The Great Barrier Reef: just unwell or terminally ill?
Starfish, chemicals, climate change. If things continue the way they are, the reef won't be great for much longer.
AT 3 pm on July 16, 1928, Charles Maurice Yonge and his team of scientists sighted the Low Isles, north of Cairns, from their boat. His wife Mattie, a doctor, described “a circular mound of sand about 250 yd. diameter”. That mound would be their home for the next year.
So began the first modern research expedition on the Great Barrier Reef.
As Professor Iain McCalman, from University of Sydney, describes in his new book The Reef – A Passionate History, they were an industrious group of young scientists from Cambridge University, both men and women.
Marine science was in its early stages and they’d been assigned one of the Earth’s uncharted treasures.
Their findings were published in seven large volumes; among them were revelations about the interdependence of corals and algae and the growth rates of corals – which had rings like trees, they noticed – as well as the first observation of coral bleaching.
In the 1970s, more than 40 years later, septuagenarian Sir Maurice – who by then had been knighted – returned to the Low Isles. He was dismayed by what he found; or more precisely, by what he didn’t. For all the silt from agricultural run-off, he couldn’t locate the places he’d conducted his experiments.
Sir Maurice may have been appalled, but scientists now yearn for the days of his disappointment, so badly has the reef deteriorated in recent decades.
In 1985 the Australian Institute of Marine Science began monitoring more than 100 locations on the reef. In the years since, coral cover has diminished by half, on average. At the current rate of decline, it will halve again by 2022.
The relentless degradation of one of the seven natural wonders of the world has not gone unnoticed. Next June, UNESCO’s World Heritage Committee will convene in Qatar for its annual meeting. It has foreshadowed that “without evidence of substantial progress” it will classify the reef as “in danger”.
Queensland’s tourism industry nervously awaits UNESCO’s verdict. The reef is estimated to create up to $6 billion dollars annually for Australia’s economy, supporting 50,000 jobs.
Daniel Gschwind, from the Queensland Tourism Industry Council, believes a downgraded classification would deter visitors and could put his industry in danger. “Regardless of the actual health of the reef, the damage to our reputation as a destination of natural wonders would be serious,” he says.
In early November, in response to warnings issued by UNESCO, the reef’s management authority produced a 650-page, draft strategic assessment report.
It stated that the northern third of the reef is in good condition, but south of Cooktown, its health has “declined significantly”.
Biodiversity is deteriorating. While humpback whales are increasing in number, the populations of dugongs, turtles and some seabirds are diminishing. Coral reefs and seagrass meadows are “in serious decline”.
The authority declared that climate change is “still the most serious threat facing the reef”. The ocean is increasing in temperature and becoming more acidic, and sea levels are rising. “More frequent and severe extreme weather is also predicted,” it said.
Until now, the major cause of damage has been poor water quality. Wherever the land has been cleared for farming and settlement, polluted water drains into the inshore reef, laden with fertilizer and silt. In the last decade, cyclones and floods have battered the coast and consequently, rivers have clogged the reef with plumes of mud visible from space.
The authority noted another “key concern” caused by the development and operation of ports: the dumping of dredge spoil at sea. Overall, it concluded, “a business-as-usual approach to managing these impacts will not be enough”.
Dr Peter Doherty, from the Australian Institute of Marine Science, began studying the reef in the 1980s. He helped create the long-term research program that revealed the loss of half the reef’s coral cover since monitoring began.
He says cyclones and the crown-of-thorns starfish are each responsible for more than 40 per cent of the damage, while coral bleaching currently accounts for about one-tenth.
Coral bleaching and cyclones are matters of extreme weather, Doherty says. Locally, we can do nothing to prevent them, but “we probably can do something about crown-of-thorns”.
Since it was first observed as a problem in the 1960s, there have been four outbreaks of the coral-eating starfish, roughly 15 years apart.
The cycle is too fast to allow the corals to recover naturally. “In the 1960s, there was a large-scale increase in the application of inorganic fertiliser to sugarcane fields,” Doherty explains. “It’s likely that this is a major driver in the frequency and severity of the current outbreaks of starfish.”
In 2003, the federal and state governments adopted Reef Plan, a ten-year strategy to reduce water pollution. Updated in 2009, it included targets to halve nitrogen and pesticide runoff, and dramatically improve the land management practices of graziers, sugarcane growers and horticulturalists.
Doherty sits on the scheme’s independent scientific panel. “In recent times we are putting 5 times more sediment, up to 8 times more nitrogen and 6 times more phosphorous into the reef than we should be. Turning that around is a very large task.”
So far, the results have fallen well short of the targets, which have been deferred until 2018. Both levels of government have committed more funding.
Doherty describes Reef Plan as “a substantial response”, which is beginning to show small gains. But it may not be enough. “Like anything, it’s going to get harder and harder to make deeper gains.”
Right now, just as the reef is in the most precarious condition we’ve known, the crown-of-thorns starfish is on the brink of its worst infestation.
Heavy rains in the last five years have flooded the continental shelf north of Cairns with “nutrient-enriched plumes”, creating what Doherty describes as “the perfect broth for feeding larval starfish”.
A large female starfish can produce tens of millions of eggs at each spawning. Carried on southerly currents, they’re causing cascading outbreaks in the central reef that could last for ten years.
The tourism industry is attempting triage. Funded by the federal government, teams of divers are killing starfish by injecting them one-by-one with bile salts. In the last 18 months, the program has culled more than 100,000 starfish, mainly around popular tourist sites.
It is a Sisyphean undertaking. “The target is in the millions, distributed over more than 1000 kilometres of reef perimeter,” Doherty says. “It’s extremely unlikely we’ll be able to effectively control the starfish population using divers with poisons.”
Instead, the reef is suffering death-by-report.
Dr Colin Hunt, an ecological economist from University of Queensland, was one of the authors of the first 25-year plan for the reef, released in 1994. Entitled The Great Barrier Reef – Keeping it Great, it called for the effects of runoff to be studied and targets set to reduce their impacts.
In practice, the goal of improving water quality has proven strictly aspirational.
Likewise, the marine park authority’s new strategic assessment stresses the need to measure “cumulative impacts”, rather than the narrow effects of each project or use of the reef. The Keeping it Great report made the same recommendation two decades ago.
More recently, the authority’s Great Barrier Reef Outlook Report declared the reef ecosystem was “at a crossroad” in 2009. “It is decisions made in the next few years that are likely to determine its long-term future,” it said.
Since then, there’s been a port-building boom along the coast, paving the way for increased coal trade and the beginning of a gas export industry.
These developments have alarmed UNESCO’s World Heritage Committee. In June, it noted “with concern” that the impacts of “ongoing coastal development on the reef continue and progress towards addressing them is limited”. It requested that ports not be permitted outside existing locations.
In December, federal environment minister Greg Hunt will decide on applications to expand the Abbot Point port, north of Bowen, and a fourth gas export plant at Curtis Island, near Gladstone. Three further coal terminals are going through Queensland’s environmental approval process.
Colin Hunt expects UNESCO will watch those decisions closely. He says the impact of dredging is limited compared to agricultural runoff and climate change, but the cumulative effects of industrialisation are clear.
“These port developments are impacting wildlife and destroying part of the reef, there’s no doubt about it,” he says. “The coal and gas companies are responsible for doing their own environmental impact statements – the system is flawed because of conflicts of interest.”
Hunt believes polluters must bear the true costs of both runoff and port development. Farmers should be fined if they don’t meet water quality targets, and resources companies should pay for dredge spoil to be disposed on land, not within the reef’s waters.
“If we really want to tackle this problem, we have to make the polluter pay,” he says. “It is time to have a proper reckoning. The reality is extremely serious: unless these trends turn around, we’re going to lose the reef.”
In the early 1970s, when Sir Maurice returned to visit the location of his 1928 expedition, he was chaperoned by a knockabout young Australian scientist, Dr J. E. N. ‘Charlie’ Veron.
Granted a post-doctoral scholarship by James Cook University, Veron was the reef’s first full-time researcher.
“Sir Maurice was very formal and dignified – a real jacket-and-tie guy – but I got to like him a lot,” recalls Veron, who is rather less formal. (Years later, the young scientist found himself “in strife” for showing a nude photo of an expedition leader during a presentation at the Royal Society in London.)
The visit was a changing of the guards; subsequently, Veron became the world authority on corals and reefs. He devised a new taxonomy for corals and discovered one-fifth of all known species.
“In the 50 years I’ve been diving, I’ve noticed a heck of a lot of change,” he says. “The drop off in shark numbers because of overfishing is the most dramatic.”
One coral, Montipora – which grows like overlapping plates on a waiter’s arm – was once the most common species near the coast, but has now all but vanished.
“On the outer slopes of the far northern Great Barrier Reef, the corals look much the same as always,” he says. “There are now very few places on the reef I would say that about.”
In 2008, Veron published A Reef in Time: The Barrier Reef from Beginning to End, a book on coral reefs and climate change. He wrote that the prognosis for the world’s reefs “does indeed seem bleak, but it is not yet hopeless”.
Every summer, he becomes nervous about the risk of mass coral bleaching – a risk that worsens as the oceans warm. During the El Niño weather cycle, warmer currents pulse into the reef’s lagoon. With clear skies for a few weeks, the water temperature can increase beyond the corals’ ability to cope.
Energised by global warming, El Niño cycles will become more extreme. Humans have already created the conditions for more intense storms and floods, droughts that trigger erosion, and frequent mass coral bleaching.
Veron is also fixated by the threat of ocean acidification – a lesser-known consequence of carbon dioxide emissions – which causes a kind of coralline osteoporosis. If it goes unchecked, the reefs will eventually erode.
He considers the health of the world’s reefs an early warning of a broader collapse. If they fail, other ecosystems will follow, rapidly.
“We’re driving the Earth into conditions for the sixth mass extinction and we’re doing it very, very quickly,” he says. “I’ve got teenage children and it terrifies me to think what they’re going to face in their later life.”
In this context, the environmental impact statements for the new coal and gas ports are dangerously incomplete. Dredging may cause localised damage, but the ports’ very reason for being – to expand fossil fuel exports – exacerbates the Great Barrier Reef’s gravest existential threat.
The emissions associated with proposed coalmines in Queensland’s Galilee Basin alone would dwarf Australia’s total carbon footprint.
“We’re making money out of doing the things that drive climate change, which will destroy the reef,” Veron says. “We are a wealthy country – we have a moral obligation to future generations to keep coal in the ground. I can’t see any rational argument against that.”
Threats to the reef
Fertiliser runoff causes plankton blooms, which promote outbreaks of the coral-killing crown-of-thorns starfish.
Sediment blocks the light required by corals, sponges and seagrass and starves marine life of normal sources of nutrition.
Pesticides poison coral larvae, even at trace levels.
Climate change sets the conditions for more frequent and intense storms, cyclones, droughts and floods, which contribute to plumes of polluted runoff. Ocean warming increases the likelihood of coral bleaching. Ocean acidification weakens coral skeletons and slows coral growth.
Dredging causes plumes of silt and disturbs local habitats.
Overfishing and illegal fishing threaten important predators such as sharks and coral trout.