By Roxi Aslan
Originally published at ScientificAmerican.com
When diving in the Blue Cavern Marine Protected Area off Catalina Island, you can’t help but notice the red-brown warty sea cucumber Parastichopus parvimensis, which lies conspicuously on the sea floor below. This creature (as do all members of the phylum Echinodermata) has the ability to regenerate parts of its body – for example, when physically threatened, P. parvimensis can expel a large component of its digestive tract (which, presumably will dissuade potential predators from eating the sea cucumber itself). Sound appetizing? I didn’t think so either.
In many parts of the world, however, sea cucumbers are a staple ingredient as well as important medicinal resource. And, as it turns out, California is one of the primary export fisheries for these organisms. With what started as a fledging fishery off Catalina Island in the late 1970s (on average, less than 50,000 pounds landed per year) is now a multi-million dollar industry with commercial landings exceeding 500,000 pounds on an annual basis.
Now that’s a lot of sea cucumbers! So where is this demand coming from?
I haven’t noticed sea cucumbers in my grocery market or on the menu at my favorite restaurants. Well, it turns out that the majority of warty sea cucumber (P. parvimensis), and California sea cucumber (P. californicus) landings are exported to China, Taiwan, and South Korea where they are marketed as a frozen, pickled, dried, powdered, and sometimes live product.
In Guam and Palau, where I will soon be traveling as part of an intensive 3-week ecosystem management field course offered by the USC Environmental Studies Program, sea cucumbers are often exploited for subsistence purposes. For example, on Guam both Holothuria atra and Stichopus horrens are consumed as a cheap and easily harvested source of protein. In one of the more egregious cases on the island, more than 11,000 sea cucumbers were harvested in a matter of weeks from a specific reef. Although consumed locally on Palau, a moratorium was placed on the commercial fishery nearly a decade ago as local sea cucumber stocks were on a rapid decline.
Until recently, Western medicine has been loath to recognize the medicinal properties of sea cucumbers. Natural products derived from these animals, which include saponins and chondroiton sulfates, are currently used as nutritional supplements as well as pharmaceutical products to treat a range of conditions including high blood pressure and arthritis. With numerous studies and research data validating the medical and health benefits of sea cucumbers, their use is becoming more common in the West. Thus, it comes as no surprise that Asian markets within the United States purchase a significant portion of the California sea cucumber fishery.
Given the demand for this marine resource it is imperative that we ensure that the commercial sea cucumber fishery is sustainable. As pointed out by University of Guam Professor Alex Kerr, “we must raise awareness and manage the population now or over-harvesting could quickly become an issue.” Although the long-term outlook for the global sea cucumber fishery is uncertain, a variety of ongoing management and research plans are in the works (both in California and abroad) to protect this valuable resource.
About the author: Roxi Aslan is a junior working toward a bachelor’s degree in biological sciences with a minor in environmental studies at USC Dana and David Dornsife College of Letters, Arts, and Sciences. She plans to pursue a career in biomedical research and hopes to hone her science diving skills in Guam and Palau this summer.
Ono, D., Rogers-Bennett, L., USA. California Department of Fish and Game Marine Region. Fish and Game Commission. Status of the Fisheries Report – An Update Through 2006. Ed. Kristine Barsky (2008)
Friedman, K., Kinch, J., Purcell, S., and Uthicke, S. “Population status, fisheries and trade of sea cucumbers in the Western Central Pacific.” FAO Fisheries and Aquaculture Technical Paper 516 (2008): 7-55
Kelman, B. 11,092 ‘balati’ gathered illegally. Guam Pacific Daily News. August 5, 2010
Borbar, S., Farooq, A., and Nazamid, S. “High-value components and bioactives from sea cucumbers for functional foods – a review.” Marine Drugs 9 (2011): 1761-805
Rising demand may threaten Guam’s ‘balati.’ Marianas Variety. June 25, 2010
Editor’s note: Scientific Research Diving at USC Dornsife is offered as part of an experiential summer program offered to undergraduate students of the USC Dana and David Dornsife College of Letters, Arts and Sciences. This course takes place on location at the USC Wrigley Marine Science Center on Catalina Island and throughout Micronesia. Students investigate important environmental issues such as ecologically sustainable development, fisheries management, protected-area planning and assessment, and human health issues. During the course of the program, the student team will dive and collect data to support conservation and management strategies to protect the fragile coral reefs of Guam and Palau in Micronesia.
Instructors for the course include Jim Haw, Director of the Environmental Studies Program in USC Dornsife, Assistant Professor of Environmental Studies David Ginsburg, SCUBA instructor and volunteer in the USC Scientific Diving Program Tom Carr and USC Dive Safety Officer Gerry Smith of the USC Wrigley Institute for Environmental Studies.