The world’s largest coral system, the Great Barrier Reef, just faced its biggest coral loss in almost 40 years. This new report brings a harsh truth. It comes from the Australian Institute of Marine Science (AIMS). The reef had shown good recovery since 2017. But last year, a major coral bleaching event hit hard. Even so, the overall coral levels are still close to the long-term average. This shows how much the reef can change.
Mike Emslie leads the AIMS long-term monitoring program. He noted the reef had its best growth in 39 years. Still, he called the recent loss significant. It’s clear that more frequent bleaching events are hurting this huge ecosystem. This UNESCO World Heritage site faces tough times.
The report split the Great Barrier Reef into three main parts. These are the Northern, Central, and Southern sections. The reef stretches for over 1,500 kilometers. Live coral dropped a lot in all areas. The Southern part lost almost one-third. The Northern area lost one-fourth. The Central section saw a 14% drop. This shows a big loss happened across the entire reef at the same time.
The US National Oceanic and Atmospheric Administration (NOAA) shares more bad news. Our planet is seeing its fourth big coral bleaching event. It’s the largest one ever recorded. This problem started in January 2023. It became a global crisis in April 2024. Very high heat now affects almost 84% of reefs worldwide. This impacts at least 83 countries. The Great Barrier Reef is among them.
Coral bleaching happens when ocean water gets too hot for too long. Corals then push out the tiny algae living inside them. These algae give coral its color. Without them, corals turn white and become weak. Bleached corals are not dead right away. But they are more likely to get sick. Their chances of staying alive go down.
Reefs can bounce back from bleaching. Yet, they usually don’t get as strong as before. A report from the UN Intergovernmental Panel on Climate Change (IPCC) in 2018 warned us. Coral reefs face huge risks if global warming goes above 1.5 degrees Celsius. Our world’s average temperature has already risen by 1.3 degrees Celsius. This is compared to times before factories became common.
The IPCC study found that tropical coral reefs are at high risk with just a 1.2-degree Celsius rise. If temperatures climb even higher, these coral homes might disappear. Many areas could see almost no coral left. The bleaching events in the Great Barrier Reef in the mid-2010s showed something important. Researchers might have thought the risk from warming was smaller than it truly is.
Source: AP