Abstract:
In this paper the Norwegian economic gains / costs of rebuilding the Norwegian spring-spawning herring (Clupea
harrengus) is analysed by including the effect of the herring stock on the cod (Gadus morhua) and capelin (Mallotus villosus)
fishery in the Barents Sea. The herring stock collapsed in the late 1960's and went through a rebuilding period until mid
1990's. The size of the herring spawning stock affects the productivity of cod and capelin. The effects are analysed by
combining the existing bioeconomic model for the Barents Sea (AGGMULT/ECONMULT) and a bioeconomic model for
herring in the Norwegian Sea. Two management strategies for herring are studied under different levels of cod TAC: 1) The
possible harvest control rule proposed by ICES (ICES), and 2) The herring stock is kept at a low level (Low). Present value
of contribution margin in the cod fishery and especially capelin fishery increases when the herring stock is at a low level. The
reduction of present value of the contribution margin in the herring fishery in the Low strategy causes the total contribution
margin to decrease compared to a large herring stock (ICES). In the low herring stock simulations a large herring fishery
takes place in the beginning to reduce the herring stock. If this fishery is not included, the difference in total contribution
margin increases a lot. Simulation results show that it is not economic optimal for Norway to reduce the herring stock and by
the increase the economic gains from cod and capelin fishery.
