Climate change: coral reef cover has been decimated by the HALF since the 1950s

Coral reef coverage has declined by more than half since the 1950s due to climate change, overfishing, pollution and other human impacts, a study finds.

Researchers led by the University of British Columbia have the first comprehensive, global look at the effect of these changes on “ecosystem services.”

This refers to the ability of coral reefs to provide essential benefits to humans.

The team found that the loss of coral reef cover has resulted in an equal reduction in ecosystem services and a 60 percent loss in fish biodiversity and biomass.

They have warned that the continued degradation of global reef systems will threaten the well-being and development of reef-dependent coastal communities.

Coral reef coverage has declined by more than half since the 1950s due to climate change, overfishing, pollution and other human impacts, a study finds.

Coral reef coverage has declined by more than half since the 1950s due to climate change, overfishing, pollution and other human impacts, a study finds.

Researchers led by the University of British Columbia have the first comprehensive, global look at the effect of these changes on “ecosystem services” – the ability of coral reefs to provide important benefits to humans. Pictured: The change in coral cover from the 1950s to today

WHAT THEY STUDY

In their paper, Dr. Eddy and colleagues on five aspects of reef systems:

  • Living Coral Cover
  • Associated fishing catches and effort
  • Differences fish on the food web
  • Coral Reef Associated Biodiversity
  • Seafood Consumption by Indigenous Peoples on the Coast

“Coral reefs are known as important habitats for biodiversity and are particularly sensitive to climate change, as marine heat waves can cause bleaching,” said author and ecologist Tyler Eddy of Memorial University of Newfoundland.

‘Coral reefs provide important ecosystem services to humans, through fisheries, economic opportunities and storm protection.’

In their study, Dr Eddy and colleagues conducted a global analysis of trends in coral reefs and associated ecosystem services, taking into account the size of living coral, related biodiversity, and associated catches from fisheries.

They also looked at differences in fisheries in the food web, as well as seafood consumption by coastal indigenous peoples.

The data for the study comes from data from a variety of sources, including coral reef surveys, biodiversity assessments and fisheries statistics — enabling the team to assess both global and national trends in coral-related ecosystem services.

“Our analysis indicates that the ability of coral reefs to provide ecosystem services has declined by about half globally,” said author and marine biologist William Cheung of the University of British Columbia.

“This study speaks to the importance of how we manage coral reefs, not just on a regional scale, but also on a global scale — and the livelihoods of communities that depend on them.”

The team found that fish catches on coral reefs peaked nearly two decades ago and, despite increasing fishing effort, have declined since.

In fact, the so-called catch-per-unit effort — often used as an indicator of biomass changes — is now 60 percent lower than it was in 1950, as is the diversity of species living on coral. reefs.

“Coral reefs are known as important habitats for biodiversity and are particularly sensitive to climate change, as marine heat waves can cause bleaching,” said author and ecologist Tyler Eddy of Memorial University of Newfoundland. Pictured: A map showing the levels of change in coral cover around the world

“Coral reefs provide important ecosystem services to humans, through fisheries, economic opportunities and storm protection,” continued Dr. Eddie. Pictured: pink coral

The team found that fish catches on coral reefs peaked nearly two decades ago and, despite increasing fishing effort, have declined since.  Pictured: Pressures including climate change, pollution and overfishing are reducing seafood production on coral reefs

The team found that fish catches on coral reefs peaked nearly two decades ago and, despite increasing fishing effort, have declined since.  Pictured: Pressures including climate change, pollution and overfishing are reducing seafood production on coral reefs

The team found that fish catches on coral reefs peaked nearly two decades ago and, despite increasing fishing effort, have declined since. Pictured: Pressures including climate change, pollution and overfishing are reducing seafood production on coral reefs

“The effects of degraded and declining coral reefs are already evident through the impacts on livelihoods and commercial fishing and tourism in Indonesia, the Caribbean and [the] South Pacific,” the researchers wrote in their paper.

Marine protected areas, if any, don’t always protect against this, they noted — as such, they can’t protect against climate change and can also be limited in their enforcement capabilities.

even when marine protected areas are in place, as they fail to protect against climate change and may suffer from a lack of enforcement and staffing capacity for marine protected areas,” the researchers write.

“Fish and fisheries provide essential micronutrients in coastal developing regions with few alternative food sources,” the team continues.

Coral reef biodiversity and fisheries are becoming increasingly important to indigenous communities, developing small island states and coastal populations, where they can be essential to traditions and cultural practices.

“The diminished capacity of coral reefs to provide ecosystem services undermines the well-being of millions of people with historical and ongoing relationships with coral reef ecosystems,” they concluded.

The study’s full findings were published in the journal one earth.

Coral expels small marine algae when sea temperatures rise, turning them white

Corals have a symbiotic relationship with a small marine algae called ‘zooxanthellae’ that live in and feed them.

When the sea surface temperature rises, corals expel the colorful algae. The loss of the algae causes them to fade and turn white.

This bleached condition can last up to six weeks, and while corals can recover as temperatures drop and algae return, severely bleached corals die and become covered by algae.

In either case, this makes it difficult to distinguish between healthy corals and dead corals on satellite images.

This bleaching has recently killed up to 80 percent of corals in some areas of the Great Barrier Reef.

These types of bleaching events are four times more common worldwide than they used to be.

An aerial view of the Great Barrier Reef in Australia.  The Great Barrier Reef's corals have undergone two consecutive bleaching events, in 2016 and earlier this year, raising experts' concerns about reefs' ability to survive under global warming.

An aerial view of the Great Barrier Reef in Australia.  The Great Barrier Reef's corals have undergone two consecutive bleaching events, in 2016 and earlier this year, raising experts' concerns about reefs' ability to survive under global warming.

An aerial view of the Great Barrier Reef in Australia. The Great Barrier Reef’s corals have undergone two consecutive bleaching events, in 2016 and earlier this year, raising experts’ concerns about reefs’ ability to survive under global warming.

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