Serpulid aggregations

The organ-pipe worm Serpula vermicularis is a beautiful marine tubeworm with a showy crown of feathery tentacles, bright red, pink and orange, contrasting with its hard white tubes. Individual organ-pipe worms have an almost worldwide distribution, except for polar seas, but in a few special places, hundreds of them grow together forming bush like structures or 'reefs'.

By far the best developed and largest area of serpulid reefs in the world occur in Loch Creran, west Scotland just north of Oban. There were previously reefs in Linne Mhuirich, Loch Sween, but these died out in the 1990s for reasons that are still not understood, and now only the dead worm tubes remain. Small aggregations of organ-pipe worms were found in Loch Teacuis, Morvern in 2006 - now part of the Loch Sunart MPA. Here, the worms form small aggregations, not yet reefs, but may grow larger and proliferate to cover a greater area of sea bed.