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(232) Environmental monitoring related to construction of a gas pipeline in a strait with contaminated sediments. Grøsvik, Bjørn Einar1, Aas, Endre1, Bjørnstad, Anne1, Øysæd, Kjell Birger1, Børseth, Jan Fredrik1, 1 ABSTRACT- During construction of a gas pipeline from the North Sea to Kårstø, Rogaland, the traversing route included an area with PAH contaminated sediments and effort was made to prevent spreading. Possible spreading of contaminated sediment was monitored by sediment traps, local and transplant mussels and fishing. Construction work lasted from May to September 1999. The sediments were contaminated with PAH due to the vicinity to effluent from an aluminium works. Sedimentation rates and PAH levels were measured in sediment samples, PAH levels and lysosomal membrane stability was measured in mussels (Mytilus edulis), while bile FACs and EROD activities were measured in cod (Gadus morhua L.). When using mussels, a combination of local and mussels transplanted from a clean site was used. Transplant mussels were deployed in cages for three weeks before measurements. Lysosomal stability measured as neutral red retention time was equally reduced in local and transplant mussels in the area with contaminated sediments before construction work started. One additional decrease was observed for one of the stations during construction period. PAH levels were measured in mussels during one year and found to decrease in the period of construction. A possible explanation is decreased levels due to natural spawning. Levels of PAH metabolites in fish bile were high in the area before start and were not increased during period of construction work. The results demonstrated high levels of contaminants in the area before construction work started. Some spreading of sediments was observed during work, but had more local character compared to the effects of the chronic elevated PAH levels in the area. Key words: PAH, Lysosomal membrane stability, Bile FACs, EROD |
