Bottom Trawling and Scallop Dredging in the Arctic : Impacts of fishing on non-target species, vulnerable habitats and cultural heritage

This project has been developed within the frame of the Nordic Action Plan 2000-2004 (Nord 1999:29) to review the status and threats of the natural and cultural heritage in Arctic waters. Two of the most commonly used demersal fishing gears in the Arctic are the otter trawl and the scallop dredge. Detrimental effects of bottom gear towed over the seabed include incidental catch and direct mortality of a wide range of organisms and habitat alteration. Any three-dimensional fragile structures rising above the seabed, such as cold-water corals, sponges, geological formations and archaeological remains are easily destroyed. This report reviews the scallop and shrimp fisheries, the distribution and conservation of vulnerable habitats (coral reefs, sponge communities), the status of archaeological remains on the seabed and relevant legislation and the conservation measures and role of protected areas. In addition there are two case studies based on fisheries and survey data from Iceland and recommendations to improve the current situation

Population structure and seasonal movements of narwhals, Monodon monoceros, determined from mtDNA analysis

We determined the nucleotide sequence of the first 287 base pairs in the mitochondrial control region from 74 narwhals, Monodon monoceros, collected in the North-west Atlantic. We detected four polymorphic sites that defined five haplotypes, two of which were found in single specimens. The same DNA sequence was characterized in an additional 353 specimens by digestion with two restriction endonucleases. In this manner each specimen could be assigned to one of the three most common haplotypes. The nucleotide diversity for the total sample (as well as the sequenced subset) was estimated as 0.0017 and pairwise genetic distances between haplotypes ranged from 0.0035-0.0070. The low nucleotide diversity and the low average pair-wise genetic distance between haplotypes suggest a recent expansion in abundance from a small founding population. Despite the low degree of variation, frequencies of the common haplotypes differed markedly between areas. The results indicate isolation, even between geographically close areas, as well as fidelity to specific summer and autumn feeding grounds. Heterogeneity within a presumed single breeding ground suggests mixing of pods with different haplotypic composition