Counting and accounting: Inventories of marine alien species

The objective of this study is to understand how the connectivity of marinas is correlated with the level of biopollution (abundance x distribution of NIS) of marine sessile non-indigenous species both regionally and on recreational vessels and across the Mediterranean. The first targets of this work have been the identification of highly connected marinas in the Mediterranean Sea. Over 2015 and 2016, 30 marinas, i.e., 10 marinas from each of the western, central and eastern Mediterranean Sea will be sampled for NIS richness in the marinas. Also, boat owners from each marina will complete a survey on their hull cleaning practices and travel history, and then samples will be collected directly from the same hulls, so that the results of both the survey and the samples can be associated, from which, NIS richness and abundance from boat hulls will be assessed and later combined to illustrate biopollution regional trends. Finally, the project’s results will be displayed using a spatial connectivity model which evaluates each sampled marinas level of risk for the spread of NIS, and using the travel history data from the boaters, the connectivity of the marinas.  The results will also help to understand which abiotic factors contribute to higher levels of fouling in marinas. Marina selection is based on the busiest marinas visited by non-resident recreational vessels in, in combination with securing permission. Samples for Amathia verticillata will be collected from each region and genetically tested to determine if they share the same initial or secondary source of invasion. Some preliminary results are that the most fouled marinas are either at very close proximity to freshwater sources, or very old in age.