Food chains and POPs - Project title
	Persistent organic pollutants in marine organisms in the marginal ice zone in the Barents Sea.
Co-ordinating institution
	Norwegian Polar Institute
Final report
	The project was a part of a PhD-thesis, co-sponsored by the Transport- and Effects programme: Borgå, K. (2002) Organochlorine contaminants in Arctic marine food webs: distribution in pelagic and sympagic fauna. Doctor Scientiarum Thesis, Norwegian College of Fishery Science, University of Tromsø, Norway. 44 pp + 5 papers. ISBN 82-91086-27-3. Papers: . Borgå, K., Gabrielsen, G. W., Skaare, J. U. (2002) Differences in contamination load between pelagic and sympagic invertebrates in the Arctic marginal ice zone: influence of habitat, diet and geography. Marine Ecology Progress Series 325: 157-169   Hop, H., Borgå, K., Gabrielsen, G. W., Kleivane, L., Skaare, J. U. (2002) Food web magnification of persistent organic pollutants in poikilotherms and homeotherms from the Barents Sea. Environmental Science and Technology 36: 2589-2597   Borgå, K., Poltermann, M., Polder, A., Pavlova, O., Gulliksen, B., Gabrielsen, G. W., Skaare J. U. (2002) Influence of diet and sea ice drift on organochlorine bioaccumulation in arctic ice-associated amphipods. Environmental Pollution 117: 47-60   Borgå, K., Gulliksen, B., Gabrielsen, G.W and Skaare, J.U. (2002) Size-related bioaccumulation and between-year variation of organochlorines in ice-associated amphipods from the Arctic Ocean. Chemosphere 46: 1383-1392
Summary and results
	Summary of thesis: Findings of high PCB and DDT levels in Barents Sea top predators called for explanations about contaminant transport to and distribution within the Barents Sea food web. This thesis studies  i) the organochlorine distribution within selected elements of the Barents Sea pelagic food web with respect to changes in concentrations and compositional pattern, ii) organochlorine accumulation in pelagic and sympagic invertebrates where data from the Svalbard region were previously scarce, and iii) the role of sea ice on organochlorine concentrations in ice-associated fauna. The results show that there is an increasing role of dietary organochlorine uptake and reduced excretion ability by direct partitioning to water, as trophic level, body size of invertebrates and fish, and a chemical’s lipid solubility increases. Trophic position influences the contaminant uptake not only in seabirds and seals, but also in aquatic invertebrates and fish with direct exchange of contaminants with water. The organochlorines concentrations generally increased with trophic position, but with lower rate in poikilotherms (invertebrates and fish) than in homeotherms (seabirds and seals). The organochlorine elimination from invertebrates and fish is dominated by direct exchange rather than biotransformation. Increased biotransformation ability from invertebrates to fish to seabirds and seals filters the organochlorines through the food chain and changes the organochlorine compositional pattern. Thus, zooplankton, ice fauna and fish had an organochlorine pattern dominated by less hydrophobic compounds and compounds from the technical mixtures, whereas seabirds and seals had a pattern dominated by lipophilic and persistent technical compounds and metabolites. The role of sea ice on organochlorine exposure to ice fauna was attributed to its function as a habitat that keeps ice fauna in the surface layer, rather than to the release of contaminants from the sea ice itself. In the marginal ice zone, the sea ice drift route helped explain geographic differences in a-HCH, which is the contaminant with highest concentrations in the Polar Surface Water of the Arctic Ocean. Zooplankton, fish and mainly zooplanktivore and piscivore seabirds from the Barents Sea had comparable contaminant levels to similar species from the Canadian Arctic, although higher pollutants loads were previously reported in ringed seals, glaucous gulls and polar bears from the Barents Sea area. The rate of organochlorine transfer within the marine food web in the Canadian Arctic and the Barents Sea seems generally comparable, which suggests other explanations than food web structure for the geographic organochlorine difference between top predators.
Original project description
	SUMMARY Due to the high concentrations of organochlorines found in the top predators of the Barents Sea ecosystem, there is a need to study the occurrence of persistent organic pollutants (POPs) in organisms of lower trophic levels. To study the importance of transport of POPs via the sea ice, we will compare the occurrence of POPs in pelagic and sympagic communities in the marginal ice zone in the Barents Sea. The occurrence of POPs in the organisms of the pelagic and sympagic communities will be studied in relation to the trophic  structure of the food chains and the seasonal dynamics of lipids in the organisms.   PROJECT DESCRIPTION Background The presence of persistent organic pollutants (POPs) in the arctic environment has been known for decades (Bowes and Jonkel, 1975). At Svalbard and in the Barents Sea, the levels of POPs are high in top predators of marine food chains such as glaucous gull (Larus hyperboreus), arctic fox (Alopex lagopus) and polar bear (Ursus maritimus) (Wang-Andersen et al., 1993; Gabrielsen et al., 1995; Bernhoft et al., 1997). Due to properties of POPs such as high persistence and lipophilicity, they tend to bioaccumulate in organisms (Dons and Beck, 1994). High seasonal variation in productivity and food availability in the Arctic have resulted in adaptations in the organisms such as building up an energy storage of lipids which can be mobilised at times of food shortage. The transfer of lipids and energy in arctic ecosystems is fast (Falk-Petersen et al., 1990), and since POPs are highly lipophilic, there is a risk of a rapid enrichment of contaminants in the food chain. Since the burden of contaminants are transferred from the prey to the predator, the concentrations of POPs are found to increase (biomagnify) with an organism’s trophic level in the food chain (Broman et al., 1992, Jarman et al., 1997). With the use of stable isotopes of carbon and nitrogen,  the relative trophic position of the organisms in the food chain can be established (Hobson and Welch, 1992). The few existing data on POPs in pelagic organisms at low trophic levels show low levels of POPs (Joiris et al., 1997; Stange & Klunksøyr, 1997; Borgå et al., in prep). The transport of POPs to the Arctic is on a long range through the atmosphere, river outlets and ocean currents (Barrie et al., 1992), of which transport via the atmosphere is considered as the most important pathway (Bidleman et al., 1989). In the Barents Sea, POPs transported with the seaice from the Russian shelf (Pfirman et al., 1995 and 1997) is considered as a potential source of POPs to the arctic marine ecosystem as the seaice melts in the marginal ice zone and the contaminants can be accumulated by the organisms in the ice associated community (Alexander, 1995). Objective The objective of this study is to contribute to the understanding of the fate of POPs in the arctic ecosystem. The project will especially contribute with knowledge on the distribution of POPs in the lower trophic levels of marine pelagic and sympagic communities. The POPs included in this project are organochlorines, therein pesticides (HCH, HCB, chlordanes, HCB, DDT, Toxaphene) and PCBs. The occurrence of POPs in the pelagic and sympagic communities will be related to biotic parameters such as trophic position in the food chain, seasonal dynamics in the organism’s lipids content and quality, biometric measurements (length and weight), reproductive condition, and abiotic parameters such as season, temperature, salinity, concentrations of POPs in seawater and seaice, the iceage (first year or multiyear-ice), ice coverage. The project will be harmonized with the Akvaplan-NIVA project; Transfer of organic pollutants from the abiotic environment to the lower trophic levels of the ice associated food chain, which will mainly investigate the occurrence of POPs in the abiotic compartments.   The purposes of the project is to investigate:  whether the uptake of POPs in organisms of lower trophic levels is dominated by bioconcentration directly from the water or ice, or bioaccumulation from the diet. the occurence (concentrations and pattern) of POPs in an organism with respect to the seasonal lipid dynamics.  whether the bioaccumulation of POPs in sympagic organisms differs from the pelagic organisms with respect to community structure (trophic relations) and exposure to POPs transported with the sea ice which melts in the marginal ice zone.  Methods The following organisms will be collected in autumn 1998 (expedition organised by The Norwegian College of Fishery Science and the University Courses on Svalbard), spring 1999 (cruise organised by Norwegian Polar Institute) and autumn 1999 (expedition organised by Norwegian Polar Institute): Sympagic community: ice algae, ice amphipods (Apherusa glacialis, Onisimus spp., Gammarus wilkitzkii), polar cod (Boreogadus saida). Pelagic community: copepods (Calanus finmarchicus, C. glacialis, C. hyperboreus), euphausiids (Thysanoessa spp.), pelagic amphipode (Parathemisto libellula), polar cod (Boreogadus saida). Higher trophic levels: seabirds (Black guillemot Cepphus grylle, Little auk Alle alle, Brunnich’s guillemot Uria lomvia and Black legged kittiwake Rissa tridactyla). The analysis of POPs (organochlorines; HCHs, HCB, chlordanes, DDTs, non-planar PCBs, Mirex and Toxaphene) will be carried out at the Environmental Toxicology Laboratory, The Norwegian College of Veterinary Medicine, Oslo, Norway (Bernhoft et al., 1997). The analysis of stable isotopes will be carried out at The Institute for Energy Technology, Kjeller, Norway (Hobson and Welch, 1992). The analysis of polar and neutral lipids classes will be carried out at NERC Unit of Aquatic Biochemistry, School of Natural Sciences, University of Stirling, Scotland (Sargent and Falk-Petersen, 1981). Budget The Norwegian Council of Research (NFR) finances most of the costs of the project. Our finances from “Effektprogrammet” will cover expenses in relation to field assistants and chemical analysis. Cooperation and associated participants/applicants Dr. philos. Geir Wing Gabrielsen, Norwegian Polar Institute Katrine Borgå, PhD-student, Norwegian Polar Institute/University of Tromsø Dr. philos. Stig Falk-Petersen, Norwegian Polar Institute Prof. Bjørn Gulliksen, University of Tromsø Dr. Haakon Hop, Norwegian Polar Institute Prof. Janneche Utne Skåre, National Veterinary Institute Results from this project will be published in scientific journals with referee system. The papers will be included in the PhD-thesis of Katrine Borgå. In addition, preliminary results will be presented at international and national meetings and symposiums. Literature Alexander, V. (1995) The influence of the structure and function of the marine food web on the dynamics of contaminants in Arctic Ocean ecosystems. The Science of the Total Environment 160/161, 593-603 Barrie, L.A., Gregor, D., Hargrave, B., Lake, R., Muir, D., Shearer, R., Tracey, B. and Bidleman,  T. (1992) Arctic contaminants: sources, occurrence and pathways. The Science of the Total Environment 122, 1-74 Bernhoft, A., Wiig, Ø. and Skaare, J. U. (1997) Organochlorines in polar bears (Ursus maritimus) at Svalbard. Environmental Pollution 95, 159-175 Bidleman TF, Patton GW, Walla MD, Hargrave BT, Vass WP, Erickson P, Fowler B, Scott V & Gregor DJ, 1989. Toxaphene and other organochlorines in Arctic Ocean fauna: Evidence for atmospheric delivery. Arctic 42, 307-313 Borgå, K., Gabrielsen G. W. and Skaare J. U. (in prep.) Bioaccumulation of organochlorines in an Arctic marine food chain. Bowes, G. W. and Jonkel, C. J. (1975) Presence and distribution of polychlorinated biphenyls (PCBs) in arctic and subarctic marine food chains. J. Fish Res. Board Can., 32, 2111-2123 Broman, D., Näf, C., Rolff, C., Zebühr, Y., Fry, B. and Hobbie. J. (1992) Using ratios of stable nitrogen isotopes to estimate bioaccumulation and flux of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in two food chains from the northern Baltic. Environmental Toxicology and Chemistry 11, 331-345 Dons, and Beck, . (1994). Priority hazardous substances in Norway. SFT report. 94:03, 115 pp Falk-Petersen, S., Hopkins, C. C. E. and Sargent, J. R. (1990) Trophic relationships in the pelagic, Arctic food web. Trophic Relationships in the Marine Environment, Proceeding the 24th European Marine Biology Symposium, 315-333 Gabrielsen, G. W., Skaare, J. U., Polder, A. and Bakken, V. (1995) Chlorinated hydrocarbons in glaucous gulls (Larus hyperboreus) in the southern part of Svalbard. The Science of the Total Environment 160/161, 337-346 Hobson, K. A. and Welch, H. E. (1992) Determination of trophic relationships within a high Arctic marine food web using d13C and d15N analysis. Marine Ecology Progress Series, 84, 9-18 Horner, R., Ackley, S. F., Dieckmann, G. S., Gulliksen, B., Hoshia, T., Legendre, L., Melnikov, I. A., Reeburgh, W. S., Spindler, M. and Sullivan, C. W. (1992) Ecology of sea ice biota 1. Habitat, terminology, and methodology. Polar Biology 12, 417-427 Jarman, W. M., Sydeman, W. J., Hobson, K. A. and Bergquist, P. A. (1997) Relationships of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran levels to stable-nitrogen isotope abundance in marine birds and mammals in coastal California. Environmental Toxicology and Chemistry 16, 1010-1013 Joiris, C.R., Laroussi, Moatemri. N. & Holsbeek, L. (1997) Mercury and polychlorinated biphenyls in zooplankton and shrimp from the Barents Sea and the Spitsbergen area. Bulletin of Environmental Contamination and Toxicology  59, 472-478 Lønne, O. J. and Gulliksen, B. (1991) Synpagic macro-fauna from multiyear sea-ice near Svalbard. Polar Biology 11, 471-477 Pfirman, S., Eicken, D., Bauch, D. and Weeks, W. F. (1995) The potential transport of pollutants by sea ice. The Science of the Total Environment 159, 129-146 Pfirman, S., Colony, R., Nürnberg, D., Eicken, H. and Rigor, I. (1997). Reconstructing the origin and trajectory of drifting Arctic sea ice. Journal of Geophysical Research 102, 12,575-12,586 Sargent, J. R. and Falk-Petersen, S. (1981) Ecological investigations on the zooplankton community in Balsfjorden, northern Norway: Lipids and fatty acids in Meganyctiphanes norvegica, Thysanoessa raschii, and T. inermis during mid-winter. Marine Biology 62, 131-137 Stange K & Klunksøyr J, 1997. Organochlorine contaminants in fish and polycyclic aromatic             hydrocarbons in sediments from the Barents Sea. ICES J. Mar. Sci., 54: 318-332 Wang-Andersen, G., Skaare, J. U., Prestrud, P. and Steinnes, E. (1993) Levels and congener pattern of PCBs in Arctic fox, Alopex lagopus, in Svalbard. Environmental Pollution 82, 269-275 Wang-Andersen G, Skaare JU, Prestrud P & Steinnes E, 1993. Levels and congener pattern of PCBs in Arctic fox, Alopex lagopus, in Svalbard. Environmental Pollution, 82: 269-275 Werner, I. (1997) Ecological studeis on the Arctic under-ice habitat - colonisation and processes at the ice-water interface. Christian-Albrechts-Universität zu Kiel.             Sonderforschungsbereich 313. 167 pp.
Progress report(s)
	June 1999 October 1999 September 2000