Estimates of movement and life-history parameters of yellowtail kingfish (Seriola lalandi): how useful are data from a cooperative tagging programme?

Abstract

Tag—recapture data for kingfish obtained from a cooperative tagging programme were used to assess the usefulness of such information for estimating movement and life-history parameters. Numbers tagged and recaptured varied among fishing zones, seasons and years. Recapture rates varied among areas, fishers and sizes of fish. Small fish showed less movement than large fish, but few fish >1000 mm TL were tagged. The majority of fish were recaptured within 50 km of where they were tagged, although there was an indication that fish that were at large longer moved further. The maximum distance moved was 3000 km and the maximum time at liberty was 1742 days. Quantitative analyses of life-history parameters from data collected in cooperative tagging programmes are generally not possible because there are usually no estimates of fishing effort, tag-related mortality and tag loss. These are likely to vary not only along the coast, but also among taggers. Cooperative tagging programmes provide some useful biological data (e.g.movement from point x to point y , and growth), but dedicated tagging programmes may be needed for estimates of other life-history parameters (e.g.mortality) and of abundance.