Research and Development on Strategies of Sea Ranching and Stock Enhancement (click titles below to expand/collapse)
Stock enhancement of sea cucumber Holothuria scabra
Research Institute of Aquaculture 3 in Vietnam:
300 broodstock have been collected and stocked for spawning. 55,000 juveniles (2-5 g) were produced, and 3,000 of them were released into Nha Trang Bay.
SEAFDEC/AQD-UPV:
Broodstock sourcing
Potential sources of broodstock of Holothuria scabra were surveyed in Nueva Valencia, Guimaras. There was rare encounter of adult sized H. scabra (density =1 per hecare) and absence of juveniles in seagrass meadows around the SEAFDEC Igang Marine Station. Thus, Igang could be a potential site for stock enhancement activities.
Broodstock for spawning trials in Tigbauan Main Research Station was collected in Panobolon Island where significant number of adults and juveniles (Density= 45 per hectare) was observed
Pilot production of H. scabra juveniles
Hatchery-produced juveniles
A 25 sqm hatchery was allocated for pilot production of H. scabra juveniles. A total of 1.5 million auricularia (larvae) from 5 separate spawning trials between June 2007 to January 2008 were reared up to post settlement. Larval survivorship averaged 72% (range:52-91%) to competent stage. Mean percentage metamorphosis to pentactulae was 37% (range: 19-60%) while juvenile yield averaged 0.5% about a month after start of rearing.
Over 11,000 visible juveniles (<5mm length) have been produced from 5 batches. Juveniles were subsequently used for various experiments to shorten the land-based nursery period given the space requirement for sandfish nursery. By end of March 2008, some 450 juveniles (>20mm, 0.3g up) were used in experimental transfer to sea pens in Igang Marine Station.
Proposed Activities for 2008
Stock enhancement of sea cucumber Holothuria scabra
Studies on development of seed production method aimed for stock enhancement will be mainly implemented in the Research Institute of Aquaculture 3 in Vietnam. Information exchange of seed production technologies will be promoted between Vietnam and SEAFDEC/AQD.
Nursery system in pond for bigger size for release will be refined.
Suitable release strategies for stock enhancement of sandfish will be developed.
Technology information exchange and training on stock enhancement of sea cucumber Holothuria scabra will be promoted.
