Almost two-thirds of shark and coral ray species are at risk of extinction

Nearly two-thirds of reef sharks and ray species are at risk of extinction, a new study finds, with overfishing ranked as the biggest threat.

The study looked at species on the International Union for Conservation of Nature (IUCN) Red List, which are critically endangered.

The researchers studied 134 species of sharks and rays, and say the findings indicate the need for immediate protection measures on coral reefs.

This includes putting in place legal protections, managing and enforcing rules among fisheries more effectively and establishing more marine protected areas.

Only some endangered sharks and coral rays are at risk of extinction, according to a study published in Nature Communications.

Some sharks and coral rays are most threatened

The study, conducted by researchers at Simon Fraser University in Vancouver, found that 59 percent of sharks and reef ray species are threatened with extinction.

These include:

  • Bull sharks
  • Cottle Ray
  • Porcupine stingers
  • shovel rays;
  • Top Shark
  • whip boss
  • Reef manta ray
  • Gray reef shark
  • Javanese cownose ray
  • Blue Lagoon Ray

As a result of climate change, coral reefs are among the most fragile ecosystems in the world.

In the study, published in Nature Communications, researchers from Simon Fraser University in Vancouver led by Dr Samantha Sherman said: ‘Population declines have occurred over more than half a century, with the largest declines occurring before 2005.

Immediate action is required through local protection actions, along with large-scale fisheries management and marine protected areas, to avert extinctions and loss of critical ecosystem function governing coral reefs with loss of shark and rays biodiversity and ecosystem services, limiting pathways Livelihood and food security.

There are currently 150,388 species worldwide on the ICUN Red List, of which 42,108 are threatened with extinction.

This means that 28 percent of all species could disappear from the face of the Earth if no action is taken.

The IUCN estimates that about 37 percent of all species of sharks and rays, in all habitats, face extinction.

Dr. Sherman’s study further revealed that the risk of extinction for sharks and rays that live in and around coral reefs, as a percentage of endangered species, is nearly double that of the 1,199 known species of sharks and rays.

The fact that 59 percent of reef sharks and rays, including sharks and rays, are threatened with extinction means that they are the second most threatened group in the world.

The blue-spotted ribbon ray (pictured) was the only species of shark and coral ray to see a population increase

The blue-spotted ribbon ray (pictured) was the only species of shark and coral ray to see a population increase

Graph showing the increase in extinction risks for sharks and coral rays over the past half century, comparing dates from 1970, 1980, 2005, and 2021

Graph showing the increase in extinction risks for sharks and coral rays over the past half century, comparing dates from 1970, 1980, 2005, and 2021

How many species are threatened with extinction?

According to the International Union for Conservation of Nature (IUCN) Red List, 42,100 species are threatened with extinction.

This accounts for 28 percent of all species.

  • Amphibians: 41 percent
  • Mammals: 27 percent
  • Conifers: 34 percent
  • Birds: 13%
  • Sharks and rays: 37 percent
  • Corals: 36 percent
  • Selected crustaceans 28 per cent
  • Reptiles: 21 percent
  • Cycads: 69 percent

They are only behind marine mammals, such as dolphins and manatees.

Most species of sharks and rays (about 70 percent) have seen population levels decline, with only 10 percent remaining stable.

In general, stingrays were more of a threat than sharks, with only sharks present The blue-dotted bar beam is increasing its population.

For larger species such as bull sharks and reef manta rays, which live on reefs, the risk of extinction is greater.

Several reasons have been given for the increased risk of extinction, including habitat loss and climate change.

Overfishing , However, it made up 75 percent of the sharks and rays studied.

Fishermen targeting sharks or rays were a threat to two-thirds of the species, while unintentional fishing was a threat to 98 percent of the species.

Of the 134 species measured, 109 are still used in some form for human consumption.

This included making leather from ray skin and selling fins and shark meat on the international market.

In countries with greater fishing pressure and weaker governments, such as Brazil, Tanzania and Indonesia, the risk of extinction for sharks and rays was greater.

The study found that 59 percent of reef sharks and rays are threatened with extinction.  Pictured: a cowboy ray in the sand

The study found that 59 percent of reef sharks and rays are threatened with extinction. Pictured: a cowboy ray in the sand

For larger species such as bull sharks and reef manta rays, which live on reefs, the risk of extinction is greater.

For larger species such as bull sharks and reef manta rays, which live on reefs, the risk of extinction is greater.

What is the IUCN Red List of Threatened Species?

The IUCN Red List of Threatened Species was created in 1964.

It has since evolved to provide a comprehensive list of the animals, fungi, and plant species most at risk of extinction.

Provides information about population size, habitat and environment.

It documents each species used or traded, the threats and conservation decisions made to help protect the species.

The list is used by government agencies, wildlife departments, conservation NGOs, students, and businesses.

Source: IUCN

The paper concluded that if conservation efforts to improve sharks and rays do not improve, the health of coral reefs could continue to decline, with negative impacts on the millions of people who depend on them.

She said: ‘Sharks and rays are key functional components of coral reef ecosystems, yet many of the few populations of species are showing signs of local depletion and extinction.

Besides marine mammals, sharks and rays are one of the most threatened groups found in coral reefs.

Overfishing is the main cause of the high risk of extinction, and is exacerbated by climate change and habitat degradation.

“The question is whether these declines herald a global extinction crisis.”

Coral reefs are becoming increasingly endangered habitats and are extremely sensitive to small changes in their environment.

A University of Hawaii study found that half of Earth’s coral reefs will be permanently damaged by 2035 if climate change continues unabated.

This was based on the effects of sea surface temperature, ocean acidification, tropical storms, land use, and human population.

Their results revealed that when looking at a single stressor under current conditions, half of the world’s coral reefs will be permanently damaged by 2050.

However, when multiple stressors are considered, this date is in the year 2035.

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