Trout Farm Effluent Effects on Water Sediment Quality and Benthos

Several water (dissolved oxygen, pH, ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen, total phosphorus and orthophosphate) and sediment (organic matter, total nitrogen, organic carbon and phosphorus) quality parameters, as well as benthic macroinvertebrate communities were investigated monthly between May 2007 and November 2007 at a rainbow trout farm located on one of the sources of the Sakarya River in Central Anatolia. Water and sediment samples were collected from three stations, i.e., the inlet of the farm, which was a karst spring-originated pond, the outlet of the farm, and a location 200 m from the outlet of the trout farm, which has a capacity of 30 t annually. These water quality parameters were compared to the acceptable effluent limits proposed for trout farming in different countries. Ammonia-nitrogen, total phosphorus and orthophosphate were found to be higher than the acceptable effluent limits during the study period. Sediment quality parameters were also found to be higher than those at the inlet of the farm. The benthic macroinvertebrate community consisted of only Gastropoda (Limnaedae, Planorbidae, Neritidae and Pleuroceridae). Almost identical organism groups were observed at the three stations, and the highest abundance was found at the outlet of the farm during the study. Finally, as an indicator of damage to the environment, the biodiversity indices were generally measured at levels below 1 in all stations.