Sharks and rays of all shapes and sizes are at risk of serious and long-lasting depletion, primarily from overfishing for their meat as well as fins, through targeted fisheries and incidentally as "bycatch". Their tendency to grow slowly and produce few young makes them more vulnerable to overexploitation than most other species of fish.
The most threatened species in the shark and ray Class are the sawfishes; all the world's species are classified by the IUCN (International Union for Conservation of Nature) as Critically Endangered. The US population of smalltooth sawfish has declined by an estimated 99% while European sawfish are assumed extinct.
Several species of US Atlantic large coastal sharks have been severely depleted; the dusky shark doesn't reproduce until after age 20 and its recovery plan spans hundreds of years.
Hammerhead sharks are prized for their fins (for use in shark fin soup) and tend to die very quickly once caught in fishing gear; great and scalloped hammerheads are listed by IUCN as Endangered and are considered the most threatened of all the world's highly migratory sharks.
Wide-ranging, oceanic sharks are taken incidentally in large numbers by tuna and swordfish fishermen and increasingly targeted on the high seas; more than half of this group of species, including threshers and makos, are categorized by IUCN as threatened.
Porbeagle sharks have long been targeted for their meat in the North Atlantic; Canada still allows targeted fishing of the Northwest Atlantic population (classified by IUCN as Endangered) while the European Union (EU) has banned fishing on the Critically Endangered Northeast Atlantic porbeagle population.
Spiny dogfish sharks (or spurdog) in the Northwest Atlantic have recently been rebuilding from years of excessive fishing targeted at large females (which are usually pregnant as gestation lasts nearly two years). US Atlantic fishing quotas have been increased dramatically in recent years despite the population's damaged age structure and skewed sex ratio, and predictions that declines will resume in the near future. EU spiny dogfish fisheries in the Northeast Atlantic have been recently closed after decades of poorly regulated fishing drove the population to a Critically Endangered state. The EU still imports spiny dogfish from other countries, as far away as New Zealand.
Deep-sea sharks are sought for their liver oil and meat, particularly in Europe. EU fishery managers took years to bring fishing quotas down to near zero; some species in this complex are classified as Endangered and are still taken as bycatch and sold. Deepwater Greenland sharks are protected in the EU, but still taken in fair numbers in Iceland and Greenland where their meat is buried, fermented, and dried over months, and then served as a delicacy.
Skates are eaten in many parts of the world and particularly valued in Europe. They are targeted and taken as bycatch, primarily by trawl fisheries. The "common skate" has been wiped out in parts of the North Sea and are now a prohibited species in the EU. US Atlantic thorny skates are classified by IUCN as Critically Endangered and have yet to begin rebuilding since receiving US prohibited species status in 2004.
Huge manta and devil rays are at great risk, particularly in the Pacific and Indian Oceans, from surging demand for parts of their gills which are used in Chinese medicine. A recent decision to strictly protect the giant manta ray by Parties to the Convention on Migratory Species holds promise, but follow up action and attention to similar species is urgently needed. Mediterranean countries agreed more than a decade ago to protect the Endangered giant devil ray, whose main threat is bycatch, but only Malta, Croatia, and Spain have done so.
Fishing industry groups, particularly in the US state of Virginia, are aggressively marketing the meat of cownose rays to local and Asian markets, without any plans or means for limiting catches. Cownose rays usually only have one baby per year and are therefore exceptionally susceptible to overfishing.
Great white, basking, and whale sharks are the world's most protected shark species, but are still at risk from bycatch, boat strikes, and illegal fishing.