Endangered sharks and rays are caught in the Mediterranean Sea more often from protected than unprotected sites, according to a study published Tuesday (August 9, 2022) in the journal Nature Communications, highlighting the role of small fishing boats.
These animal species are among those most at risk of extinction due to overfishing. Although sharks and rays are often caught by mistake after being caught in the nets of boats looking for other fish, the demand for their meat and fins has caused their numbers in the oceans to decline by about 71% since 1970. Despite dozens of countries banning the hunting of the endangered sharks and rays. It is widely exploited, but 90% of its global catch is associated with small boats that catch this species by mistake.
A group of Italian researchers wanted to get a better picture of the status of species in partially protected areas in the Mediterranean, where fishing is legal with certain controls. To achieve their goal, the researchers recorded animals caught in boats as they arrived in ports, then created a database of small catches at 11 locations in France, Italy, Spain, Croatia, Slovenia and Greece, and then subjected them to analysis.
Using statistical models, the research team proved that the number of endangered animals caught in partially protected areas (517 animals) is higher compared to the numbers caught in unprotected areas (358 animals). Among these animals, 24 species of sharks and rays are endangered. After the team weighed the animals, it was found that sharks and rays caught in partially protected areas weighed twice as much as those in unprotected areas. The result explains that these species prefer to live in coastal waters where most fishermen prefer to work.
“Most people assume that large fishing vessels affect biodiversity, and that’s a valid idea,” said Antonio Di Franco, one of the authors of the study at the Sicilian Maritime Center, noting that there is “little research on the impact of small-scale fishing.” We do not know the details of the activities of the artisanal fishermen, not even the number of nets they actually use, nor in which areas they fish.
More than a hundred countries have pledged to increase the area of the world’s protected oceans by 30% by 2030. Antonio Di Franco believes that countries can equip small fishing boats with GPS devices and ensure that protected areas are interconnected, allowing species to more easily change where they swim.
MAH/KS (AFP)
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Photo album… global warming threatens the extinction of marine life
catastrophic consequences
Scientists are becoming more and more concerned about the catastrophic effects of global warming and climate change. Recently, a new study, some of which was published in Britain’s Guardian newspaper, warned that global warming could cause drastic changes in the world’s oceans to the extent that it could threaten the mass extinction of marine species, which could become the world’s largest species extinction in history. planet. The photo shows the Great Barrier Reef in Australia.
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Photo album… global warming threatens the extinction of marine life
Low biological richness.. the beginning!
Accelerating climate change is causing a “profound impact on ocean ecosystems” that could lead to an increased risk of extinction. Scientists say this could begin to happen with a decline in marine biological richness and diversity that has not happened in Earth’s history for tens of millions of years.
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Photo album… global warming threatens the extinction of marine life
Fossil fuels…the silent killer
The global seawater temperature is constantly rising due to the burning of fossil fuels and emissions from industrial activities, while the oxygen levels in the ocean are decreasing and the water is becoming more acidic due to the absorption of huge amounts of carbon dioxide from the atmosphere.
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Photo album… global warming threatens the extinction of marine life
Lack of oxygen in water bodies
As ocean temperatures rise, oxygen levels decrease, affecting the ability of marine organisms to breathe. The amount of water bodies depleted of oxygen has quadrupled since the 1960s. Due to the high acidity of the water, oysters, mussels and shrimp can no longer form their shells properly, and fish have suffocated in dozens of places. This means that the planet could enter a phase of “mass extinction” of marine organisms.
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Photo album… global warming threatens the extinction of marine life
A catastrophic mass extinction… could happen again!
The study, published in the journal Science, says the pressures of warming seas and oceans and the loss of oxygen are reminiscent of a mass extinction that happened about 250 million years ago. Known as the Great Dying, this catastrophe wiped out up to 96% of the planet’s marine life.
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Photo album… global warming threatens the extinction of marine life
Catastrophic levels of extinction are expected
New research suggests that catastrophic levels of extinction could be reached if the world continues to release greenhouse gases unchecked, warming the planet by more than 4°C above pre-industrial average temperatures by the end of the century. This would lead to a species extinction that could reshape life in the ocean for many centuries to come.
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Photo album… global warming threatens the extinction of marine life
Danger is fast approaching
But even in the best case scenario, the world is still on the verge of losing a significant portion of its marine life. When the temperature rises two degrees Celsius above pre-industrial levels, which is expected even in light of the current climate pledges of world governments, about 4% of the total of about two million species of marine organisms in the seas and oceans will be eliminated.
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Photo album… global warming threatens the extinction of marine life
Arctic creatures are in greater danger
According to the study, fish and marine mammals living in polar regions are most at risk, because unlike tropical species, they will not be able to migrate to colder climates and will have nowhere to go.
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Photo album… global warming threatens the extinction of marine life
Other hazards
The threat of climate change exacerbates other major threats to aquatic life, such as overfishing and pollution. The study found that between 10% and 15% of marine species are already at risk of extinction due to these various threats, according to the IUCN.
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Photo album… global warming threatens the extinction of marine life
What we do today… determines the shape of our future
Scientists say the future of life in the oceans depends heavily on what we decide to do with greenhouse gases today. Accordingly, the shape of the oceans will be determined in the future: either vast areas of water that are almost devoid of any life, or oceans that preserve their sea creatures. It depends on our success in reducing carbon dioxide emissions. Edited by: Emad Hassan
