The deepest known evidence of coral bleaching has been found in the Indian Ocean

Scientists have discovered deeper evidence of coral bleaching Indian OceanMore than 90 meters above the surface.

This unprecedented evidence of bleaching at depths previously thought to be resistant to ocean warming reveals severe damage. Coral reefs The ocean plays an important role in the ecosystem.

Study, published Natural communicationCoral reefs more than 90 meters below the surface of the Indian Ocean have suffered severe damage, with up to 80 percent of reefs in some areas affected.

Researchers from the University of Plymouth who carried out the study have said that this effect has been caused by a 30 percent increase in sea temperature in the Indian Ocean.

„It was a big surprise,” said Dr Phil Hosgood, associate professor of physical oceanography at the University of Plymouth and lead researcher on the study.

„Deep coral reefs have always been thought to be resilient to ocean warming, but that’s not clear.”

„Reefs at similar depths around the world may be at risk from similar climate changes.”

Researchers have been studying the central Indian Ocean for more than a decade, and have used a combination of underwater robots and satellite-generated oceanographic data to study damage to coral reefs.

During a research expedition in November 2019, scientists say they observed the first signs of coral bleaching using underwater vehicles equipped with remotely operated cameras.

While shallow reefs were unharmed, deeper reefs were found to be bleaching, highlighting the stark contrast in their vulnerability.

Experts say the bleaching is caused by a deepening thermocline, a layer where temperatures change faster with depth. This deepening is linked to regional climate systems such as El Niño, which are worsening and intensifying. Climate crisis.

„Due to climate change, cycles of this variability are increasing. Deep-sea bleaching here and elsewhere will become more regular,” said Clara Diaz, lead author of the study.

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Although parts of the affected reef will be recovered between 2020 and 2022, scientists are stressing the urgency of increasing monitoring efforts in the deep sea.

As damage to shallow-water coral reefs increased, mesophotic coral reefs were expected to compensate by providing essential ecological benefits. However, the findings challenge that assumption and reveal the vulnerability of deep-sea coral reefs.

The tropical Indian Ocean has experienced a rapid increase in ocean warming in recent decades, with an average sea surface temperature (SST) rise of 1C over the period 1951-2015, according to Indian government data.

This warming is happening at a rate of 0.15C per decade.