The Effect of Rainbow Trout (Oncorhynchus mykiss Walbaum, 1792) Cage Culture on Sediment Quality in Kesikkoeprue Reservoir, Turkey

摘要

Sediment quality in Kesikkoeprue Reservoir, was monitored at two stations (one located under a rainbow trout cage farm with a capacity of about 20 t year-1, the second serving as a control site, located about 60 m away from the cage farm) at monthly intervals from December 2005 to May 2006 to determine the effects of rainbow trout cage culture on the reservoir sediment. Variables measured including organic matter (OM), total carbon (TC), total nitrogen (TN) and total phosphorus (TP) were elevated in the sediment at the cage site in comparison with the control site (p<0.01). At the sampling station under the cages, redox potential (Eh) was found to decrease to negative values, measured in March, April and May. Organic matter and total nitrogen in the sediment under the cages increased by 1.08 and 1.3 times, respectively, in comparison with the control site. When compared to the control station, TP and TC concentrations in the cage sediment showed 2.6 and 1.4-fold increases, respectively, reaching the highest values in February. These results indicate that the cage farm had a localized effect on the reservoir sediment at its recent production level, so it is thought that sediment quality parameters particularly TP and TC concentrations of sediment must be monitored for the sustainable cage fish farming in the reservoir.