Fangstsammensetning i snurpenotsteng gjort ved hjelp av kunstig lys i Hordaland og Sogn og Fjordane

Abstract

During the period 1964—69 investigations were carried out on the composition of fish species caught with purse seine for herring and sprat in Norwegian fjords. In the districts of Hordaland and Sogn og Fjordane on the west coast of Norway 70 catches were examined. The greater part of the hauls were made by artificial light during the months of August to November. Besides herring and sprat, 27 other fish species were found in the purse seine catches. Among these the most frequent species was whiting (Merlangus merlangus) which was found in most of the seine catches taken by artificial light. The number of whiting usually was from 20 to 50, sometimes even up to 300. In some deeper fjords on the west coast two other gadoid fishes. i.e. blue whiting (Micromesistius poutassou) and Norway pout (Boreogadus esmarkii) were common in catches taken by artificial light. In one single haul in the Osterfjord 2400 blue whiting and 6000 Norway pout were found. In the autumn of 1966 a large number of sand eels (Ammodytes lancea) were present in catches from the southern part of the area. This species seemed to be strongly attracted by artificial light, and up to 200 hectolitres could be caught in one night by a single boat. In the deep fjords the bycatches were generally small. Common food fish as cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) were only found in purse seine catches from closed inlets or in shallow and narrow fjords. Our material so far indicates that on the west coast of Norway the catches of other species than herring and sprat in the purse seine catches obtained by use of artificial light are not of such a quantity that they could be detrimental to other commercial fisheries.