Australian Blacktip Shark - Human Interactions

Human Interactions

Along with the spottail shark, the Australian blacktip shark is one of the most economically important sharks off northern Australia. It was historically fished for its meat and fins by a Taiwanese gillnet fishery, which began operating off northern Australia in 1974. The annual catch initially averaged around 25,000 tons (live weight), with approximately 70% consisting of Australian blacktip sharks, spottail sharks, and longtail tuna (Thunnus tonggol). Following the establishment of the Australian Fishing Zone (AFZ) in November 1979, the Australian government progressively excluded Taiwanese gillnet vessels from large portions of Australian waters and imposed fishing quotas. The fishery eventually became uneconomical when Australia restricted gillnet lengths to 2.5 km (1.6 mi) in May 1986, and Taiwanese vessels ceased fishing in Australian waters that year. At end of the fishery, Australian blacktip shark numbers were estimated to have been diminished by around 50%. Given its relatively high reproductive rate, its population has likely since recovered.

Since 1980, the Australian blacktip shark has also been targeted by Australian commercial gillnetters and longliners in the Northern Shark Fishery. It is additionally caught incidentally by other commercial fisheries targeting bony fishes or prawns. The contemporary northern Australian shark catch is estimated to be between 100 and 900 tons (live weight) annually, of which most are Australian blacktip and spottail sharks. The meat of this species is sold in Australia as "flake", though it may contain high concentrations of mercury. The fins are exported to Asia, while the cartilage, liver oil, and skin may also be used. Since fishing pressure on the Australian blacktip shark is now much lower than historical levels, the International Union for Conservation of Nature (IUCN) has listed it under Least Concern. However, of potential concern are Indonesian fishers in the Arafura Sea, who are increasingly trespassing into the AFZ.