Rational harvesting of the cod–capelin–shrimp complex in the Icelandic marine ecosystem

Abstract Environmental conditions in Icelandic waters are reviewed. The period from 1920 to 1964 was particularly warm in Icelandic waters and following this a sharp downward trend in temperature and salinity in both surface and intermediate layers was observed in all of the years from 1965 to 1971. From 1972 to 1996 cold and mild years have alternated and ice conditions generally improved from the preceding cold period. The cod catches have twice reached more than half a million tonne (early 1930s and mid-1950s). Both peaks were associated with immigration of strong year classes from Greenland. Other important demersal species are haddock, saithe, Greenland halibut and redfish. Only two pelagic species have been of importance in the Icelandic fisheries, i.e. herring and capelin. Catches of these species have fluctuated widely but in most recent years their yield has been in the range of one to one and half a million tonne. The fishery for northern shrimp has increased dramatically during the previous two decades. The management of marine resources in Iceland has varied over the years as have the methods for assessing the stocks. Recently, the emphasis has changed from simple stock assessments to the evaluation of harvesting strategies, which is seen as a part of a larger process, the comprehensive assessment. Important ingredients of such comprehensive assessments include risk analyses and multispecies considerations .