The Great Barrier Reef recently experienced its biggest yearly loss in coral cover in almost 40 years. This shocking decline is raising immediate red flags among environmentalists and scientists alike over the long-term health of this invaluable UNESCO World Heritage site. The Australian Institute of Marine Science (AIMS) eloquently describes this dramatic decline in marine health in their newly released report. This significant decline highlights the increasing threats posed by climate change, pollution, and deteriorating water quality.
Max Hirschfield, marine campaigner at Australian Marine Conservation Society laid bare the stakes. He reiterated our calls for a holistic approach to address the multiple threats the reef is facing. He reiterated what we don’t know — how well reef water quality programs work. We’ve got to admit that we don’t know this nitty gritty. There’s not a lot of publicly available data so we can’t truly measure the cost-effectiveness.
The UNESCO World Heritage Committee is aware. They said that they were “dismayed” at the ongoing inability to reach targets for improving water quality into the reef. In fact, starting in 2016, the Great Barrier Reef and adjacent Coral Sea have endured six mass coral bleaching events. These disasters have greatly set back the rehabilitation of the coral habitat.
Declining Coral Cover Highlights Urgent Need for Action
According to the recent AIMS report, coral cover has plummeted alarmingly, prompting calls from various stakeholders for immediate action. The report highlights that between 2015 and 2030, the Queensland and Commonwealth governments plan to spend in excess of $5 billion combatting threats to the reef. This funding will help improve the reef’s resilience and protect its health. Even with these investments, the challenges are still overwhelming.
Professor Damien Burrows, head of TropWATER in north Queensland, said the research money was critical. Perhaps most importantly, he highlighted that collaboration with landholders is key to getting it right. He stated, “Within a catchment most of the nutrients running off to the reef comes from a small portion of those catchments.” This shows that with the right focus and direction, water quality improvements can be effectively and greatly achieved.
XParks Associate Scientist Dr. Renee Gruber of AIMS noted that some regions have already experienced a decline in dissolved inorganic nitrogen concentrations. This indicates a growing trend of innovative water management practices. She warned that the 2025 water quality targets for additional reductions are not on track. Gruber explained that these types of disasters, such as cyclones, flooding and marine heatwaves, are increasing with the impacts of climate change. He highlighted that these events increase threats to water quality.
The Role of Climate Change and Pollution
Recent months have seen massive flooding that has visually and physically impacted the marine ecosystems along the east coast. Floodwaters surging down the Herbert River catchment have had a catastrophic impact. They are responsible for the deaths of nearly 3,000 giant clams at Orpheus Island, about 50 km off Lucinda. From marine warming to ocean acidification, such incidents act as sad reminders about how environmental stressors are compounding and eroding the landscape for marine species.
Gruber found that freshwater flood plumes traveled up to 100 kilometers to connect with their adjacent coral reefs. This is what played out earlier this year across North and Far North Queensland. “They’re increasing in intensity and frequency and that’s very, really worrying for water pollution ending up on the Great Barrier Reef,” she stated.
Led by Dr. Richard Braley, specialists have sounded the warning about damage flooding does to marine animals. They write that increased salinity would threaten these animals with dramatically adverse effects. “These organisms are stenohaline, so it means they can’t handle a big wide range of salinity changes,” he explained. Looking back on such a costly loss of giant clams, he remarked, “It was a sad event. They had lived there 40 years without a problem.”
Moving Towards Sustainable Solutions
Not everyone is giving up on the Great Barrier Reef just yet. They know there’s still hope to improve the river’s health. Burrows expressed optimism about future developments: “We can’t completely restore the reef to how it was in the face of regular climate change, but we absolutely can both slow down the decline and maintain a much higher level of condition.”
In fact, as many experts have noted, addressing water quality is one of the essential keys to saving our coral reefs. Jake Brooker, a marine scientist from the University of Warwick, Acting Director of Britain’s Ocean, explained that too much nitrogen causes algal overgrowth which outcompetes corals for space. It can cause harmful algal blooms, or toxic plankton blooms, in the water,” she explained. Second, she powerfully articulated how nutrient runoff destroys marine food webs.
To meet these challenges head on, stakeholders need to work together by placing renewed emphasis on multi-agency cooperation among governmental agencies, scientists, and local landholders. By working together and sharing data, they can better understand water quality impacts on the reef and implement strategies to mitigate pollution.
