Blacktip reef shark  (Carcharhinus melanopterus)

The blacktip reef shark is classified as Near Threatened (NT) on the IUCN Red List (1).

The blacktip reef shark (Carcharhinus melanopterus) is the most commonly encountered species of shark in tropical Indo-Pacific reefs (4). Its medium-sized, streamlined body is brownish-grey, with a white underside. As its name suggests, it has brilliant black fin tips, (particularly distinctive on the first dorsal fin), which are all the more conspicuous against the adjacent white patches (4). The short snout is bluntly rounded and the eyes are almond-shaped (4). Running along the flanks is a noticeable white band (2).

Occurs in the western Pacific, the Indian Ocean, including the Arabian Gulf, and also in the eastern Mediterranean, which the blacktip reef shark has apparently invaded through the Suez Canal from the Red Sea (1) (2).

The blacktip reef shark prefers very shallow water on coral reefs, but is also found near reef drop-offs and occasionally just offshore. It is also thought to penetrate into brackish lakes, estuaries and even fresh water in some areas (2).

This powerful swimmer is well known for its tendency to enter incredibly shallow water, and is often found in water only 30 centimetres deep or less, with its distinctive dorsal fin protruding from the surface of the water. It is also found near the bottom or in mid-water in deeper water, singly or in small groups (2). It feeds on a wide variety of small fish and invertebrates, including mullet, groupers, wrasses, cuttlefish, squid, shrimp (2). Blacktip reef sharks are viviparous, and therefore the embryos develop inside the mother, for about 16 months. Females generally give birth between late winter and early summer, to between two and four pups (2). However, reproductive cycles appear to vary throughout the blacktip reef shark’s range, with reports of annual, biannual and biennial reproductive cycles (5).

The blacktip reef shark is not an extremely dangerous species, although it is responsible for several provoked and unprovoked attacks on humans. Many are on people that are swimming or wading on reefs, presumably because they were mistaken for prey. These sharks are more cautious when encountering divers and can usually be driven off (2).

The blacktip reef shark is regularly caught by inshore fisheries in many parts of its range, (2). It is caught for human consumption, fishmeal, and their fins enter the oriental sharkfin trade, for sharkfin soup. Their livers are also sought as a rich source of oil (6). In Indonesia, it forms part of the catch of sharks, rays and skates, which has increased dramatically from 1,000 tonnes in 1950 to 95,600 tonnes in 1997 (7). It is also fished off India and Thailand (2), and in the western Indian Ocean, where it is caught on longlines and in gill nets (6). In northern Australia it is occasionally caught and eaten by some Aboriginal communities (8). Due to such extensive exploitation, it is thought that blacktip reef shark populations are likely to be depleted (4).

It is possible that the blacktip reef shark may also be impacted by the destruction of coral reefs (4). It is estimated that 20 percent of the world’s coral reefs have already been effectively destroyed and show no immediate prospects of recovery, and 24 percent of the world’s reefs are under imminent risk of collapse. This is the result of numerous human activities that cause an increase in sediment, nutrients and pollutants to enter the oceans and stress the fragile reef ecosystems (9).

At present there are no known conservation measures in place for the blacktip reef shark.

View information on this species at the UNEP World Conservation Monitoring Centre.

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For further information on sharks and their conservation:

• Save Our Seas Foundation:
  http://www.saveourseas.com/
• Project Aware:
  www.projectaware.org

For more information on the blacktip reef shark:

• 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. Part 2: Carcharhiniformes. Food and Agriculture Organization of the United Nations, Rome. Available at:
  www.fao.org/docrep/009/ad123e/ad123e00.htm
• Blacktip Reef Shark Biological Profile, Ichthyology Department, Florida Museum of Natural History:
  www.flmnh.ufl.edu/fish/Gallery/Descript/BlacktipReefShark/BlacktipReefShark.html