasshopper prey, successfully cause grasshoppers to change their foraging behaviors enough to alter the whole plant community. But scientists were split as to whether the same fear-based ecology held sway at larger scales.

"There's been quite a bit of controversy over whether these cascading effects of fear have any real relevance for wildlife like large carnivores and their prey in real ecosystems," said Justin Suraci, an ecology doctoral candidate at the University of Victoria in Canada. "This is because previous attempts to study the cascading effects of fear in wildlife have been unable to disentangle the effects of fear from other factors affecting wildlife, such environmental change."

For instance, many scientists believe the reintroduction of wolves to Yellowstone National Park has reduced elk overgrazing, allowing plants to regrow and beavers and songbirds to take up residence in the park once again. But opponents of wolf reintroduction have argued that other environmental changes, not the wolves' reign of terror, is responsible for the resurgence of a vibrant ecosystem in the park, Suraci said.

Suraci and his colleagues wanted to isolate the effects of terror in food webs involving larger creatures. To do so, the team studied the ecosystems on the Gulf Islands, an island chain off the coast of British Columbia, Canada. On the islands, wild raccoons prowl the shorelines for shore and red rock crabs and fish that live in the tidal zone. Historically, black bears, cougars and wolves hunted raccoons, but now that those predators have been exterminated, the only animals that prey on raccoons are wild domestic dogs, which local aboriginal people have kept for millennia, the researchers wrote.

While dogs likely don't kill that many raccoons and can't take the place of authentic top predators like cougars, "probably the vast majority of raccoons have been harassed by dogs (chased or barked out), which our data show is enough to instill a healthy predator fear," Suraci told Live Science in an email.

To see whether fear alone could impact raccoon behavior, Suraci's team played the sounds of wild dogs barking along the shoreline. As a control, they played the sounds of harbor seals, stellar sea lions and other pinnipeds along a separate shoreline. Throughout the month, they used cameras to track the number of raccoons prowling the beaches, as well as to survey the number of red rock and shore crabs and intertidal fish before and after the experiment.

When the raccoons heard the dog barks, they startled and shied away. Overall, raccoons on this fear-filled island spent 66 percent less time foraging in their favorite spots. The innocuous seal sounds, by contrast, produced no such effect.

The impact of those barking dog sounds reverberated through the food chain. At the end of this month-long experiment, the number of shore crabs nearly doubled, while there was an 81 percent jump in the number of intertidal fish and a 61 percent increase in red rock crabs, likely because fewer raccoons were scooping them up. Meanwhile, the small invertebrates that those crabs ate decreased, likely because the crustacean numbers increased.

The findings suggest that the fear provoked by top predators such as mountain lions and wolves may tie the whole food web together in surprising ways.

"The fear large carnivores inspire in their prey can account for a major component of their role in structuring ecosystems, reinforcing the value of large carnivore conservation in ensuring the continuation of this critical ecosystem service," the researchers wrote in the paper.

Follow Tia Ghose on Twitterand Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.

Biologist Josh Grinath seized a rare chance to study an ecosystem from top to tiny bottom when a black bear blundered through his Rocky Mountain meadow research plot, gobbling up ants and gnawing on equipment.

Grinath, a researcher at Florida State University, was already analyzing the codependent relationship between ants and treehoppers, which are tiny insects that poop sweet honeydew juice. The ants ward off predators that eat treehoppers, and in return, gorge on honeydew. The sap-sucking treehoppers chew on yellow rabbitbrush, a native plant that also hides sage grouse and provides forage for deer and elk. Grinath's earlier research in the meadow showed that rabbitbrush produces fewer seeds and struggles to grow whenever ants and treehoppers are present on the plants.

When the hungry bear appeared, wreaking havoc on ant nests for a high-protein snack, Grinath decided to track the cascading effects of this top predator. "When you look at a real ecosystem, it's not just predator-prey interactions," Grinath told Live Science. "There are many different kinds of interactions, and they all influence each other." [Gallery: Out-of-This-World Images of Insects]

Where the black bear toppled ant nests, nearby rabbitbrush grew better and produced more seeds, Grinath and his colleagues reported in the February 2015 issue of the journal Ecology Letters. A camera trap confirmed that bears were the culprit, Grinath said. In four years, bears attacked 26 to 86 percent of the 35 ant nests in the meadow research plot at the Rocky Mountain Biological Laboratory, near Almont, Colorado, the study reported.

The researchers further tested the effects with controlled experiments in the years following the bear's arrival. For example, they completely removed insect predators so the treehopper population thrived, and on other plants they scattered treehopper predators, such as lady beetles, to decimate the insects. Ultimately, the plants with the most predators responded with the most growth, mimicking the effects of a bear removing the protective ants.

"I think that ants are the most interesting species in this chain of species I've been interacting with," Grinath said. "Because the bears are targeting this one highly connected species, they have the potential to influence all of the organisms in this meadow."

Black bears, rabbitbrush, ants and treehoppers all have wide ranges across the Rocky Mountains, so the species likely cross paths in many places throughout the West, Grinath said.

For Grinath, the results highlight the many important roles that top predators fill in ecosystems. "My research shows there are multiple ways in which predators can influence plants and other organisms, and therefore it's important to conserve these top predators to maintain species diversity."

Follow Becky Oskin @beckyoskin. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.

Centuries of over-exploitation of whales for their meat and blubber has seen populations of most species plummet. But with no small amount of irony, the tables have turned with research discovering that we need whales for a healthy marine ecosystem, or at least their poop.

Large areas of the Southern Ocean are known as high-nutrient, low-chlorophyll (HNLC) waters. This is where phytoplankton abundance is very low despite high concentrations of major nutrients such as nitrate, phosphate and silicate.

Phytoplankton is crucial in marine ecosystems as the main food source that supports all marine life. It also plays a key role in removing carbon dioxide from the atmosphere through photosynthesis.

Uneaten phytoplankton eventually die and sink from the euphotic zone – the top 200-300m where light can penetrate – transferring the carbon to the deep sea.

Iron’s role in the Southern Ocean

One factor that limits the production of phytoplankton in HNLC waters has been the availability of iron. Iron is an important nutrient that acts as an electron carrier and a catalyst during photosynthesis.

When iron is in short supply, phytoplankton can’t grow, leading to less carbon dioxide removed from the atmosphere.

Until recently, it was thought that the main new sources of iron in the ocean were from atmospheric dust, shelf sediments, underwater volcanoes and icebergs.

Research has shown that large animals, including whales, are part of a positive feedback loop that consumes and retains nutrients at the ocean surface, and consequently are a slow-release source of recycled iron to the upper ocean.

Diving mammals such as whales require iron for myoglobin, the oxygen-storage protein in muscles. Filter-feeding, or baleen, whales mostly eat Antarctic krill and are capable of converting the iron found in solid form in their prey into a liquid form that is released as a slurry into the euphotic zone.

Other types of whales, such as sperm whales, migrate to waters much deeper than the euphotic zone and they can scavenge iron from below and then return to the surface layer to defecate.

Unlike some animals, such as zooplankton, that can defecate at depth, whales only defecate near the surface. Their warm, fluid-like feces rise to the surface before being dispersed, thereby releasing the nutrients exactly where the phytoplankton need them.

The richness of whale poop

During the short summer feeding season in the Southern Ocean, adult blue whales consume approximately two tonnes of krill per day. As they are accumulating blubber instead of building muscle to last them through the subsequent calving period, most of the iron consumed is excreted in their feces.

The concentration of iron in whale feces was found to be more than 10 million times higher than seawater concentrations. So whale poop acts as a fertiliser that increases phytoplankton growth, leading to a more productive ecosystem and enhanced atmospheric carbon dioxide removal.

If whale populations had not been hunted to near-extinction, whales would have recycled more iron because of their abundant numbers.

In the Southern Ocean, iron defecation by the 12,000-strong population of sperm whales removes approximately 200,000 tonnes of carbon per year from the atmosphere.

This is equivalent to 70,000 vehicles that each travel 15,000 km per year. Blue and fin whales, being much larger than sperm whales, could recycle far more iron.

Conservation of whales in the Southern Ocean

With the discovery of the important role of whales in recycling iron and its link to ecosystem productivity and carbon removal, our thoughts turn to the greater context of conserving and restoring whale populations in the Southern Ocean.

In addition to the moratorium on whaling under the International Whaling Commission’s Schedule to the International Convention for the Regulation of Whaling, there is also a specific ban on commercial whaling in the Southern Ocean Sanctuary. This reflects the conservation-based approach of most members of the International Whaling Commission.

The only permissible killing, taking or treating of whales from the Southern Ocean falls under scientific permit whaling.

The whale hunting’s over … for now

Japan is the only country that has issued such permits in the Southern Ocean, with the International Court of Justice recently ruling that Japan’s whaling actions in the Antarctic were not “for the purposes of scientific research”.

The court ruling also ordered that Japan revoke its current Southern Ocean scientific permits.

The decision did not ban Japan from returning to the Southern Ocean with a revised programme, so lethal scientific whaling may soon resume.

The International Whaling Commission’s next meeting in September 2014, the first since the court’s decision, may raise the scientific value of research into Southern Ocean whale populations and the methods by which they are studied.

Greater cooperation between member nations in researching these populations (the lack of which was raised in the court’s decision) could lead to greater knowledge of whales, and the potential of the Southern Ocean to become a more productive ecosystem and hence a more effective carbon sink.

Lavenia Ratnarajah receives funding from the University of Tasmania, the Antarctic Climate and Ecosystems Cooperative Research Centre and the Holsworth Wildlife Research Endowment.

Andrew Bowie currently receives funding from the Australian Research Council. He has previously received funding from the Cooperative Research Centres program through the Antarctic Climate and Ecosystems CRC and funding for shiptime from Australia's Marine National Facility.

Indi Hodgson-Johnston is affiliated with, and receives funding from, the University of Tasmania and the Antarctic Climate & Ecosystems CRC.

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

This Research in Action article was provided to LiveScience in partnership with the National Science Foundation.

Who do you call when your coral-reef neighborhood starts going downhill? The goby fish. These inch-long, biotic hedge trimmers enjoy nothing more than removing toxic algae from the knobby skyscraper villages erected by Acropora coral. Good thing, too. Without the gobies' compulsive cleaning, the alga commonly known as turtleweed can severely damage a coral reef through bleaching.

"The gobies are very defensive about their territory. They live in this coral their entire lives and feel like this is their house," says Mark Hay, a Georgia Institute of Technology biologist who studies the unique relationship shared by the gobies, algae and coral.

To learn more about just how the gobies defend their turf, Hay and fellow Georgia Tech biologist Danielle Dixson travel to Fiji, where a defunct dive shop serves as their home, lab and field office. Through a series of laboratory and underwater experiments, Hay and Dixson discovered that the gobies immediately respond to the coral when the turtleweed algae sweeps against it. The coral sends out a chemical that acts like a "911 call" to the gobies. The fish arrive and begin trimming away the seaweed. "It's the combination of the alga and coral together that the fish respond to," says Hay.

What's interesting about this interrelationship is that all involved are native to their habitat. "These are neighborhood players," says Hay. "The fish prefer to live in this species of coral and they know if it's their species being damaged. It's very finely tuned."

In the reef under study, just two species of goby fish take charge of removing the alga — the broad-barred goby (G. histrio) and the redhead goby (P. enchinocephalus). The scientists found that other fish leave the area when the coral comes into contact with the chemically noxious algae. And while both species trim the algae, the broad-barred goby actually consumes it. The turtleweed tidbits help boost the potency of the tiny gardener's own noxious mucus, which it uses to deter predators.

Because Hay and Dixson suspect that these types of behaviors may exist elsewhere, Dixson plans to travel to Australia in the near future to study other goby species in their coral habitats.

Knowing how widespread these behaviors are will help researchers protect Acropora coral. Thesecoral species are important because they form much of a reef's structure and provide a protective habitat for a myriad of other animals and plants.

Editor's Note: Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation. See the Research in Action archive.

David Festa, vice president of the Land, Water, Wildlife Program at the Environmental Defense Fund, contributed this article to LiveScience's Expert Voices: Op-Ed & Insights.



I recently was struck by a line in an article in the new issue of Scientific American. It called the loss of Louisiana's coastal wetlands "the greatest environmental, economic and cultural tragedy on the North American continent."

It's easy to see why they would say that. Since the 1930s, efforts to control the Mississippi River and widespread energy development in the Mississippi delta have resulted in the sacrifice of 1,900 square miles of Louisiana's coastal wetlands to the sea. If that had happened on the east coast, an area twice the size of Boston, New York City, Philadelphia and Washington, D.C. put together would be under water. Of course, the engineering projects on the Mississippi spurred over a century of economic development and navigation. But the cost has been the loss of the original delta ecosystem, leaving coastal communities more exposed to storm surges and a rising sea level.

As dramatic as that is, the thing that caught my eye even more was another line in the article: "Many wetland recovery programs have failed by trying to re-create the original ecosystems."

The article goes on to make a point that we don't have to re-create the past to make things better for people and the planet. In fact, when you think clearly and specifically about the need we as a society are trying to meet, and then ask how nature can help meet that need, surprisingly positive things can happen.

Consider the article's example of the Delaware Bay, an ecosystem that was teeming with aquatic life before settlers built dikes and drained thousands of acres to grow crops.

"Looming on the New Jersey shore of the bay is the Salem nuclear power plant, owned by utility giant PSEG," the article states. "The plant sucks in billions of gallons of water a day for cooling and kills millions of tiny fish and other creatures as they get drawn through the intake valves. In the early 1990s state regulators asked PSEG to build cooling towers to end the carnage. Reluctant to spend $1 billion to $2 billion, the utility proposed an alternative: restore enough salt marsh to compensate for the loss of fish — more than 10,000 acres."

The restoration team decided to take a less-is-more approach — cut gaps in the dikes that would let just the right amount of water into the marsh to create an initial maze of tidal creeks, and then let the rest of the creeks develop on their own. "If you engineer a drainage system in great detail, the system is forced to go the way you think it ought to be," a restoration expert told the publication. "But if you allow it to develop itself, it's more likely to be stable."

Today, reports Scientific American, the increase in fish populations more than makes up for the losses from the power plant's water intake, and the restoration looks like the natural marshes next door. Plus, it saved consumers money because letting nature meet the need cost hundreds of millions of dollars less than the concrete cooling towers.

Reversing damage

You see this principle at work in the efforts of EDF and our allies in the Gulf of Mexico. Last year, as part of ongoing efforts to reverse losses in the Mississippi River Delta, Louisiana passed the Comprehensive Master Plan for a Sustainable Coast. This landmark plan serves as the blueprint for restoring Louisiana's wetlands, and it follows two tenets that proved so successful in the Delaware Bay. First, it focuses on a single goal: rebuilding and sustaining hundreds of square miles of land. Secondly, it relies on nature to do the bulk of the reconstruction. Sediment-laden water from the Mississippi River will be diverted into marshes and shores. Over time, the sediment will create new land and a more resilient coastline.

In the face of extreme weather and global sea-level rise, this new approach takes on great meaning. Superstorm Sandy provided powerful illustrations of how wetlands can serve as a first line of defense against extreme weather events. Salt marsh remnants along Long Island's Jamaica Bay, for example, helped to protect residents there, while the lack of wetlands around Manhattan left it exposed to crashing waves.

More than 3 billion souls — 40 percent of the world's population — live as close to the sea as New Orleans. By letting nature back into the game, people can help rebuild coastal Louisiana and turn "a North American tragedy" into a model of success for protecting nearly half the planet's population.

The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on LiveScience.

Andrew Wetzler is director of the Land & Wildlife Program at the NRDC. This Op-Ed originally appeared on the NRDC blog Switchboard. Wetzler contributed this article to LiveScience's Expert Voices: Op-Ed & Insights.

Tuesday marked the official end of the public comment period on the U.S. Fish and Wildlife Service's proposed nation-wide regulation removing the gray wolf from the federal list of endangered species.

The proposed regulation is the culmination of the administration's push to finally strip every gray wolf in the country (outside of a small population in Arizona and New Mexico) of federal Endangered Species Act protections. If the Fish and Wildlife Service gets its way, not only will established wolf populations in states like Idaho and Minnesota continue to be unprotected, but any wolves who make it to other states — California, Maine, Utah or Colorado, for example — will also be completely at the mercy of local governments.

Some of those states may manage wolves wisely, but far more have shown a pattern of disturbing hostility to wolves and a complete aversion to wolf recovery. Just last week, news broke of a wolf killing "tournament" in Idaho. The Utah state legislature regularly appropriates hundreds of thousands of dollars in taxpayer money to private groups to lobby against any wolf protections. Wyoming has designated over 80 percent of the state a wolf "free fire zone," where wolves may be shot at any time of the year and in unlimited quantities. In Michigan, the state legislature has passed laws to bypass a popular referendum, which was almost certain to prohibit a public wolf hunt. And gray wolves that have made it to Maine have been shot by hunters, who claim they mistook the wolves for coyotes.

For all the success that the wolf has enjoyed in some parts of the country, there remain huge areas of suitable habitat for wolf populations to establish themselves in the lower-48 states. From the vast forests of northern New England, to the rich elk and deer habitat in Colorado, to northern California's forests and rugged mountains, true wolf recovery means restoring healthy wolf populations not to a tiny fraction of its suitable habitat, but as the Endangered Species Act right demands, to a "significant portion" of that range.

These wild areas cry out for a return of their wolves. As ecologists now recognize, the presence of wolves and other top-predators are a crucial part of restoring the health of our wild places. From vegetation near streams, to trout and beaver populations, to song birds, owls and foxes, we now know that the entire fabric of ecosystems are transformed and made more healthy, diverse and resilient when wolves are present.

Yet, despite this, the U.S. Fish and Wildlife Service and the Obama administration have continued their inexorable march to strip wolves of the few federal protections they now enjoy. And I can't help but wonder, why? It's not a popular decision. Close to 1,000,000 comments have been filed with the administration opposing the delisting proposal.

It's not the science. As NRDC makes clear in our comment letter, the scientific evidence justifying the delisting of wolves, particularly in the Northeast is shaky at best. It's not the law. There are numerous legal problems with the delisting. And it's probably not politics. Unlike a few years ago, there are no vulnerable Democrats in the U.S. Senate demanding a wolf delisting. My money rests on bureaucratic inertia and a lack of vision. Regardless, I hope the administration sees the error of its ways. If not, NRDC and our conservation allies will be there to fight, every step of the way.

This Op-Ed originally appeared as "Public Comment Closes on the Obama Administration's Proposal to Remove Protections for Wolves Across the Country -- Narrow Thinking Where We Need Bold Vision" on the NRDC blog Switchboard. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on LiveScience.

This article was originally published at The Conversation. The publication contributed the article to LiveScience's Expert Voices: Op-Ed & Insights.

Meteorite impacts can be very destructive. One that fell in Mexico around 66m years ago created a 180km crater and caused the extinction of dinosaurs while spewing debris and molten rock into the air. Now, in what is a fascinating tale of serendipity, researchers have found that these events don’t entirely destroy all traces of life at the site of impact. Molten rocks can capture and preserve organic matter as they cool down to form glass beads.

When a meteor enters Earth’s atmosphere, the air around the meteor gets very quickly compressed causing it to heat up, scorching everything in its path. Most of the time that is where the story ends, as the meteor burns up in the sky as a “shooting star”. But sometimes it is big enough to reach all the way to the surface and transfer its remaining energy to the ground.

This energy is dissipated, as mild earthquakes, sound shockwaves – but mostly as heat. The heat energy can be so great that it melts rocks on the surface and hurls them up in the atmosphere. Anything that comes in contact with this molten rock would presumably get burnt, leaving nothing but rocky material that cools down in the atmosphere, forming glass beads and tektites (gravel-sized natural glass). This is what City University of New York researcher Kieren Howard assumed, but he was able to show that his assumptions were wrong.

For his PhD, Howard was studying the glass beads and tektites found near the Darwin crater in Tasmania. The 1.2km wide crater was created by a meteorite impact about 800,000 years ago.

The natural glass formed during cooling is (as implied by the term glass) not crystalline. Instead of a regular arrangement of atoms, the atoms inside it are randomly arranged. Howard’s analysis, however, kept showing the presence of crystals. At first, he dismissed this as a problem with the machine or with his method of analysis. But when it kept showing up, as a good scientist, he thought he should ask an expert to look at his data.

“This is unusual,” says Chris Jeynes, a physicist at the University of Surrey. “If there were indeed crystals, then it was the result of uneven cooling, which can occur when something gets trapped inside these glass beads.”

Jeynes used proton-beam analysis, a method to peer inside the glass to reveal its elemental make-up. Inside he found carbon. “Howard had no idea what his samples were, and he was very surprised when I told him,” Jeynes says.

The natural glass formed should contain only silicon, titanium, oxygen and other metallic elements in trace amounts. Detection of carbon meant that there was some organic matter inside. The only hypothesis was that, somehow during the formation of these glass beads, they captured organic matter that was floating in the atmosphere. That organic matter might have already been in the air, but it might also include material thrown up by the impact.

Howard then went to another expert to break open these glass beads and reveal what the carbon-rich matter was. It turned out that it included were cellulose, lignin and other biopolymers. This meant that somehow this matter, which originated from plants, had survived the temperature of more than 500°C, which is what the molten rock would have reached before cooling into a glass bead. Usually these temperatures will break down the organic matter, but clearly it didn’t in this case.

Mark Sephton, a geochemist at Imperial College London, was surprised and pleased: “What the results show is that these glass beads can capture an aliquot of the atmosphere of the planet at impact. It is like a time capsule of that ecosystem.” These results are published in Nature Geoscience.

The implications are enormous. It shows that other meteorite impacts, like the one that wiped out the dinosaurs, could have created such time capsules too. Sephton is now working on finding glass beads from other impact sites to reveal information about Earth’s ancient atmosphere.

This method of analysis means that we could also go looking for similar beads on other planets, like Mars, where meteorite impacts are common. They could also reveal vital information about the past atmosphere of those planets. Maybe they captured organic matter – if it ever existed there.

“We would not know any of this if it wasn’t for Howard,” Jeynes says, adding that Howard’s persistence to find out what “the wrong results” led the researchers to a phenomenon that nobody knew existed.

This article was originally published at The Conversation. Read the original article. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on LiveScience.

Inside Science Minds presents an ongoing series of guest columnists and personal perspectives presented by scientists, engineers, mathematicians, and others in the science community showcasing some of the most interesting ideas in science today.

(ISM) -- Throughout most of the world sharks are in trouble. Big trouble. In some areas, with adequate management, shark populations have stabilized, but likely at levels far below what they were decades ago. In the rest of the world, shark fishing continues to be a major threat to many species. Recent estimates suggest that around 100 million sharks are taken by fisheries every year. 

Because of their slow growth – sharks may take a decade or more to reach maturity – and low rate of reproduction – many species have fewer than a dozen young a year – this rate of catches is unsustainable. The decline of sharks will continue.

Why should we care? What will that mean for the oceans and even for fisheries targeting species other than sharks? We know from studies on land that when large predators are removed, entire ecosystems can be destabilized. That can be bad for animals and people. If similar things happen in the oceans, we not only need to think about halting declines of sharks, we will probably need to find ways to rebuild their numbers.

The attention that the Discovery Channel's Shark Week brings to these animals is great, but that attention needs to extend beyond the first week of August for these predators and the places they live to recover and eventually thrive.

For the past fifteen years, my colleagues and I have been trying to figure out how important tiger sharks are in the aptly named Shark Bay, Western Australia. Why travel halfway around the world? Quite simply, to study sharks in a place where their ecosystem is relatively untouched. Also, because Shark Bay features some of the world’s largest seagrass beds. Seagrass is important because it provides a habitat that supports populations of fish and shellfish that people rely on. It also helps to combat climate change by pulling carbon dioxide out of the atmosphere. By working in Shark Bay we can understand the role of sharks and what might happen to Shark Bay and its seagrass if tiger sharks were to disappear. It also lets us predict what might happen in other places where sharks have been overfished.

In Shark Bay, we have worked not only on sharks, but on their prey — including dolphins, sea turtles and sea cows — as well as the wider ecosystem. Our findings demonstrate that tiger sharks are critical to the Shark Bay ecosystem. But not in the way you might think. It turns out that the fear of sharks – by the sea cows and sea turtles that eat the seagrass – helps protect the seagrass from being over-grazed.  

Here is how it works: Tiger sharks like to hunt in shallow waters in the bay; a perfect place for seagrass to grow. To avoid becoming a shark snack, turtles and sea cows generally avoid these areas. The seagrass can grow into a lush habitat that provides shelter for small fish and shellfish that will grow up into species people want to catch. In areas that sharks don’t frequent, seagrass is heavily grazed and does not support big populations of fish and shellfish. That means that if we were to lose tiger sharks from the bay, the seagrass likely would be grazed down all over.

The loss of seagrass would be bad news for fish and fishermen – and maybe even for turtles and sea cows! It also could result in the loss of a large amount of carbon dioxide back into the atmosphere that would no longer be stored by seagrasses. There is evidence that the loss of sharks is hurting seagrass in some places. 

In Bermuda and the Indian Ocean, where shark populations have declined, increasing populations of sea turtles are causing entire seagrass beds to virtually disappear. And it isn’t just in seagrass ecosystems where sharks are important. Recent studies point to the possibility that healthy coral reefs need sharks, too.

Luckily, many countries have begun to recognize that sharks can draw tourists. The associated economic benefits of shark tourism can outpace the income from fishing for sharks. There also has been a growing realization that if we don’t slow down shark fisheries, they will disappear. This has led some countries to adopt fishing quotas aimed at keeping sharks at sustainable population levels. 

Other countries have gone further. Shark sanctuaries – where they are protected from being fished - have been declared throughout the waters of a number of countries around the world. This kind of precautionary approach is vital to protecting and restoring shark populations while scientists work to learn more about their potentially critical role in coral reef and other marine ecosystems. 

Inside Science News Service is supported by the American Institute of Physics. Mike Heithaus is a professor of Biological Sciences at Florida International University in Miami. His research has focused on predator-prey interactions and understanding the ecological importance of large marine animals, including sharks. He also has been active in bringing the excitement of scientific research to K-12 students and the public.

Red List of Ecosystems

The International Union for the Conservation of Nature published 20 case studies illustrating its new criteria for a Red List of Ecosystems May 8 in the journal PLOS ONE.

The list, which measures an ecosystem's risk of collapse, will be similar to the group's authoritative Red List of Endangered Species, which created internationally accepted criteria for assessing extinction risk.

Here are the example ecosystems used to come up with the list criteria, from most to least endangered.

Aral Sea — Uzbekistan and Kazakhstan

Status: collapsed

The fourth largest body of water in the world, the Aral Sea's ecosystem has been irrevocably changed by draining for irrigation, pollution and drought, scientists concluded in the study.

Raised bogs — Germany

Status: critically endangered

Shallow, flat and elevated above the surrounding landscapes, these peat bogs have a unique peat moss ecosystem that thrives in the acidic habitat. The plants survive only on rainwater.

Gonakier forests — Senegal River floodplain

Status: critically endangered

A verdant forest dominated by Acacia trees (also called Gonakier), the Senegal River floodplain stands in sharp contrast to the arid steppes and desert nearby. The forest provides critical habitat for fish, birds and other species, including humans.

Cape Sand Flats — Fynbos, South Africa

Status: critically endangered

With beautiful and sturdy wildflowers but poor soils, these sand flats, located near Cape Town in South Africa, rely on regular fires to regenerate their seed banks.

Coorong lagoons — Australia

Status: critically endangered

One of the largest and most diverse wetlands in the world, the Coorong lagoons support millions of local fish and migrating birds.

Karst rising springs — South Australia

Status: critically endangered

South Australia's karst landscape, a province with features like caves, springs and water-filled sinkholes, connects to the ocean. Some fish species spend part of their lives at sea and in the freshwater pools, amid the swamp-like vegetation.

Coastal sandstone upland swamps — Australia

Status: endangered-critically endangered

These treeless bogs near Sydney provide essential water during drought and shelter from predators in dense vegetation.

Swamps, marshes and lakes in the Murray-Darling Basin — Australia

Status: endangered-critically endangered

This diverse ecosystem depends on floods raging through Australia's Murray-Darling Basin. The swamps, marshes and lakes are filled with reeds, grasses and shrubs that provide a wetland habitat for a wide range of birds.

Giant kelp forests — Alaska

Status: endangered-critically endangered

Up to 50 feet (15 meters) tall, Alaska's giant kelp forests are home to a diverse array of marine life. Sea otters hunt for urchins and sea stars, and predators from Pacific cod up to killer whales rely on the brown kelp ecosystem.

Caribbean coral reefs

Status: endangered-critically endangered

Coral reefs face a variety of threats, including ocean acidification, warming temperatures, pollution, invasive species and overfishing.

Seagrass meadows — South Australia

Status: endangered-critically endangered
Like an underwater meadow, seagrass covers the sandy seafloor off South Australia. Seagrass is a habitat and a nursery for a variety of marine life.

German tamarisk pioneer vegetation — Europe

Status: endangered

Tamarisk are wispy but tough shrubs that pioneer new spots to grow in wet, sandy sites such as ever-shifting riverbanks.

Coolibah-Black Box woodland — Australia

Coolibah-Black Box woodland — Australia
Status: endangered

This mature woodland features large eucalyptus, coolibah and black box trees, fed by floods.

Tapia forest — Madagascar

Status: endangered

The remarkable Tapia tree forests of Madagascar are named for one of the island's many unique species, evolved in near-isolation over millennia.

Semi-evergreen vine thicket — Australia

Status: endangered

The dense vegetation of this vine thicket was home to one of the few southern Australia sightings of the black-striped wallaby. Much of the habitat has been cleared to grow wheat.

Great Lakes Alvar — U.S. and Canada

Status: vulnerable-endangered

Alvars are flat expanses of limestone bedrock, ground smooth by glaciers and covered with a thin scrim of soil. Almost all of North America's alvars are found near the Great Lakes.

Reedbeds — Europe

Status: vulnerable

In Europe, reedbeds provide vital breeding habitat for several vulnerable and endangered bird species. The reeds, dominated by one species, Phragmites australis, grow in wetlands, marshes, river deltas and even ditches — any marginal habitat with stagnant, brackish water.

Floodplain ecosystem of river red gum and black box — southeastern Australia

Status: vulnerable

Both the river red gum and black box trees thrive along the banks of rivers crossing the Murray-Darling Basin, Australia's largest floodplain. Several rare species call the forest home, and live nowhere else on Earth.

Tepui shrubland — Venezuela

Status: least concern

The Tepui shrubland is a lofty province of table mountains elevated above 4,900 feet (1,500 meters). Tepui, the local word for table mountains, now also refers to the distinctive vegetation growing on the flat-topped peaks.

Granite gravel fields and sandplains — New Zealand

Status: least concern

The granite gravels and sand dunes of New Zealand's spectacular Fiordlands, on the South Islands, are a rare example of sediments formed entirely from granite. The pink, white and black speckled igneous rock dominates the local geology, creating the unique piles of sediment as it erodes.

With many of the world's ecosystems threatened or endangered by human activities like logging and urbanization, the International Union for Conservation of Nature (IUCN) published its criteria for a new "Red List" of endangered ecosystems today (May 8) in the journal PLOS ONE.

The list, which measures an ecosystem's risk of collapse, will be similar to the group's authoritative Red List of Endangered Species, which created internationally accepted criteria for assessing extinction risk.

"The Red Lists for species and ecosystems will together provide a more comprehensive view of the status of the environment and its biodiversity than either can on its own," said lead study author David Keith, a professor at the University of New South Wales in Australia.

"The Ecosystem Red List focuses on a high level of biodiversity, the habitats for species, as well as their interactions and dependencies, including food webs,” Keith told OurAmazingPlanet in an email interview. “These are difficult or impossible to address in Red List assessments of individual species, but very important for the functioning of ecosystems and the services that they provide to support our standards of living."

Through 20 case studies, Keith and an international team of biologists and conservationists designed criteria that could assess the health of all of Earth's varied ecosystems, from spring-fed limestone caves to sparkling coral reefs.

"This is really a unifying framework," said study co-author Richard Kingsford, also a professor at the University of New South Wales. "The most important thing here, from my point of view, is providing evidence that pushes governments to do things to protect these magnificent parts of the world."

Of the ecosystems examined in the case studies, the most endangered site was the Aral Sea. Drained by a massive irrigation project and further devastated by drought and pollution, the inland sea's ecosystem has collapsed — the equivalent of species extinction, the study concludes.The rest of the ecosystem threat categories mirror those for species: critically endangered, endangered, vulnerable and least concern.

North American ecosystems appearing in the case studies included Alaska's giant kelp forests; the Great Lakes' rare Alvar beaches, a legacy of glaciers grinding across the landscape; and Caribbean coral reefs.

The IUCN group that developed the Red List of Ecosystems criteria plans to formally propose the framework to IUCN leadership this year. Funding is in place for listing ecosystems in the Americas, and the organization hopes to have a global list in place by 2025.

Development of ecosystem and species Green Lists are also underway — the carrot to the Red Lists' stick — to help the IUCN promote conservation by rewarding successes.

Here are the 20 case studies published today, from most to least endangered, with the ecosystem type noted if available.

• Aral Sea — Uzbekistan and Kazakhstan: freshwater, collapsed
• Raised bogs — Germany: critically endangered
• Gonakier forests — Senegal River floodplain: freshwater, critically endangered
• Cape Sand Flats — Fynbos, South Africa: terrestrial, critically endangered
• Coorong lagoons — Australia: freshwater/marine, critically endangered
• Karst rising springs — Southern Australia: freshwater, critically endangered
• Coastal sandstone upland swamps — Australia: freshwater, endangered/critically endangered
• Swamps, marshes and lakes in the Murray-Darling Basin — Australia: freshwater, endangered/critically endangered
• Giant kelp forests — Alaska: marine, endangered/critically endangered
• Caribbean coral reefs — Caribbean: marine, endangered/critically endangered
• Seagrass meadows — Southern Australia: marine, endangered-critically endangered
• German tamarisk pioneer vegetation — Europe: freshwater, endangered
• Coolibah-Black Box woodland — Australia: freshwater/terrestrial, endangered
• Tapia forest — Madagascar: terrestrial, endangered
• Semi-evergreen vine thicket — Australia: terrestrial, endangered
• Great Lakes Alvars — United States and Canada: terrestrial, vulnerable/endangered
• Reed beds — Europe: freshwater, vulnerable
• Floodplain ecosystem of river red gum and black box — southeastern Australia: freshwater, vulnerable
• Tepui shrubland - Venezuela: terrestrial, least concern
• Granite gravel fields and sand plains - New Zealand: terrestrial, least concern

Email Becky Oskin or follow her @beckyoskin. Follow us @OAPlanet, Facebook & Google+. Original article on LiveScience's OurAmazingPlanet.

The fate of a major European ecosystem depends on populations of a tiny, mouse-like creature: the vole.

Herbivorous voles play a critical role in the food chain. They are prey for many predators and important consumers of vegetation. Historically, voles have had three- to five-year boom-and-bust population cycles. However, over the past half-century, these cycles have been much less pronounced, a new study finds. The widespread flattening of vole populations may be due to climate change, and it could have detrimental effects on species that rely on these little creatures.

Voles are close to the bottom of the food chain, and the fate of these animals tends to have a ripple effect on the rest of the ecosystem, said ecologist Xavier Lambin of the University of Aberdeen in the U.K., and senior author of the study published today (April 4) in the journal Science.

In a typical boom year, a grassy area the size of a football field could be home to more than 500 voles. In a bust year, however, that number might dwindle to just a handful. This fluctuation in the populations of these little creatures acts as a kind of pacemaker for the ecosystem that depends on them. [In Photos: Adorable Voles]

Lambin and his colleagues analyzed vole-population data gathered over the past 60 years from areas across Europe. They found that over the last 20 years, there has been a gradual change in the population cycles, leading to smaller peaks in vole populations. Without this pacemaker in the ecosystem, "the strength of the heart beat is much, much weaker than it used to be," Lambin told LiveScience.

The shrinking of population booms will have a profound effect on vole predators, such as owls, kestrels, weasels and foxes, Lambin said.

"Many species are in deep trouble ― some species are completely unable to breed unless you have a vole outbreak," he said. The Arctic fox, in Sweden, for example, can have up to 14 pups per litter in a vole peak year but nothing in between — so a smaller peak might mean few to no pups, Lambin said.

So what's causing the vole-population peaks to diminish? Both local and global factors could be at play, but the one consistent change across Europe has been less population growth during the winter. The best candidate for such a widespread effect is climate change, Lambin said.

"It's a bit of a warning shot," Lambin said. "The way the natural world responds to changes in the environment can be quite unpredictable."

Follow Tanya Lewis on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science.

The dirt in Spain — and the rest of the planet — comes mainly from the plain.

Most of the world is flat, and more than 90 percent of the world's sediment comes from these gentle, low-lying slopes, a new study finds. The discovery overturns accepted geologic wisdom, which holds that steep mountain rivers create most of the sediment carried to the world’s oceans. These sediments from relatively flat areas also take the prize for trapping the most carbon in dirt. 

"I learned [sediment] all came from the mountains," said Jane Willenbring, a geologist at the University of Pennsylvania and lead author of the study. "The result is quite unexpected."

Whether its sand, mud or clay, knowing the dirt on the planet's sediment is key to understanding how surface changes affect climate. Erosion draws carbon dioxide from the atmosphere, trapping it in soils and rocks. "Most people, if they're geologists, thought mountains, and the uplift of mountains, were a really good way of sequestering [carbon dioxide] over a really long time scale," Willenbring said. "But in fact, where carbon sequestration happens is in these lowland rivers and places that are gently sloping," she told OurAmazingPlanet.

One of the ways carbon ends up in dirt is through chemical weathering, which occurs when rock turns into sediment. Carbon dioxide molecules and rain combine to dissolve rock, and the weathering products include sand, clay and other types of sediment. Physical weathering, such as from wind or glaciers, can also grind down rocks into dirt.

Willenbring and her colleagues examined erosion rates and topography around the world with a relatively new technique that looks at what is called cosmogenic nuclides. They analyzed the movement of sediment with radioactive isotopes of the element beryllium produced by cosmic rays (high-energy particles that rain down on Earth from space). Isotopes are created when beryllium in rocks exposed at the surface are bombarded by cosmic rays, producing varieties of the element that have differing numbers of neutrons. The concentration of isotopes is linked to the erosion rate.

Low-lying areas, such as those dominated by rivers, far outpaced the planet's tiny fraction of steep, mountainous slopes when it comes to making dirt, the study found.

"It turns out that we shouldn't expect mountain erosion to impact global climate much, and that the flatlands are very important instead," Willenbring said. "We've been looking at the problem in a wrong way."

The study will appear in the March 2013 issue of the journal Geology.

Reach Becky Oskin at boskin@techmedianetwork.com. Follow her on Twitter @beckyoskin. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

Data collected over the last 100 years by explorers of the Andes, combined with satellite images of the Andes-Amazon basin of Peru and Bolivia, show that many of the species unique to the area lack vital national-level protection, a new study concludes.

"Conservation across the Andes needs urgent revising, and we hope that our data will help protect this incredibly unique region," study researcher Jennifer Swenson of Duke University said in a statement.

To locate the geographic distributions of species and ecosystems in the Andes-Amazon basin, a multinational team, including researchers from the United States, Bolivia and Peru, analyzed the biodiversity of approximately 800 endemic species.

Endemic species, or species that are restricted to a specific area and do not live anywhere else, are an ideal indicator for measuring biodiversity. The researchers looked at more than 7,000 individual records of endemic species locations for 115 birds, 55 mammals, 177 amphibians and 435 plants.

The researchers then created species-distribution maps by comparing the species statistics to a combination of environmental information, including digital topography data from NASA's Shuttle Radar Topography Mission, vegetation images taken by NASA's MODIS satellite sensor and climate data.

Using the species and geographical information, researchers mapped a wide range of ecosystems in Bolivia and Peru, including the wetlands of the Beni savanna, the dry Interandean valleys and the cool, humid forests along the eastern Andean slope. [Journey Into the Tropical Andes]

Their findings showed that one of the areas with the highest levels of species and ecosystems "irreplaceability," as well as the highest number of birds and mammal species, is an unprotected region surrounding Machu Picchu, a World Heritage site located in Cordillera de Vilcabamba, Peru.

The findings showed the highest concentration of endemic birds and mammals along a narrow band of the Andes Mountains, located between 8,200 feet (2,500 meters) and 9,840 feet (3,000 m) above sea level. Endemic amphibian species peaked at 3,280 feet to 4,920 feet (1,000 m to 1,500 m) and were concentrated in southern Peru and northern Bolivia.

The researchers also found that a total of 226 species endemic to the Andes-Amazon basin of Peru and Bolivia have no national protection, while about half of the ecological systems have 10 percent or less of their range protected.

Additionally, only 20 percent of the areas with high numbers of endemic species and 20 percent of the irreplaceable areas are currently protected, according to the findings. The researchers suggest that new protected areas are needed to safeguard endemic species and ecosystems in order to preserve biodiversity.

"Biodiversity in the Andes is under threat from oil and gold mining, infrastructure projects, illegal crops and many other activities," Swenson said.

Climate change also poses a challenge, the researchers wrote in the study, because it may cause the ranges of various species to shift across the landscape and possibly out of protected areas.

"There is already evidence of species migrating upslope to keep up with climate change in this region," Swenson said.

The study was published Jan. 27 in the journal BMC Ecology.

This story was provided by OurAmazingPlanet, a sister site to LiveScience. You can follow LiveScience writer Remy Melina on Twitter @remymelina. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience  and on Facebook.

Rare, Unprotected Species

A recent study based on data collected over the last 100 years by explorers, as well as satellite images of the Andes-Amazon basin of Peru and Bolivia, found that many of the area's 800 rare and unique species are unprotected.

A multinational team of researchers analyzed records of the endemic species, or species that are restricted to a specific area and do not live anywhere else, finding that a total of the 226 species have no national protection, while about half of the ecological systems have 10 percent or less of their range protected.

Here's a gallery of some of the least protected endemic species including the Black-faced Brush-finch shown above found in the Andes-Amazon basin of Peru and Bolivia, as provided to OurAmzingPlanet by study researcher Jennifer Swenson of Duke University.

Magnificent Valleys

For the study, which was published Jan. 27 in the journal BMC Ecology, researchers used various sources of environmental data, including vegetation images taken by NASA's MODIS satellite sensor, to study the endemic species and ecological systems of the Andes-Amazon basin of Peru and Bolivia.

Peru's Yungas Valley, shown in the above photo, is one of the ecosystems about which the researchers collected geographical information.

Adorable and Endangered

The Andean Titi monkey (Callicebus oenanthe) is so rare that it remained hidden in the tropical forests of Peru until 1990, when it was officially recognized as a valid species, according to the International Union for Conservation of Nature (IUCN).

Losing Its Home

The critically endangered Andean Titi monkey species has undergone a population reduction of more than 80 percent over the last 25 years due to the massive deforestation of its habitat. The deforestation is attributed to increased human population in its habitat area, as well as the intensification of local agricultural activities and a lack of concrete conservation efforts.

Hanging On

Previous research has shown that at least 60 percent of the Andean Titi monkey species' original habitat, located in the forests of Peru's Alto Mayo, has already been lost.

Beautiful Brush Finch

One of the bird species analyzed by study researchers, the Black-faced Brush-finch (Atlapetes melanolaemus) is endemic of Peru. Although its habitat range is decreasing, it has not yet reached the threshold to be considered vulnerable by IUCN standards.

Misty Forest

Noel Kempff Mercado National Park is another ecosystem that was analyzed by the multinational team of researchers for the study. The national park is located in the Province of José Miguel de Velasco in Bolivia, on the border with Brazil.

The researchers mapped a wide range of ecosystems in Bolivia and Peru, including the wetlands of the Beni savanna, the dry Interandean valleys, and the cool, humid forests along the eastern Andean slope.

Elusive Owlet

The Long Whiskered Owlet (Xenoglaux loweryi) is shown here at the Abra Patricia Reserve-Alto Nieva Private Conservation Area, located in the tropical forests of Abra Patricia in the Andes of Peru.

The species is endangered and its known range is extremely small, according to the IUCN. Very little is known about the Long Whiskered Owlet, and although it was first discovered in 1976, it wasn't until 2007 that the elusive species was observed in the wild for the first time.

The owlet's numbers are continuing to decline because its remaining areas of suitable habitat around Abra Patricia are being lost to deforestation as a result of land being cleared for timber and agricultural activities.

Threatened by Habitat Loss

The Mishana Tyrannulet (Zimmerius villarejoi) is another bird species that is endemic of Peru. The vulnerable species' population is declining as a result of habitat loss due to continued timber extraction for building materials.

Although most of the species' known range is within a protected area, the few areas where the species is known to live on the upper Rio Nanay in Peru are completely unprotected.

Protection Is Needed

Another stunning shot capturing the beauty of the Noel Kempff Mercado National Park in Bolivia. The area is home to many endangered, endemic species and was declared a World Heritage Site by the United Nations Educational, Scientific and Cultural Organization in 2000.

The new study's researchers noted that a total of 226 species endemic to the Andes-Amazon basin of Peru and Bolivia have no national protection, while about half of the ecological systems have 10 percent or less of their range protected.

White-tufted Sunbeam

The colorful White-tufted Sunbeam (Aglaeactis castelnaudii) hummingbird is another one of the least protected species, according to the researchers. It lives within a restricted range in Peru, and its population is decreasing, according to the IUCN.

For the study, the researchers looked at more than 7,000 individual records of endemic species locations for 115 birds, 55 mammals, 177 amphibians and 435 plants.

Restored wetlands pale in comparison to their natural states, even after 100 years, a new study shows.

A wetland is a ground area that is saturated with water, be it fresh, brackish or salty, and includes everything from mangroves to marshes. These ecosystems hold more life per acre than other types of habitats, including forests and grasslands, and are often important fishery resources. Moreover, wetlands act as natural flood and erosion control, said David Moreno-Mateos, a wetlands researcher with the University of California at Berkeley.

But these ecosystems also hold value on the global scale, because they store carbon. "When you degrade a wetland, you put a lot of carbon dioxide into the atmosphere," Moreno-Mateos told Livescience. Carbon dioxide is a greenhouse gas with ties to global climate change.

In many cases, wetlands fall prey to agriculture — developers will drain the land to make way for crops, or wetlands will slowly degrade due to agriculture pollutants such as pesticides. So a common mitigation strategy used by land developers, Moreno-Mateos said, "is to degrade a wetland and build five more in its place."

But how do new man-made wetlands and wetlands that have been restored compare with the real McCoy?

To find out, Moreno-Mateos and his colleagues analyzed 124 previous studies monitoring more than 600 wetlands across the globe that had been restored in some way or created from scratch, a few of which were restored or created more than 100 years ago. When they compared these ecosystems with pristine, natural wetlands, they found that the restored and created wetlands were, on average, much less productive — they contained 23 percent less carbon in the soil, and had plant densities and native plant varieties that were 26 percent lower than in natural wetlands.

They also found that wetlands recover most slowly if they are in cold regions, small (less than 100 hectares, or 247 acres), or separated from tides or river flows.

The take-home message, Moreno-Mateos said, is that "you have to think a lot before you degrade the wetlands, because it will take a long time for them to go back to natural conditions." Carbon takes hundreds of years to return to the soil once it's released into the atmosphere, he explained, and the study shows that most plant ecosystems don't completely return to their reference states, even after a century.

"[Developers] change the conditions so much that the wetlands are not able to fully recover," he said.

The study was published today (Jan. 24) in the journal PLoS Biology.

Like dominoes given one nudge, climate change in the form of reduced winter snowfall on mountaintops has subtle but powerful cascading effects felt throughout entire ecosystems, a new study finds.

In the northern mountains of Arizona, elk spend their winters in lower elevations where there’s much less snow and the cold is less pronounced. But the decrease in high-elevation snowfall in the mountains over the last 25 years has allowed elk to forage in these areas throughout winter. Researchers found that the elks' year-round high-elevation browsing has decimated the density of seasonal woodsy plants, which, in turn, has impacted the populations of songbirds (animals you might expect would actually benefit from less snow).

By preventing elk from entering several study sites for six years, the researchers were able to reverse the multi-decadal decline in plant and bird populations in these locations.

"Ecologic communities are pretty complex. There are all these tight interactions going on," said study co-author Tom Martin, a wildlife researcher with the U.S. Geological Survey. "Perturbation from climate can affect those communities in many indirect ways and cause all of these ramifying effects." [Odd Effects of Climate Change]

Dramatic declines

The densities of seasonal woodsy plants, including aspen and maple trees, in the northern Arizona mountains have steadily declined over the last two decades. Martin and his colleague John Maron, a biologist at the University of Montana, hypothesized that this decline is primarily the result of one of two things: decreased soil water or increased exposure to hungry elk.

To find out, the researchers set up 25-acre enclosures around three drainages, or vegetation-rich valleys created by snowmelt. By keeping the elk out, the enclosures essentially mimicked the effects of large snowfall.

The researchers found that plant populations in the enclosures rebounded to levels last seen in 1996 — suppressing winter-browsing elk for six years effectively reversed 15 years of plant-density decline. Plant populations in nearby open drainages, however, did not improve over the six years.

Similarly, the populations of five key songbird species rebounded in enclosed drainages. "With more vegetation, there are more nesting areas, and it becomes harder for predators to find the nests," Martin told Livescience.

Since the populations of elk have also strongly declined over the last 11 years, the results show that the elks' new tendency to stick around over winter is ravaging the plant and bird communities. "It doesn't take very many animals to have a pretty large impact if they’re there year-round," Martin explained.

Conservation implications

Eric Post, a biologist at Pennsylvania State University who was not involved with the research, said that the study demonstrates how observational and experimental research can compliment each other. "Both are necessary to study climate change ecology," Post told LiveScience.

While impressed with the study, Post thinks that the researchers "didn't nail down the driving factor in the relationship between plant growth and bird abundance." It seems convincing that the architecture of the vegetation would provide the birds with more nesting opportunities, he said, but that theory doesn't take into account the effect of invertebrate (animals without a backbone) abundance. The winter elk may also be affecting the populations of local insects, which the birds eat.

Still, Post believes that the study has important implications for conservation. "If you are interested in the conservation of birds, you need to look at more than just the birds and the vegetation they are dependent on," Post said. "You need to look at the broader system of browsing animals."

Martin agrees, adding that by "recognizing that these things happen, we can target priority habitats for conservation."

The study was published online Jan. 10 in the journal Nature Climate Change.

Aliens have invaded the Mediterranean by the hundreds — alien species, that is.

In recent decades, more than 900 new alien marine species, including the poisonous puffer fish, have been encountered in the coastal environments of the eastern Mediterranean Sea,according to a new study. This alien invasion has wrought changes on the food web of the sea, the four-year study conducted at the University of Gothenburg in Sweden found. The study warns, though, that a limited understanding of the ecosystems at risk makes dealing with the invaders more difficult. "The Mediterranean is the world's most invaded sea, but our understanding of how alien species affect ecosystems is inhibited by a lack of basic knowledge of the animal and plant communities on the coast," said study team member Stefan Kalogirou. "Once species have become established in the Mediterranean it is almost impossible to eradicate them." The completion of the Suez Canal in 1869 opened a pathway for alien species to invade the eastern Mediterranean. In recent years, regular reports of alien species from several of the coastal environments of the eastern Mediterranean have caused concern over what will happen to indigenous species and ecosystems. Over a period of four years, Kalogirou, in cooperation with the Hellenic Centre for Marine Research, has studied the structure and function of fish communities in sea grass meadows and on sandy bottoms in two important coastal environments on the island of Rhodes in southeastern Greece. This has provided important insights into the possible ecological consequences of alien species in the food chain. "The results show a clear ecological impact when alien species either become dominant, like puffer fish, or are piscivores [fish-eating species], like barracuda and cornetfish," Kalogirou said in a statement. "It is evident that the food chain is being restructured, but the lack of previous studies limited our conclusions." The poisonous puffer fish is one of the alien species that have recently been introduced. The puffer fish toxin, tetrodotoxin, causes muscle paralysis, which can lead to respiratory arrest. In worst cases the outcome can be fatal. In the coastal environments that Kalogirou has studied, the puffer fish has become a dominant species, which has led to both ecological and social effects. The study was Kalogirou's doctoral thesis and was successfully defended.

This story was provided by OurAmazingPlanet, sister site to LiveScience.

Rather than wreaking havoc on a tiny island in the Indian Ocean -- as alien species can sometimes do -- a giant tortoise appears to be helping to restore the native ecosystem. 

Wildlife scientists introduced Aldabra giant tortoises -- which can reach up to 661 pounds (300 kilograms) -- to an island, called Ile aux Aigrettes, off the coast of the island nation of Mauritius. By 2009, 19 adult giant tortoises called the island home. The tortoises were to replace the role of their extinct kin. [Extinct Giant Tortoises Could Be Revived]

Before humans first arrived on Ile aux Aigrettes, various giant tortoises lived there, as did giant skinks -- a type of lizard -- and, most likely, flightless dodo birds. The disappearance of these animals affected other things living on the island, in particular the native ebony trees, which have been devastated by people hunting for firewood.

The giant tortoises and the skinks ate the fruit of these trees, spreading the seeds. Without these fruit-eaters around, the trees could no longer disperse; young trees only grew directly below the adults.

Worldwide, invasive species are considered one of the greatest threats to biodiversity, so, the idea of replacing an extinct creature with a foreign one is controversial. It has been done elsewhere with the new species often closely related to the one being replaced.

For example, the North American peregrine falcon was re-established from seven subspecies from four continents, and yellow crowned night herons have been introduced to Bermuda to replace extinct herons and to control pesky land crabs. At the most extreme end of the spectrum, conservation scientist Josh Donlan has suggested that the Pleistocene ecosystems of North America be reconstituted with large African mammals -- horses, camels, tortoises, lions, elephants and cheetahs -- thus protecting these species from the threats they face in their natural range.

Replacing extinct giant tortoises with another giant tortoise on an uninhabited island is a much simpler prospect, for a number of reasons, according to Christine Griffiths, a research associate at the University of Bristol and the lead author of a study on the tortoise experiment, done in collaboration with the Mauritian Wildlife Foundation.

Isolated islands often lack predators, meaning a shorter food chain to consider, and the giant tortoises are easy to find and remove if they were to become a problem, Griffiths said.

Initially, researchers were concerned that the new arrivals might eat a great deal of the native plants. In 2000, the first four Aladabra tortoises arrived, and later several others followed. They were kept in pens where surveys indicated that there were no significant problem with native plants, and, in late 2005, 11 were allowed to roam free.

Now, few ripe fruits remain under the ebony trees, and dense patches of seedlings have appeared in the areas most heavily used by the tortoises. Griffiths and other researchers found that seeds that had passed through a tortoise’s gut germinated better than other seeds.  And, it turns out, the tortoises eat a lot of the non-native plants.

While the re-introduction appears successful so far, it remains to be seen if the tortoise-dispersed ebony seedlings will develop into adult trees that reproduce, write Griffiths and her colleagues in a recent issue of the journal Current Biology. A similar project is under way on Mauritius’ Round Island.

You can follow LiveScience writer Wynne Parry on Twitter @Wynne_Parry. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.

Invasive, plankton-sucking Asian carp might become less of a menace, some suggest, if we ate them for dinner.     

These invasive species – which include the flying silver carp, which has injured boaters with its acrobatics  – are believed responsible for declines among native fish within the Mississippi River system, and the fear they may establish themselves in the Great Lakes has prompted a national plan to control them.  

In the United States they have been poisoned, and kept at bay with an electric barricade. But elsewhere in the world these fish make for popular meals. So why not try eating them?

Well, if you've ever bitten into a cooked one, you'd know they are notorious for the load of bones hidden in their meat. There is also an image problem that comes along with the word "carp."

In a multi-part YouTube video, Duane Chapman, a research fisheries biologist with the U.S. Geological Survey, demonstrates how to fillet the fish and handle the remaining bones within its "white, flaky and mild" meat, which he says is more like cod than like the common carp.

To Louisiana-based chef Philippe Parola, the meat is "between scallops and crab meat." He has devised his own technique to debone the fish and has a plan to rebrand them as "silverfin" and popularize them as a low-cost, healthy, pre-cooked, flavored product for picky American consumers. [Why Are Asian Carp So Fearsome?]

Carp basics

Depending on how you count them, there are as many as seven species of invasive Asian carp, which include the common carp, introduced in the 19th century, and the goldfish. The two species that have caused the most fretting are the silver and bighead carp, which are encroaching upon the Great Lakes. (The federal government also includes grass and black carp as need-to-watch species.)

As filter feeders that suck up plankton floating in the water, silver and bighead carp were brought to the United States to clean wastewater-treatment and aquaculture-retention ponds in the early 1970s. Their importers also harbored hopes of marketing them as food, according to Chapman.

In high abundance, these fish can leave behind only the smallest of the floating plants. "What you end up with is very green water with a lot of really tiny plankton in it that are so small the fish can't eat them," he said. "Some of our native fishes that feed on plankton have taken it badly."  

These include the gizzard shad and bigmouth buffalo in the Missouri River, he said.

The carp are eaten in Asia and Europe, but catching them is labor-intensive and they do not command high-enough prices to make selling them overseas economically feasible, he said.

Cooking with carp

While carp eaters elsewhere in the world are content to pick out bones, Americans are resistant. So Parola has developed an efficient way to remove the bones and has repackaged the fish as silverfin, the star ingredient in recipes he has created, including "silverfin steak and fresh berries" and "silverfin cakes."

"I did it because I love fishing, I love the outdoors, and l understand the problem, and I really would like to make a difference in this," he said.

Chapman, meanwhile, demonstrates how to make what he calls flying carp wings.

Parola's determination to create a "silverfin craze" promises not only to add items to restaurant menus, but to reduce and manage carp populations, create jobs and improve the quality of fish available in the United States.

This isn't Parola's first venture into cooking with invasives. Roughly a decade ago, he lent his hand to an attempt to popularize the meat of nutria, an invasive, semi-aquatic rodent blamed for damaging fragile Louisiana marshes.

Official strategy

Other chefs and conservationists are also exploring ways to serve and promote Asian carp. This strategy, to control the population by creating an appetite for them among Americans, is part of the national official action plan to control the spread of these fish and keep them out of the Great Lakes, where it is feared they could alter the ecosystem and harm native fish. The plan includes strategies like releasing sterile carp to reduce reproductive success, strengthening an electrical barrier system to keep them out of Lake Michigan and investigating poisons that could be used to kill them (known as piscicides).  

Eating invasive species is not a cure-all and comes with its own set of risks, according to Chapman.

Demand for the species in question could prompt entrepreneurs to spread the species to new places, and so aggravate the problem. A market could also tie people's livelihoods to the invader, creating resistance to any attempts to eradicate the species, he said.

In the case of Asian carp, attempts to create a market look promising. In China, where the fish are native and a popular food, the fish are often considered overharvested. What's more, there are few new, habitable places in central North America – with the possible exception of the Great Lakes – where the Asian carp could establish themselves, according to Chapman.

"It is a judgment call," he said. "Twenty years down the line we will know whether it was a good idea or not."

You can follow LiveScience senior writer Wynne Parry on Twitter @Wynne_Parry.