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One-third of shark and ray species on the brink of extinction due to overfishing

By on September 8, 2021 0

Overfishing makes a third of shark and ray species susceptible to extinction, according to an eight-year scientific study.

Professor Nicholas Dulvy, Simon Fraser University in Canada, lead author of the article, said: “Sharks and rays are the canary in the overfishing coal mine. If I tell you that three quarters of tropical and subtropical coastal species are threatened, imagine a David Attenborough series with 75% of its predators gone. If the sharks are in decline, there is a serious problem with the fishery. ”

(Photo: Getty Images)

The former co-chair of the International Union for Conservation of Nature (IUCN) Shark Specialist Group whose name is Dulvy said the health of all ocean ecosystems and food security are at risk.

The number of species of sharks, chimaeras and rays which are all called chondrichthyan fish, experiencing “a global extinction crisis” in less than a decade has more than doubled, according to the article published Sept. 6 in the journal Current Biology.

Read also: Freshwater in danger: marine giants face extinction risk

Threatened species

The most threatened of these is the skate and 41% of the 611 species studied are at risk; for shark species, 36% of the 536 species are at risk; and for chimeric species, 9% of the 52 species are at risk.

Dulvy said the study reveals a growing grim reality. Currently, these species constitute one of the most endangered lines of vertebrates followed by amphibians in the risks they incur.

He said: “The widespread depletion of these fish, especially sharks and rays, threatens the health of entire ocean ecosystems and the food security of many countries around the world.”

The analysis is the second to be conducted since 2014 and it follows a January study which found that the shark and ray population had declined by more than 70% in the past 50 years, with species once widespread. like the endangered hammerhead sharks.

Sea ray

(Photo: Getty Images)

Overfishing

Sharks, chimaeras and rays are susceptible to overfishing and this is because they gradually grow up and give birth to a few young. It has been roughly calculated that humans kill 100 million sharks a year, completely nullifying their slow reproductive capacity.

The main threat to chondrichthyans was industrial fishing, either alone or in combination with other fisheries, the authors said.

The report says most sharks and rays are not caught on purpose, but perhaps the “unauthorized target” in most fisheries, and are kept for food and feed. The authors said habitat loss and degradation, pollution and the climate crisis worsen overfishing.

Experts have found that in tropical and subtropical waters, species are disproportionately threatened, mostly off countries like Indonesia and India, due to the very high demand from large coastal populations associated with mostly uncontrollable fisheries, generally driven by demand for higher value products such as fins.

Associated article: Global freshwater fish threatened with extinction, 16 have already gone extinct in 2020

For more news, fish updates and similar topics, be sure to follow Nature World News!

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