The importance of large-scale variation of predation pressure on the organization of sessile communities

Abstract

The relative importance of the ecological processes behind community organization and invasion susceptibility is affected by local, regional and historical processes. In tropical communities the large number of species and the functional redundancy of species suggest that stochastic processes play a fundamental role on the final organization of sessile communities, while in temperate areas, community succession seems to be more deterministic. In the last years the number of marine facilities on the coast and intercontinental traffic of vessels has increased, providing additional space for sessile organisms but exposing native communities to extensive physical and biological disturbances, which can cause both ecological as economic issues. An indirect harmful effect of marine facilities is the reduction of predation to which communities are exposed. Because marinas and harbours are frequently exposed to strong fishing effort, the removal of predators can facilitate the monopolization of space by good competitors and facilitate the introduction of exotic species. In this project, we propose to compare the relative importance of predation on sessile communities from urbanized coastal areas in two different regions: Brazil and UK. Understanding how the communities are assembled and how anthropic activities change directly and indirectly the organization of those would help us to deal with the impacts of such activities. (AU)