A highly invasive marine species, the sea squirt Didemnum vexillum, has recently been discovered for the first time in Scottish waters. A colonial species, it has been spreading around the world in recent years, colonizing marine structures, ships’ hulls, and natural marine habitats.

Thought to be originally from Japan, it has become a pest in other countries by smothering native species and interfering with fishing, aquaculture and other activities. It has recently been found in some marinas in England and Wales and there are strong concerns that it will spread more widely. The discovery at Largs is the first record of the species in Scotland, and its presence south of border and on the Irish coast means that there is a high chance that it will turn up on the Solway.
A guide has been produced showing how to identify the species (PDF ID guide, 2Mb) and a poster produced for display and distribution (PDF poster, 2.8Mb). Any confirmed or suspected sightings should be reported immediately to Scottish Natural Heritage on 01463 725000.