The Marine Aliens consortium is coordinating research and public engagement activities with the primary objective of protecting native biodiversity from the impacts of marine invasive non-native species that enter the UK marine environment via hull fouling and unintentional aquaculture activity. It has produced a second edition of the waterproof identification guide to marine invasive species, aimed at marina and port operators, recreational boat owners and all those who have an interest in maintaining healthy and productive inshore waters. It is available from MarLIN, The Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB. Information is key to tackling biological invasions. Boat owners, fishers and members of the public can all help to minimize the negative impacts of invasive non-native species by being informed and reporting any sightings of alien species.
In September 2004, a rapid assessment survey for non-native species was conducted at 12 harbours along the south coast of England from East Sussex to Cornwall, focusing on communities of algae and invertebrates colonizing floating pontoons in marinas. Over 80 taxa each of algae and invertebrates were recorded, including 20 recognized non-native species.
The southern hemisphere solitary ascidian Corella eumyota was recorded in the UK for the first time and was present at three sites. The colonial ascidian Botrylloides violaceus was also recorded as new to the UK, but was very widespread and has probably been present for a number of years but misidentified as the native congener B. leachi, which was infrequent. Other ascidians included Styela clava, introduced at Plymouth in the early 1950s, which was recorded at all locations visited, and Perophora japonica, which was found only at the Plymouth locality where it first occurred in the UK in 1999.
The diverse algal flora included nine alien species previously recorded in the British Isles. Range extensions and population increases were noted for the kelp Undaria pinnatifida and the bryozoan Tricellaria inopinata, both first recorded in UK waters during the 1990s. The widespread occurrence of another non-native bryozoan, Bugula neritina, appears significant, since in earlier times this was known in UK waters predominantly from artificially heated docks. The results of this survey indicate that dock pontoon systems in southern England are significant reservoirs of non-native species dispersed by vessels and other means. The proliferation of these structures is therefore of conservation importance. The new UK records highlight the need for periodic monitoring of ports for non-native species. (Arenas, F. et al. Alien species and other notable records from a rapid assessment survey of marinas on the south coast of England. Journal of the Marine Biological Association of the UK (2006), 86: 1329-1337 Cambridge University Press).