On the 26th of June 2015, the Hawaii Board of Land and
Natural Resources announced that it would be illegal to harvest any species of
sea cucumber from Hawaii State waters for 120 days. This emergency ruling has
been implemented to immediately stop the continued depletion of sea cucumber
numbers, after an investigation by officers from the DLNR Division of
Conservation and Resources Enforcement confirmed that a new commercial fishery
had begun (Department of Land and Natural
Resources, 2015).
(Clayton Wakida, KITV,
2015)
Sea cucumbers along with other echinoderms
are described as a “keystone species” as they play a major role in structuring
many marine ecosystems (Skillings, Bird and
Toonen, 2014). They work as the “vacuum cleaners” of the
sea floor consuming organic detritus (waste) and help to prevent the growth of
slime algae that can damage coral reefs (Skillings,
Bird and Toonen, 2011).
Sea cucumbers like many other species are also the target of artisanal
or commercial fishing activities. Stocks of sea cucumbers are being continually
depleted, with the more valuable species being depleted first (Skillings et al., 2011). Studies have shown the loss
of sea cucumbers from an ecosystem can result in the hardening of sands around
reefs, which can lead to the loss of soft bottom species, increased growth of micro
and macro algae and reduced nutrient processing (Skillings et al., 2014).
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| Black sea cucumber. Image Hawai'i Institute of Marine Biology |
Why is removing them such a problem? Little is known about the growth rate, longevity, or sexual maturity of these
animals. The few studies of wild populations of sea cucumbers suggest that
these are very long-lived animals with slow growth and reproductive rates. These are characteristics that make a
species very sensitive to overharvest (Skillings et al.,2014). Studies conducted on species of sea cucumber
that are harvested for consumption, primarily Holothuria whitmaei and Holothuria (Microthele) nobilis, suggest that it can take one sea cucumber 10-35 years to reach sexual maturity (Shiell
and Uthicke, 2005). Sea cucumbers show
no visible sings of ageing and theoretically in perfect conditions they could
live forever. However in a wild population the likelihood of this happening is
very rare. It is estimated that that the average life span of a sea cucumber is
approximately 40-60 years (Shiell and Uthicke, 2005).
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| Black sea cucumber. Image Hawai'i Institute of Marine Biology |
Why has the harvesting of sea cucumber become such a problem? Sea
cucumbers have been harvested for consumption for over 1000 years in China and
India (James and James, 1994). These
traditional practices only harvested a small amount of sea cucumber for
consumption. This was not a problem because they were not depleting the stocks to a
point that they could not recover (Friedman et.al, 2010). The commercialization
of the sea cucumber, primarily as ‘beche-de-mer’ the dried form, in the
Asia-Pacific region saw a spike in the amount of sea cucumbers being harvested.
As this industry was unregulated, sea cucumbers were being harvested in huge
number in the early 1800's but the trade declined by the early 20th
century as the populations were reduced to a point that there were insufficient
numbers to support a trade or to replenish the stock numbers (Ward, 1972;
Moore, 2003).
Over a hundred years later, in the 1980's, another boom in the harvesting of sea cucumbers
occurred, as there was a spike in the demand from the Chinese communities
around the world (Friedman et.al, 2010).
Today, the demand from the Chinese communities around the world is still
increasing. Even with the introduction of an aquaculture industry, the demand
for sea cucumber greatly outweighs the supply. One kilogram of sea cucumber has
been recorded selling for US $2,950. This has caused sea cucumbers to be
harvested from wild populations in numbers that have not been seen before
(Friedman et.al, 2010). If this trend is
to continue, irreversible damage will be done to the sea cucumber populations
resulting in the extinction of many species (Purcell et.al, 2010).
Written by Jardine Gunn
Department of Land and Natural
Resources, (2015). 06/26/15 - Sea Cucumber Harvesting Banned For 120 Days in
Hawaii. [online] Available at:
http://dlnr.hawaii.gov/blog/2015/06/26/nr15-94/ [Accessed 7 Jul. 2015].
Friedman, K., Eriksson, H., Tardy, E.
and Pakoa, K. (2010). Management of sea cucumber stocks: patterns of
vulnerability and recovery of sea cucumber stocks impacted by fishing. Fish
and Fisheries, 12(1), pp.75-93.
James, D.B., and James, P.S.B.R. (1994). A hand book on Indian sea-cucumbers. CMFRI Special Publications, 59, pp. 47
Moore, C. (2003). New
Guinea: Crossing Boundaries and History. University of Hawaii Press,
Honolulu.
Purcell, S., Lovatelli, A.,
Vasconcellos, M. and Ye, Y. (2010). Managing sea cucumber fisheries with an
ecosystem approach. Rome: Food and Agriculture Organization of the United
Nations.
Shiell, G. and Uthicke, S. (2005).
Reproduction of the commercial sea cucumber Holothuria whitmaei [Holothuroidea:
Aspidochirotida] in the Indian and Pacific Ocean regions of Australia. Marine
Biology, 148(5), pp.973-986.
Skillings, D., Bird, C. and Toonen, R.
(2011). Gateways to Hawai 'i: genetic population structure of the tropical sea
cucumber Holothuria atra. Journal of Marine Biology, pp.1-16.
Skillings, D., Bird, C. and Toonen, R.
(2014). Comparative population structure of two edible Indo-Pacific coral reef
sea cucumbers (Echinodermata: Holothuroidea). Bulletin of Marine Science,
90(1), pp. 359-378.
Ward, R. (1972). The Pacific Beche-de-mer trade with specific
reference to Fiji. In: Man in the
Pacific: Essays on Geographical Change in Pacific Islands (ed. R. Ward).
Oxford, Clarendon Press. pp. 91-123
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