Aug. 30 (UPI) -- In a report issued Friday, the Great Barrier Reef Marine Park Authority downgraded the outlook for Australia's Great Barrier Reef from "poor" to "very poor."
Every five years, the Great Barrier Reef Marine Park Authority issues a report detailing the Great Barrier Reef's health, major threats and future.
Climate change remains the park's gravest threat, which has caused water temperatures to rise, acidity levels to increase and exacerbated the effects of marine heat waves, triggering record-breaking coral bleaching events in recent years.
Other threats include coastal development, land-based run-off and direct human use like illegal fishing. The compilation of threats are taking a toll on the health of the reef.
"Anyone following the state of the Great Barrier Reef over the last 10 years is well aware of the pressures and challenges facing the ecosystem," Josh Thomas, the CEO of the Great Barrier Reef Marine Park Authority, said in a news release. "This report brings together scientific information to provide a comprehensive overview of the reef's health."
The park authority was created by the Australian government in the 1970s to protect and manage a large swath of the Great Barrier Reef. This week's report is the third issued by the park authority.
Locally, the agency works to curtail as many of the reef's threats as possible.
"A range of actions are underway to improve Reef resilience -- from ramping up compliance in no-take areas to tackling the outbreak of coral-eating crown-of-thorns starfish at high value sites to improve coral cover," Thomas said. "These and other management actions are having a real, measurable and positive impact on the Great Barrier Reef now, and we need to continue to invest in these areas."
But the dramatic changes in the earth's oceans are beyond the control of park authority. As carbon emissions have increased over the last century, the climate has warmed at an accelerating rate, heating up the ocean and altering marine chemistry.
"Gradual sea temperature increase and extremes, such as marine heat waves, are the most immediate threats to the Reef as a whole and pose the highest risk," said David Wachenfeld, the authority's senior scientists. "Global action on climate change is critical."
Given the massive size of the Great Barrier Reef, a World Heritage Site and one of the seven wonders of the world, various reefs and ecosystems have been affected differently. Some coral reefs have been spared from the ill effects of climate change, while others have been able to adapt.
"Of the 31 ecosystem health components assessed, about 60 percent remain in good to very good condition, but the remainder are in poor to very poor condition," researchers wrote in the report. "Some critical ecosystem functions have deteriorated since 2014, mainly due to declines in ecological processes, such as symbiosis and recruitment, and deterioration of some physical processes, such as sea temperature and light."
To save the Great Barrier Reef and the many marine species that rely on it, authors of the new report argue global action on climate change is a necessity.
"While the Reef is already experiencing the impacts of climate change, its future is one we can change," Thomas said.