Muskellenges are the biggest freshwater fishes in North America.
Credit: Eric Engbretson/ U.S. Fish and Wildlife Service
Werewolves and vampires aren't the only creatures likelier to bite during the full moon.
The best time to catch a muskie, one of the country's largest and most ferocious fish, is during a full or new moon, new research has found. The new study provides scientific backing to decades of fishing lore. [6 Wild Ways the Moon Affects Animals]
The muskellunge (Esox masquinongy) is the largest freshwater fish in North America and can grow as long as 6 feet (1.8 meters) and weigh up to 70 lbs. (32 kilograms).
Yet these "muskies," though common in the lakes of North America, are incredibly tough to catch.
"They say it takes, on average, 10,000 casts to catch a muskie," said study co-author Mark Vinson, a fish biologist for the U.S. Geological Survey in Ashland, Wisconsin, referring to casting a fishing line. "For a lot of people it's a once-in-a-lifetime catch."
Angling wisdom is filled with ideas about how to improve the odds of catching a muskie.
"Everyone swears by their secret technique, and if you go to a big sporting goods store in northern Wisconsin, there's a giant, extensive wall of lures that are the sure thing," Vinson said.
Many anglers believe that muskies are likelier to bite during the full moon and new moon (the first phase of the moon). Newspapers publish solar and lunar tables based on that premise. For other fish species, some evidence suggests that their feeding habits wax and wane with the moon's cycles, which could in turn affect how easy the fish are to catch, Vinson said. But for muskies, the idea had never been tested.
Full moon effect
To see whether science backed up fishing lore, Vinson and his colleague Theodore Angradi, a researcher at the Environmental Protection Agency in Duluth, Minnesota, pored over data from 341,959 muskie catches between 1970 and 2013. The information was collected by Muskies Inc., a fishing and conservation organization that logs the data. The researchers focused on fishermen who spent most of their time trying to catch muskies.
Muskie catches were more likely during the full and new moons. An angler who only fished on the full and new moons would increase his chances of landing the fish by 5 percent, the study found.
Many avid anglers already fervently believe in fishing during the full and new moons, so it's still possible that more fish are caught during those times because more anglers are out there looking for them.
But the lunar effect was even stronger at higher latitudes, for bigger fish and for fish caught in midsummer. Taken together, the findings suggest that anglers aren't catching more fish simply because more of them are out there. Instead, muskies may actually be feeding more during the full and new moons, making them easier to catch, Vinson said.
To test that theory, Vinson and Angradi hope to look at the stomach contents of muskies to assess whether they eat more during the full and new moons.
The findings published today (May 28) in the journal PLOS ONE.