A flame shell, a rare saltwater clam found in Scotland.
Credit: Graham Saunders
A huge, colorful shellfish reef discovered off Scotland's west coast could be the largest of its kind in the world, according to the Scottish government.
Packing at least 100 million bright-orange shells into 4.5 square miles (7.5 square kilometers), the living reef consists of flame shells, a rare saltwater clam found near Scotland. Neon-orange tentacles emerge from between the clam's paired shells, waving gently in the current.
The flame shell reef is located in Loch Alsh, a sea inlet between the Isle of Skye and the Scottish mainland. The overall population of flame shells in the inlet is likely to exceed 100 million and is the largest known flame shell reef anywhere in the United Kingdom, the Scottish government said in a statement.
"This important discovery may be the largest grouping of flame shells anywhere in the world," Scottish Environment Secretary Richard Lochhead said in the statement. "And not only are flame shells beautiful to look at, these enigmatic shellfish form a reef that offers a safe and productive environment for many other species."
Flame shells (Limaria hians) build 'nests' by binding gravel and shells together with thin, wiry threads. The shellfish are around 1.5 inches (4 centimeters) in length and group together in such numbers that they cover the seabed with a felt-like organic reef of nest material several inches thick. Flame shell beds are found in only eight sites in Scottish waters.
"There were some records of flame shells in Loch Alsh, but scientists had no idea of the bed's true size," said Ben James, marine survey and monitoring manager at Scottish Natural Heritage.
Heriot-Watt University in Edinburgh carried out the Loch Alsh survey on behalf of Marine Scotland.
"Too often, when we go out to check earlier records of a particular species or habitat, we find them damaged, struggling or even gone," said Dan Harries, a marine ecologist with the university's school of life sciences. "We are delighted that, in this instance, we found not just occasional patches, but a huge and thriving flame shell community extending right the way along the entrance narrows of Loch Alsh. This is a wonderful discovery for all concerned."
The Loch Alsh inlet was surveyed as part of a program to identify new Marine Protected Areas, which help defend marine habitat. The reef's discovery strengthens the case for proposing the inlet as a protected area, said Calum Duncan, Scotland program manager for the Marine Conservation Society.