Colpomenia peregrina Sauvageau, 1927

Kakkonen, Jenni E., Worsfold, Tim M., Ashelby, Christopher W., Taylor, Andrea & Beaton, Katy, 2019, The value of regular monitoring and diverse sampling techniques to assess aquatic non-native species: a case study from Orkney, Management of Biological Invasions 10 (1), pp. 46-79 : 55

(1) Colpomenia peregrina Sauvageau, 1927

Status in U.K. – non-native.

Colpomenia peregrina (“oyster thief”) has been frequently recorded through the monitoring programme, at several sites each year since 2014. It was recorded at five new sites in 2016: Westray and Stromness marinas and at Burray, Shapinsay and Stronsay Visitor Yacht Moorings. In both 2016 and 2017, it was most frequently found in rapid assessment samples but was also present in a few scrape samples in 2017.

Import of oysters from the U.S.A. has frequently been cited as the vector for the introduction of C. peregrina to Europe ( Blackler 1964; Eno et al. 1997). However, a recent molecular study ( Lee et al. 2014) suggests that European populations were derived from the north-west Pacific rather than America. Cotton (1908) believed that it may have reached Britain via natural dispersal from previously introduced French populations but did not discount vessel transport or transport on imported oysters as possible vectors. It is thought to have arrived in Britain in 1906–1907 and was already present in two discrete locations, Swanage and Torquay, and in relatively high abundance when it was discovered; it had not been detected at Swanage in early 1906 ( Cotton 1908). Following its first known occurrence in the U.K., it quickly spread through natural dispersal and was first recorded from the Orkney Islands in 1940 ( Lund 1949). More recently, Want et al. (2017) recorded it fouling marine renewable energy structures in Orkney.