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(75-05) Transfer of organochlorines from the abiotic environment to the lowest trophic levels of ice-associated foodwebs. Olsson, Kristina*,1, Kallenborn, Roland2, Borgå, Katrine3, John-Olof, Thörngren4, 1 Akvaplan-niva, Tromsoe, Troms, Norway2 Norwegian Institute for Air Research, Tromsoe, Troms, Norway3 Norwegian Polar Institute, Tromsoe, Troms, Norway4 The institute of Applied Environmental Chemistry, Stockholm, Stockholm, Sweden ABSTRACT- The role of sea ice in transport and transformation of contaminants in the Arctic is to a large extent still covered in haze. As a step in gaining further knowledge about basic properties such as levels, distribution and uptake of pollutants from polar abiotic environments, a suite of samples for organic contaminant analyses have been collected in the marginal ice zone of the three geographical areas: the Barents Sea, the eastern and western Fram Strait. The sample pool collected in summer and fall 1999 consists of snow, sea ice (clean and sediment-laden), seawater (particulate and dissolved phases), ice algae and phytoplankton. The study area was selected on the basis of water circulation and ice drift patterns, with water mass identification through onboard measurements of biogenic silicate and CTD profiles. The samples are currently under chemical analyses for content of PCB (33 congeners) and pesticides (DDTs, HCHs, HCB, chlordanes, nonachlor). Preliminary PCB results from seawater and algae samples collected in the Barents Sea and in the eastern Fram Strait show homogenous distribution of PCB congeners in the dissolved phase of seawater. Bio-concentration of PCBs in ice algae and phytoplankton in general follow the degree of chlorination. However, there is a difference in congener patter for phytoplankton (<180 mm) collected from the same stations by hand nets and with the onboard large volume filtration system. The results obtained from the survey will be discussed in view of sources and medium characteristics, as well as algae composition and trophic relation, with special emphasis on the role of sea ice as transportation agent. Key words: Organochlorines , marginal ice zone, abiotic media, bio-concentration |
