Management of summer-spawning herring off Iceland

The Icelandic summer-spawning herring stock collapsed during the late 1960s as a result of a combination of high fishing pressure and deteriorating environmental conditions. Following a moratorium on fishing the stock, a small fishery of about 10 000 t started in 1975. From analyses of several harvesting strategies it was decided to recommend fishing at or near F 0.1 . When the fishery was reopened it was managed by individual non-transferable quotas per boat that gradually developed into an individual transferable quota (ITQ) system. The development, the implementation, and the effect of the harvesting strategy and the management system are discussed and evaluated. Results indicate that a strategy of catching 20% of the adult stock biomass (3-ringers and older) would be useful from the point of view of achieving an optimal sustainable harvest from the stock without risking stock depletion. This is not markedly different from the current exploitation strategy, which has now been very successful for almost a quarter of a century.