Biodiversity of the Upper Slope Demersal Community in the Eastern Mediterranean: Preliminary Comparison Between Two Areas With and Without Trawl Fishing

Faunal assemblages and relative biodiversity of two neighboring deepwater areas of the North Ionian Sea basin (southeastern Italian coast and off the coast of northern Greece) that are subject to different degrees of fishing intensity were studied. The area off the Italian coast has a trawl fishery at 300-700 m depths that targets deep-sea shrimps, while in the area off the Greek coast, fishing only reaches to the 400 m depth. Two trawl surveys were conducted in July and August 2000 in both areas. Univariate diversity indices did not detect much difference in community structure between the two areas considered as a whole, but multivariate analysis showed different depth-dependent patterns highlighting abundance differences among species. Depth was the main factor differentiating faunal assemblage clusters, with one on the upper slope and one on the middle slope. The implications of these findings for fishing intensity and environmental conditions in these areas are discussed.