Organochlorine pesticides and PCBs in Southern Right Whales (Eubalaena australis) breeding at Peninsula Valdes, Argentina

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were assessed in blubber from 35 dead Southern Right Whales (SRW - Eubalaena australis) stranded at Peninsula Valdes, Argentina. The life cycle includes a feeding period in high productivity areas of the SouthWest Atlantic and a reproductive period in coastal template waters of Argentina. Organochlorine pesticides showed higher concentrations (22.6 +/- 13.8 ng center dot g(-1) ww) than PCBs (7.5 +/- 10 ng center dot g(-1) ww). Among pesticides, HCHs, DDTs, endosulfans, dieldrin, chlordans, heptachlor epoxide, and trans-nonachlor were detected. p,p'-DDE and p,p'-DDT were present in 69% and 26% of samples, respectively. p,p'-DDT/p,p'-DDE ratio showed lowvalues (< 0.33) as a result of agedDDT inputs. However, the occurrence of only p,p'-DDT in some samples suggests a recent pesticide input. alpha-HCH/gamma-HCH ratio (< DL-0.37) indicated no recent contribution of technical HCH mixture and/or current use of lindane. Dieldrin was present in 77% of the samples and endosulfan was detected in all samples with predominance of alpha- (75%) over beta-endosulfan (19%) and scarce contribution of endosulfan sulphate (7%), suggesting a recent input of this insecticide to the environment in the SRWforaging area. A predominance of pentachlorobiphenylswas observed. In 21 samples at least one PCB indicator was found and PCB # 118, highly toxic, contributed in 5% to total PCBs. Although all these organochlorine compounds are forbidden they were bioaccumulated in the blubber of SRW with a predominance of endosulfans, the more recently used pesticide. The absence of data on chemical pollutants in stranded dead whales is highlighted as a priority for research. This is the first study on levels, compositional patterns, and organochlorine sources in SRW. Moreover, more research including milk, and other tissues/organs is recommended considered that in the studied specimens, mostly calves, pollutants are likely transferred from the mother during pregnancy and nursing. (C) 2015 Elsevier B.V. All rights reserved.