Kitefin Shark - Human Interactions

Human Interactions

The kitefin shark inhabits depths too great for it to be a danger to humans. Its upper teeth have been found lodged in underwater fiberoptic cables. This species has a long history of human exploitation: the meat is consumed in the eastern Atlantic and Japan, and the offal processed into fishmeal. The liver oil is utilized in Portugal, Japan, and South Africa. The skin is made into a type of shagreen useful in the making of furniture and jewelry, and is also favored for the manufacture of "boroso", a Spanish polished leather. This shark has no commercial value in the western Atlantic.

The continuing expansion of commercial fisheries into the deep sea has raised concerns about the vulnerability of this and other deepwater shark species to overfishing, as these sharks have slow growth and reproductive rates. This is exemplified by the rapid stock depletion and collapse of the Azores kitefin shark fishery. This targeted fishery began in the early 1970s for the production of liver oil. In the early 1980s, the fishing fleet was enlarged with the addition of industrial vessels equipped with demersal gillnets, resulting in a fishery peak in 1984 of 937 tons landed. After 1991, kitefin shark catches declined precipitously to under 15 tons annually which, along with a drop in the global price of liver oil, led to the fishery becoming unprofitable by the end of the decade. A population assessment has suggested that the northwestern Atlantic stock had fallen to 50% of the pre-exploitation biomass.

Fisheries operating off Portugal and Japan are responsible for most commercial landings of the kitefin shark, generally as bycatch in bottom trawls and on hook-and-line. Portugal reported a kitefin shark bycatch of 282 tons in 2000 and 119 tons in 2003. In other areas of the northeastern Atlantic this shark is rare and reported catches are likely confounded by misidentifications of other species; some are caught by mixed-species gillnet fisheries operating in deep water west of the British Isles, where surveys suggest that kitefin shark numbers may have declined by 94% since the 1970s. In the Mediterranean, this shark is caught incidentally by bottom trawl and gillnet fisheries. Although it is generally discarded alive, many are unable to return to deep water and do not survive. In the Southern Hemisphere, catches by the Australian South East Trawl Fishery are increasing following the relaxation of regulations regarding seafood mercury content; this species is not included under Australian fishery quotas. New Zealand kitefin shark catches peaked from 1986 to 1997. The International Union for Conservation of Nature (IUCN) has assessed the kitefin shark as Near Threatened worldwide, and as Vulnerable in the northeastern Atlantic in light of documented population declines.