Flame shells: Scotland’s marine construction workers

Sand and gravel seabed is a difficult place to live, with no shelter, and nowhere to hide. Just a few specialists have adapted to life in this desert.

But one shellfish hasn’t just adapted to life in this barren place, it has decided to build a nest big enough for him and ALL his neighbours. Meet the Flame Shell, a 30mm bivalve with big ideas. It spins sticky fibres together, bonds small stones and shells, and makes a labyrinth of chambers with walls and a roof.

A diver swimming past could easily assume this was a common rocky reef, with all the life you would normally expect to find. But these are castles built on sand. They are fragile, and have been put under pressure by scallop dredgers, bottom trawlers, fish farms, and pollution. They’re mostly found in Scottish Lochs, in fast-flowing channels where trawling doesn’t take place. In 2012, a team from Heriot Watt University discovered a flame shell reef in Loch Alsh with an estimated 100 million flame shells, where a reef has been built across 75 hectares of seabed. That’s kind of like shellfish building their own underwater Dubai.

So these are no ordinary shellfish. And nor do they look ordinary – imagine a small scallop with a See-You-Jimmy hat on. Bright orange fringes lick from their shells like flames, the shade varying across the population. They jet along in flamboyant bursts, opening and closing their shells. It’s easy to imagine them singing a song from the Muppet show, or calling instructions to their co-workers as they build the next part of their impossible palace in the marine desert.

Flame-shells are our new favourite shellfish. And no, we don’t eat them.

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Images by Andy, words by Jackie