| Summary: | Master's thesis in Environmental technology Expanding petroleum activities into northern marine areas have resulted in need for tools that specify Arctic specific characteristics when assessing environmental risks for these regions. In order to estimate the environmental impact of mechanically or chemically dispersed oil, on marine populations in sensitive northern environments, laboratory studies need to be developed. Such studies would be useful fir risk assessments and modelling potential effects of oil related pollution. The overall objective of the thesis was to establish an exposure study that would be useful for estimation of the effects of oil in ice or blowout scenarios on northern marine keystone organisms. Further, some basic parameters of growth and moulting of the Northern krill from the Stavanger area was established under different experimental conditions. A moult pre-study tested three different feeding regimes (Artemia nauplii + commercial shrimo larvae feed (EZ larvae), Thalassiosira algae paste + EZ Larvae and starved) studied over a period of two months. The length measurements recorded for moults and frozen animals only differentiated between the starved group and the fed treatments, and overall negative INC values at the end in all treatments were most likely caused by maintenance procedures. The study showed that the fed groups kept their moulting rhythm while the starved group did not. The CFS exposure experiment conducted on M. norvegica revealed no significant difference between the Control (no oil), Low (0.54 mg/l) or Medium (1.6 mg/l) treatments of mechanically dispersed crude oil exposures in the moults frequency or animal lengths or weights. However, all individuals in the High (4.9 mg/l) exposure group died before first sampling, and all in Medium died before the second sampling. Still, the Low treatment was persistently lower than the Control in all measured parameters and visual observation of the moults revealed potential bacterial infection on oil exposed individuals. The ...
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