Exploring biocontamination in associated macrofaunal assemblages in marinas: Soft bottoms vs artificial hard substrate. Where and what to look for?

Marinas are hot spots of non-indigenous marine species (NIS). Introductions of NIS, regardless of their actual or potential impacts, can be considered as a biocontamination of the ecosystem. To characterize the biocontamination status of a marina it is important to know which habitats and major taxa can provide the most useful information. To address this issue, we analyze the associated macrofaunal community associated to soft substrate (sediment; SS) and artificial hard substrate (lateral surface of pontoons; AHS) of six marinas from Southern Spain. 9 NIS were found, including 8 crustaceans (7 peracarids) and 1 polychaete; 8 NIS were found on AHS and 4 in sediments. Indeed, site-specific BioContamination Index (SBCI) showed higher values in AHS than SS. Our results indicate peracarids in AHS should be the primary target for assessing the level of biocontamination in marinas. This may help scientists and environmental managers to stablish strategies for monitoring marine bioinvasions.