Ecological Gradients of Epimegafaunal Distribution along The Sectors of Gulf of İzmir, Aegean Sea

Abstract

During 2009-2010 epifaunal materials were collected seasonally with a beam trawl from seven fixed stations in the infralittoral of Gulf of Izmir to study spatiotemporal distribution of megabenthic fauna and their ecology. A total 153 megafaunal species were identified belonging to nine phyla, comprised mostly of 54 molluscans, 43 chordates (mostly fish), 20 arthropods, and 18 echinoderms. Nine alien species were recorded. Four species (two fish species, one gastropod and one Asteroidea species) were constant species and 16 species were common species in the study area. Lesueurigobius friesii, Buglossidium luteum, Turritellinella tricarinata and Astropecten irregularis were the most frequently occurred, and Lesueurigobius friesii, Varicorbula gibba, Anomia ephippium, Turritellinella tricarinata and Dentalium sp were the most abundantly occurred species. Excluding the evenness index, faunistic characteristics tended to increase as a factor of depth. Seasonal density (abundance and biomass) was minimal in April and maximal in February, followed by November having 2-fold higher abundance than that inJuly. Faunal assemblages were correlated with regions of the gulf and habitat type. Buglossidium luteum overspread the entire gulf excluding the inner gulf. Varicorbula gibba and Fulvia fragilis, a pollution indicator predominated the inner gulf. Hydrographical parameters and depth were associated to dictate faunal assemblages with difference among the sectors and habitats.

Keywords

• megabenthic fauna
• spatiotemporal distribution
• ecology
• aegean sea
• i̇zmir gulf