Title: Exploitation and conservation of Norwegian spring-spawning herring: Open acess versus optimal harvesting strategies

Authors: Virpi Junttila, Marko Lindroos and Veijo Kaitala

Status: Systems Analysis Laboratory Research Reports E1 October 1999

In this report we study a three-fleet bioeconomic model of the Norwegian spring-spawning (or Atlanto-Scandian) herring fishery. The biological model is described by a discrete time age structured model. The economic model is based on constant price and log-linear costs. We study the optimal mix between the three fleets from the viewpoint of a single exploiter of the herring stock. In addition, we study several adaptive strategies of the fleets. We show that adaptive strategies based on spawning-stock biomass (SSB) produce largest economic rents for the fishery. Further, we show that open access leads to stock extinction and zero profits after a period of 60 years.