Småsildundersøkelsene i Nord-Norge 1960/61

Abstract

1. During the autumn of 1960 the distribution of the 0- and I-groups of herring was investigated along the coast of Northern Norway, in the northeastern part of the Norwegian Sea, and in the Barents Sea. At the beginning of October the 0-group was numerous just outside the entrance of the fjords in the Røst-Torsvåg area. Off the northernmost district, Finnmark, the herring were a mixture of the 0- and I-groups, which were also observed around Bear Island and in the Barents Sea, especially in the eastern and southeastern part of the sea. During the second half of October schools, mainly of the 0-group, which were located near the coast, migrated into the fjords and became available to the fishing fleet. 2. The temperature was high just outside the entrances of the fjords, decreasing inwards. During the immigration the herring thus moved towards lower temperature. During the winter 1960-61 the herring stayed in the fjords, being found in areas with low temperatures, except in some fjords in Troms ( e. g. Ullsfjord), where the herring were found in a warm, intermediate layer. During the spring the herring left the fjords, earlier in Troms than in Finnmark. 3. In seven localities (Table 1) a total of 7800 herring (6800 of the 0-group and 1000 of the I-group) was tagged with internal steel tags. No recaptures have been reported from the taggings in the Barents Sea (Sørdjupet and Skolpenbank NW) and off Bear Island. The recaptures from taggings in the Ullsfjord-Lyngenfjord and Varangerfjord areas were all taken near the tagging localities, the fishing mortalities of the tagged herring being 20.6 % and 15.5 % respectively.