Shark mortality is on the rise

(Montreal) The measures adopted in recent years to ban the harvesting of shark fins have been accompanied by an increase in mortality due to the fishing of these predators, reveals a study to which several Canadian researchers contributed.

The study published by the prestigious journal Science indicates that mortality increased from 76 million to 80 million sharks per year between 2012 and 2019, even though the number of laws aimed at combating finning increased tenfold during this same period.

About a third of the sharks killed during this period were from species threatened with extinction.

“The number of endangered shark species in the world continues to increase, not decrease,” said the study’s lead author, Professor Boris Worm of the Department of Biology at Dalhousie University, in New York. -Scotland.

“We found, because we went country by country, that regulations in some countries (…) were actually successful in reducing mortality, but this was offset by increases in other regions. So we’re not seeing an overall decline, but we’re seeing some signs of hope that if we actually address mortality, not just finning, it’s possible to bring mortality down. »

Shark fins are very popular in certain markets, particularly in Asia. The practice called “shark finning” in English consists of amputating the shark’s fins and tail before throwing the carcass back into the water.


Shark fins

No study has until now looked into the effectiveness of the measures adopted to combat this practice. The researchers therefore examined shark mortality in 150 countries where they are fished, as well as on the high seas.

Inshore fishing was responsible for 95% of all sharks caught and killed during the study period. Mortality in these fisheries increased by 4% between 2012 and 2019. In contrast, during the same period, mortality decreased by 7% in open sea fisheries, especially in the Atlantic and western Pacific.

The crackdown on shark finning seems to have had the perverse effect of opening up new markets for the flesh. Now that they were forbidden to keep only the fins, fishermen began keeping and selling the whole animal.

The authors of the study noted an increase in demand in countries such as Brazil and Italy. Because shark meat is a cheap substitute for that of other fish, they say, misidentification of the product is common and many consumers are likely eating it without knowing it.

For example, a survey carried out in the United Kingdom discovered that 90% of fish and chip samples analyzed contained shark meat.

“We’re seeing these emerging markets for shark meat and then shark oil and other shark products where we didn’t see them before,” said researcher Laurenne Schiller of Carleton University in Ontario. This shows that if we want to put regulations in place, we have to think about potential unintended consequences. And if the real objective is to fight against species mortality, you must ensure that what you put in place will really achieve this objective. »

Truly effective measures to protect sharks are rare. A complete ban on their fishing ― for example, in marine sanctuaries ― is one, the study authors warn.

Another solution is strict supervision of fisheries, especially with regard to endangered species, as is the case in Canada where these species must be returned to the water alive when possible, said Professor Worm.

“And thirdly, a more selective practice of fishing while trying to avoid sharks,” he added.

This would involve replacing fishing gear that catches sharks by mistake with gear that is more selective, or at least gear that allows the shark to survive while waiting for fishermen to return, Professor Worm added.

The authors call for the adoption of new policies specifically to discourage the conservation of overexploited and threatened species. They also underline the importance of making fleets, fishing companies and management bodies accountable to promote the proper implementation of these measures.

“The health of sharks in an ecosystem is a very good indicator of the health of the marine environment,” recalled Professor Schiller. When we see this level of mortality, we see what’s working, but also what we still need to focus on. We need to think more critically about our role, as humans, in protecting these species in order to hope for more resilient ecosystems in the future. »

Sharks have been swimming in the oceans for around 400 million years and are estimated to have survived at least five extinctions. However, today they are considered to be among the most endangered species on the planet.


Leave a Comment