Temporal trends of POPs in arctic foxes from Svalbard in light of a changing climate

Abstract

The present study investigates concentrations and temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard, Norway, adjusted for sex, age, body condition, diet, reindeer mortality and sea ice coverage. Number of reindeer carcasses in Adventdalen and sea ice coverage of Isfjorden in the spring preceding the trapping season were used as indexes for climate influenced food availability between years. We analysed liver of 100 foxes from Svalbard, collected in 1997/98, 1998/99, 1999/00, 2001/02, 2002/03, 2003/04 and 2010/11 for concentrations of polychlorinated biphenyls (PCBs; PCB -28, -52, -101, -118, -138, -153 and -180), chlordanes (cis-chlordane, trans-nonachlor and oxychlordane), p-p’-DDT, p-p’-DDE, HCB, mirex and β-HCH. The POPs found in highest concentrations were oxychlordane, PCB-180 and PCB-153. We found evidence for a temporal decrease in ∑PCBs (PCB -118, -138, -153, -180), and ∑chlordanes (trans-nonachlor and oxychlordane) when controlling for possible confounding variables. We also found evidence for an effect of body condition and δ13C on the POP concentrations, as thinner foxes and foxes feeding from the marine food web had significantly higher levels of POPs. There was no evidence for effects of sex, age, reindeer mortality and sea ice coverage on the concentrations of POPs, although increased reindeer mortality had a non-significant negative effect on all the POPs analysed. This study shows that correcting for body condition and diet is vital when investigating temporal trends of POPs in biota. It also illustrates some of the difficulties of investigating POP concentrations in an arctic predator living in an environment influenced by climatic variations.