Reference |
Leber, K. M., N. P. Brennan, and S. M. Arce. 1995. Marine enhancement with striped mullet: are hatchery releases replenishing or displacing wild stocks? American Fisheries Society Symposium 15:376-387. |
Abstract |
The hypothesis that marine hatchery releases can increase
fish abundance has at least two corollaries that need to be tested: (1)
cultured fish can survive and grow when released into coastal environments;
and (2) cultured fish do not displace wild individuals. Both are being
tested in Hawaii. The present study was conducted to evaluate whether
hatchery releases of striped mullet Mugil cephalus actually increase
abundances or displace wild stock. In summer 1993, 5,811 wild striped mullet
nursery habitats within the bay to evaluate pretreatment dispersal of wild
fish. Following those initial collections, cultured striped mullet were
released to establish the primary treatment condition, a hatchery release. A
total of 29,354 cultured striped mullet were tagged and released, but at
only one of the nursery sites (treatment site). Monthly monitoring was
conducted over an 8-month period to determine if there was greater dispersal
of wild fish at the treatment site. There was no significant difference in
the dispersal rates of wild fish from the treatment site compared with the
control (no hatchery release) site. As expected, based on earlier pilot
hatchery releases, a majority of tagged and released cultured and wild
striped mullet remained within those nursery habitats where they were
released. Hatchery releases in this study did not result in displacement of wild individuals from the principal nursery habitat in Kaneohe Bay. The cultured fish released there increased abundances of striped mullet at the treatment site by around 33%. Thus it appears that even small-scale releases could help replenish the depleted striped mullet fishery in Kaneohe Bay; conducting small-scale hatchery releases in several nursery habitats in Kaneohe Bay should increase overall stripe mullet abundances in this estuary. This study also corroborated earlier experiments in Hawaii showing a direct relationship between fish size at release and recapture rate. These results indicate hatchery releases can increase abundances of targeted inshore fish populations in Hawaii. If a careful approach is used marine stock enhancement appears to have considerable potential as an additional fishery management tool. |
Tag |
Coded Wire Tag (CWT) |
Objective |
Evaluate stocking programs |
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