Biological and economic implications of a multi-gear fishery for greenland halibut (Reinhardtius hippoglossoides)

Abstract

This paper focuses on the level and distribution of fishing mortality in a multigear fishery, and its effect on biological and economic parameters. The Greenland halibut stock in ICES Sub-areas I and Il is at a historically low level. Due to a lack of recruitment observed for this stock, and in order to have an increase in the spawning stock, a cessation of fishing has been advised. Since 1992 trawlers, and gillnet vessels and longliners larger than 90 feet have not been allowed to fish Greenland halibut as target species, but only as bycatch when fishing for other species. Gillnet vessels and longliners smaller than 90 feet have been allowed to participate in a directed fishery for Greenland halibut within a limited quota, a limited area and a limited period each year. This paper focuses on the economic yield one can expect from the Greenland halibut stock in ICES Sub-areas I and Il when gear specific selective properties are taken into consideration. The biological data were collected during a 1992- 1994 research programme using trawlers, longliners and gillnet vessels in a limited commercial fishery in the same geographical area, i.e., the historical most important fishing area. Quantitative effects of the three gears' different selectivity have been judged out from yield and spawning biomass per recruit (age 3). The profitability analysis of the different gears is based on prices and value of the catch and cost analysis of the fishery the last year of no catch-regulation (1991). Finally, the biological and economic analysis have been combined and evaluated together. The results may be used as guidelines for the management of the stock.