2013 Northern Ireland Environment Agency Northern Ireland Rapid assessment of marinas for the invasive alien species Undaria pinnatifida, Caprella mutica and Crassostrea gigas

Eleven marina sites were sampled using the Abundance and Distribution Range methodology during late August to early September 2012 on the coastline of Northern Ireland. This study involved sampling thirty different positions at each large marina for non-indigenous species that were targeted, following an initial study of the current distribution of non-indigenous species within northern Europe. The fifty sevenspecies selected for the target list were mainly of species that have demonstrated some impact elsewhere or were otherwise of general interest. Nine smaller floating units (pontoons) were sampled at small marina sites or where there was a single floating boardwalk. Some shore surveys took place, both during this survey, and a post-contract survey. Oysters were selected for examination at some sites.