The influence of caged mariculture on the early development of sublittoral fouling communities: a pan-European study

The development of fouling communities was assessed to investigate the influence of caged mariculture on sublittoral epibiota. Artificial structures were deployed within 10 m of caged mariculture and at a "reference" location between 150 and 500 m of the study site at four coastal locations (Oban, Scotland; Sitia, Crete; Piran, Slovenia; and Eilat, Israel). The fouling community on the artificial structures was measured both quantitatively and qualitatively bi-monthly between June 2001 and December 2001. Multivariate statistical analysis was used to compare community structure between the study sites and locations. Artificial structures deployed at the mariculture site supported a higher epibiotic biomass than at the reference site at Oban and Eilat. Community composition was significantly different between the mariculture and reference site at Eilat. The biological succession on the structures changed from an autotrophic to a heterotrophic mode over the experimental period at all locations with the exception of Oban, where negligible quantities of macroalgae were observed on the structures. Differences in community biomass and succession observed between artificial structures deployed at mariculture and reference sites, particularly in oligotrophic environments, may be caused by enhanced larval settlement and an elevated supply of particulate material and dissolved nutrients to structures adjacent to the fish cages.