Sea cucumbers: an economic savior

Sea cucumbers are in high demand both as a source of food and for their reported medicinal qualities. They are also a critical source of cash income for many poor and remote coastal communities throughout the Asia Pacific region. However, their high value has led to their over-exploitation, with sea cucumber fisheries in crisis globally.

While wild stocks of sea cucumbers are diminishing, there is growing excitement about the prospect of commercially cultivating one of the most desirable tropical species: Holothuria scabra, or sandfish as it is commonly known. Since the mid 1990s, the Australian Centre for International Agricultural Research (ACIAR) and the WorldFish Center have been investing in sea cucumber cultivation research in Vietnam, the Philippines, Solomon Islands, New Caledonia, Fiji and Australia.

Current projects focus on hatchery culture, techniques for releasing sandfish into the wild, and sea ranching and pond culture in the Philippines, Vietnam and northern Australia.

Besides the supplementary income derived from sandfish harvesting, the project’s participating communities in the Philippines have benefited from new knowledge and skills, the opportunity to share what has been learned, and the use of sea ranching to improve the management of fisheries for future generations. Perception surveys conducted after 3 years indicate that, despite the challenges, communities are willing to continue with sea ranching activities and would also like to see them institutionalized by their local government body, even when the project ends.

Research in Vietnam, which concentrates on pond aquaculture, using ponds previously used for shrimp farming, has helped simplify hatchery and breeding techniques, making the breeding system easier to adopt in developing countries.

“The aim is to ensure all levels of sea cucumber cultivation can be undertaken at a community level, maximizing the benefit to communities,” said Dr. David Mills, a WorldFish scientist who overseas ACIAR’s cucumber research. “Key achievements have been the adoption of simple algal paste coatings to promote settlement of larvae on plastic plates, and a refinement of algae food sources for the larvae and juvenile sea cucumbers.”

The benefits of sea cucumbers as an alternative to shrimp and also when grown in rotation with shrimp is also being evaluated. Sea cucumbers clean the ponds, which can become sludgy and toxic if used consistently for shrimp production.

“They [sea cucumbers] have a positive environmental benefit,” says Dr. Mills. “Disease can also cause two out of three shrimp crops to be lost, but growing alternate crops of shrimp and sea cucumbers may be able to help reduce the disease risk.”

Both benefits have the potential to extend the lifespan of ponds, which are otherwise rebuilt every 10 years or so. This is important because sensitive coastal habitats, including mangrove areas, are often cleared for the construction of new ponds.

Find out more in this recent ACIAR report on sea ranching

Picture courtesy WorldFish Center