Scientists are sounding the alarm: the number of deep-sea sharks and rays is declining due to overfishing

An international team of scientists has called for stricter regulations on fishing and trade in deep-sea sharks and rays. This was announced on its website by the Institute of Ecology and Evolution named after A.N. Severtsov (IPEE) RAS with reference to a study published in the authoritative journal Science.

"The ocean depths are the last natural refuge of biodiversity, virtually untouched by human activity. And deep-sea sharks and rays are among the marine vertebrates most sensitive to overfishing. Populations of a third of the species of deep-sea sharks and rays are in a threatened state, and half of the species involved in the international trade in fish oil from the liver are threatened with extinction," IPEE said in a statement.

Researchers from 16 countries, including the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences and IPEE RAS, analyzed long-term data on the biodiversity of deep-sea sharks and rays, the state of their populations and the fishing of species extracted for the production of liver fat, as well as for fins and meat.

"The results of the study showed that the number of populations of deep-sea sharks and rays has decreased due to overfishing, aggravated by the presence of specific life cycle features in these species. This combination of biological traits, overfishing and international trade has led to a doubling of the number of endangered species of deep-sea sharks and rays over the past 10 years," the report says.

According to scientists, the situation requires urgent measures to stop and reverse the sharp decline in the populations of these animals. However, this "is not an easy task due to the high life expectancy of most species, low reproduction rates and the almost complete lack of management of their fishery."