Can science and tourism save the reef? 3j5ev

A GIANT BIRTHING

At 20:30 on 27 November 2018, lucky divers and snorkellers in the northern part of the Great Barrier Reef would have borne witness to what is possibly the greatest sex show on Earth. 

This spectacular phenomenon, when corals reproduce en masse over just a few days each year, is essentially synchronised sex on a grand scale as millions of corals on more than 1,000km of reefs along the Great Barrier Reef area simultaneously release their eggs and sperm into the water in the hope they’ll combine and create new coral colonies. It’s an underwater snowstorm, a sexual soup, where clouds of pink- or red-hued egg-sperm bundles whirl and swirl in all directions, carried by the waves and currents. 

Coral spawning is one of the highlights on the Great Barrier Reef calendar. Yet it was only discovered as recently as the 1980s by Professor Peter Harrison, who is now director of the Marine Ecology Research Centre at Southern Cross University, New South Wales, and his colleagues. 

Back then, Harrison was a 23-year-old PhD student up in Townsville at James Cook University who was fascinated by the sexual reproduction of corals and knew that what he was seeing on the reef did not match what he was reading in the textbooks. Over a two-year period of studying the corals around Magnetic Island in North Queensland, he and his colleagues realised that they reproduced by spawning instead of brooding their larvae internally, as was originally thought, and that many different coral species were in fact spawning together at the same time, triggered by the lunar cycle and a rise in sea temperature. 

“It’s one of the world’s great reproductive events. I was literally surrounded by billions of eggs and sperm, and I knew that most of those were going to develop into larva,” Harrison said. 

It was a spectacular discovery, and one that amazed the world when Harrison and colleagues published a paper on the event in Science magazine in March 1984.

On the Great Barrier Reef, where Harrison was, the mass spawning typically takes place four to six nights after the first full moon in November when sea temperatures get warmer, while the timing is different for the northern hemisphere reefs. 

The World Economic Forum’s 2019 Global Risk Report was dominated by climate change and environmental disasters, and the world has recently watched this play out across the globe, from cyclones battering Mozambique to extreme flooding in the US Midwest. Heat waves have been hotter, droughts have been dryer and storm surges have been higher. Temperature records have been repeatedly smashed across the planet. 

Queensland, home to the Great Barrier Reef, has seen bushfires, extreme heatwaves, a tropical cyclone, record rainfall and extreme flooding in the last nine months alone. 

Yet climate experts believe that all this is just the precursor to something far worse. According to a 2018 study by the Intergovernmental on Climate Change (IPCC), human activities have currently caused around 1°C of global warming above pre-industrial levels. At this level, coral reefs have been hit hard by heat stress and have experienced large-scale mortalities. 

“In the last three years alone (2016–2018), large coral reef systems such as the Great Barrier Reef (Australia) have lost as much as 50% of their shallow water corals,” the IPCC study reports. 

But if global warming rises by an additional degree (to 2°C above pre-industrial levels), the study says, there will be unprecedented consequences: 99% of coral reefs across the world’s tropical and sub-tropical oceans will disappear. And even if countries around the world adhere to the Paris Agreement (to pursue efforts to limit global warming to 1.5°C above pre-industrial levels), the world will still lose 70–90% of reef-building corals compared to today.

These are sobering statistics, which hit home even harder when you see the evidence for yourself.

Dive in the northern parts of the Great Barrier Reef, north of Townsville, and you may be greeted by ghostly swathes of pure white staghorn coral, likely bleached in one of the back-to-back bleaching events caused by rising sea temperatures in 2016 and 2017. 

Elsewhere you might see thick clusters of purplish-blue or reddish-grey crown-of-thorns starfish, covered in venomous barbs. These starfish occur naturally in low numbers on the Great Barrier and other coral reefs, and play a part in the reef ecosystem by helping to maintain coral species diversity. However, recent years have seen an explosion in their numbers, likely caused by overfishing of their natural predators or increased nutrients in the water due to agricultural runoff into the ocean. 

When outbreaks occur, crown-of-thorns starfish are no longer just feeding on the coral, but stripping entire reefs bare.

IVF FOR THE REEF

But fortunately for the Great Barrier Reef, there are many brilliant minds working on ways to protect its coral for future generations, whether that’s through cryopreserving coral sperm or coral genomics sequencing, where scientists are studying genetic differences in corals to understand why some types are better equipped to withstand heat stress.

Harrison is at the forefront of the innovation. He is currently six years into a larval restoration project that’s working to capture and rear millions of coral larvae produced during the annual spawning and re-settle them on degraded reefs to rapidly re-establish new corals – like coral IVF on a massive scale. 

“We started the project in 2013 when we put millions of microscopic larvae on the reef system, and they’ve grown into very large size corals. Over three years they reached dinner-plate size, were sexually reproductive and started spawning,” Harrison said, proudly. 

He now has 14 out of 14 successful experiments under his belt, where the larvae have not only settled, grown and, in some cases, started reproducing, but with much higher settlement rates compared to in the natural environment, where currents and tides can wash away much of the larvae. He’s quietly confident that this project could play a huge part in saving both the Great Barrier Reef and other reefs around the world.

Initially, Harrison was capturing coral spawn manually, rearing them in ‘fertility clinics’ – either small, floating ponds on the reef or back in the lab – for five to six days, depending on the temperature, until the larvae were ready to settle and be put back out on the reef. However, he needed to scale up, and a fortuitous meeting in 2018 with Matt Dunbabin, chief investigator with the Australian Centre for Robotic Vision at Queensland University of Technology, gave him the opportunity he needed. 

Dunbabin is the creator of the world’s first underwater robotic system, relying solely on robotic vision, that’s designed specifically for coral reef environments. He was initially using it to seek out and inject crown-of-thorns starfish with poisonous bile salts, in hope of culling their ever-increasing numbers. However, after talking with Harrison, he adapted his drone to both deliver coral larvae onto the reefs – almost like an underwater crop duster – and use AI to learn the optimum spots for reseeding. 


The results were spectacular: at a coral spawning event in the Philippines in April 2019, Harrison and Dunbabin were able to reseed three 1-hectare areas of reef, which had been decimated by blast fishing and pollution, in just six hours. 

“Based on the success of this first trial of LarvalBot [as this version of Dunbabin’s robot is called], we’re now really excited and plan to scale this up so we may have an army of underwater robots delivering billions of coral larvae over kilometre scales,” Harrison told me, explaining that the next test is the coral spawning event on the Great Barrier Reef this coming November. “Once we start getting to that scale of reef recovery we can really make a difference in of effectively changing the pathway of destruction to the recovery of coral reefs.” 

However, for all the optimism surrounding the futuristic-sounding project, Harrison is aware that larval restoration is just one part of the solution to the coral crisis.

“What we’re trying to do at the moment is rescue the surviving corals that have survived major bleaching events and other destructive forces. But we can’t effectively continue to have coral reefs unless we manage climate change. Corals and the reefs they build are so sensitive to changes in environment such that we know that unless we control climate change in the next few decades, we’re going to lose more and more corals to the point where we won’t have functioning reefs on the planet.”

CITIZEN SCIENCE 

Although science and AI can play a huge part in helping repair the reef, the consensus among most reef experts is that this needs to be a global concern. 

One man who is tackling that head on is Andy Ridley, who is recognised as one of the world’s most successful movement creators. He was the brains behind Earth Hour, which launched in 2007 and has become world’s largest grassroots movement for the environment, with millions of people coming together across the globe by turning their lights off for one hour. Today, Ridley is based in Cairns in Far North Queensland, whose surrounding reef areas have been hardest hit by bleaching, trying to once again use the power of the people – this time to save the Great Barrier Reef.

Ridley launched non-profit Citizens of the Great Barrier Reef in 2017. He believes that technology, data and a collaborative approach to conservation need to be part of the solution, and his charisma is such that when he talks to you about his projects, you start to get really excited by the possibilities, too.

“We’ve designed a 21st-Century conservation organisation, which means that people can connect whether they’re on the reef or in London, Amsterdam, New York or Kigali,” he said, ionately. “And we’re building to scale, so although it’s now Citizens of the Great Barrier Reef, one day it will be Citizens of the Reef.”

He and his team of just three are working to create a platform to engage people from all over the world in the reef’s future and inspire them to take action to help protect it, whether that’s through simple actions travellers can take, citizen science projects, tracking marine life online or a new project encouraging children to get involved. Even the ScUber submersible – which took people underwater onto the Great Barrier Reef in a pilot programme over May and June 2019 – was in partnership with Citizens of the Great Barrier Reef and the Queensland government. 

He firmly believes that telling the world the true status of the reef is vital, both from a science perspective and from a human-engagement perspective. “The biggest danger is that people give up,” Ridley said. “The reef is not dead. The next three years are critical.” 

The story, he says, needs setting straight.

WHAT’S THE SOLUTION?

For all the complex work that both Ridley and Harrison – among many others – are undertaking, they’re both 100% clear on one point: that tourism is a vital part of the solution and that people need to keep coming to the Great Barrier Reef. 

Although many people think that travellers are a major contributor to the damage, the truth is that around 80% of all tourism activity occurs within just 7% of the Great Barrier Reef Marine Park, and is far from the biggest threat to this fragile ecosystem. 

In fact, Ridley firmly believes that getting people to visit the reef and to experience its splendour will play a huge part in saving it. For starters, day visitors pay an environmental levy of up to A$6.50 that goes towards the care and protection of the Great Barrier Reef Marine Park, which means that each of these tourists is contributing to the scientific research and innovation that could, hopefully, save the reef for generations to come. 

He’s also well aware that initiatives like ScUber, despite its obvious gimmicky aspects, can have immense mainstream impact and reach. Uber, for example, has enabled GPS tracking and GoPros on the two-man submersible to collect reef data during every ride that will be made available for research purposes. They’re also enabling their employees to work with Citizens of the Great Barrier Reef on data analysis and research collection throughout 2020 while the census takes place. 

But most crucially, people need to keep visiting the reef in order to fall in love with its beauty and be inspired to advocate for it. They need to understand that, while threatened, the reef is indeed still there, still spectacular, and not beyond the point of saving. Apathy, Ridley believes, can be as much of a threat to the reef as climate change.

And although scuba diving or snorkelling or even glass-bottom boats allow travellers to get up close to the underwater magnificence, the two-man submersible might just be the thing to help amplify the message.