Impact of an open-sea suspended mussel culture on macrobenthic community (Western Adriatic Sea)

The potential impact of a suspended mussel farm on the coastal macrobenthic communities of the Western Adriatic Sea was seasonally evaluated through a multi-control sampling strategy over 1 year. Both univariate biological indices and multivariate analysis indicated that the variations of benthic macrofauna were mainly due to seasonality rather than location of the sampling sites in respect to the farm, and that the main species contributors were common to most sites and seasons. Most of these species are known as indicators of organic enrichment and/or pioneer species in recolonization of defaunated bottoms and commonly occur in the macrobenthic populations inhabiting the seabed of the North-Central Adriatic Sea between 12 and 15 m depth. Only the different abundances of filter- and deposit-feeders gave some evidence of a limited, spatial influence on the culture in the surroundings. The external sites showed a significant difference compared to the reference sites (ANOSIM: R = 0.395, P = 0.5). The overall results suggest that open-sea mussel culture has minimal detrimental effects on the zoobenthic communities of the Western Adriatic Sea that are usually in an immature stage due to subsequent environmental and anthropogenic disturbances. Although one-year study might not be sufficient to evaluate the effects of mussel culture, the results of this work represent a useful tool for the monitoring of the potential environmental impact of mussel farms to ensure the sustainable development of shellfish culture in the Italian shallow coastal waters.