Atlantic Common Thresher Shark

Common Thresher Shark Image

Alopias vulpinus

ALSO KNOWN AS:

    Thresher Shark, Fox Shark, Sea Fox, Swingletail, Whiptail Shark, Thintail Shark

SOURCE:

    U.S. wild-caught from New York to North Carolina
 

STATUS

  • POPULATION
  • FISHING RATE
  • HABITAT IMPACTS
  • BYCATCH
 

Click the icons to learn more about each criteria

 
 

OVERVIEW

Common Thresher Shark at the surface

As top predators in the ocean, sharks have an extremely sensitive sense of smell, eyes that can adapt to dim light, lateral line receptors that sense movement in the water, and electroreceptors that can detect prey even in the absence of scent or visual clues. Common thresher sharks are also armed with powerful jaws and rows of blade-like teeth that are replaced often, so they always have a sharp set to inflict a clean bite.

LAUNCH GALLERY

There are three species of thresher sharks: common (Alopias vulpinus), pelagic (A. pelagicus), and bigeye (A. superciliosus). Pelagic and common threshers are caught and sold in the United States, but fishermen are prohibited from harvesting bigeye threshers in the Atlantic due to their low population levels.

Common thresher sharks are caught by several nations in temperate waters around the world. In the United States, they’re harvested incidentally in longline fisheries for swordfish and tuna in the Atlantic and Gulf of Mexico, and on rod and reel gear by recreational fishermen. In the Pacific, they’re caught as bycatch and in a highly regulated directed fishery off California, which supplies most of the U.S. harvest of this species (see Pacific common thresher shark).

Common thresher sharks, like many shark species, are especially vulnerable to overfishing because they live a long time, take many years to mature, and only have a few young at a time. Recovery from overharvest can take years or decades. Sharks require special attention - NOAA Fisheries is conducting research, implementing restrictions and working with fishermen domestically, and pursuing conservation of shark species worldwide to maintain healthy shark populations and recover populations that are overfished.

Looking Ahead

Conservationists and foodies take note - a key federal law prohibits the practice of "shark finning," where valuable shark fins are removed and the remainder of the shark is discarded at sea. In the U.S. Atlantic shark fisheries, sharks must be landed with their fins naturally attached to the rest of their body.

This Just In

8.11
It's Always Shark Week at NOAA

 

 
 
 

LOCATION & HABITAT

Common thresher sharks are found in temperate waters around the world. In the northwest Atlantic Ocean, they range from Newfoundland to Cuba. Common thresher sharks are a highly migratory species, often traveling over entire ocean basins. They’re most common near land and are often found in areas rich with plankton, where their prey is also abundant.

 
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BIOLOGY

Common thresher sharks, like many shark species, live a long time (19–50 years), reproduce late in life, and only have a few young at a time. They grow slowly, up to 20 feet long. Males sexually mature when they’re 8 to 11 feet long and 3 to 6 years old. Females are able to reproduce when they’re 8 to 9 feet long and 4 to 5 years of age. Thresher sharks mate in midsummer. In general, sharks have low reproductive rates compared to other marine fish. Their eggs are fertilized internally and develop within the mother. Females bear live, fully developed young after a long gestation period (9 months for thresher sharks), and only have a few pups.

Common thresher sharks provide a valuable balance to the marine ecosystem. They’re aggressive predators feeding near the top of the food web, mainly on schooling fish such as herring and mackerel and occasionally on squid and seabirds. They have few predators - younger, smaller common thresher sharks may fall prey to larger sharks from a variety of species. Humans are one of the few species that eat sharks.

 
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PHYSICAL DESCRIPTION

Common thresher sharks are brown, gray, blue-gray, or blackish on the back and underside of their snout. They’re lighter on the sides, and fully white below. Their pectoral, pelvic, and dorsal fins are blackish, and there are sometimes white dots on the tips of the pectoral, pelvic, and tail fins. The tail fin is sickle-shaped, and the upper part is extremely long - about half the length of their body.

 
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OVERVIEW

Scientists have not formally assessed the common thresher shark stock as they lack the data needed to perform a stock assessment.

 
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POPULATION STATUS

Common thresher shark has not been formally assessed, so the population status is unknown. The International Commission for the Conservation of Atlantic Tunas recently reviewed an ecological risk assessment disclaimer for pelagic sharks caught in Atlantic longline fisheries and ranked thresher sharks as the least vulnerable to longline fisheries and more productive than the other species included in the risk assessment.

 
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ADDITIONAL RESEARCH

Scientists at NOAA’s Northeast Fisheries Science Center and the University of Rhode Island are conducting age and growth studies on thresher shark. Scientists are also studying the life history of thresher shark, including reproductive and food habits, in addition to age and growth information.

NOAA Fisheries runs the Cooperative Shark Tagging Program to study the life history of Atlantic sharks. Started in 1962, the program involves thousands of recreational and commercial fishermen, scientists, and fisheries observers. Participants tag large coastal and pelagic sharks and record information about the shark (date and location where caught, gear used, and the size and sex of the shark). When fishermen catch previously tagged sharks, they’re asked to record and submit similar information. Between 1962 and 2010, over 221,000 sharks of 52 species had been tagged and more than 13,000 sharks of 33 species had been recaptured. Data from this program provide valuable information on shark migrations, help increase our understanding of shark biology, and improve management of the resource.

 
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Harvesting Common Thresher Sharks

Atlantic common thresher shark is generally harvested commercially as bycatch in pelagic longline fisheries for swordfish and tuna. Fishermen also fish for thresher sharks recreationally, usually with rod and reel gear.

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Management

Who’s in charge? NOAA Fisheries Atlantic Highly Migratory Species Management Division and the International Commission for the Conservation of Atlantic Tunas, a.k.a. ICCAT

With highly migratory species such as common thresher sharks, management is complicated. A fish that is off the coast of Massachusetts one week could be caught off the coast of Canada the next. These types of resources must be managed both in the United States and at the international level. The United States negotiates with Regional Fisheries Management Organizations including ICCAT, the Food and Agriculture Organization of the United Nations disclaimer, and the Convention on International Trade in Endangered Species of Wild Fauna and Flora disclaimer to enhance shark management worldwide.

Current management: The 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan includes numerous measures to rebuild or prevent overfishing of Atlantic sharks in commercial and recreational fisheries:

  • Commercial quotas.
  • Limits on how much common thresher shark can be caught per fishing trip.
  • Gear restrictions- circle hooks are required for pelagic longlines; all vessels must carry safe handling and release gear.
  • Fishermen must have a permit to harvest sharks, and management has limited the number of available permits.
  • Fishing season is generally year-round; individual shark fisheries close when the majority of their quota is reached.
  • Area closures to protect nursery areas, sensitive habitats, and populations.
  • Vessel monitoring system on board to enforce these area closures.
  • Fishermen fishing with longline gear must complete a “Protected Species Safe Handling, Release, and Identification Workshop.”
  • Shark dealers are required to attend Atlantic Shark Identification workshop to help them better identify shark species.
  • Last but not least, all sharks must be landed with their fins naturally attached.
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Annual Harvest

Most common thresher shark comes from fisheries off the West Coast; the Atlantic fishery only supplies about a third of the annual harvest. In 2010, U.S. fishermen caught 61,290 pounds of thresher shark off the East Coast, mainly off North Carolina, New Jersey, and Virginia.

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Economy

Common thresher sharks are traded commercially, and also are economically important in recreational fisheries through individual angler expenditures, recreational charters, tournaments, and the shoreside businesses that support those activities.

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Recreational

Recreational fishermen also fish for common thresher sharks, mainly with rod and reel gear. Sharks must be a minimum size to be caught, and there is a limit on how many sharks can be caught per fishing trip. Managers also encourage recreational fishermen to use circle hooks to increase the survival of sharks that are caught and released.

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OVERVIEW

Common thresher shark has a mild flavor. It’s firm, dense, and meat-like in texture. Raw, thresher shark is white to tan with a pink blood line.

 
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SEASONAL AVAILABILITY

Year-round

 
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NUTRITION

Shark is high in protein and low in fat. It is a good source of niacin, vitamins B6 and B12, and phosphorus and a very good source of selenium. Shark may contain amounts of methylmercury in excess of the FDA’s recommended limit for nursing moms, moms-to-be, and young children. For more information, see EPA and FDA advice on what you need to know about mercury in fish and shellfish. disclaimer

Servings 1
Serving Weight 100 g (raw)
Calories 130
Protein 20.98 g
Fat, total 4.51 g
Saturated fatty acids, total 0.925 g
Carbohydrate 0 g
Sugars, total 0 g
Fiber, total dietary 0 g
Cholesterol 51 mg
Selenium 36.5 mcg
Sodium 79 mcg

Atlantic Common Thresher Shark Table of Nutrition

 
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