Organochlorines in Antarctic and Arctic Avian Top Predators

Bustnes (2006) compared organochlorines (OCs) levels in Antarctic and Arctic avian top predators analyzing blood sampled from the wing vein of south polar skuas (142 skuas, 73 females and 69 males) breeding at Svarthamaren (71° 53' S, 05° 10' E) in Dronning Maud Land (Antarctica) in December 2001 and January 2002. South
polar skuas had 8% and 29% of the blood OCs concentrations (45 ng/g, ww) found in glaucous gulls and great black-backed gulls (158 ng/g) living in the northern hemisphere. PCBs (here the sum of congeners: CB-101, -99, -118, -153, -138, -180, and –170), p,p'-DDE, and oxychlordane concentrations were much lower in the skuas. The level of the semivolatile HCB instead was relatively high (7 ng/g) and Mirex (an insecticide and flame retardant) was the dominant OC in south polar skuas. To record changes in OC concentrations in south polar skuas during the breeding season, a subsample (n = 66) was recaptured after 2 weeks, and new blood samples were taken. In skuas, the mean levels of most OCs increased by about 30% between the two blood samplings, and the mirex level increased by nearly 60%. The 58 increases in HCB and mirex seem to be more related to local exposure than to lipid dynamics, suggesting that skuas are accumulating these compounds during the breeding season at Svarthamaren.. In skuas at Svarthamaren, the HCB/PCBs ratio was 0.8, whereas this ratio was less than 0.05 in northern emisphere, which could means that skuas at Svarthamaren are exposed to HCB locally.
Examining the relationships between fitness components and concentrations of OCs in this species,. using principal component analyses (PCA) this study found associations between concentrations of OCs and fitness components in Antarctic birds. birds; i.e. the timing of the reproduction and hatching mass of chicks were both adversely related to the mothers' blood residues of OCs