Global overfishing has wiped out more than 70 percent of sharks and rays, a “huge hole” in ocean life with unknown consequences, a report warned on Wednesday.
The decline of some species such as the hammerhead shark or the mantle ray is annoying.
Others, such as the ocean shark, are on the verge of extinction. Fishermen are looking for them for their fins, which are highly prized culinary. In 60 years, its population has decreased by 98%.
“It’s a worse decline than most large land mammals and similar to or equal to the blue whale,” Professor Nick Dulvy of Simon Fraser’s University of Biological Sciences told AFP.
His team collected and analyzed data to produce a reliable portrait of 31 species of sharks and rays.
Three quarters are in danger of extinction.
“We knew the situation was bad in many places, but that came from various studies and reports, it was difficult to get an idea of the global situation,” scientist Nathan Pacoureau, who signed the study published in Nature, told AFP.
“We reveal … an increasing risk of extinction for large species in the largest and most isolated habitats on the planet, which we often believe are protected from human influence,” Pacoureau told AFP.
“Data reveals a huge and growing hole in ocean life” denounces the experts, who call for an end to overfishing.
For the 18 species for which most data are available, researchers estimate that those populations have declined by more than 70% since 1970.
The results surprised the experts, explains Pacoureau.
Besides the ocean shark, The common hammerhead shark and the great hammerhead have reached a critical point: their populations have decreased by over 80%.
Sharks and rays are particularly vulnerable species because they grow slowly and reproduce little.
According to the study, the use of longlines and fence nets has doubled in fifty years, capturing marine life without discrimination.
And regional bodies regulating international fishing companies “have not included shark and ray protection as a priority,” Pacoureau said.
The application of protection rules also works an example is in the great white shark, a legendary species that has returned to American waters, explains this expert.