Information by Fishery
Commercial Sea Cucumber Dive Fisheries
The giant red sea cucumber (Parastichopus californicus) is the only commercially harvested sea cucumber in Alaska. The species is common in many nearshore areas from Baja California (Mexico) north and west to the Gulf of Alaska to at least Chignik where it inhabits a variety of intertidal and subtidal habitats to at least 816 ft (249 m) (Lambert 1997). Alaska’s largest fishery occurs in Southeast Alaska and a smaller scale fishery occurs in the Kodiak and Chignik areas (sea cucumber management activities map).
The red sea cucumber is a slow moving benthic detritus feeder. Ecologically, it functions as a bioturbator, ingesting significant amounts of fine substrate and recycling detritus into nutrients for primary producers in the marine food web. This species is most common in protected embayments on hard and sandy substrates, avoiding mud bottoms and areas with freshwater or glacial runoff. The species is an important subsistence food resource; traditional harvest methods include use of spears on long poles. Commercial harvesting is by divers, who deliver eviscerated but live animals to shore based processors. The animals are processed by hand by separating the five longitudinal muscles bundles from the skin with a scraper or knife. The skin is cooked or boiled and then dried into a product known as trepang or beche de mer. The frozen muscles and dried skin products are marketed domestically and in Asia.
The first commercial harvest of sea cucumbers was in 1983 in the Ketchikan area under an experimental harvest permit. The fishery accelerated beginning in 1986 (harvest, 1983-2002) with an influx of participants in southern Southeast Alaska, driven in part by increasing restrictions on harvests imposed by rapidly developing sea cucumber fisheries in Washington State and British Columbia. Harvesting peaked in 1989 with 2.3 million pounds of eviscerated product landed by 205 permit holders. The rapid expansion of the fishery in Southeast Alaska and the state’s lack of authority to control effort under the existing permit system led to closure of the fishery in May 1990. The fishery reopened in October 1990 following development of the Southeast Alaska Sea Cucumber Commercial Fisheries Management Plan, later adopted by the Board of Fisheries (5 AAC 38.140). This plan seeks to protect subsistence opportunities and provides for sustained commercial fishing harvests. The essence of that plan, requiring abundance surveys and maximum harvest rates, is in effect today.
Entry into the fishery was restricted by moratorium in 1996, with entry limited to 436 permit holders in 2000. This relatively large allowance for permits is over twice the 2004 participation. The limit was imposed based largely on overwhelming public opposition to open access, fearing further influx of participants.
An exploratory sea cucumber fishery began in the Kodiak area in 1991. The fishery peaked in 1993 with 564,000 lb (256 mt) harvested by 50 permit holders. Harvests then dropped steeply in subsequent years to a recent 5-year average of about 150,000 lb.
The Southeast Alaska sea cucumber fishery management plan (5 AAC 38.140) requires that harvest rates are based on a surplus production fisheries model, and parameters of the model are specified such that the annually-calculated harvest rate is 6.4% of the most recently estimated biomass. Biomass surveys are conducted by department divers prior to fishery openings in each management area, with areas opening on a 3-year rotational basis such that about one-third of approximately 46 areas are open each year, beginning in October (Please see our area rotation maps: Sea Cucumber Fishery Area Rotation Overview (PDF 2,747 kB), Sea Cucumber Fishery Area Rotation – Northern Southeast (PDF 2,894 kB), and Sea Cucumber Fishery Area Rotation – Southern Southeast (PDF 3,611 kB) for more information). The 3 year rotation was put into place as a means of reducing management costs for surveys and management, and not as a method to allow stock rebuilding between harvests. The plan also identifies several areas closed to commercial sea cucumber fishing in order to provide for subsistence harvests and research sites (Please see our area status maps: Sea Cucumber Fishery Area Status Map 1 (PDF 678 kB), and Sea Cucumber Fishery Area Status Map 2 (PDF 666 kB) for more information).
Kodiak area harvests are managed using separate GHLs for 8 areas corresponding to Tanner crab management areas. GHLs are set each season depending on fishery performance as measured by catch rate information obtained from logbooks. Recent experimentation with drop video cameras has shown promise for remotely assessing sea cucumber densities but the methods are still under development. Recent (2004/05) season GHLs have totaled 150,000 lb. The Chignik harvest is limited to a GHL of 25,000 lb, and the Alaska Peninsula, Aleutian Islands, and Bering Sea each have GHLs of 5,000 lb to allow for exploratory fishing.
Sea cucumber harvesting is restricted to hand picking. Divers use scuba or surface supplied air and gather the animals in mesh bags for transport to the surface.
Recent Harvest and Status
Statewide harvests have averaged slightly over 1.6 million lb per year taken by 229 divers. Harvests in Southeast Alaska have stabilized at around 1.47 million lb per year with about 210 divers participating. Kodiak area harvests have averaged around 153,000 lb in the past 5 years with an average of 19 participants. (harvest, 2000-2004).
Conservation and Other Issues
Commercial harvests of sea cucumbers in tropical areas of the Pacific and elsewhere have generated concerns for over harvest. It was recognition of these and similar concerns that led the department to impose a conservative management program in Southeast Alaska, requiring stock assessments prior to harvests. Commercial divers in Southeast Alaska have expressed concerns that favorite harvest areas are not recovering between each 3 year rotational harvest. These highly localized depletions, occurring principally in areas offering some protection from inclement fall weather and sea conditions, would not be expected to recover during the three year management cycle given the slow growth rates and sporadic recruitment of sea cucumbers. The goal of the current management approach is to provide sustained harvests over larger areas of approximately 100 km of shoreline. An alternative management strategy will be needed if concerns of highly localized depletions are to be addressed.
[Based on excerpts from the publication, Commercial Fisheries in Alaska, Woodby et al. Alaska Department of Fish and Game, Special Publication 05-09, June 2005 (PDF - 1,059K). Information or data on this web page may have been updated and may no longer match the original publication.]