Sea Cucumber Ecosystem Based Management Plan

Dive fisheries in Southern Southeast Alaska are important to the local area and have a significant impact that some people aren’t very aware of. With the increasing use of sea cucumbers in the past few years, it is important that there are plans to keep the populations up without harming or affecting the environment in a negative way.

Abstract

There is much research necessary for a full ecosystem-based management plan for the red sea cucumber dive fishery in Southeast Alaska. After conducting a case study at a local processor and analyzing various fishery-related and economic factors, our team confirmed the importance of this dive fishery to the economy of the region and came up with some ideas for a revised management policy after some research has been completed. A forum for local interest groups to have formalized input, as well as fishery enhancement and predator control are vital aspects of our proposed plan.

Background

Dive fisheries in Southern Southeast Alaska are important to the local area and have a significant impact that some people aren’t very aware of. With the increasing use of sea cucumbers in the past few years, it is important that there are plans to keep the populations up without harming or affecting the environment in a negative way. We felt strongly that more research needed to be done on sea cucumbers because it is a relatively new product that has come to Ketchikan and is a new way to help stabilize and further our economy. There are many companies and people in the world that use sea cucumbers in their daily lives. Subsistence users depend on the sea cucumbers that they can harvest and use, if the population were to decrease they would have to find an alternative source of food. Companies use sea cucumbers’ skins in various products, and the meat is packaged and sold to consumers. If they were to disappear, then the economy would probably suffer negative impacts.

Sea Cucumber Ecology

The red sea cucumber (Parastichopus californicus) is found only in the Pacific Ocean and can be found from Southern California to the Gulf of Alaska. It is the largest sea cucumber species in the Pacific Northwest at 50 cm in length and 5cm in width. They can be found from the low intertidal zone to a depth of 250 meters and are most abundant in places with low to moderate current and rocky outcrops. These areas have the most abundance due to organic matter known as detritus that accumulates on the bottom on which they feed. (http://www.dfo-mpo.gc.ca/species-especes/aquatic-aquatique/giant-red-sea-cucumber- eng.htm)

The red sea cucumber, also known as the California sea cucumber, has a soft cylindrical body and has leathery skin, which is usually red-brown to yellow. The red sea cucumber has 5 rows of tube feet that extend from the anus to the mouth, to which it uses to move around on the rocky bottom. The red sea cucumber feeds by sifting sediment through the tentacles located around their mouth. Unlike many sea cucumbers, the red sea cucumber does not store toxins in its body to fend off predators. (http://www.northislandexplorer.com/echinoderms/californiaseacucumber.htm)

When threatened by predators the red sea cucumber can expel its stomach contents through its anus. The hindgut of the sea cucumber has a pair of largely branched diverticula, which extend into the coelomic cavity and act as water lungs. Oxygenated water is pumped through these diverticula in several inhalations and expelled by one exhale. (Williams, Kelly, 2002)

The red sea cucumber has seasonal migrations to different depths caused by temperature and current changes. It takes four years for a sea cucumber to mature and they may live up to ten years. The red sea cucumbers eggs are fertilized externally through spawning. Spawning takes place during August where a single female can release thousands of eggs. (http://en.wikipedia.org/wiki/Giant_California_sea_cucumber) The fertilized eggs become planktonic larvae which metamorphose into adult sea cucumbers after a couple of weeks.

Current Sea Cucumber Fishery

The first commercial harvest of sea cucumbers was in the Ketchikan area in 1983 under an experimental harvest permit. The business lifted off officially in 1986 with a whole lot of people going after them. Harvests were at their pinnacle in 1989 with the disemboweled harvest mass equaling over two million pounds from only 205 permit owners. The fishery shut down in May 1990 due to the lack of control over harvesting. The fishery then opened back up in

October of 1990 after a management plan was set in place to protect the opportunities for subsistence harvesting and to provide continued commercial fishing. Getting into the fishery was cut off by suspension in 1996 with a limit of 436 permit holders in 2000. In 2004 the amount of people participating was nearly half that. (Fishery Commercial Sea Cucumber Dive Fisheries, 2011) The price of sea cucumbers per pound has been increasing, and in 2008-2009 it reached about $2.05 (Figure 1).

Figure 1: Sea Cucumber Historical Harvest Data courtesy of Alaska Department of Fish & Game

Current Sea Cucumber Management Plan

Under the Southeast Alaska sea cucumber fishery management plan, a maximum of 6% of the assumed biomass is the harvest rate limit to be conservative. To find the estimated biomass, Fish and Game department divers conduct surveys prior to the opening of fisheries in each management area. The areas are on a 3-year rotational basis so that out of about 46 harvest areas, only one-third are open every year on October 1st – March 31st. This 3-year rotational plan was created to reduce cost for surveys and management. It was not designed, however, with the thought of allowing the stock to rebuild between harvests. (Alaska Department of Fish and Game, 2011)

This plan does, though, have a limit of 1kg of sea cucumbers for every linear meter of shoreline, as well as identifying 20 areas that prohibit commercial sea cucumber harvesting, and sites that allow research and subsistence harvesting. Sea cucumber harvesting is restricted to handpicking and limited to 2,000 lb. for individual divers per area. Also the divers are limited to two per boat and cannot use mixed gas in their tanks. This year’s winter season harvest areas are only open for two days (Monday from 8 a.m. to 3 p.m. and Tuesday from 8 a.m. to 12 p.m.) per week before moving to the next area. This is to help prevent over-harvesting in a certain area. On average, statewide harvests have reached just over 1.6 million lbs every year, and there are roughly 229 divers currently participating. In Southeast Alaska, harvests are stable at around 1.47 million pounds with about 210 divers. In fact, the Southeast holds the majority of divers for this fishery, 210 out of 229. The number of sea cucumber divers reached their peak in the years 1996-1997 at over 400 divers. Today the number has leveled out to just above 250 divers (Figure 2). (Alaska Department of Fish and Game, 2011)

Figure 2: Sea Cucumber Historical Harvest Information data courtesy of Alaska Department of Fish & Game

Figure 3: Sea Cucumber Historical Harvest Data courtesy of Alaska Department of Fish & Game

The Dive fisheries present in the graph above appear to be shaped in similar fashions, where the sea cucumber diver numbers increase, so do the number of divers in the geoduck and red urchin fisheries. They also tend to fall at the same points in time, and appear to have become some what stable.

Divers notice, quite unsurprisingly, that as catches increase, some local populations are decreasing, because it is more difficult to recover than before. There is a program conceived for captive breeding of sea cucumbers to help protect wild stocks and make the fishery more sustainable. (Alaska Department of Fish and Game, 2011) Alaska is able to capitalize on the knowledge from other sea cucumber fisheries around the world.

In tropical areas of the Pacific, commercial harvesting of sea cucumbers has raised concerns around over harvesting of the population. These concerns led to a conservative management plan in Southeast Alaska. The plan requires an assessment of stock before harvesting. Divers in the area express their concerns that their favorite areas to harvest are not recovering within the rotational three year harvest guidelines. Localized depletions that occur in prime locations are not expected to recover with the three-year management cycle due to the slow growth and sporadic recruitment of sea cucumbers. The current management approach from Alaska Department of Fish and Game, involves providing sustained harvests, over larger areas. An alternate strategy may be needed, they say, if concerns of highly localized depletion are to be addressed. (Alaska Department of Fish and Game, 2011) Figure 4 shows, that in some cases, the harvesters of sea cucumbers appeared to be impatient, and they overshot the legal amount of sea cucumbers that they were allowed to collect. Though nowadays they seem to be following the set amount strictly.

Figure 4: Sea Cucumber Historical Harvest Data courtesy of Alaska Department of Fish & Game

As far as an analysis of this plan goes, it can be clearly seen that it doesn’t accommodate for the other species in the sea cucumber’s environment and for physical factors such as currents. This plan also leaves out the potential importance of the various stages of the sea cucumber life cycle. Some things that can be worked towards in the management of this fishery are making a greater survey effort, tabulating catches, and gathering weight and size data. Monitoring stocks is also an important factor. Conducting biomass assessments and determining biological information is key in creating a harvestable surplus. It may also help to look at reviewing fishery and harvest trends and data.

Sea cucumber farming is becoming a more and more realistic alternative for increasing local stock. Southeast Alaska Regional Dive Fisheries is currently funding breeding research for this purpose. With sea cucumber trade to China growing more profitable, divers worry about the local populations. A captive breeding program was created to help expand, and protect the fishery in a manageable, sustainable way. The Chinese already aquaculture (or farm) sea cucumbers in huge artificial ponds, but the Alaskan species are more valuable because of their superior quality, size and nutritional value. (Tacio 2010) As you can see the value of fresh unprocessed sea cucumbers have been increasing exponentially over the years (Figure 5).

Figure 5: Sea Cucumber Historical Harvest Data courtesy of Alaska Department of Fish & Game

Sea Cucumber Dependent Industry in Ketchikan Alaska: A Case Study

In order to present a detailed example of how economics come into play in Southeast Alaska, our research team visited a local business that depends on the harvest of sea cucumbers. The sea cucumber harvest allows for the EC Phillips processing facility to have a year round staff that also deals with other aspects of seafood processing. If they did not handle the sea cucumber season, they would have to let go of, or layoff a significant amount of workers, according to the EC Philips plant manager. By including the sea cucumber harvest, they are able to keep a full workforce with out having to go find new people at the end of each season. This constantly present workforce was mentioned to be especially helpful in changing the equipment over in preparation for the next processing task.

In the EC Phillips processing facility the staff is split into three main sections. The people who unload cucumbers, people who process, and people who cook the sea cucumber skins. The people who unload the sea cucumbers put them into large bins and then take the bins to the processing line. On the processing line, the sea cucumbers are pinned to a cutting board and then split down the middle. After they are sliced opened, the people who process the sea cucumber use a specialized skinning knife to dislodge the meat inside a membrane stuck to the skin. After the sea cucumbers are skinned alive, the meat is swept away in a continuously moving flow of water. The water takes the meat to a specialized turner, usually used for caviar, were it is tumbled until clean. Once clean, the meat is then taken to the people that chop off any remaining pieces of skin. It is then weighed and put into vacuum pack bags and readied for shipment or sale. While the meat is being processed the skins are collected and brought over to the cookers. The cookers then cook the skin in giant specialized boilers for a set period of time, stirring them occasionally. They then store the skin in giant bins and mix them with salt. The skin is then ready for shipment and further processing for use.

Figure A: Salted sea cucumber skins at EC Phillips, Ketchikan, October 2011

After the workers separate the sea cucumbers meat from the skin, the skin is then cooked and put into bins full of salt for shipping.

Figure B: EC Phillips seafood processing facility in Ketchikan during a sea cucumber opening October 2011

The EC Phillips seafood processing facility employs workers year round. In the fall they employ a significant number of people just to handle the sea cucumber harvest.

Figure C: Sea cucumber processing at EC Phillips, Ketchikan, October 2011

When they unload the sea cucumbers from the fishing boats, the first thing they do is put them into bins and then take them over to the slime lines.

Figure D: Sea cucumber processing at EC Phillips, Ketchikan, October 2011

The bins have plastic lining them to make clean-up and storage easier.

Figure E: Sea cucumber dive boat offloading at EC Phillips, Ketchikan, October 2011

After the sea cucumbers are unloaded, the divers must clean the containers on the fishing boat and get it ready for the next harvest.

Figure F: Processed sea cucumber “meat” at EC Phillips, Ketchikan, October 2011

When the meat is separated from the skin, it is then put through a complicated cleaning process. Then its put into a little tray, were it is weighed, and packaged.

Figure G: Sealed sea cucumber “meat” ready for transport at EC Phillips, Ketchikan, October 2011

After being weighed the meat is then vacuum packed and boxed, ready for sale and shipment.

An Ecosystem Based Management Plan for Sea Cucumbers

The current sea cucumber management plan does include a comprehensive fishery based management plan but would be stronger if it included a formalized way to include economics. One way this could be improved is to have Fish and Game set a forum where people can file suggestions and complaints that pertain to the management plan. Another aspect that the current management plan does not include would be more ecosystem-based surveys. There are currently no baseline studies on factors contributing to the distribution of sea cucumbers, for example. (Walker 2011) What could be done is add more comprehensive environmental factors to surveys and include surveys of the other marine specimens in the area. In addition, studies should take note of any predators present in the area. They should also include things such as physical factors, for example how currents will affect the sea cucumbers’ food supply and how their spat is distributed. Another thing that could be taken into account is the subsistence gatherers and how their activities might impact such surveys.

Regulating authorities will need to have further studies on multiple factors before a concrete management plan can be put together. They will need to take into account what will happen if the climate changes. If the climate changed, then other things in the sea cucumber’s environment would change, such as the direction and strength of currents and salinity due to the melting or freezing of local glaciers. Research would need to be done on whether salinity changes would even effect sea cucumbers. After studies have been done on the biological effects of environmental change, researchers can move on to how the possibility of sea otters population increasing would affect sea cucumber numbers, habitat, and the broader economy, including sea cucumber processors like EC Phillips.

Surveys by the U.S. Fish and Wildlife Service have recently indicated that the sea otter population in Southeast Alaska is growing and is approximately around 20,000 individuals. Sea otters will instinctively eat any invertebrate they can catch. They are very efficient predators, needing over a quarter of their body weight in nutrition each day. In Southeast Alaska, their favorite snacks are sea urchins, sea cucumbers, and abalone, but they also eat geoduck, clams, and crab. These are all vitally important species to subsistence, personal use, and commercial fishermen. As the number of sea otters increase, we become more aware of the threat that their population has on the local fisheries, and it is now obvious that the impact is serious. (Tacio, 2011) To combat this growing problem regulating authorities should look into enhancement ideas, like gathering sea cucumber spat, and introducing it into areas where sea otters have come through.

The potential for enhancement of sea cucumbers has just recently become a realistic achievement and should also be seriously considered as a way of increasing the current population. The Alutiiq Pride Shellfish Hatchery, in Seward, Alaska has had recent success this year, and is expecting more than 100,000 juveniles from the first couple spawns, despite the fact that sea cucumbers are notorious for difficult transfers. (Smith, 2011) Sea cucumbers have a tendency to extrude all of their internal organs when under stress.

Other possibilities of managing the growth rate in the numbers of sea otters could also be explored. One way could possibly be to capture and detain some sea otters so they can be sterilized. Instead of hunted and destroyed, as sea otters are under the marine mammal protection act. Therefore experts should look into the possibility of birth control for sea otters, so that the populations are regulated and have a chance to increase just at a slower rate. As to minimize the affect of their growth will have on all types of marine animals. Though before any enhancement or birth control ideas are introduced, thorough studies of the impacts on the ecosystem should be conducted.

Another thing that could be explored in order to create an effective ecosystem based management plan is the effects that increasing or decreasing sea cucumber numbers would have on the sea cucumber processors, divers, and logistics companies, along with anybody that deals with sea cucumbers indirectly.

References:

  1. Alaska Department of Fish and Game. 2011; Commercial sea cucumber dive fisheries. 10/3/2011 http://www.adfg.alaska.gov/index.cfm?adfg=CommercialByFisheryDive.seacucumber
  2. Alaska Sea Grant. 2010. The Southern Southeast Alaska Sea Otter Project. http://seagrant.uaf.edu/research/projects/10/otter/
  3. Bowlen, Scott. December 3, 2011. Sea Otters….Ketchikan Daily News.
  4. Woodby, D., Carlile, D., Siddeek, S., Funk, F., Clark, J., & Hulbert, L. 2005. Alaska Department of Fish & Game Division of Sport Fish and Commercial Fisheries. Special Publication No. 05-09. Commercial Fisheries of Alaska.
  5. Freitag, Gary. October – December 2011. MAP Agent Alaska Seagrant. Robertson/Hamilton Technical Center, 600 Stedman, Ketchikan, AK 99901. (907) 228-4551.
  6. Mehen, Bob. 2011. Alaskan sea cucumber farming could help bolster native stocks. 10/6/2011 http://www.practicalfishkeeping.co.uk/content.php?sid=4181.
  7. Smith, Brian. 2011. Spawning a Sea of Possibilities? Peninsula Clarion. 11/14/2011 http://peninsulaclarion.com/news/2011-07-17/spawning-sea-possibilities?
  8. Tacio, Henrylito D. 2010. There’s big demand for sea cucumbers. 10/6/2011 http://www.agribusinessweek.com/theres-big-demand-for-sea-cucumbers/
  9. Tamone, B., Roemeling, E., Monkman, T., Connolly, J., & Kummins, K. 2011.The affects of sea otter (Enhydra lutris) reintroduction in Southeast Alaska on the dive fisheries of southern Southeast Alaska. 10/3/2011 http://seagrant.uaf.edu/nosb/papers/2011/juneau-otters.php/
  10. Walker, Scott. Alaska Department of Fish and Game – Commercial Fish Division. October, 11, 2011. 2030 Sealevel Drive, Suite 205 Ketchikan, AK 99901-6073. (907) 225-5195
  11. Walla Walla University. Williams, Kelly. 2002. Parastichopus californicus (Stimpson, 1857) http://www.wallawalla.edu/academics/departments/biology/rosario/inverts/Echinodermata/Class Holothuroidea/Parastichopus_californicus.html
  12. Woodby, D., Smiley, S., & Larson, R. 2000. Depth and habitat distribution of Parastichopus californicus near Sitka, Alaska. SARDFA Sea Cucumber Research Reports, Retrieved from http://gdyn.sardfa.org/species/sea-cucumbers

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Sea Cucumber Ecosystem Based Management Plan

Dive fisheries in Southern Southeast Alaska are important to the local area and have a significant impact that some people aren’t very aware of. With the increasing use of sea cucumbers in the past few years, it is important that there are plans to keep the populations up without harming or affecting the environment in a negative way.

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