Scientists Alarmed by Unprecedented Coral Death in the Great Barrier Reef
Australian research revealed on Tuesday that certain areas of the Great Barrier Reef have experienced the highest recorded coral mortality, with scientists concerned that other parts of the reef may have been affected in the same way.
Coral Mortality and Environmental Stressors on the Great Barrier Reef
However, the Australian Institute of Marine Science reported that surveys conducted on 12 reefs revealed coral mortality rates of up to 72%, caused by a summer of widespread bleaching, two cyclones, and flooding.
In one northern part of the reef, approximately a third of the hard coral died, marking the “largest annual decline” in 39 years of government monitoring. The Great Barrier Reef, often referred to as the world’s largest living structure, spans 2,300 kilometers (1,400 miles) and is home to a remarkable diversity of life.
Impact of Repeated Mass Bleaching Events on the Great Barrier Reef
Repeated mass bleaching events have jeopardized the Great Barrier Reef’s status as a major tourist attraction, transforming once-vibrant coral formations into pale, lifeless expanses. Bleaching happens when elevated water temperatures force corals to expel microscopic algae, called zooxanthellae, as a survival mechanism. If these high temperatures continue, the coral can bleach permanently and eventually die.
This year marked the fifth mass bleaching event on the reef in just eight years. The latest survey also revealed that acropora, a fast-growing type of coral, experienced the highest mortality rate. While acropora is known for its rapid growth, it is also one of the first to be affected by bleaching.
Severe Heat Stress and Major Losses on the Great Barrier Reef
Lead researcher Mike Emslie shared with ABC that the previous summer was “one of the most severe events” the Great Barrier Reef has experienced, with heat stress levels exceeding those of prior events. “These are significant impacts. These are major losses,” he stated.
Richard Leck, head of oceans at WWF-Australia, expressed that the initial surveys confirmed his “worst fears.” He added, “The Great Barrier Reef can recover, but there are limits to its resilience.”
“It can’t withstand repeated damage like this. We’re rapidly nearing a tipping point,” Leck warned.
He also noted that the surveyed area was “relatively small” and expressed concern that when the full report is released next year, “similar levels of mortality” would likely be found.
Leck emphasized that this underscores Australia’s need to adopt stronger emissions reduction goals, aiming for at least a 90% reduction from 2005 levels by 2035, and to shift away from fossil fuels. The country, a major exporter of gas and coal, has only recently established carbon neutrality targets.
Read the original article on: Science Alert
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