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Shark

Overview

  • Weight
    up to 11 tons
  • Length
    8 in.-40 ft.
  • Habitats
    Oceans

Sharks have been around for over hundreds of millions of years. While many of us may be familiar with a few shark species, there are over 400 of them, from the 8-inch-long dwarf lanternshark to the 40-foot-long whale shark. Sharks are efficient predators with a highly developed sense of smell, hearing and sight. They can detect their prey’s scent from a great distance. Sensitive eyes see clearly even in the dim light of the ocean depths.

Sharks are carnivorous and eat fish (including other sharks) as well as larger animals such as seals. Others, like the whale shark and the basking shark, feed on tiny plankton or krill. Despite their fearsome reputation as ruthless predators, sharks are much more likely to be killed by humans than the other way around. WWF is working to stop overfishing of sharks to make sure these magnificent animals continue to thrive in the oceans.

Greater Protection for Sharks and Manta Rays

A new conservation milestone means greater protection for sharks and manta rays. Five shark and two manta ray species are now under the protection of the CITES. The species include three types of hammerhead sharks, two manta ray species as well as the oceanic whitetip shark and porbeagle sharks.

Oceanic whitetip shark

Why They Matter

  • Shark populations around the world are in rapid decline. Sharks grow relatively slowly, take many years to mature and produce relatively few young. These characteristics make sharks, like this porbeagle, particularly vulnerable to over-exploitation.

  • This vulnerability is exacerbated by the large and growing demand for shark fins and the general lack of management of shark fishing. Populations simply cannot replenish at the same rate as they are caught and finned to meet market demand.

  • Sharks play a very important role in marine areas, sitting at the top of the food chain, and help maintain the delicate balance of marine life.

Threats

Hammerhead shark caught in a gillnet

Scalloped hammerhead shark caught in a gillnet, Gulf of California, Mexico.

Pirate Fishing

Overfishing and illegal fishing of sharks for their fins is depleting populations worldwide. There is often a general lack of even basic management monitoring, control, and surveillance of many fisheries. Improving the capacity to combat pirate fishing (illegal, unreported and unregulated fishing) of sharks is a key factor in ensuring that shark fishing and shark populations are sustainable.

Demand for Shark Fin

The growing trade in shark fins –often used to make an expensive Asian soup—has become a serious threat to many shark species. The latest research suggests that around 100 million sharks may be killed annually, often targeted for their fins. This practice affects many different shark species, including whale sharks.

The overfishing of sharks happens because of the huge demand—mainly for shark fins—and a lack of management to ensure shark fisheries are sustainable. Some species, such as spiny dogfish and porbeagle, are targeted primarily for their meat.

The oceanic whitetip, porbeagle and three hammerhead species are some of the shark species of concern for WWF, where the impact of trade is contributing to declines in populations. Millions of these sharks continue to be fished annually to supply the persistent demand for their fins and meat. Controls on fishing are woefully insufficient. As a result, the oceanic whitetip, porbeagle, and the smooth hammerhead are classified as vulnerable by the IUCN, while scalloped and great hammerhead sharks are classified as endangered.

Sharks are often caught incidentally by fishing gear set for other types of fish—such as tuna longlines, trawls and seine nets—and many will simply be discarded. This contributes to the decline of many species of sharks.

What WWF Is Doing

Whale Shark Research

Logging details about a whale shark satellite tag. 

WWF and other conservation organizations are leading the fight to save the world's sharks. We are working through TRAFFIC, the world’s largest wildlife trade monitoring network, to regulate the trade in shark fins and meat and reduce market demand. We are also trying to ensure that conservation and management measures for sharks are implemented by fishery management organizations and by countries participating in multi-lateral trade agreements.

Tagging Great White Sharks

WWF supports research and monitoring of white sharks as they migrate to and from the Gulf of California. Sharks are tagged and the movements are tracked by satellite. This information on their behavior will help with a management plan for the protected area where they are found (Guadalupe Island Biosphere Reserve), such as how to protect them from bycatch and to regulate tourism.

Great White Shark
Whale shark

WWF experts continue to study shark habits and gather information in the Coral Triangle on individual sharks by using satellite tags, sonar devices and digital cameras. The information is used to create further protections for whale sharks.

Every whale shark has a unique pattern of spots and stripes on their skin, and WWF uses them to identify individual sharks. Divers photograph the animal right above their pectoral fins and behind their gill slits. The photos are then fed into a computer database. In the Philippines, WWF has identified 458 individual whale sharks since 2007.

WWF has also placed satellite tags on 29 whale sharks. The data from these tags indicate that whale sharks are highly mobile and are transient feeders.

Addressing Overfishing

At the 2013 meeting around the Convention on International Trade in Endangered Species (CITES), WWF urged member governments to take strong action and support all proposals for sharks and manta rays. Our efforts paid off, and in an historic vote, three species of hammerhead sharks, porbeagle sharks, oceanic whitetip sharks and manta rays all gained stronger protections. These protections give CITES the authority to regulate trade for these species. Since they take a long time to reach maturity and produce relatively few young in their lifetime, they are extremely vulnerable to overfishing. Creating new protections under CITES helps ensure that such species are caught legally and traded at sustainable levels.

Reducing bycatch

Fish Aggregating Devices (or FADs) are floating structures placed at sea by fishermen to attract large schools of fish. They are often composed of old netting underneath a raft, which can cause an entanglement hazard for sharks and other marine animals. WWF, through its partner organization, ISSF, has supported the scientific development of ways to address this problem of shark bycatch. So far, tests have shown that improved FAD design nearly eliminates shark entanglement.

Related Species