Tiger Shark

Tiger Shark

The tiger shark is caught by commercial, recreational, small-scale, and artisanal fisheries as a target species or incidental bycatch for its high quality fins, skin, liver oil, meat, and cartilage.

Globally, the tiger shark is caught by commercial, recreational, small-scale, and artisanal fisheries as a target species or incidental bycatch and is subject to illegal, unreported, and unregulated (IUU) fishing operations. The species is one of the major components in catches from shark control programs that target large shark species in Australia, South Africa, and more recently Reunion Island in the Western Indian Ocean.

The tiger shark is valued for its high quality fins, skin, liver oil, meat, and cartilage. The tiger shark has been increasingly exploited by fisheries since the 1950’s due to the increasing demand from the shark fin trade as the fins of this species are a common component of the Hong Kong fin trade.

Catches of tiger shark in directed shark fisheries have been documented for a number of regions including the western Atlantic, Brazil, Australia, Papua New Guinea, Peru, Taiwan, India, and Saudi Arabia.

The tiger shark is a common component of the U.S. east coast/Gulf of Mexico commercial shark bottom longline fishery, accounting for 8-36% of the catch. The fishery catches mostly juvenile and sub-adult tiger sharks, although some larger sharks are also taken.

In Australia, the tiger shark is targeted by commercial shark fisheries in northern New South Wales and in Western Australia. The species accounted for 3 tonne (t) and 5.9% of total catch of the Ocean Trap and Line Fishery in eastern Australia. However, catches by this fishery are probably smaller than landings from recreational fisheries in that same area. In the Western Australia Tropical Shark Fishery, this shark was caught as a target species and annual catches averaged approximately 41 t between 2000 and 2004. This fishery was closed in late 2005. The Offshore Net and Line Fishery operating in the northern Australia catches the species incidentally (27 t in 2012), although mesh size is assumed to prevent capture of greater numbers. This shark is also taken in the Southern and Western Demersal Gillnet and Demersal Longline Fishery in Western Australia with a catch of 112 t reported in 2005-06. The Tiger Shark is a bycatch in trawl fisheries although normally in small numbers and there are few records of catches for these fisheries. The Australian Commonwealth Trawl Sector reported a total catch for the species of 4.7 t from 2004-2011.

The tiger shark is relatively common in the Indonesian shark fishery and contributed 5.2% of the total shark biomass of catches from between 2001 and 2006. The tiger shark is also commonly caught in the seamount gillnet and longline fishery off the west coast of India, where 242 t and 144 t of various shark species were taken during 2010 and 2011, respectively, but species-specific catches were not recorded. The Tiger Shark is caught occasionally in the longline fisheries of Costa Rica, Mozambique, and Saudi Arabia and by purse seiners in the Indian Ocean. Although little species-specific catch data information is available for the Arabian Seas area, the high level of level of fishing pressure in the region is of concern with steep increases in both small-scale and industrial fishing effort between the 1990s and 2000s.

In tuna longline fisheries, the species is typically caught in small numbers relative to pelagic sharks and is often not reported. Between 2007 and 2013, an average of 54 t was landed annually by tuna longline boats regulated by the International Commission for the Conservation of Atlantic Tuna. Tiger shark represented less than 10% of the total bycatch of all shark species in each of the management zones of the U.S. pelagic longline fishery. In the Panama longline fishery, the tiger shark represented 1.6% of shark catches of the estimated total catch of 109,500 t of various sharks since the mid-1980’s. In the Central and Western Pacific, the tiger shark is caught in low numbers (0.025 sharks per set) by tuna longline boats from most countries operating in that region. The tiger shark is a common target of recreational fisheries in the United States, Australia, and South Africa. Approximately 96% of the catch in USA waters are released alive. In the New South Wales Gamefish Tournament, tiger shark catches were approximately 8 t per year between 1993 and 2005. Recreational fishing may account for mortality in the tiger shark population in other countries, although catches are unmonitored.

Artisanal fisheries and IUU fisheries are also likely to be catching tiger shark, however information about landings from these fisheries is scarce as they remain mostly unmonitored. The tiger shark is commonly caught in artisanal fisheries in the tropics and subtropics, including in Mexico, Panama, Brazil, and a few African countries. In Bangladesh, landings of 4.5 t represent on average 1.36% of total catch. There is evidence that the species has been overfished by Indonesian fishing boats at Ashmore and Cartier Islands, and Scott Reef in northern Australian waters. This area had been targeted by Indonesian fishermen since the 1800’s but fishing was banned in 1988 and 2000, respectively. A survey in the region showed the absence of tiger shark at reefs historically fished despite years of protection whereas they were found present at nearby atolls that had been always protected from fishing. The species comprised 19% of the total shark biomass and 7.4% of total catch in numbers from Indonesian and Taiwanese IUU fishing vessels.

The tiger shark is a target species of shark control programs in Queensland and New South Wales, Australia, in South Africa, and more recently at Reunion Island. In Australia, the Queensland Shark Control Program (QSCP) captured 4,757 tiger shark individuals between 1993 and 2010 and the species represented approximately 10-30% of total catch in the northern locations of the QSCP between 1964 and 2007. Standardized catch rates from 1964-2007 for the QSCP in northern Queensland showed an increase in the relative importance of the tiger shark, from approximately 10 to 30% of total catch. This pattern is most likely due to the move in fishing gear from nets to drumlines. In southeast Australia, the tiger shark was commonly captured by the New South Wales Shark Meshing Program from 1950-2010 with approximately 30 sharks per year between 1950 and 2008, representing approximately 10% of the common shark species caught by the program in each of its locations. In South Africa, the KwaZulu-Natal beach protection program has caught approximately 50 individuals annually from 1978-2003. Since 1989, sharks caught alive are released; however, fishing mortality of the tiger shark in nets is 27% of captures.


Image | ©️ tobze, Some Rights Reserved (CC BY-NC-ND 2.0)
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