Distribution of modern agglutinated foraminifera along an inner neritic- to mid-bathyal transect in Saros Bay (northern Aegean Sea)

Agglutinated benthic foraminifera were investigated in the central Northern Aegean Sea. Eighteen samples were collected along a neritic to mid-bathyal transect in Saros Bay at water depths ranging from 15 to 500m in March 2003. This study documents for the first time in detail, agglutinated foraminiferal species and their bathymetric distribution in this area.Atotal of 96 species belonging to 51 genera were recognised. Statistical analyses (CA and PCA) allowed us to identify different assemblages that can be related to bathymetric depth and trophic level and, in turn, to different hydrological zones. The shallowest assemblage (15m) is characterised by the lowest species richness that might result from the influence of the Black Sea outflow into Saros Bay. The shallow assemblages stations (21-70m) are characterized by relatively low diversity and higher dominance values. On the other hand, assemblages from intermediate water (80-200m) are characterised by high diversity values and the dominance of elongate keeled forms associated with elongated tapered forms, providing evidence of mesotrophic conditions. The deepest assemblages, including stations ranging from water depths of 200 to 500m, are very well-diversified and mainly represented by epifaunal taxa. The dominance of tubular morphogroup might be due to the low food supply, which acts as a limiting factor for more eutrophic dependent taxa and meso-oligotrophic conditions might be inferred.