The most beautiful bivalve

 

Flame shells are bivalve molluscs found mainly on the west coast of Scotland. In the Hope Spot they live in Loch Sunart and Loch Creran.

 

North of the area, Loch Carron’s bed is now believed to be the largest in the world, following surveys of the damage caused by a scallop dredger.

 

Flame shells are distinguished by their bright red and orange filamentous mantle and tentacles which are permanently on display.

 

Image: Flame shell, Mark Woombs

 

Due to their inability to retract their mantle and tentacles into the shell, flame shells hide, by burrowing under the top layer of sediment and binding algae, shells or gravel together, using byssal threads, to form nests.

 

Image: Flame shell byssus threads, Mark Woombs

 

Flame shell nests support a high diversity of associated organisms including 19 species of algae, 265 species of invertebrates as well as juvenile cod. They also offer ideal conditions for scallop spat.

 

Image: Flame shell amongst Brittle stars, Mark Woombs

Flame Shell

Limaria hians

Image: SNH

 

Priority Marine Feature

 

Length: 4cm

 

Depth: 1-100m

Current Research
The Loch Creran flame shell beds have been surveyed for years by Heriot-Watt University, measuring the sensitivity of these biogenic habitats to seabed disruption activities, such as trawling and dredging. Now research is focused on learning more about their life cycle and how to protect them.

 

Threats
The UK’s flame shell population is declining. Once substantial communities in Scotland no longer exist, for instance in Loch Sween and the Clyde. Some flame shell beds are protected but outside MPAs they remain at risk from mobile fishing techniques that contact the seabed. In 2017, such fishing damaged the flame shell bed in Loch Carron. Following a public outcry, the Scottish Government created an emergency Marine Protected Area.

In May 2019, the part of Loch Carron containing the flame shells was confirmed as Scotland’s newest Marine Protected Area.