We’re killing an Australian Reef More Economically Valuable That the Great Barrier Reef, Says Leading Coastal Commentator and It’s Hiding in Plain Site – Right under Our Noses
“We have to engage with the issues confronting the Great Southern Reef. Our current levels of scientific involvement and public discussion aren’t good enough to avoid the perils that lie ahead. One of the continent’s greatest ecosystems has been living – and could die – hidden in plain sight,” warnsCoastalwatch.com journalist and author Jock Serong, on the emerging concept and implications of the degradation of the ‘Great Southern Reef’.
There is an Australian reef worth more than $10 billion annually (worth at least more $4 billion annually that the Great Barrier Reef) which the scientific community is increasingly terming the ‘Great Southern Reef’.
The majority of Australia’s commercial fisheries (namely rock lobster and abalone), recreational fishing and regional tourism operate along the reef.
Around 67% of Australians (or 16.2 million people) live within 50km of the reef, and that number will double by 2060.
The reef spans 8,000 km, five states and runs along the entire southern coastline of Australia and along large parts of the country’s west and east coasts, with almost every one of Australia’s 2.7 million surfers paddling over it.
And yet, most Australians would never have heard of the term ‘Great Southern Reef’ – nor does the Australian government invest significant funding into its research. Between 2010 and 2014, coral reef research received AU$55.3 million in research funding from the Australian Research Council, while temperate reef research (The Great Southern Reef) received $4 million.
Coastalwatch.com journalist and author, Jock Serong, has written about the implications of Australia’s ‘Great Southern Reef’ – an emerging scientific term used to collectively describe huge stretches of interconnected temperate reefs along Australia’s south, west and east coasts.
What is the Great Southern Reef?
Stretching from Kalbarri in Australia’s west, all the way across the southern coast of Australia and around Tasmanian then up to around Tweed NSW, the Great Southern Reef is a massive swathe of coolwater reefs that are increasingly being grouped together by scientists as a single entity
Much like the Great Barrier Reef is interconnected by nearly 3,000 separate coral reefs, joined by continuous geography and an interdependence of natural systems – The Great Southern Reef is a collection of temperate reefs linked geographically and by a common habitat-forming species called kelp.
The Great Southern Reef is a nursery and a shelter and a gigantic living museum of biodiversity, hosting marine plants, sponges, crustaceans, chordates, bryozoans, echinoderms and molluscs.
Despite the value of the reef, it is facing a number of threats
Serong says the reef is experiencing stress from “human pressures: pollution, development and climate change.”
“Some specific parts of the reef are in terrible shape: in the west and southeast, reef water temperatures are rising two to four times faster than global averages,” he explains.
“On those western reefs, the kelp forests are dying in the north and growing in the south.”
Because of the east-to-west alignment of Australia’s southern coast, there will come a point when continued warming means kelps will have no southerly habitat to retreat to.”
Serong says this will decimate fishing and tourism industries worth more than $10 billion per year and have “devastating impacts on thousands of species within the Great Southern Reef that need kelp forests to survive.”
Serong points to a loss of giant kelp in eastern Tasmania, which saw Australian giant kelp forests become the first marine community to be listed as endangered under the Environment Protection and Biodiversity Conservation Act.
Some scientists have witnessed the decimation of kelp forests in the space of a year. In 2011, a “marine heatwave” blasted across southwestern Australia, pushing tropical water polewards and resulting in extensive damage to the Great Southern Ocean. In Kalbarri in Western Australia, scientists witnessed kelp forests disappear completely in 12 months. After jumping back into the reef a year later “they thought (they) were in the wrong spot.”
“When that happens, everything suffers: marine plants, invertebrates and fish. And the fish and seaweed mix changes – fishes and seaweeds you would once find in one reef no longer exist, and you have new varieties,” says Serong.
The impact of climate change on the Great Southern Reef
The outcome at Kalbarri is seen as an example of one of the most dramatic climate-driven ecosystem shifts ever recorded.
“Kelps in Australia are sensitive to warming, and have adapted to stable environmental conditions over the past 20 years which has allowed the GSR to thrive. However, short term anomalies of only 2-3 degrees are enough to wipe out local populations – and they‘re becoming more frequent,” says Serong.
Development and Industry
“Kelp forests in the eastern and central GSR have suffered where they share space with intense coastal development. Mostly the damage is done by nitrogen enrichment from sewage and storm-water outfalls like the notorious Gunnamatta pipe on Victoria’s Mornington Peninsula,” says Serong.
“These habitat losses will only increase alongside the desirability of coastal living.”
The implications for surfers and fisherman
“If almost every surfer in the nation calls some part of the GSR home, then there’s a nagging question of self-interest: if all of these interrelated ecosystems collapse, so what? We’re left with bare rocks – they’re still good to surf over, aren’t they?” Serong questions.
“But there’s an intrinsic value in surfing a clean and healthy ecosystem, where you can sit out the back and feel part of nature,” he adds.
“Depending where you live, climate change might materialise as a blessing or a curse,” Serong adds.
“Take abalone: they’re sensitive to warming in various ways. During the 2011 heatwave in WA, they were one of the species worst affected by the high temperatures themselves. But in the south-eastern GSR, the abs are highly dependent on the canopy to provide the right habitat, so whatever affects the kelp forest will affect them.
“In Tassie, anglers are now catching pink snapper, King George whiting and yellowtail kingfish – species that never previously ventured that far south. In the northern reaches of the GSR, where the currents are providing tropical species pressure, there are losses.
“Movements of species similar are happening all over the temperate oceans of the world, as species migrate to try to stay within their preferred temperature bands. It’s been described by the University of Tasmania’s Gretta Pecl as “the largest climate-driven redistribution of species since the last (Ice Age).”
So what can humans do?
Serong says, “there remains a troubling disconnect between the low public awareness of, and investment in, Australia’s temperate reefs, and their significance to our shared future across five states.
“We need consistent governance across state borders, but it must be flexible enough to manage the reef across southern Australia. For example, if one fish species ranges across several states, it’d be logical to co-ordinate licensing, closed seasons and catch limits.
“Localised strategies like controlling sewage run-offs, (which weaken kelps and thereby exacerbate climate change effects), are good, but they’re really only band-aids.
“The only big-picture solution is the one that’s been eluding the world for decades now: we all have to massively reduce our carbon dioxide emissions.”