Summer fish larval assemblages and station groups in the northern Aegean Sea

Abstract

Fish larvae were collected in two surveys, carried out at the beginning of July 2002 and 2003 in Kavala Gulf (northern Aegean Sea) aimed at studying ichthyoplankton species assemblages and station groupings. The similarity dendrograms revealed the existence of four species assemblages associated with three station groups in 2002 and five species assemblages associated with four station groups in 2003. These groupings were confirmed by non-metric multidimensional scaling (NMDS) analysis. Analysis of similarity showed that the station groups were significantly different for 2002 (global R=0.748; P<0.001) and 2003 (global R=0.931; P<0.001). High dissimilarity between species assemblages as obtained from dendrograms and NMDS analyses was also recorded for 2002 (global R=0.834; P<0.001) and 2003 (global R=0.767; P<0.001). The assemblage structure was mainly determined by the most abundant and frequently occurring larvae, especially the European anchovy (Engraulis encrasicolus), and was largely influenced by the reproductive traits and spatial distribution of adult fish. Differences among station groupings were also determined by the spatial occurrence and abundance of each taxon.