Long-Term Movement Patterns and Habitat Use Of Nearshore Groundfish: Tag-Recapture in Central and Southern California Waters

ABSTRACT

We conducted a mark-recapture tagging study evaluating long-term movement patterns and broad-scale habitat use by groundfish off southern and central California. Thirty-two species (32,366 fish) were tagged in nearshore and offshore island areas from Point Estero, California to the U.S. – Mexico border during 253 chartered fishing trips over 4 years. There were 1,569 (4.9%) tag recoveries with recorded days at liberty (DAL) ranging 0 – 2,603 days (mean 288 d). Observed capture and handling mortality was 1,532 fish (4.52%). Median recovery straight-line distance was 5 km from original tagging site for all recaptured fish; 64% of all recaptures were greater than 100 DAL. Recovery distances of 50 km or more were observed for 51 fish among nine species. Longest minimum distances recorded were 510 km (342 DAL) by a mature olive rockfish (Sebastes serranoides) and 488 km (1,222 DAL) for an immature copper rockfish (S. caurinus). The two greatest DAL were for a brown rockfish (S. auriculatus) recaptured at 2,603 DAL and 3 km from tag/release site and a California scorpionfish (Scorpaena guttata) recaptured at 2,126 DAL and 0.3 km from tag/release site. Tag recoveries, though obtained primarily in recreational fishing locations, were not spatially restricted indicating the importance of rocky reef habitat and may reflect the extent of fishable, quality habitat in southern California waters. Large sample size and tag recoveries indicate use of multiple groundfish habitats and greater movement than previously suspected.