Why are shark populations depleting?
Sharks have different life history strategies from other bony fishes. Most bony fish species mature early and produce a large number of tiny eggs, which allow for some populations to increase at rates of up to 30% per year. Hence, even if there is a decline in their original numbers to a small proportion due to human activities, extinction is unlikely for these bony fishes, unless other environmental factors prevent recovery. Shark biology however, is more closely related to cetaceans (such as whales and dolphins) than bony fishes. Similar to cetaceans, most sharks have slow rates of growth, mature late and give birth to a small numbers of well-developed young after a long gestation period. For example, Basking sharks take at least 15 years to mature, have a gestation period of 2-3 years and produce only 4-6 pups. Sharks life history strategy is typical of top predators with few natural enemies; therefore their populations usually decline rapidly when threatened. Hence, if given the op
