Long-term changes in the fouling community of buoys around Helgoland: a comparison between 1937/39 – 2004/06

A careful study of the fouling community on buoys around Helgoland in the 1930s (Caspers 1952) was repeated about 70 years later. The qualitative data indicate a dramatic increase in macrofaunal species diversity (from 23 to 61 species). Half this increase may be related to the fact that buoys since the 1990s have no longer been treated with toxic paints. About half the “new” species, however, represent introduced (non-indigenous) species and expanding “southern” species which have been establishing in the area only during the past two decades.