WMU Professor Co-Authors Important Global Study on Deep Water Shark and Ray Extinction Risk
World Maritime University (WMU) Professor, Dr Francis Neat, has co-authored important research findings in a new analysis, “Fishing for oil and meat drives irreversible defaunation of deepwater sharks and rays,” published in the journal Science, March 2024 issue.
As deep as 3000 metres below the surface of the ocean there are over 500 species of deep-sea sharks. The deep ocean is the last natural biodiversity refuge from the reach of human activities, and according to the research, deepwater sharks and rays are among the most sensitive marine vertebrates to overexploitation. In recent decades they have been severely and globally overfished for their valuable liver oil, meat or they are inadvertently killed as unwanted bycatch. One-third of threatened deepwater sharks are targeted and half the species targeted for the international liver oil trade are threatened with extinction.
The trade of shark liver oil (squaline), is a lucrative business connected to the cosmetic and medical/supplement industry, among others. The research highlights that deep sea shark fisheries are not only wasteful, due to only the liver being retained with the carcass most often discarded overboard, but are wholly unsustainable and a significant threat to ocean biodiversity.
The unusual looking deep-sea sharks are generally not featured in marine conservation campaigns. Nevertheless, the article highlights that they are evolutionarily and ecologically important and need urgent protection. Steep population declines cannot be easily reversed as most deep sea sharks are slow growing, live to be very old, mature late and have very few offspring.
The research shows that deep sea sharks cannot withstand commercial fishing pressure. Depth and spatial limits to fishing activity could improve conservation when implemented alongside catch regulations, bycatch mitigation, and international trade regulation. Immediate trade and fishing regulations are required to prevent irreversible defaunation and promote recovery of this threatened megafauna group of deepwater sharks and rays.
This new research is the consolidated global outcome of a 2019 meeting of the International Union for the Conservation of Nature’s (IUCN) shark specialist group in Vancouver, Canada that aimed to compile information and assess the conservation status of deep sea sharks around the world, identifying species that are threatened with extinction and that should be on the IUCN’s so-called Red List. Information on all 521 known deep shark species is included in this new research that suggests around 20 percent are now classed as threatened with extinction.
Professor Neat has carried out over a decade of research on the deepwater ecosystems and fisheries of the North Atlantic and he participated in the 2019 IUCN meeting. Regarding this new research, Professor Neat remarked, “This paper is an important global call for conservation in the deep ocean and is especially timely given the recent agreement reached at the UN for a treaty on Biodiversity Beyond National Jurisdiction. Protecting these sharks will most likely be achieved through prohibition of targeted deep sea shark fisheries or through depth specific fishery restricted areas, such as the 800 metre trawl depth ban in European waters.”
To access the article click here.
