Following dire warnings of reef die-off after massive coral bleaching in 2016 and 2017, Tourism and Events Queensland has issued a “positive update” on the status of Australia’s Great Barrier Reef, reporting some areas affected are showing “substantial signs of recovery.”
The Reef & Rainforest Research Centre (RRRC), a non-profit organization, has reported signs of recovery due to a milder 2017–18 summer as well as the cooperation between science, industry, and government in supporting the recovery of the reef, according to the report issued by the Queensland State Government on Wednesday.
Stretching more than 1,430 miles along Queensland’s spectacular coastline, the Great Barrier Reef is the longest coral reef in the world and the first coral reef ecosystem to be awarded Unesco World Heritage Status.
Coral bleaching occurs when coral experiences stress resulting from increased water temperatures or poor water quality. In response the coral ejects a photosynthetic algae called zooxanthellae, which removes the coral’s distinctive color. If the stress conditions persist the coral will die, the report says, but if conditions return to acceptable levels some coral can reabsorb the substance and recover.
The RRRC in cooperation with the Association of Marine Park Tourism Operators conducted detailed surveys at key dive tourism sites around the city of Cairns in 2016 and 2017 and note that today, some reefs which were quite strongly affected in the bleaching event are showing strong signs of improvement.
Coral bleaching occurs in multiple stages, according to RRRC Managing Director Sheriden Morris, ranging from the equivalent of a mild sunburn to coral mortality.
“When a reef is reported as ‘bleached’ in the media, that often leaves out a critical detail on how severe that bleaching is, at what depth the bleaching has occurred and if it’s going to cause permanent damage to the coral at that site,” Morris said in the statement, adding that the Barrier Reef “has significant capacity to recover from health impacts like bleaching events.”
Reports that the entire reef is dead due to severe bleaching are “blatantly untrue,” Morris said, but warns the continued recovery now being witnessed is “contingent on environmental conditions” and that the reef “may suffer further bleaching events as the climate continues to warm.”
The full impact of the 2016 bleaching, which saw 30 percent of the reef’s shallow water coral damaged or destroyed, has not yet fully been assessed, according to a report released on Tuesday by the Nature Research Journal.
Deeper reefs are often considered a refuge from thermal anomalies such as those experienced in 2016 and 2017, but the report argues both shallow and deep reefs are under threat from mass bleaching events and notes that when the upwelling of warmer water stopped at the end of summer, even temperatures at depth rose to record-high levels. Researchers found bleached coral colonies down to depths of 131 feet beneath the ocean’s surface, according to the report.
News of the recovery comes only two months after the RRRC co-hosted the Great Barrier Reef Restoration Symposium in Cairns, which saw more than 300 scientists, engineers, and marine tourism representatives from 14 countries convene to focus on restoration and recovery of coral reef systems under threat from warming climates.
In April, the Australian Federal Government announced a A$500 million ($379 million) funding grant for the Great Barrier Reef in order to tackle challenges such as climate change, coral-eating starfish, and water quality affected by agricultural runoff.
Deloitte Access Economics valued the reef at A$56 billion in 2017, basing their number on the fact that the reef supports tens of thousands of jobs and contributes A$6.4 million a year to the economy.
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