A new expert assessment has downgraded the health status of Australia’s Great Barrier Reef from “poor” to “very poor” after finding the near-shore ecosystem’s habitat and species are significantly at-risk from the effects of climate change.
Marine heatwaves are the most immediate threat and pose the highest risk to the reef system, coupled with poor inshore water quality, habitat loss, and degradation. Both habitat and species have been downgraded from “poor” to “very poor” following the pressures of a changing and warming planet.
“Climate change is escalating and is the most significant threat to the region’s long-term outlook. Significant global action to address climate change is critical to slowing deterioration of the Reef’s ecosystem and heritage values and supporting recovery,” reads the report.
Every five years, the country produces an analysis to look at the reef’s health, pressures, and its future as required under the Great Barrier Reef Act. In 2019, the authors found that significant pressures are being imposed on the reef at both a local and global scale, which has altered conservation strategies to manage a “changed and less resilient reef.”
One of the most complex natural systems on the planet, the Great Barrier Reef has faced an accumulation of impacts in recent years that have reduced its ability to recover. In 2016 and 2017, two successive mass bleaching events caused an unprecedented coral loss that impacted fish and invertebrate species. Inshore pollution, as well as agricultural and developmental runoff, have further suffocated coral species and degraded habitat.
But it’s not all bad news. In their assessment of more than 30 ecosystem health components, researchers found that as much as 60 percent remain in "good" to "very good" standing.
Designated a World Heritage Area, the reef is home to oceanic life, from the smallest of coral-habiting fish to the largest of marine megafauna. Though a study last fall found that the reef was showing “significant signs of recovery” after years of coral bleaching, the reef is still having a difficult time bouncing back. Since 2016, half of all coral in the northern part of the reef died. Meanwhile, a 2018 report by the Australian Institute of Marine Science found that the reef coral cover was the lowest in recorded history following a deadly combination of starfish outbreaks, bleaching events, and severe weather.
The challenge to restore the reef is “big but not insurmountable,” write the authors, noting that international climate change mitigation efforts paired with effective implementation of a long-term sustainability plan may help the reef recover. Just like the Amazon wildfires, officials say protecting the reef is a global issue and world leaders must address climate change at a global level.