Consequences of the modifications caused by recreational marinas on coastal environments for marine sessile organisms

Abstract

The construction of marine facilities on the coast, as harbors and marinas, promote several modifications on marine environments. For sessile organisms, marinas increase the amount of space available for recruitment, however because these facilities are usually exposed to extensive sources of pollution the new habitat is under selective pressures very distinct from those on natural substrata, what can facilitate the introduction of non-native species. A very effective process that prevents bioinvasion is natural predation. Predators can control the income of exotic propagules and also the structure of sessile communities. However, the importance of predation is extremely variable depending where the community occurs. In tropical regions, intense predation can reduce diversity of sessile organisms and also control the invasion by exotic species, but this is hardly observed in temperate zones where predation is less intense. Besides all the modification on species number and composition, marinas also affect the phenotypic diversity of organisms. As example, copper, which is used in antifouling paints, is one of the most abundant heavy metals in marinas, inducing the manifestation of alternative phenotypes in sessile organisms. Besides that, the metabolic changes behind the phenotypic plasticity induced by copper are still unknown. This project aims to test how the availability of hard substrata affect the structure of sessile communities in six marinas from the Southeastern Brazil, compare the importance of predation between tropical/subtropical communities in Brazil, tropical communities in Angola and Temperate communities in Wales - UK, and to describe the metabolic changes caused by copper in an sessile invertebrate. (AU)