Welfare Issues Related to Fish Stocking

The process of stock enhancement, where large numbers of fish are reared and then released, is an increasingly common practice aimed at improving the numbers of fish in rivers, lakes and along coasts. Stock enhancement practices, however, raise a number of welfare issues both for fish that are reared within captivity, and for the local populations and habitats that are in contact with fish rearing and release activities. In this presentation we highlight examples that illustrate how captive rearing of fish can directly affect fish welfare; in terms of husbandry and health care in the hatchery, the interactions between captive reared and wild fish, and survival of fish released for stock enhancement. Currently, relatively little attention is given to promoting the behavioral development of fish in hatcheries, yet to survive in a changeable natural environment fish need to be able to respond by adapting and changing their behavior. We will suggest some simple techniques that could be adopted within the hatchery to help promote behavioral flexibility in captive reared fish. While awareness of fish welfare is certainly growing, so is the rate at which we rear fish in captivity, there is therefore a pressing need for us to understand the welfare issues that are affected by fish rearing and stock enhancement.