(AU ABC) Coral Reefs Across The World 'In Danger' As Scientists Note Slowing Calcification

ABC News - Myles Houlbrook-Walk

Lord Howe Island and the Great Barrier Reef are among the reefs across the planet where calcification is slowing. Supplied: Dr Kay Davis, Southern Cross University

Key Points The research found calcification, the growth process of coral reefs, is declining steadily The data has been drawn from 116 studies across a 50-year period and found calcification dropping at several Australian reefs including Lord Howe Island and the Great Barrier Reef Scientists warn climate change is the biggest threat to reef populations

A new report has issued a dire warning for the future of coral reefs in Australia and the rest of the world.

Research led by Kay Davis at the National Marine Science Centre in Coffs Harbour analysed 116 scientific studies looking at coral reef growth known as "calcification" over 50 years and found it could cease into the future.

Calcification allows corals to build the hard outer shells they need to survive.

Dr Davis said the reduction in calcification made it harder for reefs when they endured bleaching events.

"As coral growth decreases, it reduces the resilience for future stress events," she said.

Case studies looking at calcification included the Great Barrier Reef, Lord Howe Island and Western Australia as well as international sites. Lord Howe Island was included in the study. Supplied: Ian Hutton

Dr Davis found calcification rates had dropped at world-heritage site Lord Howe Island, which is the southernmost coral reef in the world.

"Calcification rates were between 30 to 55 per cent lower than healthy conditions," she said.

"Coral reefs globally could stop calcifying around 2054, which is really concerning because we need to preserve these coral reefs for the biodiversity they house."

Associate Professor of Physics Scott Heron at the Centre of Excellence for Coral Reef Studies was not involved with the research but said the findings were concerning.

Scientists say action needs to be taken in the next decade to secure the future of reefs around the world. Supplied: Victor Huertas

"The calcium carbonate skeleton of the reef is the foundational structure — if we take away the structure we take away the habitat," Dr Heron said.

The paper titled 'Global coral reef ecosystems exhibit declining calcification and increasing primary productivity' has been published in the scientific journal Communications Earth & Environment. 

Climate change key threat

Dr Davis noted calcification was influenced by a number of factors including sunlight, plastics or physical pollution, and the temperature of the water among others.

She was clear in what posed the biggest threat to reef health.

"The future of all coral reefs is on the line with global climate change," Dr Davis said.

Dr Heron echoed Dr Davis's sentiment.

"It really is critical this decade we take serious steps and significant action to reduce greenhouse gas emissions and minimise the impact on coral reefs," he said.

A spokesperson for Federal Environment Minister Sussan Ley told the ABC the government's strategy for improving the long-term outlook for coral reefs was to contribute to the global effort to reduce emissions reductions and take direct action to reduce pressures like poor water quality.

"Australia is also leading the way in reef adaptation science through the $150 million Reef Restoration and Adaptation Program — a world-leading project, which is being delivered by a consortium that includes Southern Cross University, to find innovative ways for coral reefs to adapt to the impacts of climate change," the spokesperson said.

Links

• Half of the Great Barrier Reef's coral has died since 1995, report says
• World's oceans absorbed the heat of 10 nukes every second in 2020, study finds
• The Great Barrier Reef breeding bonanza has kicked off with a bang, but bleaching legacy could make it a bust
• It Might Be The World’s Biggest Ocean, But The Mighty Pacific Is In Peril
• A Race Against Time To Rescue A Reef From Climate Change
• (AU) Barrier Reef Doomed As Up To 99% Of Coral At Risk, Report Finds
• (AU) Australia Marine Hotspots Found To Store 2bn Tonnes Of 'Blue Carbon'
• (AU) Great Barrier Reef Outlook Worsens To 'Critical' As Climate Change Named Number One Threat To World Heritage Sites
• (AU) 'There Is No Time To Lose': Great Barrier Reef Has Lost Half Its Corals
• (AU) Australia Cannot Wait For Climate Decision To Save Reef: Foundation