| Summary: | Læst til 18.6.2015 The Svalbard shelf is identified as one of the chief fishing grounds for the Barents Sea shrimp fishery. While Kongsfjorden has been closed to commercial trawling in order to protect the scientific interests of the area, commercial harvesting continues in Isfjorden. In this study, trawl catches and population structure distributions of northern shrimp (Pandalus borealis) were analyzed in an investigation into the impacts of the different management strategies of the two fjords. Additionally, potential predation pressure was explored through abundance estimates of shrimp predators at various locations within the fjords. Stomach contents analysis identified the main predators, namely Atlantic cod (Gadus morhua), Greenland halibut (Reinhardtius hippoglossoides) and large polar cod (Boreogadus saida), but, with the exception of polar cod, there were no significant difference in abundance of these predators between fjords. Mix 3.0 modal analysis of length frequency distributions revealed no clear difference in growth or age at first female maturity between the fjords. However, shrimp in inner Isfjorden, where bottom temperatures are generally lower, exhibited a slight increase in age at female maturity, suggesting reduced growth rates. Generally, there were greater differences in population structure and abundances of both shrimp and predators within the fjords than between them. These results indicate that trawling has no significant effect on the distribution, abundance or population size structure of the shrimp. Instead, heterogeneity in shrimp population structure within each fjord suggested that shrimp utilize different subhabitats at different life stages. Further understanding of such preferences would be useful in the management of the shrimp fishery on the Svalbard shelf. Svalbard Environmental Protection Fund University Centre in Svalbard Norwegian Institute of Marine Research Akvaplan-niva
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