The influence of marine fish farming on water and sediment quality: Ildr Bay (Aegean Sea)

The aim of this study was to examine the possible effects of the physicochemical parameters of the water at a fish farm where aquaculture activities are carried out (temperature, pH, salinity, total dissolved solids, electrical conductivity, dissolved oxygen, Secchi depth, nitrite-nitrogen, nitrate-nitrogen, phosphate-phosphorus, ammonium-nitrogen, silica, chlorophyll-a, and suspended particle matter) and in the sediments (%burnable organic matter and %organic carbon). The area of study was an open sea network cage farm where European seabass (Dicentrarchus labrax), gilthead seabream (Sparus aurata), and meagre (Argyrosomus regius) species are cultivated with an annual capacity of 7900 tons in the Bay of Ceme Ildr (Aegean Sea). Samples of surface and bottom water and sediment were taken seasonally from four stations (three cage and one reference station) between December 2013 and October 2014. The study found that the maximum concentrations of ammonium-nitrogen, phosphate-phosphorus, and nitrite-nitrogen were observed in summer, whereas those of nitrate-nitrogen, silica, and chlorophyll-a increased in spring. In comparison with other studies conducted in the region, the amounts of nutrients, except for silica, were found to be considerably lower. Nonetheless, the values of silica and phosphate-phosphorus exceeded the limits for clean seawater. There has been no similar study conducted in recent years due to increased aquaculture capacity in this bay.