Enhancement of marine fisheries resources.

Many exploited stocks of aquatic organisms are limited by the supply of juveniles and many also suffer from recruitment overfishing. Consequently, there is much interest in stock-enhancement programs, which are aimed at improving harvests by increasing recruitment to levels approaching the carrying capacity of the habitat. Most stock-enhancement programs involve the release of juveniles reared in hatcheries or the collection, rearing, and transplantation of wild juveniles. Optimized release strategies and increased fitness for life in the wild are required. The effects of stock enhancement can be measured by marking released juveniles to distinguish them from wild stock, or by large-scale sampling of the target population and of unenhanced control populations. Several programs for stock enhancement of demersal marine species have documented encouraging rates of survival of released juveniles and are reported to be economically viable. In other cases, high production costs for producing juveniles, or low survival rates, indicate that stock enhancement is not a viable option. Careless enhancement programs could diminish the diversity of a species’ gene pool, introduce diseases, and alter the structure of communities. Decisions to use stock enhancement should be based on thorough pilot studies, including analyses of the range of projected economic and social benefits.


Munro, J.L., Bell, J.D. (1997)
Reviews in Fisheries Science 5(2):185-222