Establishment and management of communal sandfish (Holothuria scabra) sea ranching in the Philippines

Sea ranching of sandfish is being piloted as a means to enhance the recovery of depleted natural stocks and provide a supplemental source of income for artisanal fishers. Participatory and adaptive approaches were employed in the establishment and management of sea ranches to ensure that benefits accrue to both the ‘rights-holders’ and other community members. Three pilot sea-ranching sites have been established in north-western Luzon, the Philippines. The sites are managed by members of a local association of small fishers with the support of the municipal government, which granted limited exclusive-use rights to the sea-ranch managers. Each site was delineated into two major use zones: the 1-ha no-take release and nursery area, and the 4-ha reserve area. Multiple releases of cultured sandfish juveniles produced from local wild broodstock were conducted in the sites. Within 7–10 months, effective spawning populations were established in the sea-ranching sites when the density of reproductively mature (>200 g) individuals (ind) exceeded 100 ind/ha. Growth and survival rates were variable among sites. At the Bolinao sea ranch, the maximum estimated overall density reached 1,119 ind/ha, with an estimated survival rate of 39% after 19 months. Mass spawning of sandfish in the sea ranch further demonstrated that community-based sandfish sea ranching can help rebuild depleted wild populations. Among the major threats to sustainability are periodic poaching and storms, which reduce harvestable biomass and economic returns to the rights-holders. Sea ranching should be integrated within a broader fishery management framework to improve the management of sea cucumber fisheries.