44 JUNE 2014 • WORLD AQUACULTURE • WWW.WAS.ORG Socioeconomic Aspects Sea cucumber fisheries represent an important livelihood for many fisher groups and coastal communities around the globe. Sea cucumbers, as sedentary benthic animals, are easily collected in the lower intertidal or shallow subtidal by hand with no specialized harvesting equipment required, other than snorkel or dive gear and boats for deeper subtidal harvesting. Because the collection of these animals may be accomplished with relatively little capital, specialized skills or equipment, the fishery in certain parts of the world is open to people with a diverse range of age, skills and economic status. The California sea cucumber has been a traditional food of First Nations people along the northwest coast of North America including southern Alaska since at least 1804 (Bruckner 2005). Sea cucumbers are of continuing importance to coastal First Nations people in Canada, who harvest them for food and ceremonial use (DFO 2002). The California sea cucumber is a small but important component of commercial dive fisheries in Alaska, BC, Washington, Oregon and California, where it is harvested for its muscle bands and skin. The first commercial California sea cucumber landings were reported in 1971, with harvests remaining relatively small until the early 1980s (Muse 1998, Humble et al. 2008). Commercial markets for P. californicus exist in Asia and larger North American cities such as Vancouver (BC), New York and San Francisco (USA) (Bruckner 2005, Hamel and Mercier 2008). In Alaska, until the early 2000s, meat strips were sent to China and Hong Kong, and skins were shipped to Taiwan. In the USA, the export value of raw unprocessed Parastichopus spp. was US$ 0.07/kg in the early 1980s, increasing to US$ 0.82/kg by 2005, while processed sea cucumbers sold for up to US$ 9.00/kg (Bruckner 2005). In Canada in 2011, 616 t split weight of P. californicus were fished, worth approximately US$ 7.6 million (DFO 2013). (Splitting is a process where sea cucumbers are cut longitudinally to remove water and viscera.) In BC, the price paid to harvesters of California sea cucumbers has more than doubled since 2008. The average price was US$4.75/kg in 2008 and US$11.55/kg in 2012 (DFO 2013). In North America, processing of sea cucumbers is generally carried out in a processing plant. Hamel and Mercier (2008) reported that a fishing industry for sea cucumbers Cucumaria frondosa in New Brunswick (Canada) employs as many as 120 people during the fishing season. This indicates that farming of sea cucumbers could be a viable option for income generation and employment for residents of coastal communities, including First Nations. Technical Aspects As fishery catches plateau or decline for many sea cucumber species, the focus worldwide has been on increasing production through aquaculture or wild-stock enhancement programs. Holothuroid aquaculture and sea ranching or stock enhancement are already practiced successfully in Japan and China with various species. In China, sea cucumber aquaculture has expanded at such a pace that production of the temperate species Apostichupus japonicus exceeds 90,000 t/yr, surpassing production from capture fisheries (Gao et al. 2011, Robinson 2013). Although there is considerable commercial and First Nations interest in California sea cucumber aquaculture on the west coast of Canada and the USA, little research has been published on the subject. One of the major areas of inquiry needed for domestication or farming of any candidate species is development of hatchery production technology. Information on optimum culture parameters for producing high-quality juveniles or seed with the greatest growth and survival rates per unit of culture effort is critical for sustainable aquaculture development of the species of interest. Reliable techniques for hatchery production have been developed for relatively few species of holothuroids and there are no rearing protocols specifically applicable to the California sea cucumber. Broodstock conditioning, spawning induction, larval rearing, larval settlement / metamorphosis and early juvenile rearing are critical factors for successful hatchery operation of any cultured species, but little information is available on these topics for P. californicus. As a first step in evaluating the suitability of California sea cucumbers as a mariculture species, various hatchery production techniques were examined at the Centre for Aquaculture and LEFT, FIGURE 3. Early auricularia larvae of California sea cucumber. RIGHT, FIGURE 4. California sea cucumber larvae at different developmental stages.
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