Interactions between capelin (Mallotus villosus) and other species and the significance of such interactions for the management and harvesting of marine ecosystems in the northern North Atlantic

摘要

In the not too distant past the management of living marine resources was usually based on single species models where the key input parameters were overall stock abundance in number and weight at age, the biomass of the spawning stock, estimates of recruitment and natural as well as fishing mortalities. Furthermore, some account of likely changes in the physical marine environment in the immediate future, usually in terms of temperature and salinity variations, were considered on the assumption that in arctic and subarctic regions a warmer climate would favour the stock through increased bioproduction in general, while a cooler climate would have the reverse effect. Technical innovations in the fields of fish finding and catching in the last 30 years or so brought about a large increase in fishing mortality with regard to most if not all commercial species in the North Atlantic. On numerous occasions, we have witnessed the collapse of stocks, related to excess fishing, environmental variability or both.