Invaders, but not from another planet.............

............are monitored by the Marine Biological Association to assess the speed and extent of travel and the likely effect on the local environmet.
John Bishop and Chris wood are the core of the team which carries out Rapid Assessment Surveys (RAS), which provide a quick but systematic insight into a location such as a marina, and which provide the basis of the available data on extent of invasive species.

The first two encounters were with Creeping Sea Squirt (Peroptiora japonica and the Carpet Sea Squirt (Didemnum vexillum), but the species which seems to be spreading most quickly in occurrance and extent is the Tufty Tuff Bryozoan. It has appeared in 90% of the UK coast within 12 years.

The Compass Sea Squirt has travelled along the South Coast between 2010 and 2013, and clearly leisure boats and marinas are key agencies in the spread ov invasive species.

The RAS mentioned above, which are funded by govenment agencies, covered 81 sites round the coast in 2014/6, 36 of which were re-sampled in 2023. This showed significant inc reases, but the deatil is embargoed until the results are ratified.

The Purple Fan Worm seems to be a significant new arrival.

The team has also carried out detailed reviews of leakage of species from marinas and harbours to  Conservation Areas, using Southampton Water as a test case.

John and Chris demonstrated useful and interesting results from science carried out on a very limited budget.