Climate change could cause disease to 76.8% of corals by 2100

Researchers from the University of New South Wales (UNSW Sydney) have estimated that 76.8 per cent of corals across the world would catch disease by 2100 amid global warming.

In their new study published in the Ecology Letters journal on Wednesday, the researchers created a data set encompassing 108 papers on global coral disease for a further meta-analysis, reports Xinhua news agency.

They found that both rising average summer sea surface temperatures (SSTs) and weekly sea surface temperature anomalies (WSSTAs) were associated with global increases in coral disease prevalence.

According to the study, global coral disease prevalence tripled to 9.92 per cent between 1992 to 2018.

When predicting future estimates of coral disease, the model suggested that the disease prevalence could reach 76.8 per cent in 2100 if temperatures continue to rise.

Samantha Burke, lead author of the study and Ph.D. candidate at UNSW Sydney, said that the findings highlight the devastating impacts of rising temperatures on coral reefs and the dire need for swift action to mitigate climate change.

"Coral disease is a serious cause of coral mortality globally and reef decline, and our modeling predicts it will only continue to worsen," said Burke.

The scholar warned that as coral disease prevalence is climbing across the globe, more coral will become diseased without urgent action taken to address warming temperatures.

"As the ocean warms, it increases coral stress which can decrease its immune response," said Burke. "Increasing temperatures can also create more favourable conditions for the pathogen causing disease."

At the current stage, scientists have yet to identify many of the disease-causing pathogens.

"It's still relatively unknown whether the microbes associated with diseased coral are the cause or a symptom of disease, just that the coral is sick, and the tissue is dying," Burke said.

"Whether the fungi or bacteria present caused disease or merely fed on the dying tissue is unclear, so researchers need to study it further," she added.