R&D efforts to manage and restore sea cucumber populations underway

This article was published on BAR Chronicle of the Bureau of Agricultural Research for April 2010 Issue – Volume No. 11 Issue No. 4. I also submitted as an entry and won the Best National Feature Story 2010 for the 4th Brightleaf Agriculture Journalism Awards held at Sunset Pavilion, Sofitel Hotel Manila.

“Ugly as you may see it but sea cucumber is a delicious and nutritious delicacy” said Dr. Marie Antonette R. Juinio-Meñez, professor from the Marine Science Institute, University of the Philippines Diliman (UP-MSI) and a project leader of a sea cucumber research program based in Bolinao, Pangasinan.

Sea cucumbers which are locally known as “balat” are soft-bodied tubular invertebrates that live in the bottom of coastal waters. Like earthworms, they are important in the cycling of sediments and nutrients in marine ecosystems.

These bottom-living animals are considered a great delicacy in Chinese and other Asian cuisines, such as Malaysia (gamat), Singapore, Japan, Korea and Indonesia (trepang), and often eaten in feasts and holiday celebrations. Sea Cucumbers are also considered a delicacy in certain Mediterranean countries such as Spain.

Aside from being delicious and nutritious, sea cucumbers are also valued for their medicinal properties. In the Chinese medicine, sea cucumbers are good for nourishing the blood and vital essence, kidney disorders including reproductive organ problems, debility of the aged, constipation due to intestinal dryness, and the problem of frequent urination.

Sea cucumbers are also called a tonic food because of their high protein and low fat contents than most of the other food served in restaurants. That’s why dried and extracted sea cucumbers are used as a nutritional supplement and now come prepared in tablet and capsule form.

With their high market demand, sea cucumbers are a major fishery and export commodity in the fisheries sector.

In the Philippines, there are over a hundred species of sea cucumbers and about 40 species are reported to be commercially important. Production of sea cucumber relies solely on wild catch. However, most of the wild populations have been over-harvested or depleted resulting to a reduced biodiversity and the loss of an important source of livelihood for fishers. This translates into multi-million losses in both export and local markets.

To help address the problem of rapid depletion of sea cucumbers and other echinoderms, the Bureau of Agricultural Research (BAR), together with the experts from the UP-MSI, embarked on a project titled, “Refinement of sea cucumber (Holuthuria scabra) culture techniques and assessment of co-culture system for commercially important echinoderms.”

The project aims to improve the hatchery and the field grow-out methods to increase survivorship of cultured H. scabra or sandfish locally known as “putian”. It also aims to contribute to the development of environment-friendly mariculture methods and subsequently expands the options available to the local aquaculture industry.

In the first year of the project, successful spawning trials were carried out using broodstocks from Bolinao, Pangasinan and Masinloc, Zambales producing a total of 175,000 juveniles that were used in various experiments while 30,000 larger juveniles were released in the pilot sea ranching sites.

Furthermore, the project also assessed different food types to determine the best diet to improve growth and survivorship of early juveniles that led to the identification of a brown seaweed, commonly known as Sargassum, as an effective diet for sea cucumber juveniles to grow faster due to its high nutrition content.

Generally, this project has gone through important steps to manage and restore the depleting populations of sea cucumbers, said Dr. Meñez. Through this project, one of the high-valued species of sea cucumbers can now be bred in captivity with broodstock collected in the wild. Adults are induced to spawn with thermal shock. In hatchery tanks, the fertilized eggs are reared. Juveniles are reared in ponds and in ocean nursery systems to about 5g and then released in sea ranch until they attain the desired market sizes, she added.

Dr. Meñez also explained that this project is part of a broader national research program entitled “sea ranching and restocking of Sandfish in Asia Pacific” supported by the Department of Science and Technology (DOST) through the Philippine Council for Marine and Aquatic Research and Development (PCMARD), and the Australian Center for International Agricultural Research (ACIAR) through World Fish Center. This program is developing culture and resource management technologies to restore natural populations of sea cucumber not only in the Philippines but also in other regions in the Asia Pacific to provide sustainable supplemental livelihood for poor fisher families.

According to Dr. Meñez, research and development in culture technologies for commercially important invertebrates like sea cucumber is very important not only to increase its production and ease the harvest pressure in the wild, but also to enhance the country’s ability to capture the international market demand, and supply a highly valued, in-demand marine resource – the sea cucumber.(Edmon B. Agron)