Harvest of settlement stage reef fish for small-scale grow-out or stock enhancement: a feasibility study on the family Haemulidae

Abstract

Mortality rates of reef fishes are typically very high in the first few weeks after settlement. Capture and release of reef fish before or shortly after settlement may provide an opportunity to increase survival. Increasing survival at this stage could be a sustainable way of increasing fisheries resources. visual censuses of juvenile grunts (Haemulidae) during settlement pulses from January to March 2001 and July to September 2001 in Tortola, British Virgin Ilands were used to estimate local post-settlement mortality rates on a back-reef, seagrass/sand halo area. Concurrently, settling haemulids were capture from another location and reared in aquaria and sea cages. For fish smaller than 15 mm TL, aquarium-based rearing trials were used to compare the efficacy of feeding with wild-caught plankton or feeding with brine shrimp nauplii. Internally lit sea cages were tested against a plankton-pump food-delivery system for fish larger than 15 mm. Fish growth rates were rapid and mortality rates in sea cages were low for fish greater than 15 mm in size. Results are discussed in relation to potential applications for stock enhancement or mariculture.