The polychaeta of the Homa lagoon (Izmir bay)

The composition and distribution of the polychaeta fauna on the soft bottom of the Homa Lagoon were presented with the relations between key environmental variables affected on the fauna and faunal distribution patterns between sampling periods January 2006-January 2007. Environmental variables considered included water temperature, salinity, dissolved oxygen, pH, Chl-a, nutrients, sediment temperature, organic matter content in sediments and sediment grain size. The community was characterized by Heteromastus filiformis, Glycera tridactyla. These were accompanied by species Hediste diversicolor. Capitella capitata. Spio decoratus. Some species such as Polydora ciliata, Nepthys hombergii. Capitella giardi, Sigambra tentaculata, Prionospio multibranchiata, Malacoceros fuliginosus and Streblospio shrubsolii had fewer densities compared to other species in the lagoon. Diversity exhibited a seasonal pattern with highest value was occurred in spring (H?=1.06) and lowest value was in summer (H?=0.66). Secondary production and feeding guilds of the species were indicated from monthly samplings. Salinity, sediment temperature, pH, Chl-a and particle size of the sediment highly correlated with biomass and density of the fauna. A weak correlation was occurred between environmental factors and the distribution of polychaetes.