Stock Enhancement of Threatened Species in Southeast Asia

Abstract

Natural populations of global inshore fisheries are coming under heavy pressure, primarily due to overexploitation and habitat degradation. Stock enhancement of hatchery-reared seeds is perceived as an alternative strategy to enhance the regeneration process. The Aquaculture Department of the Southeast Asian Fisheries Development Center in the Philippines has been implementing activities related to stock enhancement of donkey's ear abalone (Haliotis asinina), mud crabs (Scylla spp.), giant clam (Tridacna gigas), and seahorses (Hippocampus spp.). Seed production techniques for abalone including a diet tagging method were established, and juvenile abalone were released and monitored in a marine protected area. Mud crabs conditioned before release had higher recapture rates compared to the non-conditioned crabs, which can be translated to higher survivorship. Giant clams stocked at 8–10 cm shell length have high survival 4 mo after stocking (90%), with initial mortalities occurring within the first few days due to transportation stress. Seed production trials for seahorse have begun.

Keywords:

• SEAFDEC-AQD
• restocking
• mud crab
• abalone
• giant clam
• seahorse

ACKNOWLEDGEMENTS

We thank Mark Dimzon, Jeff Bogart Abrogueña of SEAFDEC AQD, and the staff of Sagay Marine Reserve for their valuable help. The studies conducted in AQD mentioned in this article were financially supported in part by the Japanese Trust Fund, International Foundation for Science, Sweden and the Philippine Government.