The status of sea bass (Dicentrarchus labrax) stocks around England and Wales, derived using a separable catch-at-age model, and implications for fisheries management

The commercial fishery for sea bass (Dicentrarchus labrax) around the coasts of England and Wales developed rapidly in the late 1970s and 1980s and, by 1986, involved some 3000 fishers using more than 2000 boats to make landings worth <= 3-4 million. The estimated annual catch of sea bass by sport-anglers was similar to the level recorded from the commercial fishery. Sampling of landings showed strong evidence of growth-overfishing in many areas, and a package of technical measures was introduced in 1990 aimed at improving the exploitation pattern and yield per recruit. This paper describes how data collected through a fishery and biological sampling programme around England and Wales over the period 1985-2004 have been utilized in a separable catch numbers-at-age model to assess the dynamics of sea bass stocks in English and Welsh coastal waters. The model output shows that recruitment improved during the 1990s and that moderate levels of fishing mortality allied to an exploitation pattern that largely avoids juvenile fish have enabled the bass population and its fishery to develop sustainably. Results are discussed in relation to model development and management of the bass fishery.