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Prionace glauca
– Lower Risk Near Threatened
Taxonomy
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Kingdom:
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ANIMALIA
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Phylum:
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CHORDATA
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Class:
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CHONDRICHTHYES
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Order:
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CARCHARHINIFORMES
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Family:
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CARCHARHINIDAE
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Scientific Name:
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Prionace glauca
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Species Authority:
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(Linnaeus, 1758)
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Common Name/s:
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Assessment Information
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Red List Category & Criteria:
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LR/nt ver 2.3 (1994)
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Year Assessed:
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2000
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Assessor/s:
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Stevens, J.
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Evaluator/s:
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Musick, J.A. & Fowler, S. (Shark Red List Authority)
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Justification:
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While blue sharks are among the most abundant, widespread, fecund and faster growing of the elasmobranchs, and a pelagic species that is widely distributed throughout the world’s oceans, they are also the most heavily fished sharks in the world. The impact of annual fisheries mortality (mainly of bycatch), estimated at 10 to 20 million individuals, is likely to be having an effect on the world population, but monitoring data are inadequate to assess the scale of any population decline. There is concern over the removal of such large numbers of this likely keystone predator from the oceanic ecosystem.
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Geographic Range
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Range Description:
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Probably the widest ranging chondrichthyan species. P. glauca is oceanic and circumglobal, occurring in temperate and tropical waters (Compagno 1984).
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Countries:
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Native:
Albania; Algeria; American Samoa; Angola; Anguilla; Antigua and Barbuda; Aruba; Australia; Bahamas; Bangladesh; Barbados; Belize; Benin; Bermuda; Brazil; British Indian Ocean Territory; Brunei Darussalam; Cambodia; Cameroon; Canada; Cape Verde; Chile; China; Colombia; Comoros; Congo; Congo, The Democratic Republic of the; Cook Islands; Costa Rica (Cocos I.); Cuba; Cyprus; Côte d'Ivoire; Denmark; Dominica; Dominican Republic; Ecuador (Galápagos); Egypt; El Salvador; Equatorial Guinea; Fiji; France; French Guiana; French Polynesia (Marquesas, Tuamotu); Gabon; Gambia; Germany; Ghana; Greece; Grenada; Guadeloupe; Guam; Guatemala; Guinea; Guinea-Bissau; Guyana; Haiti; Honduras; Hong Kong; India; Indonesia; Iran, Islamic Republic of; Ireland; Israel; Italy; Jamaica; Japan; Kenya; Kiribati; Lebanon; Liberia; Libyan Arab Jamahiriya; Madagascar; Malaysia; Maldives; Malta; Marshall Islands; Martinique; Mauritania; Mauritius (Rodrigues); Mexico (Revillagigedo Is.); Micronesia, Federated States of; Monaco; Montenegro; Montserrat; Morocco; Mozambique; Myanmar; Namibia; Nauru; Netherlands Antilles; New Caledonia; New Zealand; Nicaragua; Nigeria; Niue; Northern Mariana Islands; Norway; Oman; Pakistan; Palau; Panama; Papua New Guinea; Peru; Philippines; Pitcairn; Portugal (Madeira); Puerto Rico; Réunion; Saint Helena; Saint Kitts and Nevis; Saint Lucia; Saint Vincent and the Grenadines; Samoa; Sao Tomé and Principe; Senegal; Seychelles; Sierra Leone; Singapore; Slovenia; Somalia; South Africa; Spain (Canary Is.); Sri Lanka; Suriname; Sweden; Syrian Arab Republic; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Togo; Tokelau; Tonga; Trinidad and Tobago; Tunisia; Turkey; Turks and Caicos Islands; Tuvalu; United Kingdom; United States; United States Minor Outlying Islands (Johnston I., Wake Is.); Uruguay; Vanuatu; Venezuela; Viet Nam; Virgin Islands, British; Virgin Islands, U.S.; Wallis and Futuna; Western Sahara; Yemen
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FAO Marine Fishing Areas:
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Native:
Atlantic-eastern central; Atlantic-northeast; Atlantic-northwest; Atlantic-southeast; Atlantic-southwest; Atlantic-western central; Indian Ocean-eastern; Indian Ocean-western; Pacific-eastern central; Pacific-northeast; Pacific-northwest; Pacific-southeast; Pacific-southwest; Pacific-western central
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Population
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Population Trend:
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Habitat and Ecology
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Habitat and Ecology:
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A wide-ranging, oceanic-epipelagic and fringe-littoral shark, occurring from the surface to at least 152 m depth. Although P. glauca is an offshore species it may venture inshore, especially at night, and often in areas with a narrow continental shelf or off oceanic islands. In temperate waters blue sharks occasionally venture to the edges of kelp forests or sufficiently far inshore to be caught in pound nets. The species prefers relatively cool water at 7 to 16°C but can tolerate water at 21°C or even more. It ranges far into the tropics but shows tropical submergence and occurs at greater depths there. When disturbed, hooked or attacking prey it is capable of bursts of speed. The species will often circle a food stimulus before moving in to devour it. In the Pacific the blue shark is present in greatest abundance between 20° and 50°N, but in this area it shows strong seasonal fluctuations in abundance, connected with yearly migrations northwards in summer and southwards in winter. In the tropics between 20°N and S it is uniformly abundant throughout the year. In the North Atlantic tagging and recapturing of individuals has shown a regular clockwise trans-Atlantic migration route with the current system there. Apparently these sharks ride the Gulf Stream to Europe, take various currents down the European and African coasts, and ride the Atlantic North Equatorial Current to the Caribbean region. The blue shark feeds heavily on relatively small prey, especially bony fishes and squid, though other invertebrates, small sharks, and mammalian carrion is readily taken and seabirds occasionally are caught at the surface of the water. Much of the prey of the blue shark is pelagic, though bottom fishes and invertebrates figure in its diet also (Compagno 1984).
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System:
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Marine
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List of Habitats:
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| 9.1 | Marine Neritic - Pelagic |
| 10.1 | Marine Oceanic - Epipelagic (0-200m) |
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Threats
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Threats:
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This shark is usually caught with pelagic longlines but also hook-and-lines, pelagic trawls, and even bottom trawls near coasts. It is utilized fresh, smoked, and dried salted for human consumption; its hides are used for leather; fins for shark-fin soup base; and also for fishmeal and liver oil. This shark is also considered a game fish and taken by sports anglers with rod and reel (Compagno 1984).
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List of Threats:
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| 3.1 | Harvesting (hunting/gathering) - Food (ongoing) |
| 3.4 | Harvesting (hunting/gathering) - Materials (ongoing) |
| 3.5 | Harvesting (hunting/gathering) - Cultural/scientific/leisure activities (ongoing) |
| 4.1.1 | Accidental mortality - Bycatch - Fisheries-related (ongoing) |
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Bibliography
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Bibliography:
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Compagno, L.J.V. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. FAO Fish. Synop. No. 125, vol. 4. Shark Specialist Group. 2000. IUCN Shark Specialist Group Red List Assessments, 2000 (unpublished report). Shark Specialist Group. For more information, see the Specialist Group website.
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