An Experimental Study of the Effects of Statfjord Crude Oil, and Application of Inipol and Fish Meal on the Sea Ice Biota in Svalbard in February-April 2004

摘要

For the study of crude oil and nutrient addition effects on arctic sea ice biota, a field experiment was carried out in Van Mijenfjorden, Svalbard, during 22.2.-25.4.2004. During the 63 day long experiment, three different compounds (Statfjord crude oil, Inipol and fish meal) were added in different combinations onto snow-free sea ice surface. In February the sea ice biota consisted solely of diatoms. In the end of the experiment the natural sea ice community consisted of both diatoms and euglenid flagellates (abundance ≤3400 cells 100 ml~(-1) melted sea ice). The treatment with oil only, oil+Inipol, and oil+fish meal lead to a general decrease in protist diversity and abundance. The most dramatic decrease in the abundance of all protists was caused by the addition of oil only, and throughout the ice cover, while the addition of oil+Inipol, and oil+fish meal lead to the disappearance of all other protist groups than diatoms. The negative effects of Inipol and fish meal were most severe in the ice surface, while the interior and the bottom parts of the ice cover were less impacted by the treatments. Heterotrophic flagellates seemed to be able to migrate downward from the ice surface when only oil was added onto the ice. Also, the use of oil only, and oil+Inipol induced the formation of diatom resting spores. In control samples, the addition of fish meal only caused a notable increase of heterotrophic flagellates (≤25 000 cells 100 ml~(-1) melted ice).