ation of Persistent Po in Norma and Dwarfed Arctic Char Salvelinus alpinus sp. comp Institute of Freshwater Research, 5;- 178 93 Drottndnghohn, Sweden and Departmrent of Zoodogy, Section of Animal Ecoiogy, University of Uppala, Uppsala, Sweden Per Larsssn Lirnnologg/, Department of Ecology, University of bund, PP.8. Box 65, S-22 f 00 bund, Sweden and Maris Klavins institute of Biology, 22902 7 Sadaspils, Latvia Hammar, I., P. Larsson, and ha. KIavins. 1993. Accumulation of persistent pollutants in normal and dwarfed Arctic char (Salve/inus alpinus sp. complex). Can. I. Fish. Aquat. Sci. 50: 2574-2580. Two extreme growth fractions of introgressed sympatric populations of the Arctic char (Sa%veBinus aipinus) species complex from Lake BlAsjiin, northern Sweden, were sampled for individual concentrations of persistent pollutants originating from atmospheric deposition. Slow growing char (dwarfs) had significantly higher levels of ZPCB isurn of PCB congeners found] and p,p-DDE (dominating DDT-compound) than fast growing char (normals). Besides demonstrating a highly divergent growth pattern the introgressed populations also inhabit a great range of depths, and the seasonal food consumption rates may differ between extreme growth fractions, although the same major invertebrates (introduced Mysis dicta and PaPhsea quadrbspa'n~sa) are consumed over the year. However, of the life history parameters differing in late spring, individual growth rate was the most important factor explaining the variation in the levels of the pollutants studied. The results support the hypothesis of a biomass '"dilution" sf pollutants in fish, illustrated by lower levels in fast growing char and higher levels in the slow-growing dwarfs. Individuals with alternative growth strategies in sympatric conspecific communities thus provide unique opportunities to study growth rate as a variable influencing levels of persistent pollutants in fish. Dans Be lac Blasjon, dans le nord de la Suede, il existe deux groupes 2 la croissance radicalement diffkrente au sein des populations sympatriques introgresskes du csmplexe dfespGcesdie I'ornble chevalier (Sabvelinus ajpinus). Ces groupes ont kt6 4chantillonnks en vue de la mesure de la concentration de certains contaminants persistants d'origine atmosphkrique. Chen les ombles 5 la croissance lente (nains), la concentration de XBPC (la somme des cong6ngres de BPC trouv6s) et du p,p-DBE (fraction dorminante du DDT) ktaient trsuv6s en concentrations significativement supkrieures 2 ce qu'elles sont dans les tissus des ombles 5 croissance normale (normaux). En plus d'une courbe de croissance fortement divergente, les populations introgress6es se tiennent 2 I'intkrieur d'une vaste plage de profondeurs; en outre, les taux saisonniers d'alimentation peuvent diff6rer entre les deux groupes m6rne si ce sont les mGmes principaux invertebrbs qui sont consomm6s au cours de I'ann6e (Mysis rdkb, introduite, et PalBasea quadrispinosa). B l derneure toutefois que, des param6tres du cycle biologique qui diff6rent 2 la fin du printemps, le taux de croissance individuel est Je principal facteur pour expliquer l'kcart de concentration dies contaminants 6tudi6s. kes r6sblitab viennent btayer ['hypothgse A I'effet qu'ii se produit une (( dilution )9 des contaminants dans la biornasse des poissons, du fait que la concentration est infkrieure chez I'omble i la croissance rapide et supkrieure ckez I'ornble main. Au sein de cornrnunaut6s de cong6nGres syrnpatriques, ceux qui ernploient des stratbgies diff6rentes de croissance nsus offrent une occasion unique d'ktudier le taux de croissance 5 titre de variable qui influence la concentration de contaminants persistants dans les tissus du poisson. Received September 9/ 3,1992 Accepted June 25, 7 993 (JB625) A nimal other suffer populations inhabiting the higher latitudes and remote areas, far from human concentrations, an increasing risk of being exposed to various persistent pollutants originating from atmospheric deposition. Several investigations have demonstrated the significance of such transport for the northem boreal and Arctic regions (e-g., Bowes and Jonkel 1975; McNeely and G u m e r 1984; O e h e 1991; see dso Hamar B989), where compounds such as hexackloroeyclokexane~~ DDT and metabolites, and poly- chlorinated biphenyls (PCBs) have been traced in landlocked fish beg., Risebrobngh and Berger 1971 ; Johnson et al. 1988; S w a c h m e r and Hites 1988; Muir et al. 1996%; Rasmussen et al. 1990; see also Wania and Mackay 1993). High levels have especially been recorded in long-lived predators such as northern pike (Esod: luckus), burbot (Lofa lota), and lake trout (a4irlvelknu~ ~zaanaycush) . Within the ecosystem, persistent pollutants reach predatory fish mainly though their prey (Jensea et al. 1982; Oliver and Can. J. Fish. Aquat. Sci. Downloaded from www.nrcresearchpress.com by China University of Science and Technology on 06/05/13 For personal use only.