Shark

Shark

Spiny dogfish shark

At a glance

Eco-rating Mercury Omega-3s
+-Common thresher shark
OK
Elevated

MORE ABOUT COMMON THRESHER SHARK

The thintail or common thresher shark is common in temperate and tropical seas. It has small eyes and a long, narrow tail fin. It feeds on large schooling fishes but is generally harmless to humans. A record size male may grow to 21 feet (6.4 meters) and may weigh up to 661 lbs (300 kg). Threshers have dramatically decreased in U.S. Atlantic waters, while they are more common in the Pacific.

Commercial Sources

Common thresher sharks are found worldwide in tropical and temperate seas. In the Atlantic, they range from Canada to Argentina and from Norway to South Africa. In the Indo-Pacific, they are scattered in several regions. In the eastern Pacific, they are distributed from Canada to Chile.

The main source of common thresher sharks is the United States.

Capture Methods

Common thresher sharks come from marine fisheries, not fish farms. They are primarily caught with nets. Additional types of fishing gear include trawls, longlines and gillnets.

+-Shortfin mako (HI, CA)
OK
Elevated

MORE ABOUT SHORTFIN MAKO

The shortfin mako is known for unprovoked attacks on swimmers and boats and can be quite dangerous. One of the fastest and heaviest of all sharks (up to 500 kg), it can leap menacingly out of the water when hooked. The shortfin mako grows up to 12 feet (3.7 meters) in length. Its jaws and teeth are often sold as ornaments and trophies.

Commercial Sources

Shortfin mako are found worldwide in tropical and temperate seas. In the Atlantic, they occur from Maine to Brazil and from Norway to South Africa, including the Mediterranean Sea. In the Indo-West Pacific, they range from East Africa to Hawaii and from Russia to New Zealand. In the eastern Pacific, they are distributed south of the Aleutian Islands, and from California to Chile.

The main sources of shortfin mako are Chile and Spain.

Capture Methods

Shortfin mako come from marine fisheries, not fish farms. They are primarily caught with nets. Additional types of fishing gear include longlines and gillnets.

+-Longfin mako
Worst
Elevated

MORE ABOUT LONGFIN MAKO

The longfin mako is potentially dangerous because of its large size and big teeth; it grows to over 12 feet, or 3.7 meters, in length.

Commercial Sources

Longfin mako are found in the Atlantic, Pacific and West Indian Oceans. In America, they occur in the Gulf Stream, Florida and Cuba. They have also been reported in southern Brazil. In Africa, they are distributed off Guinea, Ghana and Madagascar. In the Pacific, their range includes waters around Taiwan, near Phoenix Island, and Hawaii.

Capture Methods

Longfin mako come from marine fisheries, not fish farms. They are primarily caught with gillnets and longlines. It is illegal to commercially fish longfin mako in the United States.

+-Blacktip shark
Unrated
Elevated

MORE ABOUT BLACKTIP SHARK

The blacktip shark is considered dangerous when provoked, although it has actually been incriminated in few attacks. This shark, on the small side for the family, grows to 7-8 feet (2.1-2.4 meters) and lives in a wide range of coastal areas in subtropical waters. This shark frequents inshore waters, so it is highly vulnerable to fishing pressures and habitat destruction.

Commercial Sources

Blacktip sharks are found in the Atlantic and Indo-Pacific Oceans. In the Atlantic, they occur from Brazil to Canada and from the Mediterranean Sea to the western Central Africa. In the Indo-Pacific, they range from South Africa to China and from Mexico to Peru, including Australia, Tahiti, Marquesas and Hawaii.

The main source of blacktip sharks is the United States.

Capture Methods

Blacktip sharks come from marine fisheries, not fish farms. They are primarily caught with longlines. Additional types of fishing gear include gillnets and handlines.

+-Spiny dogfish
Unrated
Elevated

MORE ABOUT SPINY DOGFISH

The spiny dogfish is the lone species of horned sharks that inflicts toxins with its tail. It is found in a variety of habitats, but is vulnerable to overfishing because it matures slowly. It is relatively small, growing to 4 feet (122 cm), and can live to 100 years. Populations in the North Atlantic have been over-exploited to the point of near-collapse.

Commercial Sources

Spiny dogfish are found in the Atlantic and Pacific Oceans. In the eastern Atlantic, they occur around Iceland and from northwestern Russia to South Africa, including the Mediterranean and Black Seas. In the western Atlantic, they are distributed from Greenland to Argentina. In the Pacific, they range from New Zealand to the Bering Sea and from Alaska to Chile.

The main sources of spiny dogfish are the United Kingdom, Canada and New Zealand. Dogfish sold in the U.S. market are primarily from the United States and Canada.

Capture Methods

Spiny dogfish come from marine fisheries, not fish farms. They are primarily caught with bottom trawls. Additional types of fishing gear include seines, gillnets, hooks-and-lines and pound nets.

Recommended servings per month

Contaminant Men Women Kids 6-12 Kids 0-5
Longfin mako Mercury < 1 0 0 0
Blacktip shark Mercury < 1 0 0 0
Common thresher shark Mercury < 1 0 0 0
Shortfin mako (HI, CA) Mercury < 1 0 0 0
Spiny dogfish Mercury < 1 0 0 0
Eco details: 

Most shark species are severely depleted. The main reasons for their precipitous decline are:

  • They are caught accidentally by the thousands and discarded as waste by tuna and swordfish longline fishers.
  • There is strong demand for their fins in Asia.
  • Most sharks mature slowly and have few offspring.

Spiny dogfish are especially vulnerable to overfishing, since they have the longest gestation period of any vertebrate (two years).