The influence of place of capture, sex, and season on the organochlorine pesticide content in barbel (Barbus graellsi) from Northeastern Spain

Residue levels of the α, β, γ, and δ isomers of hexachlorocyclohexane (HCH), p,p′-DDT and p,p′-DDD in flesh samples of 68 barbels, Barbus graellsi, collected in the Gállego and Cinca Rivers, northeastern Spain, were determined. A significant positive correlation was found between fish length and organochlorine concentration only for DDT homologs. Significantly higher levels of HCH isomers were found in barbels from the Gállego River, as compared to the corresponding mean levels in barbels from the Cinca River. However, residues of DDT homologs were significantly higher in barbels from the Cinca River. In barbels from the Gállego River all organochlorines analyzed were higher in females, but only α and β HCH isomers, p,p′-DDT and ΣDDT were statistically significantly. In barbels from the Cinca River, however, organochlorine concentrations did not seem to be dependent on sex. There were strong evidences for seasonal variation regarding the levels of HCH isomers and DDT homologs in barbels, with higher levels during summer than during spring.