The Mediterranean is a "key hotspot of extinction risk" according to a report by the International Union for Conservation of Nature (IUCN). The alarming assessment refers to a new survey of shark, ray and chimera populations in the Mediterranen region. And the description seems fitting, as more than half of sharks and rays in the Mediterranean Sea are at risk of extinction.

The IUCN monitors 73 species of sharks, rays and chimeras native to the Mediterranean, and the new report updates the organization's findings from 10 years ago. It concluded that at least 50 percent of rays (16 of 32 species) and 56 percent of sharks (23 of 41 species) face an elevated risk of extinction. Even worse, 20 species in total (12 sharks and 8 rays) are critically endangered.

"There were no genuine improvements in status for the 73, whereas the status of 11 species worsened by at least one Red List Category," the study's authors wrote on the development over the past 10 years. Also, during the past 50 years, 13 species have become extinct locally.

The situation is particularly dire in the northwestern part of the Mediterranean - along the coasts of Italy, France and Spain, and to a lesser degree in the Adriatic Sea and along the coast of northwest Africa.

"The principal driver of decline and local extinction is overfishing," the report states, adding that sharks are also often caught as valuable bycatch and kept. Longline fishing, intended to catch tuna and swordfish, often hooks sharks as well.

"Governments need to support catch monitoring [...], regulate gears and establish fishing quotas, and protected areas at the domestic level," said Nicholas Dulvy, co-chair of the IUCN shark specialist group and a researcher at Simon Fraser University in Vancouver, in a statement.

"Consumers, on the other hand, need to be aware of the risk of what buying these products entails."