Shark Fisheries
Introduction
Throughout history, sharks have been fished for their meat, skin, livers, teeth and fins. They are also caught live for use in aquariums [1]. (Click here to learn more about Aquarium Fisheries) Recently, there has been concern about overfishing shark populations and the effect that this may have on marine environments. There is also growing public concern about shark finning practices. This page covers shark fishery practices, regulations, shark products, and current conservation efforts to maintain shark populations.
Contents
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Background
Sharks (along with skates, rays and chimera) belong to the vertebrate class Chondrichthyes. They lack true bone, and instead have a skeleton of cartilage. Sharks are mostly carnivorous predators or scavengers—except the whale, basking and megamouth sharks, which are filter feeders. As predators, sharks can have a large impact on the trophic structure of an ecosystem [2]. Alteration of natural shark populations can result in tremendous top-down changes in the structure of food webs. Also, sharks grow and reproduce more slowly than bony fishes. This can result in slow regrowth of populations that have been over fished.
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Why Are Sharks Fished?
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Currently, sharks are fished for their skin, meat, teeth, livers and fins. Many different species are harvested for one or all of these products. For fact sheets about different shark fisheries, please visit the Food and Agriculture Organization's list of shark resources.
Shark fins will be discussed later on this page in the Shark Fin Fishing section.
Currently, sharks are fished for their skin, meat, teeth, livers and fins. Many different species are harvested for one or all of these products. For fact sheets about different shark fisheries, please visit the Food and Agriculture Organization's list of shark resources.
Shark fins will be discussed later on this page in the Shark Fin Fishing section.
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Shark leather wallet (not dyed)
_Shark skins
are turned into a leather which can be used to produce a variety of
products such as handbags, belts and wallets. Such leather is tanned in a
similar fashion to the leather of other animals. Untanned shark skin is
commonly called shark shagreen [1]. This is abrasive was primarily used
for polishing surfaces and making grips for weapons. Now, shagreen can
be used for other products after it has been ground down to a
semi-smooth texture. Shark leathers have been commercially important in
the United States, Mexico, Venezuela, Germany, the United Kingdom and
Japan [3]. In the United States, shark leathers decreased in novelty and
popularity after an increase in the popularity and availability of
shark meat. In general, the demand for shark leather goods now resides
in niche markets [3].
Shark meat is commonly found in
fish and chips in the UK and Australia
_ Shark meat
traditionally has been prepared in coastal communities all over the
world. Each culture has a different method for preparing and preserving
shark meat [3]. Recently, commercially fished shark has become
increasingly more available in many countries including the United
States, Japan, Canada, France, Germany, the United Kingdom, and
Australia. In the United States, shark is generally marketed as
“steakfish” or “whitefish”; in the United Kingdom, shark is marketed as
“rock salmon”, “hake” or “rigg” [3]. The sharks with meat considered to
be high quality found in the market are shortfin mako, thresher, and
porbeagle sharks [3]. Dogfish (commonly called “rock salmon”) is
commonly used in the United Kingdom and Australia for fish and chips
[3]. A more comprehensive list of sharks fished for meat can be found in
a report written by the UN’s Food and Agriculture Organization. Some types of shark are not eaten because they are thought to concentrate high levels of toxins within their tissues.
Fossilized shark teeth have become popular tourist souvenirs.
__Shark teeth have
been used throughout history in weaponry and ornamentation [1, 3, 4].
They have been found at archaeological sites all over the world; at some
sites, the sheer number of teeth found indicates that people caught
sharks and extracted teeth from the carcass [4]. Currently, there is
some public interest in collecting both fossilized and fresh shark teeth
for souvenirs [3]. According to the UN Food and Agriculture
Organization, only larger teeth are of commercial interest, so teeth
from larger species such as the mako shark and white shark are sold [3].
Basking sharks are often fished for their oil-rich livers.
__Shark liver oil is
generally extracted from deep-water sharks because their livers contain
more oil [3]. Because sharks do not have swim bladders, they rely
mainly on the oils in their liver for buoyancy. Basking sharks in
particular have been fished for their oil-rich livers [5]. Oil has been
used for lamp fuel, in cosmetics, as a lubricant, and as a supplement
for alkoxyglycerols, vitamin A and omega-3 fatty acids [3].
Traditionally, it has also been used to treat respiratory and digestive
issues [3]. Shark liver oil is believed to be a possible treatment for
cancer, but no scientific data supports that idea.
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How Are Sharks Caught?
__In
the United States, shark fisheries are allowed to use only certain
types of gear to catch sharks. Longlines and gillnets are the most
common types of gear used in commercial shark fisheries [6, 7]. A longline
is a series of baited hooks spaced along a line that is deployed off
the back of a fishing ship. It is usually supported by buoys and can be
several miles long [6]. This gear can hang anywhere in the water column,
and is used to catch larger sharks such as mako and blue sharks [8]. Gillnets are
nets with a large mesh size that are suspended by buoys. When fish
larger than the mesh size try to swim through it, their gills get caught
in the net and they cannot escape [6]. These nets can be used to catch a
variety of sharks because the mesh size is variable.
The UN’s Food and Agriculture Organization reported that over 700,000 sharks, rays and chimeras were harvested worldwide in 2008 [9]. While this catch data does include commerical, subsistence and recreational fishing, it does not include bycatch estimates. (To view data for specific shark species, visit the FAO’s Fisheries and Aquaculture Yearbook of Statistics.) Sharks are common bycatch in many fisheries [Lawlor and Cook, 1987]. Dogfish are caught in trawls, mako and blue sharks can be entangled in the longline gear intended for swordfish, and salmon sharks can be caught in gillnets in the salmon fishery [9]. (Click here for more information on bycatch.) |
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Regulations
__The
Food and Agriculture Organization has expanded the Code of Conduct for
Responsible Fisheries to further include shark fisheries by starting the
International Plan of Action for the Conservation and Management of
Sharks (IPOA-SHARKS). This encourages countries to form national plans
of action for shark management and to regulate existing shark fisheries.
Click here to learn more about the IPOA-SHARKS and here to see a list of national plans of action. The remainder of this section will focus on shark fisheries regulations in the United States.
The U.S. Atlantic Coast has experienced an increase in shark fishery activity, though the total catches in this area are insignificant in the world’s total annual catch of sharks [10]. The season for this fishery is year-round. Sharks in the Northwest Atlantic are primarily fished using bottom longlines with (quick-release gear and corrodable hooks) and gillnets (attached to the boat and are shorter than 2.5 km). Currently, according to the National Marine Fisheries Service (NMFS), only 19 species are authorized catch for commercial fisheries [7]. Fishery boats with appropriate permits are allowed to take 33 large coastal sharks and any number of pelagic or small coastal sharks per trip. For incidental catch, only 3 large coastal sharks and total of 16 pelagic and small coastal sharks are allowed per vessel. All sharks must have their fins attached by at least a small flap of skin and may not be filleted at sea [7].
On the Pacific Coast of the United States, shark fishery regulations are largely set by the state [11]. In Washington, sharks may be caught with trolls, midwater trawls and set lines; in Oregon, gillnets are prohibited in the thresher shark fishery; in California, longlines may not be used in state waters [12]. Currently, the Pacific Fisheries Management Council groups shark fisheries under Highly Migratory Species (HMS). To view HMS regulations in this region, click here.
The U.S. Atlantic Coast has experienced an increase in shark fishery activity, though the total catches in this area are insignificant in the world’s total annual catch of sharks [10]. The season for this fishery is year-round. Sharks in the Northwest Atlantic are primarily fished using bottom longlines with (quick-release gear and corrodable hooks) and gillnets (attached to the boat and are shorter than 2.5 km). Currently, according to the National Marine Fisheries Service (NMFS), only 19 species are authorized catch for commercial fisheries [7]. Fishery boats with appropriate permits are allowed to take 33 large coastal sharks and any number of pelagic or small coastal sharks per trip. For incidental catch, only 3 large coastal sharks and total of 16 pelagic and small coastal sharks are allowed per vessel. All sharks must have their fins attached by at least a small flap of skin and may not be filleted at sea [7].
On the Pacific Coast of the United States, shark fishery regulations are largely set by the state [11]. In Washington, sharks may be caught with trolls, midwater trawls and set lines; in Oregon, gillnets are prohibited in the thresher shark fishery; in California, longlines may not be used in state waters [12]. Currently, the Pacific Fisheries Management Council groups shark fisheries under Highly Migratory Species (HMS). To view HMS regulations in this region, click here.
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Shark Fin Fishing
_Shark
fins have a high value in Chinese culture and history. Historically,
they were reserved for nobility, and were thought to impart many
benefits upon consumers [3]. In most cases, shark fins are harvested to
make shark fin soup, which is a popular dish at Chinese weddings and
banquets [3].
The fins of a shark are separated into two quality grades. The higher quality fins are the pectoral fins, the lower part of the tail and the main dorsal fin; lower quality fins are the second dorsal fin, ventral fins and the anal fin [3]. According to the Food and Agriculture Organization, fins are preferred from blue, dusky, hammerhead, mako, whitetip and sandbar sharks [3].
Shark finning usually occurs at sea; the rest of the shark may be retained for other products or is dumped overboard. In some areas, shark finning is illegal and catches made in these areas are largely unreported (Click here to read more about Illegal, Unregulated and Unreported Fishing) [3, 13]. All of these factors contribute to the likelihood of a global catch rate of finned sharks that has been underestimated [13].
In 2010, the United States passed the Shark Conservation Act, which amends the Magnuson-Stevens Fishery Conservation and Management Act and prohibits the removal of shark fins at sea. Further, this act prohibits the presence of any fin that is not naturally attached to a shark on-board a vessel. This encourages the use of whole-sharks and is expected to decrease the reported number of sharks finned in U.S. waters.
Worldwide shark finning still concerns the public, and many shark conservation groups are working towards a complete ban on the shark fin trade. It has become an issue that is used to spark the interest of the general public and to generate interest in conservation and global fisheries management.
The fins of a shark are separated into two quality grades. The higher quality fins are the pectoral fins, the lower part of the tail and the main dorsal fin; lower quality fins are the second dorsal fin, ventral fins and the anal fin [3]. According to the Food and Agriculture Organization, fins are preferred from blue, dusky, hammerhead, mako, whitetip and sandbar sharks [3].
Shark finning usually occurs at sea; the rest of the shark may be retained for other products or is dumped overboard. In some areas, shark finning is illegal and catches made in these areas are largely unreported (Click here to read more about Illegal, Unregulated and Unreported Fishing) [3, 13]. All of these factors contribute to the likelihood of a global catch rate of finned sharks that has been underestimated [13].
In 2010, the United States passed the Shark Conservation Act, which amends the Magnuson-Stevens Fishery Conservation and Management Act and prohibits the removal of shark fins at sea. Further, this act prohibits the presence of any fin that is not naturally attached to a shark on-board a vessel. This encourages the use of whole-sharks and is expected to decrease the reported number of sharks finned in U.S. waters.
Worldwide shark finning still concerns the public, and many shark conservation groups are working towards a complete ban on the shark fin trade. It has become an issue that is used to spark the interest of the general public and to generate interest in conservation and global fisheries management.
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Conservation
_Internationally,
there are many conservation groups that focus on sharks. These groups
can be government-operated or non-governmental organizations (NGOs).
Conservation groups have a variety of missions and projects that range
from campaigns to end the shark fin trade to public education and
outreach. This section highlights a few of these groups and their
efforts towards the conservation of sharks.
Learn about the blue shark, at the Shark Alliance website.
_The Shark Alliance is
a group of non-governmental organizations that focuses on setting
sustainable goals for shark fisheries, and conservation guidance for
endangered shark species. This group was initiated by the Pew Charitable Trusts,
and contains a lot of information concerning shark fisheries. The Shark
Alliance organizes a European Shark Week that is comprised of
shark-related events geared toward increasing public awareness.
Learn about sharks at the Shark Research Institute web page
_The Shark Research Institute
was founded in the United States as a scientific research organization
that sponsors shark research and conservation efforts. Their web page
includes educational resources for adults and children, and gives
extensive information about different shark species.
Donations can be made through the Shark Trust to fund whale shark research and conservation.
_The Shark Trust is
based in the United Kingdom, and is a charity that works towards the
conservation and protection of endangered shark species. This group
features an “Adopt A Shark” program that uses donations to support
research and conservation of basking, whale and white sharks. They also
provide volunteer and legislative campaign opportunities.
_Again,
there are many conservation groups that focus on sharks and related
species. Most provide information for the public and opportunities
to influence changes in global fishery policies.
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References
_Clicking on photos will lead to their source pages.
- Walker, T.I., 1998. Can shark resources be harvested sustainably? A question revisited with a review of shark fisheries. Marine and Freshwater Research, 49(7), pp. 553–572.
- Heithaus, M. et al., 2010. Unraveling the Ecological Importance of Elasmobranchs. In J. Carrier, J. Musick, & M. Heithaus, eds. Sharks and Their Relatives II: Biodiversity, Adaptive Physiology, and Conservation. Boca Raton, FL: Taylor & Francis Group, pp. 611-637.
- Vannuccini, S., 1999. Shark Utilization, Marketing and Trade. Available at: http://www.fao.org/docrep/005/x3690e/x3690e00.htm#Contents
- Borhegyi, S.F. de, 1961. Shark Teeth, Stingray Spines, and Shark Fishing in Ancient Mexico and Central America. Southwestern Journal of Anthropology, 17(3), pp. 273-296.
- Sims, D., 2009. Sieving a Living: A Review of the Biology, Ecology, and Conservation Status of the Plankton-Feeding Baskingn Shark Cetorhinus Maximus. Advances in Marine Biology, 54, pp. 171-220.
- Lawlor, F. & Cook, S., 1987. U.S. Shark Fishing Methods and Gear. In S. Cook, ed. Sharks: An Inquiry into Biology, Behavior, Fisheries, and Use. Portland, OR: Oregon State University Extension Service, pp. 137-146.
- National Marine Fisheries Service, Comm_Compliance_Guide_Shark.pdf. Available at: http://www.nmfs.noaa.gov/sfa/hms/Compliance_Guide/Comm/Comm_Compliance_Guide_Shark.pdf
- De Maddalena, A., Preti, A. & Smith, R., 2005. Commercial Fisheries and Various Utilizations of Mako Parts. In Mako Sharks. Malabar, FL: Krieger Publishing Company, pp. 59-63.
- Food and Agriculture Organization, Capacity Building- Sharks. FAO Fisheries and Aquaculture Department. Available at: http://www.fao.org/fishery/topic/16380/en
- Branstetter, S., 1999. The Management of the United States Atlantic Shark Fishery, Rome, Italy: FAO Fisheries.
- Hanson, D., 1999. Management of Shark Fisheries off the West Coast of the USA, Rome, Italy: FAO Fisheries.
- Pacific Fishery Management Council, 2011. HMS Fishery Management Plan, Available at: http://www.pcouncil.org/wp-content/uploads/HMS-FMP-Jul11.pdf.
- Clarke, S.C. et al., 2006. Global estimates of shark catches using trade records from commercial markets. Ecology Letters, 9(10), pp. 1115-1126
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