Video: Large marine animals are more at risk of extinction, study finds


Large marine animals are more threatened with extinction, study finds

Larger marine animals are more likely to go extinct than smaller creatures, according to a new study that blames human behaviors, such as fishing, for this unprecedented extinction pattern in the oceans.

Scientists at Stanford University in California believe humans are driving larger marine animals to extinction due to intensive fishing, with larger animals being targeted for food.

“We have found that the threat of extinction in modern oceans is very strongly associated with increased body size,” said Jonathan Payne, of Stanford University in the United States.

“This is probably because people are targeting the larger species first for consumption,” Payne said.

Researchers have examined the association between the level of threat of extinction and ecological features such as the body size of two large groups of marine animals – molluscs and vertebrates – over the past 500 years and compared it with the ancient past, stretching back 445 million years and with particular emphasis on the most recent 66 million years.

“We have used the fossil record to show, in a concrete and convincing way, that what is happening in modern oceans is really different from what has happened in the past,” said Noel Heim, postdoctoral researcher at the laboratory of Payne.

Researchers have found that the modern era is unique in that larger creatures are preferentially targeted for extinction.

“What our analysis shows is that for every 10-fold increase in body mass, the odds of being threatened with extinction increase by around a factor of 13. The fatter you are, the more likely you are to become extinct. ‘be threatened with extinction’. said Payne.

The selective extinction of large animals could have serious consequences for the health of marine ecosystems, scientists said, as they tend to be at the top of food chains and their movements in the water column and the seabed. help recycle nutrients in the oceans.

While the researchers did not directly examine why modern large marine animals are at a higher risk of extinction, their findings are consistent with a growing body of scientific literature that points to humans as the main culprits.

It is a model that scientists have already seen. On earth, for example, there is evidence that ancient humans were responsible for the slaughter of mammoths and other megafauna across the world.

“We see this over and over again. Humans are entering a new ecosystem, and the larger animals are killed first,” Heim said.

“Marine systems have been spared so far, because until relatively recently humans were limited to coastal areas and lacked the technology to fish the deep sea on an industrial scale,” he said. declared.

(With the contribution of the agency)

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