The non-returning of fish tags recovered by Norwegian fishermen

In addition to 5 N.Kr. reward for each returned cod, coalfish, haddock, halibut and catfish tag, Fiskeridirektoratets Havforskningsinstitutt introduced in 1959 an annual drawing of 1000, 500 and 250 N.Kr. for tags, Norwegian and foreign, returned by Norwegian fishermen. The extra reward system was in use during 1959-1961. After the extra rewards were introduced, the reporting rate of tags returned the same year as recovered and one or more years afterwards has increased. The non-returning rate of tags recovered by Norwegian fishermen in 1947-1957 was estimated to be at least 4-6 percent and the indication from the calculations is that the non-returning rate is decreasing with the continuous advertising and with people in the fishing ports to receive the recovered tags

Pre-recruit studies of the North-East Arctic Greenland halibut stock

Precision and relevance of pre-recruit studies for fishery management related to fish stocks in the Barents Sea and adjacent waters. Proceeding of the sixth IMR-PINRO Symposium Bergen, 14-17 June 1994Abundance indices of 0-group Greenland halibut (Reinhardtius hippoglossoides) from the international 0-group surveys in the Barents Sea showed a sudden decrease from 1987 to 1988 to a low level which has remained for the last 5-6 years. The strength of these weak yearclasses has been confirmed in later youngfish surveys, and this has caused strong regulations of the fishery at a time when the fishery itself was good. The drop in recruitment is discussed and related to a reduction of the spawning stock

Seleksjonsforsøk med torskeruser

The selection of cod in trap-nets made of cotton has been studied on the fishing localities and in an aquarium. Most of the calculations are made on data from aquarium experiments with five different mesh-sizes. The selection ranges were 2-5 cm, and the mean selection factor calculated from the mesh-size and the length in the middle of the selection range was 4,1

Pre-recruit studies of the North-East Arctic Greenland halibut stock

Abundance indices of 0-group Greenland halibut (Reinhardtius hippoglossoides) from the international 0-group surveys in the Barents Sea showed a sudden decrease from 1987 to 1988 to a low level which has remained for the last 5-6 years. The strength of these weak yearclasses has been confirmed in later youngfish surveys, and this has caused strong regulations of the fishery at a time when the fishery itself was good. The drop in recruitment is discussed and related to a reduction of the spawning stock