Tiger Shark

This species has relatively fast growth rates and large litters (on average 26-33 pups) but the likely triennial reproductive cycle reduces its ability to recover from fishing pressure. The Tiger Shark is caught by commercial, recreational, and artisanal fisheries as a target species or bycatch. However, records of Tiger Shark catches by many fisheries globally are still largely unknown. The species is one of the major components in catches from shark control programs that target large shark species in Australia, South Africa, and Reunion Island. Information on stock assessment, population structure and overall population trends are lacking for much of the species’ distribution and available trends in catch rates are based on analyses of the long term shark control programs and on observer surveys from the Western North Atlantic. In Australia, the Queensland Shark Control Program showed declines in catch rates since the 1980s and in New South Wales, evidence of a decline was also seen in the last 20 years. Additionally, a significant reduction of the proportion of mature sharks in catches over 60 years suggests shifts in population structure and raises concerns over possible effects from this program on the Tiger Shark population off New South Wales. The decline off eastern Australia is likely to continue while the shark control programs off Queensland and New South Wales remain active. In the U.S. fisheries of the Western North Atlantic, observer surveys variously recorded increases in Tiger Shark relative abundance and no change in abundance. In South Africa, the beach protection program showed a 3% increase per year in Tiger Shark catch rates. The increasing rates in the Western North Atlantic and South Africa seem consistent with the pattern observed in the first 20 years in Queensland and the interpretation of such upward trends should be made with caution. In the Arabian Seas region, the Tiger Shark has been assessed as Vulnerable based on a suspected decline of at least 30% over the past three generations based on levels of exploitation, with the continued demand from the shark fin market suspected to result in further population reduction in the future. Globally, The Tiger Shark is suspected to have declined by close to 30% over the past three generations (53-68 years) due to exploitation from commercial, recreational, and unregulated fisheries, as well as shark control programs. A further population reduction is suspected over the future three generation lengths (2018-2086) based on current levels of exploitation that are likely to continue into the future. As such this species is assessed as Near Threatened (close to meeting Vulnerable A2bd+3d).

There are no specific conservation or management measures in place for the Tiger Shark. However, there has been an increasing interest to intensify protection of the species in the Western North Atlantic. The current Fisheries Management Program for the U.S. Atlantic and Gulf of Mexico includes quotas and fishing seasons to regulate catch of coastal shark species including the Tiger Shark (Carlson et al. 2012). On the west and south coasts of Western Australia, a maximum size of 70 cm interdorsal length is applied for whaler sharks taken by recreational shark fishing, which includes the Tiger Shark. In Queensland, the maximum size allowed is 150 cm for all shark species and a possession limit of one shark of any species is imposed to recreational fishing. Similarly, in New South Wales, only one Tiger Shark can be taken per person per day. Some countries in the Arabian Seas region have banned the targeted fishing for sharks (e.g. Kuwait, Saudi Arabia, Sudan, the Maldives), whereas others impose seasonal bans on shark fishing (Iran, the UAE) (Jabado and Spaet 2017).