Spatial distribution and abundance of intertidal benthic macrofauna in the Kneiss Islands (Gulf of Gabès, Tunisia)

The Kneiss islands, located in the Gulf of Gabès (Southeastern Tunisia), represent a site of international interest in terms of their ornithological diversity (Important Bird Area, SPAMI and Ramsar Site) and are heavily exploited for clams and fish resources. In an effort to assess the ecological status of the intertidal ecosystem, and to facilitate management and conservation of the resources, an ecological survey of the macrobenthic component was carried out from January to March 2012. This study involved identifying the benthic fauna and assessing the spatial distribution on the southern unperturbed Zostera noltei mudflats by human activities. A total of 102 macrobenthos taxa is identified at 19 stations with a predominance of crustaceans (37%), polychaetes (27%) and molluscs (23%). The AMBI index shows that the area has a good ecological status. Cluster Analysis and Multidimensional scaling identify three benthic assemblages on the basis of their faunal similarity in relation to sediment types and organic matter contents.