Assessment of the colonization and dispersal success of non-indigenous species introduced in recreational marinas along the estuarine gradient

摘要: Abstract The introduction of non-indigenous species (NIS) is considered as one the main causes associated with biodiversity loss. number NIS has increased significantly emphasizing need to know and manage processes biological invasions. Recreational marinas are points entry for potential colonizers can act stepping-stones spread these species. objectives this work were assess distribution patterns fouling communities within recreational in Tagus estuary evaluate dispersion ability. assessed at four different neighbouring hard substrate areas along estuarine gradient estuary. native those showed a spatial consistent gradient, higher similarity between marine influence. A total 14 identified but none occurred marina freshwater Although pattern reflected, some extent, there was lower heterogeneity locations when compared communities, evidencing greater tolerance wider range environmental conditions. Nine also found areas, suggesting their dispersal that seem be able disperse outside have planktonic larval stages tolerance, which seems contributed successful spread. These results emphasize importance monitoring occurrence order an early warning on arrival invasion risks prevent its sensitive ecosystems.