The influence of fish cage culture on δ13C and δ15N of filter-feeding Bivalvia (Mollusca)

Abstract

The objective of this study was to evaluate the effect of Oreochromis niloticus cage culture promoted variations in the d 13 C and d 15 N in Corbicula fluminea (Mollusca; Bivalvia) and in the sediment of an aquatic food web. Samples were taken before and after net cage installation in the Rosana Reservoir (Paranapanema River, PR-SP). Samples of specimens of the bivalve filterer C. fluminea and samples of sediment were collected using a modified Petersen grab. All samples were dried in an oven (60°C) for 72 hours, macerated to obtain homogenous fine powders and sent for carbon (d 13 C) and nitrogen (d 15 N) isotopic value analysis in a mass spectrometer. There were significant differences in the