Reference | Leber, K. M., S. M. Arce, D. A. Sterritt & N. P. Brennan. 1996. Marine stock-enhancement potential in nursery habitats of striped mullet, Mugil cephalus, in Hawaii. Fishery Bulletin 94:452-471. |
Abstract | Declines in world fishery landings have prompted new interest in the use of cultured fishes to help replenish depleted fish populations. The hypothesis that hatchery releases can increase population size has at least two corollaries that need to be tested: 1) released cultured fish survive, grow, and contribute to recruitment; and 2) cultured fish do not displace wild stocks. The former corollary is considered here for striped mullet, Mugil cephalus L., in nursery habitats. Results from pilot experiments were used to modify release strategies to test marine stock enhancement potential in Kaneohe Bay, Hawaii. Of 80,507 native, cultured, striped mullet fingerlings tagged with coded wire and released during spring and summer, 2,642 fish were recovered by cast-net sampling during 11 months. Recapture rate increased 600% compared with initial studies in Kaneohe Bay. This increase was the result of confining releases to the vicinity of fresh-water streams and of imposing a minimum size of 70 mm TL during summer releases. After 11 months, cultured fish represented 50% of the striped mullet in collections at the release site, 20% in a nursery habitat 1 km to the north, and 10% in a nursery 3 km north. The location of releases (stream mouth vs. upstream lagoon) significantly affected dispersal patterns but did not affect growth or recapture rate. This study corroborated earlier results which showed that the smallest fish released (45-60 mm) could survive relatively well if released in spring. At least three measures were needed to describe hatchery effect: 1) hatchery contribution (% cultured fish in samples), 2) catch per unit of effort for cultured and wild striped mullet, and 3) recovery rate (no. captured/no. released). This study documents that survival of cultured fish in coastal nurseries can be significantly improved by using information from pilot release experiments to revise release parameters. |
Tag | Coded Wire Tag (CWT) |
Objective | Evaluate stocking programs |