Scientists appeal for stronger rules on fishing and international trade in deep-sea sharks and rays

Fig. 1. The main uses of fish oil from shark liver (left) and trends in the fishing of sharks for fat, meat and fins (right).

The ocean depths are the last natural refuge of biodiversity virtually untouched by human activity. Deep-sea sharks and rays are among the marine vertebrates most sensitive to overfishing. Populations of a third of deep-sea shark and ray species are threatened, and half of the species involved in the international trade in fish liver oil are threatened with extinction. Stopping and reversing the dramatic population declines of deep-sea sharks and rays is challenging due to the long lifespans of most species, low reproduction rates, and little or no management of their fisheries.

An international team of scientists from 16 countries, including members of the Russian Academy of Sciences from the  P.P. Shirshov Institute of Oceanology RAS and the A.N. Severtsov Institute of Ecology and Evolution RAS, long-term data on the biodiversity of deep-sea sharks and rays, the state of their populations and the fishing of species hunted primarily for the production of fat from the liver, as well as for fins and meat, were analyzed. The purpose of the study was to understand the extent to which these types of fishing affect the diversity of the fauna of deep-sea sharks and rays and the state of their populations.

The results of the study showed that the populations of deep-sea sharks and rays have declined due to overfishing, aggravated by the presence of specific life cycle characteristics of these species. This combination of biology, overfishing and international trade has led to a doubling in the number of endangered deep-sea shark and ray species over the past 10 years, requiring urgent action to halt and reverse their dramatic population declines.

Fig. 2. Catch of chilled sharks at the fish market in Busan (Republic of Korea).

Article imprint: Finucci B., Pacoureau N., Rigby C.L., Matsushiba J.H., Faure-Beaulieu N., Sherman C.S., Vanderwright W.J., Jabado R.W., Charvet P., Mejía-Falla P.A., Navia A.F., Derrick D.H., Kyne P.M., Pollom R.A., Walls R.H.L., Herman C.B., Kinattumkara B., Cotton C.F.,Cuevas J.-M., Daley R.K., Dharmadi, Ebert D.A., Fernando D., Fernando S.M.C., Francis M.P., Huveneers C., Ishihara H., Kulka D.W., Leslie R.W., Neat F., Orlov A.M., Rincon G., Sant G.J., Volvenko I.V., Walker T.I., Simpfendorfer C.A., Dulvy N.K. 2024. Fishing for oil and meat drives irreversible defaunation of deepwater sharks and rays. Science.No.383. P. 1135-1141.  https://doi.org/10.1126/science.ade9121

Fig. 3. Dried rays at the fish market in Busan (Republic of Korea).

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RAS: "Research has shown a significant decline in populations of deep-sea sharks and rays due to overfishing"