Marine protected communities against biological invasions: A case study from an offshore island

Abstract

Biological invasions are a major threat to the world's biota and are considered a major cause of biodiversity loss. Therefore,worldmarine policy has recognized the need for more marine protected areas (MPAs) as amajor tool for biodiversity conservation. The present work experimentally evaluated how protected communities from an offshore island can face the settlement and/or expansion of nonindigenous species (NIS). First, NIS colonization success in marine protected and marina communities was compared by deploying PVC settling plates at the GarajauMPA and Funchal marina (SWMadeira Island). Then, the settling plates from the MPA were transferred to Funchalmarina to test their resistance to NIS invasion under high levels of NIS pressure. Results indicated that the structure and composition of fouling communities fromtheMPA differed fromthose collected in themarina. Interestingly, communities fromthe protected area showed lower NIS colonization success, suggesting some degree of biotic resistance against NIS invasion.