Reef surveys show signs of hope and tourism can help
Australia’s greatest natural wonder, the Great Barrier Reef, has suffered the worst mass coral bleaching event in its history. The impacts are serious, but recent underwater surveys show that parts of the world’s ‘largest living thing’ are resilient, giving hope for the recovery of affected areas. And the tourism industry, with an enormous stake in the health of the Great Barrier Reef, can help shape its future.
Approximately three quarters of coral on the Reef has survived since bleaching began, according to preliminary findings from the Great Barrier Reef Marine Park Authority and the Australian Institute of Marine Science. Sadly, the 600km northern stretch of the Reef between Cape York and Lizard Island was hardest hit and suffered the worst bleaching - of the 22% of coral on the Reef that has not survived, 85% belonged to this region.
While aerial surveys conducted in March 2016 showed that less than 10% of coral reefs across the Great Barrier Reef completely escaped bleaching, underwater surveys give a more detailed picture of coral condition and mortality.
Surveys of 126 key tourism sites on 32 reefs between Cairns and Lizard Island commissioned by the Reef and Rainforest Research Centre in March and April 2016 showed that less than 5% of coral had died and less than 20% of coral suffered severe bleaching, suggesting that reefs at these sites stand a good chance of recovering. Most of the coral south of Cairns is still alive.
Coral bleaching and the road to recovery
Bleached corals are corals under stress.
Coral polyps, the soft-bodied animals whose hard limestone skeletons form the building blocks of the Great Barrier Reef, contain microscopic algae (called zooxanthellae) within their tissues. These photosynthetic algae provide corals with most of the energy they need to grow and reproduce.
When corals are exposed to stresses - like high water temperatures and poor water quality - they can eject their zooxanthellae and become transparent, revealing the white limestone skeleton beneath in a process called coral bleaching.
The ‘bleached’ white tips of a coral suffering stress. Credit: Oregon State University/Flickr.
If the stress persists for many weeks, corals can starve and die, but if conditions improve corals can take up new zooxanthellae and recover. The less severely corals are bleached, the better chance they have of recovering. However, being exposed to high temperatures and other stresses can still make corals more vulnerable to future stresses.
The 2016 bleaching event was caused by the highest average sea surface temperatures ever recorded for February, March and April; combined with poor water quality and changes to water currents. It is the third mass bleaching event that the Reef has experienced: in 1998 and 2002, bleaching affected large parts of the Reef. In both cases, most corals survived and recovered because sea temperatures dropped.
Heat stress is the most common cause of coral bleaching and is expected to happen more frequently with climate change. But other stressors including poor water quality (from sediment or pollutant runoff), influxes of freshwater and ocean acidification can also trigger bleaching.
Conservation through tourism
A single glimpse of the Reef beneath the waves can be life-changing.
At approximately 350,000km2, and made up of 2,900 separate coral reefs and 1,050 islands and coral cays, the Great Barrier Reef is home to animals from microscopic plankton to 40 tonne whales. These include one third of the world’s coral species, more than 1,500 species of fish, six of the world’s seven species of marine turtle, and many species yet to be discovered.
Reef visitors can experience the marine equivalent of Africa’s Big 5, the ‘Great 8’: clown fish, giant clams, manta rays, Maori wrasse, potato cods, sharks, turtles and whales.
Turtles are one of the Great Barrier Reef’s ‘Great 8.’ Credit: Lady Elliot Island Eco Resort.
With roughly two million tourists every year, the Reef’s tourism industry is worth $5.4 billion per year and supports 60,000 jobs. But it also helps support the Reef’s health and future.
The Great Barrier Reef has different levels of protection that allow commercial and recreational activities to take place sustainably, making it the best managed reef in the world. Activities such as fishing are not allowed in “green zones,” to ensure that important species and habitats are protected. Science shows that these no-take zones help reefs to be more resilient, and recover more swiftly from disturbances like coral bleaching, diseases and storms.
Of 187 tourism operators around Queensland that are Eco-certified by Ecotourism Australia, 68 operate in the Great Barrier Reef Marine Park, ensuring that their practices meet high environmental standards that help protect the Reef. Tourism operators also carry out programs to actively rehabilitate reefs at dive sites after events such as major storms or cyclones.
Corals provide important habitat for many fish species. Credit: Lady Elliot Island Eco Resort.
Taking a stake in the Reef’s future
Ecotourism experiences and interpretation allow tourists to experience the Reef’s wonders; learn about its diversity, threats and future; and contribute to its protection.
For example, the Great Barrier Reef Marine Park Authority’s Eye on the Reef program allows people of all skill levels to become ‘citizen scientists’, by providing managers and researchers with up-to-date information on protected species, reef health and early warnings of environmental impacts.
Tourists can identify and record what they see underwater using the Eye on the Reef app or participate in Reef Monitoring surveys. Meanwhile, scientists, tourism operators and rangers can contribute to Reef Health and Impact Surveys run in partnership with the Queensland Parks and Wildlife Service.
Snorkelers viewing coral gardens from Low Island. Credit: Sailaway.
“It’s very important that nobody’s in denial about the health of the Great Barrier Reef,” said Steve Edmondson, Owner/Operator of Sailaway, which contributes to Eye on the Reef and other environmental initiatives. “It isn’t something we can take for granted and we have a very important role to speak out about the Reef.”
“All ecotourism operators are in a very privileged position to be able to inspire, educate and increase awareness. The visitors who come to enjoy and interact with nature go home with an understanding of the bigger picture and the ability to have a positive influence on sustainability.”
A green turtle hovering over soft corals at Low Isles. Credit: Sailaway.
The true extent of damage from coral bleaching and its wider impacts on the Reef ecosystem may not become clear for several more months, but there is hope that our efforts to reduce other human impacts will improve the Reef’s resilience into the future. Visitors to the Great Barrier Reef can help with these efforts by travelling with a high standard, ECO certified tourism operators, and by supporting conservation and recovery efforts being implemented by the Great Barrier Reef Marine Park Authority.
“We must have hope and we must believe in ourselves,” said Peter Gash, Managing Director of Lady Elliot Island Eco Resort. “Thousands and thousands of small acts by people have caused the Great Barrier Reef to be in trouble and it will take thousands and thousands of small acts to fix it.”
“But the world’s full of remarkable people doing remarkable things - and they’re not all high-profile. There is enormous enthusiasm in young and old people who visit the Great Barrier Reef. I see kids coming out all the time who inspire me to keep doing what I’m doing; other people ring me up just to ask how they can help. I’ve seen such positive change in the last 35 years and that gives me tremendous hope for the future.”
Main image credit: Mike Ball Dive Expeditions.