Leopard Shark - Human Interactions

Human Interactions

Wary and quick to flee, leopard sharks pose almost no danger to humans. There is a single record from 1955 of a leopard shark harassing a skin diver with a nosebleed, though no injuries resulted. This species is caught by commercial fisheries using gillnets and longlines, and by recreational anglers and spearfishers; it is also caught as bycatch in bottom trawls. The meat is considered excellent eating and is sold fresh or frozen. However, leopard sharks living alongside human development may accumulate pollutants such as mercury, pesticides, and polychlorinated biphenyls (PCBs) within their bodies, and the California Department of Fish and Game warns against eating them regularly. The leopard shark is prized by the aquarium trade for its attractive appearance and hardiness; this led to many newborn pups being captured with hook-and-line off southern California in the late 1980s and early 1990s. It may live for over 20 years in captivity.

Most of the fishing for leopard sharks occurs in the waters off California, where commercial landings peaked at 45,953 kg (101,310 lb) in 1983 and has averaged 14,060 kg (31,000 lb) annually since 1991. These figures are believed to be underestimates, as an unknown portion of the leopard shark catch is recorded simply as "shark". In recent decades the number of sharks taken recreationally has exceeded those taken commercially, with sport fishers catching an average of 52,000 sharks per year from 1980–1988, and 45,000 sharks per year since 1993. This species contributes negligibly to fishery landings off Oregon. The status of leopard sharks off Mexico is uncertain, although Mexican shark fisheries tend to focus more on larger species.

The International Union for Conservation of Nature (IUCN) has assessed the leopard shark as of Least Concern. It is highly susceptible to local depletion due to its slow growth rate and low level of exchange between regional stocks. It was considered for, but is not managed under, the U.S. Pacific Fishery Management Council's (PMC) 1982 Groundfish Management Plan. In 1992, the State of California imposed a recreational minimum size limit of 91 cm (36 in) and a possession limit of three fish, a move that was strongly supported and promoted by the sport fishing community. In 1993, the State also instituted a minimum size limit of 46 cm (18 in) for the commercial harvesting of all sharks and rays, including for the aquarium trade. In addition, Californian restrictions on the use of certain types of fishing gear in near-shore waters confer good protection to this shark's core population. These management measures seem to have successfully reduced fishing mortality and halted the population decline from the 1980s; the status of the leopard shark off California is regarded as secure, with demographic models estimating an annual population increase of 3–6% with sustainable fishing.