CHLORINATED HYDROCARBONS IN GLAUCOUS GULLS (LARUS-HYPERBOREUS) IN THESOUTHERN PART OF SVALBARD

In 1989, a number of glaucous gulls (Larus hyperboreus) were found dea d near a seabird cliff at south Svalbard. In an effort to elucidate th e course of death, 12 individuals were sent to the Central Veterinary Institute for autopsy and analysis of chlorinated pesticides and polyc hlorinated biphenyls (PCBs) in samples of liver, kidney, brain and mus cle. Eggs of common and Brunnich's guillemots constitute important foo d for glaucous gulls during the nestling period, thus 13 eggs (3 eggs from common and 10 eggs from Brunnich's guillemots) from the same area were also analyzed for organochlorines. The autopsy of the birds did not reveal any specific cause of death. The following chlorinated pest icides were analyzed: hexachlorobenzene (HCB), hexachlorocyclohexanes (alpha-, beta-, gamma-HCH), chlordanes (oxychlordane, trans-nonachlor, heptachlor and heptachlor epoxide), the drin group (aldrin, dieldrin) and the DDT group (o,p', p,p'DDT, DDD and DDE). Relatively low hepati c concentrations of dieldrin were found (n.d.-0.17 mg/kg wet weight (w .w.), mean 0.04), Sigma HCH (n.d.-0.14 mg/kg w.w., mean 0.02), HCB (0. 03-1.01 mg/kg w.w., mean 0.51), oxychlordane (0.01-1.85 mg/kg w.w., me an 1.05), p,p'DDE (0.81-5.41 mg/kg w.w., mean 2.98), o,p'DDD (0-0.52 m g/kg w.w., mean 0.14) and Sigma DDT (0.9-6.25 mg/kg w.w., mean 2.92). Levels of the other chlorinated pesticides were below the quantificati on level. Very high concentrations of PCBs were found. The Sigma PCB ( sum of wet weight concentrations of the 21 individual congeners, the I UPAC nos. 28, 52, 74, 99, 101, 110, 118, 114, 153, 105, 141, 138, 183, 128, 187, 156, 157, 180, 170, 194 and 209) in hepatic tissue was 0.8- 32.3 mg/kg w.w. (mean 16.0), in brain 0.9-29.5 mg/kg w.w. (mean 14.8), in kidney 0.4-21.4 mg/kg w.w. (mean 9.7) and in muscle 0.5-6.0 mg/kg w.w. (mean 3.1). The concentrations of the individual PCB congeners ar e also given. Relatively low concentrations of all the organochlorines were found in guillemot eggs, mean concentrations of Sigma DDT and PC Bs were 0.25 and 0.47 mg/kg w.w., respectively. A toxicological evalua tion of the PCB results is difficult; however, it cannot be excluded t hat PCBs might have contributed to the death of the gulls.