Advances in marine stock enhancement: shifting emphasis to theory and accountability.

Abstract

Abstract After over a century of use in the United States, marine stock enhancement is still at an early stage of development as a fisheries management tool in coastal environments. The principal constraint to rapid development of enhancement's potential is clear - the rush to use stock enhancement, and use it now, has nearly always led to emphasis on hatchery production at the expense of developing the science of stock enhancement. Until we develop, test and demonstrate a clear predictive capability about the outcome of hatchery release effect, premature conclusions will prevail and continue to hamper the development of stock enhancement as a fishery management tool. Multidisciplinary teams are needed, coupled with an experimental approach and adaptive management to resolve critical uncertainties. Two of the most important uncertainties are 'does stock enhancement increase production' and, if so, 'is this at the expense of wild individuals'? The theoretical background needed to stimulate hypothesis testing has yet to be transferred from related fields, such as aquatic ecology and fisheries economics. Since 1989, development of stock enhancement theory has accelerated, based on several basic hypotheses, which are beginning to appear in scientific papers and symposia discussions. The basic hypotheses are now being tested by several research groups around the world, and the need for a responsible approach to enhancement has been recognized. Within the past decade, several new examples of effective stock enhancement have emerged, along with a cautious optimism about the potential to manage enhancement effectively. However, there remains a compelling need to identify research priorities to help focus global research on the key issues that will resolve critical uncertainties about stock enhancement potential.