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Record coral cover doesn’t necessarily mean the Great Barrier Reef is in good health (despite what you may have heard)

In what seems like excellent news, coral cover in parts of the Great Barrier Reef is at a record high, according to <a href="https://www.aims.gov.au/information-centre/news-and-stories/highest-coral-cover-central-northern-reef-36-years" target="_blank" rel="noopener">new data</a> from the Australian Institute of Marine Science. But this doesn’t necessarily mean our beloved reef is in good health. In the north of the reef, coral cover usually fluctuates between 20% and 30%. Currently, it’s at 36%, the highest level recorded since monitoring began more than three decades ago. This level of coral cover comes hot off the back of a <a href="https://theconversation.com/another-mass-bleaching-event-is-devastating-the-great-barrier-reef-what-will-it-take-for-coral-to-survive-180180" target="_blank" rel="noopener">disturbing decade</a> that saw the reef endure six mass coral bleaching events, four severe tropical cyclones, active outbreaks of crown-of-thorns starfish, and water quality impacts following floods. So what’s going on? High coral cover findings <a href="https://theconversation.com/a-lot-of-coral-doesnt-always-mean-high-biodiversity-10548" target="_blank" rel="noopener">can be deceptive</a> because they can result from only a few dominant species that grow rapidly after disturbance (such as mass bleaching). These same corals, however, are extremely susceptible to disturbance and are likely to die out within a few years. <h2>The data are robust</h2> The <a href="https://peerj.com/articles/4747/" target="_blank" rel="noopener">Great Barrier Reef spans</a> 2,300 kilometres, comprising more than 3,000 individual reefs. It is an exceptionally diverse ecosystem that features more than 12,000 animal species, plus many thousand more species of plankton and marine flora. The reef has been teetering on the edge of receiving an “in-danger” <a href="https://theconversation.com/not-declaring-the-great-barrier-reef-as-in-danger-only-postpones-the-inevitable-164867" target="_blank" rel="noopener">listing</a> from the World Heritage Committee. And it was <a href="https://theconversation.com/this-is-australias-most-important-report-on-the-environments-deteriorating-health-we-present-its-grim-findings-186131" target="_blank" rel="noopener">recently described</a> in the State of the Environment Report as being in a poor and deteriorating state. To protect the Great Barrier Reef, we need to routinely monitor and report on its condition. The Australian Institute of Marine Science’s long-term monitoring program has been collating and delivering this information since 1985. Its approach involves surveying a selection of reefs that represent different habitat types (inshore, midshelf, offshore) and management zones. The <a href="https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-condition-summary-2021-22" target="_blank" rel="noopener">latest report</a> provides a robust and valuable synopsis of how coral cover has changed at 87 reefs across three sectors (north, central and south) over the past 36 years. <h2>The results</h2> Overall, the long-term monitoring team found coral cover has increased on most reefs. The level of coral cover on reefs near Cape Grenville and Princess Charlotte Bay in the northern sector has bounced back from bleaching, with two reefs having <a href="https://www.aims.gov.au/sites/default/files/2022-08/AIMS_LTMP_Report_on%20GBR_coral_status_2021_2022_040822F3.pdf" target="_blank" rel="noopener">more than 75% cover</a>. In the central sector, where coral cover has historically been lower than in the north and south, coral cover is now at a region-wide high, at 33%. The southern sector has a dynamic coral cover record. In the late 1980s coral cover surpassed 40%, before dropping to a region-wide low of 12% in 2011 after Cyclone Hamish. The region is currently experiencing outbreaks of crown-of-thorns starfish. And yet, coral cover in this area is still relatively high at 34%. Based on this robust data set, which shows increases in coral cover indicative of region-wide recovery, things must be looking up for the Great Barrier Reef – right? <h2>Are we being catfished by coral cover?</h2> In the Australian Institute of Marine Science’s report, reef recovery relates solely to an increase in coral cover, so let’s unpack this term. Coral cover is a broad proxy metric that indicates habitat condition. It’s relatively easy data to collect and report on, and is the most widely used monitoring metric on coral reefs. The finding of high coral cover may signify a reef in good condition, and an increase in coral cover after disturbance may signify a recovering reef. But in this instance, it’s more likely the reef is being dominated by only few species, as the report states that branching and plating Acropora species have driven the recovery of coral cover. Acropora coral are renowned for a “boom and bust” life cycle. After disturbances such as a cyclone, Acropora species function as pioneers. They quickly recruit and colonise bare space, and the laterally growing plate-like species can rapidly cover large areas. Fast-growing Acropora corals tend to dominate during the early phase of recovery after disturbances such as the recent series of mass bleaching events. However, these same corals are often susceptible to wave damage, disease or coral bleaching and tend to go bust within a few years. Inferring that a reef has recovered by a person being towed behind a boat to obtain a rapid visual estimate of coral cover is like flying in a helicopter and saying a bushfire-hit forest has recovered because the canopy has grown back. It provides no information about diversity, or the abundance and health of other animals and plants that live in and among the trees, or coral. <h2>Cautious optimism</h2> My <a href="https://theconversation.com/almost-60-coral-species-around-lizard-island-are-missing-and-a-great-barrier-reef-extinction-crisis-could-be-next-163714" target="_blank" rel="noopener">study</a>, published last year, examined 44 years of coral distribution records around Jiigurru, Lizard Island, at the northern end of the Great Barrier Reef. It suggested that 28 of 368 species of hard coral recorded at that location haven’t been seen for at least a decade, and are at risk of local extinction. Lizard Island is one location where coral cover has rapidly increased since the devastating 2016-17 bleaching event. Yet, there is still a real risk local extinctions of coral species have occurred. While there’s no data to prove or disprove it, it’s also probable that extinctions or local declines of coral-affiliated marine life, such as coral-eating fishes, crustaceans and molluscs have also occurred. Without more information at the level of individual species, it is impossible to understand how much of the Great Barrier Reef has been lost, or recovered, since the last mass bleaching event. Based on the coral cover data, it’s tempting to be optimistic. But given more frequent and severe heatwaves and cyclones are predicted in the future, it’s wise to be cautious about the reef’s perceived recovery or resilience. This article originally appeared on The Conversation. Image: Shutterstock

Travel Trouble

Illegal fishers and wayward sharks are in the sights of new multispectral imaging

The oceans are warming. Reefs are dying. Fish are on the move. As a result, sharks and illegal fishers are scouring Australia’s coast in search of an increasingly elusive catch, and that, says ESpy Ocean founder Ian Dewey, is having an immense impact on everything from regional tourism to ocean ecologies. Illegal fishers, like sharks, are elusive predators. Their survival depends on being fast, silent and unexpected. They’re threatening a $1.6-billion regional Australia industry. Sharks also aren’t behaving the way they used to. They’re turning up in unexpected places, at unexpected times, which can result in tragedy. “Everyone says use drones or dirigibles to spot them,” Dewey says. “But everyone knows that when we’re on the beach in our string bikinis and Speedos, the last thing we want is a drone above us.” With dark fleets of illegal fishing boats turning off their tracking systems to breach international boundaries, time is of the essence in addressing the problem, just as it is with wayward sharks. “Both are increasing problems,” Dewey says. “I only know in terms of the illegal fishing missions that we’ve been involved in, but invariably there are people around protected areas on a daily basis”. Traditional spotter aircraft can’t cope, and using satellites to track vessels isn’t anything new. What is new is multispectral imaging. A regular camera captures an image on just three channels red, green and blue (RGB) – generating a crisp image of the visible spectrum if the weather is clear. A multispectral image has up to 110 different frequencies, ranging from ultraviolet to microwave. This imaging technology is nothing new. What is new is applying machine learning to identifying what it “sees”. “So it was a matter of working out what we can do through clouds in all kinds of weather, preferably right on dawn,” says Dewey. “I just started going through what frequencies can do what and – if we are looking for a boat – what the hell’s it gonna look like?” It’s a similar story for sharks – what multispectral signatures do different species give, at what depth, under what conditions, at what time? Dewey says the potential to extract such detail from hyperspectral imaging is enormous. It can identify what a boat is made from, what sort of paint has been used (and how old it is), and what equipment is on the deck. “All these things mean that your picture is different to every other boat in the ocean,” he says. “If we see you today, we can see you tomorrow, match those frequencies, and say – we got you!” ESpy demonstrated the potential of the technology for New South Wales Fisheries over the last Easter long weekend. Suitable satellites were identified, access to their hyperspectral cameras was secured, and patrol vessels were stationed in strategic locations waiting for a call to action. “Our system is incredibly fast, which gives us the edge,” Dewey says. “Generally, our system allows boats to be caught red-handed. That makes it so much easier where the courts are concerned.” The shark-spotting challenge is a more recent project. ESpy is in initial discussions with NSW Fisheries and the University of South Australia’s Industrial AI Research Centre to develop techniques to spot the predators first thing in the morning and use established behavioural patterns to predict where they could move during the day. While trespassing trawlers present a major issue, the deadliest offender is often someone much closer to home. One dragnet can strip an ecosystem of everything from algae and small crustaceans to dolphins and turtles, leaving damage that can take years to recover. “Our big problem in Australia is the little guy who throws out a net once or twice,” Dewey says. “He’s generally local, or at least from within 100-or-so kilometres. But he’s got a high risk of being caught, so he just wants to get in and take as much as possible as quickly as possible.” <img id="cosmos-post-tracker" src="https://syndication.cosmosmagazine.com/?id=195119&title=Illegal+fishers+and+wayward+sharks+are+in+the+sights+of+new+multispectral+imaging" width="1" height="1" />This article originally appeared on <a href="https://cosmosmagazine.com/earth/oceans/espy-oceans-tracking-waters/" target="_blank" rel="noopener">cosmosmagazine.com</a> and was written by Jamie Seidel. Image: Shutterstock

Travel Trouble

Artificial intelligence tool learns “song of the reef” to determine ecosystem health

Coral reefs are among Earth’s most stunning and biodiverse ecosystems. Yet, due to human-induced climate change resulting in warmer oceans, we are seeing growing numbers of these living habitats dying. The urgency of the crisis facing coral reefs around the world was highlighted in a recent <a class="spai-bg-prepared" href="https://www.gbrmpa.gov.au/the-reef/reef-health" target="_blank" rel="noreferrer noopener">study</a> that showed that 91% of Australia’s Great Barrier Reef had experienced coral bleaching in the summer of 2021–22 due to heat stress from rising water temperatures. Determining reef health is key to gauging the extent of the problem and developing ways of intervening to save these ecosystems, and a new artificial intelligence (AI) tool has been developed to measure reef health using… sound. Research coming out of the UK is using AI to study the soundscape of Indonesian reefs to determine the health of the ecosystems. The results, <a class="spai-bg-prepared" href="https://www.sciencedirect.com/science/article/pii/S1470160X22004575?via%3Dihub" target="_blank" rel="noreferrer noopener">published</a> in Ecological Indicators, shows that the AI tool could learn the “song of the reef” and determine reef health with 92% accuracy. The findings are being used to track the progress of reef restoration. “Coral reefs are facing multiple threats, including climate change, so monitoring their health and the success of conservation projects is vital,” says lead author Ben Williams of the UK’s University of Exeter. <div class="newsletter-box spai-bg-prepared"> <div id="wpcf7-f6-p193163-o1" class="wpcf7 spai-bg-prepared" dir="ltr" lang="en-US" role="form"> </div> </div> “One major difficulty is that visual and acoustic surveys of reefs usually rely on labour-intensive methods. Visual surveys are also limited by the fact that many reef creatures conceal themselves, or are active at night, while the complexity of reef sounds has made it difficult to identify reef health using individual recordings. “Our approach to that problem was to use machine learning – to see whether a computer could learn the song of the reef. Our findings show that a computer can pick up patterns that are undetectable to the human ear. It can tell us faster, and more accurately, how the reef is doing.” Fish and other creatures make a variety of sounds in coral reefs. While the meaning of many of these calls remains a mystery, the new machine-learning algorithm can distinguish overall between healthy and unhealthy reefs. Recordings used in the study were taken at the <a class="spai-bg-prepared" href="http://www.buildingcoral.com/" target="_blank" rel="noreferrer noopener">Mars Coral Reef Restoration Project</a>, which is restoring heavily damaged reefs in Indonesia. The study’s co-author Dr Tim Lamont, a marine biologist at Lancaster University, said the AI method provides advantages in monitoring coral reefs. “This is a really exciting development,” says Lamont. “Sound recorders and AI could be used around the world to monitor the health of reefs, and discover whether attempts to protect and restore them are working. “In many cases it’s easier and cheaper to deploy an underwater hydrophone on a reef and leave it there than to have expert divers visiting the reef repeatedly to survey it, especially in remote locations.” <img id="cosmos-post-tracker" class="spai-bg-prepared" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=193163&title=Artificial+intelligence+tool+learns+%E2%80%9Csong+of+the+reef%E2%80%9D+to+determine+ecosystem+health" width="1" height="1" /> <div id="contributors"> <a href="https://cosmosmagazine.com/technology/artificial-intelligence-reef-song/" target="_blank" rel="noopener">This article</a> was originally published on <a href="https://cosmosmagazine.com" target="_blank" rel="noopener">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/evrim-yazgin" target="_blank" rel="noopener">Evrim Yazgin</a>. Evrim Yazgin has a Bachelor of Science majoring in mathematical physics and a Master of Science in physics, both from the University of Melbourne. Image: Getty Images </div>

Technology

No, sunscreen chemicals are not bleaching the Great Barrier Reef

For the sixth time in the last 25 years, the Great Barrier Reef <a href="https://www.gbrmpa.gov.au/the-reef/reef-health" target="_blank" rel="noopener">is bleaching</a>. During bleaching events, people are quick to point the finger at different causes, including <a href="https://owlcation.com/stem/Coral-Bleaching-and-Oxybenzone-Choose-Your-Sunscreen-Carefully" target="_blank" rel="noopener">sunscreen</a>. Why sunscreen? Some active ingredients can wash off snorkelers and into the reef, contaminating the area. So could this be the cause of the Barrier Reef’s bleaching? In a word, no. I reviewed the evidence for sunscreen as a risk to coral in my <a href="https://www.publish.csiro.au/CH/CH21236" target="_blank" rel="noopener">new research</a>, and found that while chemicals in sunscreen pose a risk to corals under laboratory conditions, they are only found at very low levels in real world environments. That means when coral bleaching does occur, it is more likely to be due to the marine heatwaves and increased water temperatures that have come with climate change, as well as land-based run-off. Why have we been concerned over the environmental impact of sunscreens? After we apply sunscreen, the active ingredients can leach from our skin into the water. When we shower after swimming, soaps and detergents can further strip the these sunscreen chemicals off and send them into our waste water systems. They pass through treatment facilities, which cannot effectively remove them, and end up in rivers and oceans. <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454296/original/file-20220325-21-1agae0v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="hands putting on sunscreen" /></a><figcaption>Sunscreen isn’t the cause of the coral bleaching. Shutterstock</figcaption></figure> It’s no surprise, then, that sunscreen contamination has been detected in freshwater and seas across the globe, from <a href="https://pubmed.ncbi.nlm.nih.gov/15996716/" target="_blank" rel="noopener">Switzerland</a> to <a href="https://link.springer.com/article/10.1007/s11356-015-5174-3" target="_blank" rel="noopener">Brazil</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/27235899/" target="_blank" rel="noopener">Hong Kong</a>. Contamination is highest in the summer months, consistent with when people are more likely to go swimming, and peaks in the hours after people have finished swimming. Four years ago, the Pacific island nation of Palau made world headlines by announcing plans to <a href="https://www.theguardian.com/world/2018/nov/02/pacific-island-to-introduce-world-first-reef-toxic-sunscreen-ban" target="_blank" rel="noopener">ban all sunscreens</a> that contain specific synthetic active ingredients due to concern over the risk they posed to corals. <a href="https://www.cntraveler.com/story/these-destinations-are-banning-certain-sunscreens" target="_blank" rel="noopener">Similar bans</a> have been announced by Hawaii, as well a number of other popular tourist areas in the Americas and Caribbean. These bans are based on independent scientific studies and <a href="https://coralreefpalau.org/wp-content/uploads/2017/10/CRRF-UNESCO-Sunscreen-in-Jellyfish-Lake-no.2732.pdf" target="_blank" rel="noopener">commissioned reports</a> which have found contamination from specific active ingredients in sunscreen in the water at beaches, rivers and lakes. Notably, the nations and regions which have banned these active ingredients, like Bonaire and Mexico, have local economies heavily reliant on summer tourism. For these areas, coral bleaching is not only an environmental catastrophe but an economic loss as well, if tourists choose to go elsewhere. How do we know sunscreen isn’t the issue? So if contamination concerns over these active ingredients are warranted, how can we be sure they’re not the cause of the bleaching in the Great Barrier Reef? Put simply, the concentrations of the chemicals are too low to cause the bleaching. The synthetic ingredients used in most products are highly <a href="https://www.corrosionpedia.com/definition/653/hydrophobic#:%7E:text=Hydrophobic%20is%20a%20property%20of,Oils%20and%20fats%20are%20hydrophobic." target="_blank" rel="noopener">hydrophobic</a> and <a href="https://www.greenfacts.org/glossary/jkl/lipophilic.htm" target="_blank" rel="noopener">lipophilic</a>. That means they shun water and love fats, making them hard to dissolve in water. They’d much prefer to stay in the skin until they break down. Because of this, the levels found in the environment are very low. How low? Think nanograms per litre (a nanogram is 0.000000001 grams) or micrograms per litre (a microgram is 0.00001 grams). Significantly higher levels are found only in waste water treatment sludge and some sediments, not in the water itself. So how do we reconcile this with studies showing sunscreen can damage corals? Under laboratory conditions, many active ingredients in sunscreen have been found to damage corals as well as <a href="https://pubmed.ncbi.nlm.nih.gov/22828885/" target="_blank" rel="noopener">mussels</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/17889917/#:%7E:text=BP%2D2%20was%20accumulated%20in,and%20female%20fish%20were%20observed." target="_blank" rel="noopener">fish</a>, <a href="https://pubmed.ncbi.nlm.nih.gov/24359924/" target="_blank" rel="noopener">small crustaceans</a>, and plant-like organisms such as <a href="https://www.sciencedirect.com/science/article/abs/pii/S0269749111006713" target="_blank" rel="noopener">algae and phytoplankton</a>. The key phrase above is “under laboratory conditions”. While these studies would suggest sunscreens are a real threat to reefs, it’s important to know the context. Studies like these are usually conducted under artificial conditions which can’t account for natural processes. They usually don’t account for the breakdown of the chemicals by sunlight or dilution through water flow and tides. These tests also use sunscreen concentrations up to thousands of times higher – milligrams per litre – compared to real world contamination levels found in collected samples. In short, laboratory-only studies are not giving us a reliable indication of what happens to these chemicals in real world conditions. <figure class="align-center zoomable"><a href="https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454298/original/file-20220325-21-1wft8gc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" alt="Sea wave seen side on" /></a><figcaption>Laboratory studies don’t tend to account for dilution in seas or rivers. Shutterstock</figcaption></figure> If it’s not sunscreen, what is it? The greatest threats to the reef are climate change, coastal development, land-based run-off like pesticides, herbicides, and other pollutants, and direct human use like illegal fishing, according to a <a href="https://www.gbrmpa.gov.au/our-work/outlook-report-2019" target="_blank" rel="noopener">2019 outlook report</a> issued by the reef’s managing body. Reefs get their striking colours from single-celled organisms called <a href="https://oceanservice.noaa.gov/education/tutorial_corals/coral02_zooxanthellae.html" target="_blank" rel="noopener">zooxanthellae</a> which grow and live inside corals. Importantly, these organisms only grow under very specific conditions, including narrow bands of temperature and light levels. When conditions go outside the zooxanthellaes’ preferred zone, they die and the coral turns white. As a result, the likeliest cause of this bleaching is <a href="https://www.gbrmpa.gov.au/our-work/threats-to-the-reef/climate-change" target="_blank" rel="noopener">climate change</a>, which has increased ocean temperatures and acidity and resulted in more flooding, storms, and cyclones which block light and stir up the ocean floor. So do you need to worry about the impact of your sunscreen on the environment? No. Sunscreen should remain a key part of our sun protection strategy, as a way to protect skin from UV damage, prevention skin cancers, and slow the visible signs of ageing. Our coral reefs face much bigger issues than sunscreen.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/179938/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/nial-wheate-96839" target="_blank" rel="noopener">Nial Wheate</a>, Associate Professor of the Sydney Pharmacy School, <a href="https://theconversation.com/institutions/university-of-sydney-841" target="_blank" rel="noopener">University of Sydney</a> This article is republished from <a href="https://theconversation.com" target="_blank" rel="noopener">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/no-sunscreen-chemicals-are-not-bleaching-the-great-barrier-reef-179938" target="_blank" rel="noopener">original article</a>. Image: Getty Images

Domestic Travel

5 major heatwaves in 30 years have turned the Great Barrier Reef into a bleached checkerboard

Just 2% of the Great Barrier Reef remains untouched by bleaching since 1998 and 80% of individual reefs have bleached severely once, twice or three times since 2016, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0960982221014901">our new study</a> reveals today. We measured the impacts of five marine heatwaves on the Great Barrier Reef over the past three decades: in 1998, 2002, 2016, 2017 and 2020. We found these bouts of extreme temperatures have transformed it into a checkerboard of bleached reefs with very different recent histories. Whether we still have a functioning Great Barrier Reef in the decades to come depends on how much higher we allow global temperatures to rise. The bleaching events we’ve already seen in recent years are a result of the world warming by 1.2℃ since pre-industrial times. World leaders meeting at the climate summit in Glasgow must commit to more ambitious promises to drastically cut greenhouse gas emissions. It’s vital for the future of corals reefs, and for the hundreds of millions of people who depend on them for their livelihoods and food security. <h2>Coral in a hotter climate</h2> The Great Barrier Reef is comprised of more than 3,000 individual reefs stretching for <a href="https://www.gbrmpa.gov.au/the-reef/reef-facts">2,300 kilometres</a>, and supports more than 60,000 jobs in reef <a href="https://www.gbrmpa.gov.au/our-work/Managing-multiple-uses/tourism-on-the-great-barrier-reef">tourism</a>. Under climate change, the frequency, intensity and scale of climate extremes is changing rapidly, including the record-breaking marine heatwaves that cause corals to bleach. Bleaching is a stress response by overheated corals, where they lose their colour and many struggle to survive. If all new COP26 pledges by individual countries are actually met, then the projected increase in average global warming could be brought down <a href="https://www.climate-resource.com/tools/ndcs">to 1.9℃</a>. In theory, this would put us in line with the goal of the Paris Agreement, which is to keep global warming below 2℃, but preferably 1.5℃, this century. However, it is still not enough to prevent the <a href="https://www.ipcc.ch/sr15/chapter/spm/">ongoing degradation</a> of the world’s coral reefs. The damage to coral reefs from anthropogenic heating so far is very clear, and further warming will continue to <a href="https://www.science.org/doi/10.1126/science.aan8048">ratchet down</a> reefs throughout the tropics. <h2>Ecological memories of heatwaves</h2> Most reefs today are in early <a href="https://www.aims.gov.au/reef-monitoring/gbr-condition-summary-2020-2021">recovery mode</a>, as coral populations begin to re-build since they last experienced bleaching in 2016, 2017 and 2020. It takes about a decade for a decent recovery of the fastest growing corals, and much longer for slow-growing species. Many coastal reefs that were severely bleached in 1998 have never fully recovered. <a href="https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="" /></a> The fringing reef flat at Orpheus Island on the central Great Barrier Reef, prior to mass coral bleaching in 1998. Bette Willis and Andrew Baird, Author provided <a href="https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="" /></a> The same reef flat at Orpheus Island after further bleaching in 2002 and 2016. Bette Willis and Andrew Baird, Author provided Each bleaching event so far has a different geographic footprint. Drawing upon <a href="https://www.mdpi.com/2072-4292/6/11/11579">satellite data</a>, we measured the duration and intensity of heat stress that the Great Barrier Reef experienced each summer, to explain why different parts were affected during all five events. The bleaching responses of corals differed greatly in each event, and was strongly influenced by the recent history of previous bleaching. For this reason, it’s important to measure the extent and severity of bleaching directly, where it actually occurs, and not rely exclusively on water temperature data from satellites as an indirect proxy. We found the most vulnerable reefs each year were the ones that had not bleached for a decade or longer. On the other hand, when successive episodes were close together in time (one to four years apart), the heat threshold for severe bleaching increased. In other words, the earlier event had hardened regions of the Great Barrier Reef to subsequent impacts. <a href="https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="Bleached coral" /></a> Bleaching is a stress response by overheated corals. Shutterstock For example, in 2002 and 2017, it took much more heat to trigger similar levels of bleaching that were measured in 1998 and 2016. The threshold for bleaching was much higher on reefs that had experienced an earlier episode of heat stress. Similarly, southern corals, which escaped bleaching in 2016 and 2017, were the most vulnerable in 2020, compared to central and northern reefs that had bleached severely in previous events. Many different mechanisms could generate these historical effects, or ecological memories. One is <a href="https://www.nature.com/articles/s41586-018-0041-2">heavy losses</a> of the more heat-susceptible coral species during an earlier event – dead corals don’t re-bleach. Nowhere left to hide Only a single cluster of reefs remains unbleached in the far south, downstream from the rest of the Great Barrier Reef, in a small region that has remained consistently cool through the summer months during all five mass bleaching events. These reefs lie at the outer edge of the Great Barrier Reef, where upwelling of cool water may offer some protection from heatwaves, at least so far.<a href="https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="" /></a> Map of the Great Barrier Reef showing the cumulative level of bleaching observed in 2016, 2017 and 2020. The colours represent the intensity of bleaching, ranging from zero (category 1, dark blue) to severe bleaching that affected more than 60% of corals (category 4, red) Author provided In theory, a judiciously placed network of well-protected, climate-resistant reefs might help to repopulate the <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.12587">broader seascape</a>, if greenhouse gas emissions are curtailed to stabilise temperatures later this century. But the unbleached southern reefs are too few in number, and too far away from the rest of the Great Barrier Reef to produce and deliver sufficient coral larvae, to promote a long-distance recovery. Instead, future replenishment of depleted coral populations is more likely to be local. It would come from the billions of larvae produced by recovering adults on nearby reefs that have not bleached for a while, or by corals inhabiting reef in deeper waters which tend to experience less heat stress than those living in shallow water. Future recovery of corals will increasingly be temporary and incomplete, before being interrupted again by the inevitable next bleaching event. Consequently, the patchiness of living coral on the Great Barrier Reef will increase further, and corals will continue to decline under climate change. Our findings make it clear we no longer have the luxury of studying individual climate-related events that were once unprecedented, or very rare. Instead, as the world gets hotter, it’s increasingly important to understand the effects and combined outcomes of sequences of rapid-fire catastrophes.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/170719/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/terry-hughes-9894">Terry Hughes</a>, Distinguished Professor, <a href="https://theconversation.com/institutions/james-cook-university-1167">James Cook University</a> and <a href="https://theconversation.com/profiles/sean-connolly-94343">Sean Connolly</a>, Research Biologist, <a href="https://theconversation.com/institutions/smithsonian-institution-1227">Smithsonian Institution</a> This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/5-major-heatwaves-in-30-years-have-turned-the-great-barrier-reef-into-a-bleached-checkerboard-170719">original article</a>.

Domestic Travel

Can selective breeding of ‘super kelp’ save our cold water reefs from hotter seas?

Australia’s vital kelp forests are disappearing in many areas as our waters warm and our climate changes. While we wait for rapid action to slash carbon emissions – including the United Nations climate talks now underway in Glasgow – we urgently need to buy time for these vital ecosystems. How? By ‘future-proofing’ our kelp forests to be more resilient and adaptable to changing ocean conditions. Our recent trials have shown selectively bred kelp with higher heat tolerance can be successfully replanted and used in restoration. This matters because these large seaweed species are the foundation of Australia’s <a href="https://theconversation.com/australias-other-reef-is-worth-more-than-10-billion-a-year-but-have-you-heard-of-it-45600">Great Southern Reef</a>, a vast but little-known <a href="https://www.abc.net.au/news/2020-05-19/great-southern-reef-needs-more-attention-scientists-say/12227998">temperate reef system</a> and a global hotspot of biodiversity. The reef’s kelp forests run along 8000 km of Australia’s southern coastline, from Geraldton in Western Australia to the Queensland border with New South Wales. These underwater forests support coastal food-webs and fisheries. Think of the famous mass-spawning of Australian Giant Cuttlefish off Whyalla, the rock lobster and abalone fisheries, or our iconic weedy and leafy seadragons. Unfortunately, these seas are hotspots in the literal sense, with the nation’s southeast and southwest waters <a href="https://link.springer.com/article/10.1007/s11160-013-9326-6">warming several times faster than the global average </a>and suffering from some of the <a href="https://theconversation.com/how-much-do-marine-heatwaves-cost-the-economic-losses-amount-to-billions-and-billions-of-dollars-170008">worst marine heatwaves recorded</a>. These increasing temperatures and other climate change impacts are devastating our kelp, including shrinking forests and permanent losses of golden kelp (Ecklonia radiata) on the <a href="https://www.abc.net.au/news/2021-08-22/tropical-fish-sea-urchins/100396162">east</a> and <a href="https://theconversation.com/a-marine-heatwave-has-wiped-out-a-swathe-of-was-undersea-kelp-forest-62042">west coasts</a>, and <a href="https://www.imas.utas.edu.au/news/news-items/satellite-images-track-decline-of-tasmanias-giant-kelp-forests">staggering declines</a> of the now-endangered giant kelp (Macrocystis pyrifera) forests in Tasmania. <a href="https://images.theconversation.com/files/429669/original/file-20211102-27-9dqafn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/429669/original/file-20211102-27-9dqafn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="Golden kelp forest" /></a> We need novel measures to buy time for climate action Australian researchers are leading the way to try to find ways of future-proofing our critical ocean ecosystems, such as kelp forests and <a href="https://theconversation.com/meet-the-super-corals-that-can-handle-acid-heat-and-suffocation-122637">coral reefs</a>. In part, that’s because climate change is hitting our ecosystems early and hard. Climate change is moving much faster than kelp species can adapt. In turn, that threatens all the species that rely on these forests, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3810891/">including us</a>. If climate change wasn’t happening, we could try to halt or reverse the losses of kelp forests by using traditional restoration methods. But in a world getting hotter and hotter, that is futile in many cases. Even if we slash carbon emissions soon, decades more warming are <a href="https://www.nytimes.com/2021/08/09/climate/climate-change-report-ipcc-un.html">already locked in</a>. If we want to keep these forests of the sea alive, we must now consider cutting-edge methods to help kelp survive current and future ocean conditions while governments pursue the urgent goal of reducing emissions. <h2>How to future proof an underwater forest</h2> Together and separately, we’ve been exploring techniques to speed up the natural rate of evolution to boost kelp resilience. Along with other researchers, we’ve put several techniques to the test in the real world, with promising results. Others remain hypothetical. At present, there are <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00237/full">several broad approaches</a> to future-proofing restoration work. These include: <ul> <li> Genetic rescue focuses on enhancing the genetic diversity of genetically compromised populations to boost their potential to adapt to future conditions. This involves planting and restoring a mix of kelp from <a href="https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.13707">disconnected populations</a> of the same species. Improved genetic diversity can boost the ability of these forests to respond to change. We expect this approach to be especially useful in areas where climate change poses a limited threat at present. </li> <li> Assisted gene flow strategies introduce naturally adapted or tolerant kelp individuals into threatened populations to increase their ability to survive specific threats, like hotter seas. This could help kelp forests in areas affected by climate change now or in the near future. In these situations, the genetic rescue technique could be counterproductive if the new genetic diversity introduced isn’t able to cope with the heat. </li> <li> Selective breeding is a well-known agricultural technique, and can be used to identify the best kelp to use in these cases. In short, we try to identify kelp with naturally higher tolerance, and then use these as the basis for restoration efforts. These can be transplanted into ailing kelp forests. <a href="https://www.abc.net.au/news/2021-10-13/kelp-forests-off-tasmania-regrowing-a-year-since-project-began/100532756">Trials are presently underway</a> in Tasmania using giant kelp. Early results are exciting, with the largest ‘super kelp’ growing over 12 metres high a year after being planted. </li> </ul> In the future, we may have to explore more cutting-edge strategies to deal with the changing conditions. These include: <ul> <li> Genetic manipulation. This technique extends what is possible with selective breeding by directly manipulating genes to enhance the traits or characteristics that might further boost kelp’s ability to thrive in hotter waters. </li> <li> Assisted expansion is when species with little chance of survival are relocated to better but novel locations, assuming these exist. This technique could also see new species of kelp being planted to replace existing species, guided by the need to protect the forest ecosystem as a whole, rather than save specific species. </li> </ul> <a href="https://images.theconversation.com/files/429674/original/file-20211102-13-1o4uuod.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img src="https://images.theconversation.com/files/429674/original/file-20211102-13-1o4uuod.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="Scientist experimenting on kelp" /></a> <h2>Are these approaches ethical?</h2> Each of these techniques – tested or untested – pose challenging ethical questions. That’s because we are not undertaking traditional conservation, where we work to restore a historic kelp ecosystem. Instead, we are modifying these ecosystems in the hope they can better cope with conditions at the extremes of their current survival limits. That means we must move carefully, weighing potential downsides like genetic pollution and maladaptation (accidental poor adaptation to other stressors) against the probability of further kelp forest destruction from doing nothing. Such future-proofing interventions could be well suited to areas already hit hard by severe kelp forest losses, those that will be threatened in the near future, or where kelp losses would be particularly damaging environmentally, socially, or economically. What is certain is that communities that live and rely on our southern coasts must now talk about what they value from kelp forests, and how they want them to look and function into the future. Our view is that traditional approaches focused on recreating previous ecosystems are likely to be increasingly challenging, given the rate and scale of ongoing disruption in our oceans. It is crucial that we do not restore nostalgically for ocean conditions which are quickly changing, but instead, work to ensure the long-term survival of these spectacular underwater forests while we wait for rapid action to reduce carbon emissions.<img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important; text-shadow: none !important;" src="https://counter.theconversation.com/content/170271/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/cayne-layton-104355">Cayne Layton</a>, Postdoctoral fellow and lecturer, <a href="https://theconversation.com/institutions/university-of-tasmania-888">University of Tasmania</a> and <a href="https://theconversation.com/profiles/melinda-coleman-1285592">Melinda Coleman</a>, Principal Research Scientist This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/can-selective-breeding-of-super-kelp-save-our-cold-water-reefs-from-hotter-seas-170271">original article</a>. Image: Institute for Marine and Antarctic Studies

Domestic Travel

The first step to conserving the Great Barrier Reef is understanding what lives there

Look at this photo of two coral skeletons below. You’d be forgiven for thinking they’re the same species, or at least closely related, but looks can be deceiving. These two species diverged tens of millions of years ago, probably earlier than our human lineage split from baboons and macaques. Scientists have traditionally used morphology (size, shape and colour) to identify species and infer their evolutionary history. But most species were first described in the <a href="https://www.nature.com/articles/027073a0">19th century</a>, and based solely on features of the coral skeleton visible under a microscope. Morphology remains important for species recognition. The problem is we don’t know whether a particular morphological feature reflects species ancestry, or evolved independently. Our new study <a href="https://www.sciencedirect.com/science/article/abs/pii/S1055790320302165">examined</a> the traditional ideas of coral species and their evolutionary relationships using “<a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/1755-0998.12736">phylogenomics</a>” – comparing thousands of DNA sequences across coral species. Our results revealed the diversity and distributions of corals are vastly different to what we previously thought. It shows we still don’t know many fundamental aspects about the corals on Great Barrier Reef. And after three mass bleaching events in five years, not having a handle on the basics could mean <a href="http://elibrary.gbrmpa.gov.au/jspui/bitstream/11017/3569/4/Draft-restoration-adaptation-policy.pdf">our attempts to intervene</a> and help coral survive climate change may have unexpected consequences. How do we know which species is which? Despite being one of the <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/j.1755-263X.2010.00146.x">best-studied</a> marine ecosystems on Earth, there are fundamental knowledge gaps around the Great Barrier Reef, including: <ol> <li>how many coral species live there?</li> <li>how do we identify them?</li> <li>where are they found across the vast Great Barrier Reef ecosystem?</li> </ol> Finding the answers to these questions starts with accurate “taxonomy” – the science of naming and classifying living things. Identifying species based on how similar they look may seem straightforward. As Darwin famously said, closely related species often share morphological features because they inherited them from a common ancestor. However, this can be misleading if two unrelated species independently acquire similar features. This process, called convergent evolution, often occurs when different species are faced with similar ecological challenges. A <a href="https://www.nationalgeographic.com/science/phenomena/2015/02/06/why-an-ichthyosaur-looks-like-a-dolphin/">classic example</a> of convergent evolution is dolphins and the prehistoric ichthyosaurs. These animals are unrelated, but share many similarities since they both occupy a similar ecological niche. At the other end of the spectrum, morphology can vary considerably within a single species. An alien taxonomist visiting Earth could be forgiven for describing the Chihuahua and the Irish Wolfhound as two distinct species. Bringing coral taxonomy into the 21st century We used molecular phylogenetics, a field of research that uses variations in DNA sequences to reconstruct genealogies. From corals to humans, molecular phylogenetics has revolutionised our understanding of the origins and evolution of life on Earth. Molecular approaches have <a href="https://link.springer.com/chapter/10.1007/978-3-319-31305-4_4">revolutionised</a> our understanding of the diversity and evolution of corals, shedding light on <a href="https://www.nature.com/articles/nature02339">deeper branches</a> in the coral “tree of life”. But within hyper-diverse, ecologically-important coral groups, such as the staghorn corals from the genus Acropora, we are still in the dark. <a href="https://www.sciencedirect.com/science/article/abs/pii/S1055790320302165">Our new technique</a> addresses this by comparing thousands of key regions across coral genomes (the entire genetic code of an organism) to help identify species in this ecologically important group for the first time. This method will also allow us to identify morphological features that do reflect shared ancestry and help us recognise species when diving in the reef. About a quarter of all coral species on the Great Barrier Reef are staghorn corals, and they provide much of the three-dimensional structure fishes and many other coral reef animals rely on, just like trees in a forest. Unfortunately, staghorn corals are also highly susceptible to threats such as thermal bleaching and crown-of-thorns seastar predation. The future of reefs will be heavily influenced by the fate of staghorn corals. The risk of ‘silent extinctions’ While we don’t yet know how many coral species occur on the Great Barrier Reef or how widespread they are, many species appear to have far smaller ranges than we previously thought. For example, we now know some of the corals on Lord Howe Island are endemic to only a few reefs in subtropical eastern Australia and <a href="https://www.mapress.com/j/zt/article/view/zootaxa.3626.4.11">occur nowhere else</a>, not even on the Great Barrier Reef. They evolved in isolation and bleach at <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14772">much lower temperatures</a> than corals on tropical reefs. This means Lord Howe Island’s corals are of far greater conservation concern than currently recognised, because <a href="https://theconversation.com/bleaching-has-struck-the-southernmost-coral-reef-in-the-world-114433">one severe bleaching event</a> could cause the extinction of these species. The risk of “silent extinctions”, where species go extinct without even being noticed, is one of the reasons behind the Australian Academy of Science’s <a href="https://www.science.org.au/support/analysis/decadal-plans-science/discovering-biodiversity-decadal-plan-taxonomy">Decadal Plan for Taxonomy</a>, which has led to the ambitious goal to document all Australian species in the next 25 years. Intervening now may have unexpected consequences In April, the <a href="https://www.gbrrestoration.org/reports#technical-reports">Reef Restoration and Adaptation Program</a> concept feasibility study found 160 possible interventions to help save the Great Barrier Reef. <a href="https://www.gbrrestoration.org/">Proposed interventions</a> include moving corals from warm to cooler waters, introducing genetically-engineered heat-tolerant corals into wild populations, and the harvest and release of coral larvae. What could go wrong? Well-intentioned interventions may inadvertently threaten coral communities, for example, through introduction or movement of diseases within the Great Barrier Reef. <a href="https://www.nationalgeographic.com/animals/amphibians/c/cane-toad/">Cane toads</a> are a famous example of unintended consequences: introduced in the 1930s to control an insect pest, they are now wreaking havoc on Australian ecosystems. Any intervention affecting the ecology of a system as complex as the Great Barrier Reef requires a precautionary approach to minimise the chance of unintended and potentially negative consequences. What we need, at this time, is far greater investment in fundamental biodiversity research. Without this information, we are not in a position to judge whether particular actions will threaten the resilience of the reef, rather than enhance it. Written by Tom Bridge, Andrea Quattrini, Andrew Baird and Peter Cowman. Republished with permission of <a href="https://theconversation.com/the-first-step-to-conserving-the-great-barrier-reef-is-understanding-what-lives-there-146097">The Conversation.</a>

Cruising

The first step to conserving the Great Barrier Reef is understanding what lives there

Look at this photo of two coral skeletons below. You’d be forgiven for thinking they’re the same species, or at least closely related, but looks can be deceiving. These two species diverged tens of millions of years ago, probably earlier than our human lineage split from baboons and macaques. Scientists have traditionally used morphology (size, shape and colour) to identify species and infer their evolutionary history. But most species were first described in the <a href="https://www.nature.com/articles/027073a0">19th century</a>, and based solely on features of the coral skeleton visible under a microscope. Morphology remains important for species recognition. The problem is we don’t know whether a particular morphological feature reflects species ancestry, or evolved independently. Our new study <a href="https://www.sciencedirect.com/science/article/abs/pii/S1055790320302165">examined</a> the traditional ideas of coral species and their evolutionary relationships using “<a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/1755-0998.12736">phylogenomics</a>” – comparing thousands of DNA sequences across coral species. Join 130,000 people who subscribe to free evidence-based news. Get newsletter Our results revealed the diversity and distributions of corals are vastly different to what we previously thought. It shows we still don’t know many fundamental aspects about the corals on Great Barrier Reef. And after three mass bleaching events in five years, not having a handle on the basics could mean <a href="http://elibrary.gbrmpa.gov.au/jspui/bitstream/11017/3569/4/Draft-restoration-adaptation-policy.pdf">our attempts to intervene</a> and help coral survive climate change may have unexpected consequences. An international team of scientists have developed a new genetic tool that can help them better understand and ultimately work to save coral reefs. How do we know which species is which? Despite being one of the <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/j.1755-263X.2010.00146.x">best-studied</a> marine ecosystems on Earth, there are fundamental knowledge gaps around the Great Barrier Reef, including: 1. how many coral species live there? 2. how do we identify them? 3. where are they found across the vast Great Barrier Reef ecosystem? Finding the answers to these questions starts with accurate “taxonomy” – the science of naming and classifying living things. Identifying species based on how similar they look may seem straightforward. As Darwin famously said, closely related species often share morphological features because they inherited them from a common ancestor. However, this can be misleading if two unrelated species independently acquire similar features. This process, called convergent evolution, often occurs when different species are faced with similar ecological challenges. A <a href="https://www.nationalgeographic.com/science/phenomena/2015/02/06/why-an-ichthyosaur-looks-like-a-dolphin/">classic example</a> of convergent evolution is dolphins and the prehistoric ichthyosaurs. These animals are unrelated, but share many similarities since they both occupy a similar ecological niche. Ichthyosaurs dominated the world’s oceans for millions of years. At the other end of the spectrum, morphology can vary considerably within a single species. An alien taxonomist visiting Earth could be forgiven for describing the Chihuahua and the Irish Wolfhound as two distinct species. Bringing coral taxonomy into the 21st century We used molecular phylogenetics, a field of research that uses variations in DNA sequences to reconstruct genealogies. From corals to humans, molecular phylogenetics has revolutionised our understanding of the origins and evolution of life on Earth. Molecular approaches have <a href="https://link.springer.com/chapter/10.1007/978-3-319-31305-4_4">revolutionised</a> our understanding of the diversity and evolution of corals, shedding light on <a href="https://www.nature.com/articles/nature02339">deeper branches</a> in the coral “tree of life”. But within hyper-diverse, ecologically-important coral groups, such as the staghorn corals from the genus Acropora, we are still in the dark. <a href="https://www.sciencedirect.com/science/article/abs/pii/S1055790320302165">Our new technique</a> addresses this by comparing thousands of key regions across coral genomes (the entire genetic code of an organism) to help identify species in this ecologically important group for the first time. This method will also allow us to identify morphological features that do reflect shared ancestry and help us recognise species when diving in the reef. About a quarter of all coral species on the Great Barrier Reef are staghorn corals, and they provide much of the three-dimensional structure fishes and many other coral reef animals rely on, just like trees in a forest. Unfortunately, staghorn corals are also highly susceptible to threats such as thermal bleaching and crown-of-thorns seastar predation. The future of reefs will be heavily influenced by the fate of staghorn corals. The risk of ‘silent extinctions’ While we don’t yet know how many coral species occur on the Great Barrier Reef or how widespread they are, many species appear to have far smaller ranges than we previously thought. For example, we now know some of the corals on Lord Howe Island are endemic to only a few reefs in subtropical eastern Australia and <a href="https://www.mapress.com/j/zt/article/view/zootaxa.3626.4.11">occur nowhere else</a>, not even on the Great Barrier Reef. They evolved in isolation and bleach at <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14772">much lower temperatures</a> than corals on tropical reefs. This means Lord Howe Island’s corals are of far greater conservation concern than currently recognised, because <a href="https://theconversation.com/bleaching-has-struck-the-southernmost-coral-reef-in-the-world-114433">one severe bleaching event</a> could cause the extinction of these species. The risk of “silent extinctions”, where species go extinct without even being noticed, is one of the reasons behind the Australian Academy of Science’s <a href="https://www.science.org.au/support/analysis/decadal-plans-science/discovering-biodiversity-decadal-plan-taxonomy">Decadal Plan for Taxonomy</a>, which has led to the ambitious goal to document all Australian species in the next 25 years. Intervening now may have unexpected consequences In April, the <a href="https://www.gbrrestoration.org/reports#technical-reports">Reef Restoration and Adaptation Program</a> concept feasibility study found 160 possible interventions to help save the Great Barrier Reef. <a href="https://www.gbrrestoration.org/">Proposed interventions</a> include moving corals from warm to cooler waters, introducing genetically-engineered heat-tolerant corals into wild populations, and the harvest and release of coral larvae. What could go wrong? Well-intentioned interventions may inadvertently threaten coral communities, for example, through introduction or movement of diseases within the Great Barrier Reef. <a href="https://www.nationalgeographic.com/animals/amphibians/c/cane-toad/">Cane toads</a> are a famous example of unintended consequences: introduced in the 1930s to control an insect pest, they are now wreaking havoc on Australian ecosystems. Any intervention affecting the ecology of a system as complex as the Great Barrier Reef requires a precautionary approach to minimise the chance of unintended and potentially negative consequences. What we need, at this time, is far greater investment in fundamental biodiversity research. Without this information, we are not in a position to judge whether particular actions will threaten the resilience of the reef, rather than enhance it. Written by Tom Bridge, Andrea Quattrini, Andrew Baird and Peter Crowman. Republished with permission of <a href="https://theconversation.com/the-first-step-to-conserving-the-great-barrier-reef-is-understanding-what-lives-there-146097">The Conversation.</a>

Cruising

We just spent two weeks surveying the Great Barrier Reef – What we saw was an utter tragedy

The Australian summer just gone will be remembered as the moment when human-caused climate change struck hard. First came drought, then deadly bushfires, and now a bout of coral bleaching on the Great Barrier Reef – the third in just five years. Tragically, the 2020 bleaching is severe and the most widespread we have ever recorded. Coral bleaching at regional scales is caused by spikes in sea temperatures during unusually hot summers. The first recorded mass bleaching event along Great Barrier Reef occurred in 1998, then the <a href="http://www.bom.gov.au/climate/change/archive/media99.shtml">hottest year on record</a>. Since then we’ve seen four more mass bleaching events – and more temperature records broken – in 2002, 2016, 2017, and again in 2020. This year, February had the<a href="https://www.abc.net.au/news/2020-03-15/cyclone-great-barrier-reef-bleaching-record-seas-temperatures/12050102"> highest monthly sea surface temperatures</a> ever recorded on the Great Barrier Reef since the Bureau of Meteorology’s records began in 1900. Not a pretty picture We surveyed 1,036 reefs from the air during the last two weeks in March, to measure the extent and severity of coral bleaching throughout the Great Barrier Reef region. Two observers, from the ARC Centre of Excellence for Coral Reef Studies and the Great Barrier Reef Marine Park Authority, scored each reef visually, repeating the same procedures developed during early bleaching events. The accuracy of the aerial scores <a href="https://www.nature.com/articles/nature21707?dom=icopyright&src=">is verified</a> by underwater surveys on reefs that are lightly and heavily bleached. While underwater, we also measure how bleaching changes between shallow and <a href="https://www.nature.com/articles/s41467-018-05741-0">deeper reefs</a>. Of the reefs we surveyed from the air, 39.8% had little or no bleaching (the green reefs in the map). However, 25.1% of reefs were severely affected (red reefs) – that is, on each reef more than 60% of corals were bleached. A further 35% had more modest levels of bleaching. Bleaching isn’t necessarily fatal for coral, and it affects <a href="https://theconversation.com/how-much-coral-has-died-in-the-great-barrier-reefs-worst-bleaching-event-69494">some species more than others</a>. A pale or lightly bleached coral typically regains its colour within a few weeks or months and survives. But when bleaching is severe, many corals die. In 2016, half of the shallow water corals died on the northern region of the Great Barrier Reef <a href="https://www.nature.com/articles/s41586-018-0041-2">between March and November</a>. Later this year, we’ll go underwater to assess the losses of corals during this most recent event. Compared to the four previous bleaching events, there are fewer unbleached or lightly bleached reefs in 2020 than in 1998, 2002 and 2017, but more than in 2016. Similarly, the proportion of severely bleached reefs in 2020 is exceeded only by 2016. By both of these metrics, 2020 is the second-worst mass bleaching event of the five experienced by the Great Barrier Reef since 1998. The unbleached and lightly bleached (green) reefs in 2020 are predominantly offshore, mostly close to the edge of the continental shelf in the northern and southern Great Barrier Reef. However, offshore reefs in the central region were severely bleached again. Coastal reefs are also badly bleached at almost all locations, stretching from the Torres Strait in the north to the southern boundary of the Great Barrier Reef Marine Park. For the first time, severe bleaching has struck all three regions of the Great Barrier Reef – the northern, central and now large parts of the southern sectors. The north was the worst affected region in 2016, followed by the centre in 2017. In 2020, the cumulative footprint of bleaching has expanded further, to include the south. The distinctive footprint of each bleaching event closely matches the location of <a href="https://www.nature.com/articles/nature21707?dom=icopyright&src=">hotter and cooler conditions in different years</a>. Poor prognosis Of the five mass bleaching events we’ve seen so far, only 1998 and 2016 occurred during <a href="http://www.bom.gov.au/climate/updates/articles/a008-el-nino-and-australia.shtml">an El Niño</a> – a weather pattern that spurs warmer air temperatures in Australia. But as summers grow hotter under climate change, we no longer need an El Niño to trigger mass bleaching at the scale of the Great Barrier Reef. We’ve already seen the first example of back-to-back bleaching, in the consecutive summers of 2016 and 2017. The gap between recurrent bleaching events is shrinking, hindering a full recovery. After five bleaching events, the number of reefs that have escaped severe bleaching continues to dwindle. Those reefs are located offshore, in the far north and in remote parts of the south. The Great Barrier Reef will continue to lose corals from heat stress, until global emissions of greenhouse gasses are reduced to net zero, and sea temperatures stabilise. Without urgent action to achieve this outcome, it’s clear our coral reefs will not survive business-as-usual emissions. Written by Terry Hughes and Morgan Pratchett. Republished with permission of <a href="https://theconversation.com/we-just-spent-two-weeks-surveying-the-great-barrier-reef-what-we-saw-was-an-utter-tragedy-135197">The Conversation.</a>

Travel Tips

New $10 million floating hotel lets you stay in the Great Barrier Reef

A new $10 million floating hotel on the Great Barrier Reef is offering Australia’s first underwater suites, which means tourists are able to wake up to the natural wildlife. The <a href="https://cruisewhitsundays.com/experiences/reefsuites/">Reefsuites</a> at Hardy Reef are set to be a “game changer” for the local tourism industry, according to Tourism Minister Kate Jones. “This will be one of the most iconic tourism projects in the world,” she said in a <a href="http://statements.qld.gov.au/Statement/2019/8/1/new-attraction-to-bring-thousands-of-tourists-to-the-whitsundays">statement</a>. “We want to invest in tourism attractions that we know will attract more visitors to the Whitsundays and support local jobs – this project will achieve just that.” The two exclusive suites sit four metres below the surface, with just three inches of glass separating you from the reef life outside. At night, outside lights illuminate the waters so you can see what happens in the reef after dark. Floor to ceiling windows are a part of the experience so you don’t miss anything. The project began in 2017 as the pontoon was reconstructed after damage from Cyclone Debbie. The project was developed by Cruise Whitsundays and the Queensland Government. “Today is a landmark moment for Australia,” says Luke Walker, from Journey Beyond, the parent company of Cruise Whitsundays. “We are extremely privileged to have access to such a truly breathtaking and remote part of Australia and to provide both local and international guests the chance to gain a deeper appreciation of our wonderful Great Barrier Reef,” he says. Each Reefsuite has a two-person capacity, but guests can also camp under the stars as the roof of the pontoon is set up to accommodate a dozen queen beds in custom-built canvas canopies. Up to 28 visitors at a time can be on the pontoon. Scroll through the gallery to see the pontoon and how the suites will look underwater. Photo credits: <a href="https://cruisewhitsundays.com/experiences/reefsuites/">Cruise Whitsundays</a>

Domestic Travel

How you can see Australia’s iconic Heart Reef up close and personal

It doesn’t get much better than the beautiful and mesmerising Heart Reef – and now, for the first time ever, people are able to experience it up close and personal. Until recent months, the only way travellers were able to experience the Heart Reef was way above in the sky for a stunning scenic flight. <blockquote style="background: #FFF; border: 0; border-radius: 3px; box-shadow: 0 0 1px 0 rgba(0,0,0,0.5),0 1px 10px 0 rgba(0,0,0,0.15); margin: 1px; max-width: 540px; min-width: 326px; padding: 0; width: calc(100% - 2px);" class="instagram-media" data-instgrm-permalink="https://www.instagram.com/p/BysEZFRFSiR/" data-instgrm-version="12"> <div style="padding: 16px;"> <div style="display: flex; flex-direction: row; align-items: center;"> <div style="background-color: #f4f4f4; border-radius: 50%; flex-grow: 0; height: 40px; margin-right: 14px; width: 40px;"></div> <div style="display: flex; flex-direction: column; flex-grow: 1; justify-content: center;"> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; margin-bottom: 6px; width: 100px;"></div> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; width: 60px;"></div> </div> </div> <div style="padding: 19% 0;"></div> <div style="display: block; height: 50px; margin: 0 auto 12px; width: 50px;"></div> <div style="padding-top: 8px;"> <div style="color: #3897f0; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: 550; line-height: 18px;">View this post on Instagram</div> </div> <p style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; line-height: 17px; margin-bottom: 0; margin-top: 8px; overflow: hidden; padding: 8px 0 7px; text-align: center; text-overflow: ellipsis; white-space: nowrap;"><a style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: normal; line-height: 17px; text-decoration: none;" rel="noopener" href="https://www.instagram.com/p/BysEZFRFSiR/" target="_blank">A post shared by SALTY WiNGS (@saltywings)</a> on Jun 14, 2019 at 4:30am PDT </div> </blockquote> Now, after a decade of development and $2 million spent to make an impossible mission possible, visitors will now get the rare opportunity to see it up close with the launch of Whitsundays Heart Island. What makes it a sight to behold isn’t just the fact that it’s in the most iconic destination filled with privacy and solitude, but travellers can also take pride in the fact that they are one of the first people to have exclusive access to the luxury experience. <blockquote style="background: #FFF; border: 0; border-radius: 3px; box-shadow: 0 0 1px 0 rgba(0,0,0,0.5),0 1px 10px 0 rgba(0,0,0,0.15); margin: 1px; max-width: 540px; min-width: 326px; padding: 0; width: calc(100% - 2px);" class="instagram-media" data-instgrm-permalink="https://www.instagram.com/p/Bz7MTAfnBDG/" data-instgrm-version="12"> <div style="padding: 16px;"> <div style="display: flex; flex-direction: row; align-items: center;"> <div style="background-color: #f4f4f4; border-radius: 50%; flex-grow: 0; height: 40px; margin-right: 14px; width: 40px;"></div> <div style="display: flex; flex-direction: column; flex-grow: 1; justify-content: center;"> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; margin-bottom: 6px; width: 100px;"></div> <div style="background-color: #f4f4f4; border-radius: 4px; flex-grow: 0; height: 14px; width: 60px;"></div> </div> </div> <div style="padding: 19% 0;"></div> <div style="display: block; height: 50px; margin: 0 auto 12px; width: 50px;"></div> <div style="padding-top: 8px;"> <div style="color: #3897f0; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: 550; line-height: 18px;">View this post on Instagram</div> </div> <p style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; line-height: 17px; margin-bottom: 0; margin-top: 8px; overflow: hidden; padding: 8px 0 7px; text-align: center; text-overflow: ellipsis; white-space: nowrap;"><a style="color: #c9c8cd; font-family: Arial,sans-serif; font-size: 14px; font-style: normal; font-weight: normal; line-height: 17px; text-decoration: none;" rel="noopener" href="https://www.instagram.com/p/Bz7MTAfnBDG/" target="_blank">A post shared by Hamilton Island (@hamiltonisland)</a> on Jul 14, 2019 at 9:59pm PDT </div> </blockquote> "Heart Island provides our guests with an unsurpassable way to explore the wonders of the Great Barrier Reef," Bourke said in a statement. "Since being purchased by the Oatley family in 2003, Hamilton Island has worked to become a world-class destination, epitomised by our six-star luxury resort qualia. We are proud to offer this preeminent experience for our guests in partnership with Hamilton Island Air."

Cruising

This destination is the crowning glory of the Great Barrier Reef

Lying in the heart of one of Australia's greatest national treasures, the Great Barrier Reef, the Whitsunday Islands are its crowning glory. These 74 tropical islands prove that the region’s beauty is just as rich above water as below it. It’s one of the most prized and revered natural destinations in Australia. With so many islands to discover and explore, many of them completely secluded, the choice of where to stay and what to do is almost endless. But you can’t leave this incredible environment without taking a peek under the water at the pristine reef, finding an isolated bay and settling in for a beach picnic, or trekking the national park trails that cover many of the islands. From the resorts on Hamilton Island to the white silica sands of Whitehaven Bay, the heart-shaped reef and incredible marine life, the Whitsundays are best explored by foot, by plane and, of course, by boat. Named after Captain James Cook recorded his sighting of the islands in his diary as ‘Whitsunday Passage’, the passage wasn’t actually discovered until Whit Monday, as the International Date Line had not yet been established. Sailing through the islands is still one of the most popular ways to discover them, and many visitors today would have the same view of the beautiful passage that Cook enjoyed in 1770. “Hamilton Island is without doubt the ultimate getaway! Perched on the edge of the Great Barrier Reef and nestled among the Whitsunday Islands, it offers the discerning traveller an experience of a lifetime. With stunning coral reefs, inviting beaches and perfect weather, this destination has to be at the top of everyone’s bucket list … just add champagne and ice!” - Viv Chelin, Cooma, New South Wales What to do: <ul> <li>Snorkel or dive from any number of sites around the Whitsundays for some of the world’s best underwater experiences.</li> <li>Spend some time on Hamilton Island, the commercial heart of the islands and where resorts, shops, restaurants, bars, cafes and the airport can all be found.</li> <li>Get pampered at one of the many day spas on the islands; relaxation is the name of the game here.</li> <li>Learn about the Whitsundays’ original inhabitants, the Ngaro people, and follow the Whitsunday Ngaro Sea Trail walk to discover their history and culture.</li> </ul> “One of our favourite places in Australia is the Whitsunday islands. We’ll never forget our adventure with our friend, yachtsman Jesse Martin, who wrote himself into the history books by sailing around the world when he was just 17 years old. We chartered a catamaran with him and set off for a couple of days exploring the islands. Leaving from Airlie Beach, we headed straight into the wind and set sail, wanting to go in one direction, but the wind had other ideas. Skipper Jesse declared with a smile, ‘Sometimes you’ve just gotta go where the wind takes you …’ (wisdom we still use today). And with that we decided to just make everything up as we went along! That’s the beauty of the Whitsundays: while you might encounter all manner of weather, there are so many islands and sheltered inlets where you can anchor. We headed to a place called Nara Inlet on Hook Island and, after checking out some Aboriginal rock art, settled in for the night. As the sun started to set, we enjoyed a barbie, while Jesse played guitar on the front deck. There was not another boat in sight. With the gentle slapping of the water against the hull, it was one of the best sleeps we’d ever had. The next day we sailed to Hamilton Island for a coffee. It was quite weird just being able to pull up and moor the boat, but it really was as simple as that.” – Jen and Clint <img width="175" height="214" src="https://oversixtydev.blob.core.windows.net/media/7815921/1_175x214.jpg" alt="1 (94)" style="float: right;"/> This is an edited extract from Australia’s Ultimate Bucket List by Jennifer Adams & Clint Bizzell published by Hardie Grant Books RRP $29.99 and is available in stores nationally.

Cruising

The huge threat facing our coral reefs

There are more than 11 billion pieces of plastic debris on coral reefs across the Asia-Pacific, according to our new research, which also found that contact with plastic can make corals more than 20 times more susceptible to disease. In our study, <a href="http://science.sciencemag.org/cgi/doi/10.1126/science.aar3320" target="_blank">published in Science</a>, we examined more than 124,000 reef-building corals and found that 89% of corals with trapped plastic had visual signs of disease - a marked increase from the 4% chance of a coral having disease without plastic. Globally, more than 275 million people live within 30km of coral reefs, relying on them for food, coastal protection, tourism income, and cultural value. With coral reefs already under pressure from climate change and mass <a href="https://theconversation.com/back-to-back-bleaching-has-now-hit-two-thirds-of-the-great-barrier-reef-76092" target="_blank">bleaching events</a>, our findings reveal another significant threat to the world’s corals and the ecosystems and livelihoods they support. In collaboration with numerous experts and underwater surveyors across Indonesia, Myanmar, Thailand and Australia, we collected data from 159 coral reefs between 2010 and 2014. In so doing, we collected one of the most extensive datasets of coral health in this region and plastic waste levels on coral reefs globally. There is a huge disparity between global estimates of plastic waste <a href="http://science.sciencemag.org/content/347/6223/768" target="_blank">entering the oceans</a> and the amount that <a href="http://www.pnas.org/content/114/23/6052.abstract" target="_blank">washes up on beaches</a> or is found <a href="http://www.pnas.org/content/111/28/10239.full" target="_blank">floating on the surface</a>. Our research provides one of the most comprehensive estimates of plastic waste on the seafloor, and its impact on one of the world’s most important ecosystems. The number of plastic items entangled on the reefs varied immensely among the different regions we surveyed - with the lowest levels found in Australia and the highest in Indonesia. An estimated 80% of marine plastic debris originates from land. The variation of plastic we observed on reefs during our surveys corresponded to the estimated levels of plastic litter entering the ocean from the nearest coast. One-third of the reefs we surveyed had no derelict plastic waste, however others had up 26 pieces of plastic debris per 100 square metres. We estimate that there are roughly 11.1 billion plastic items on coral reefs across the Asia-Pacific. What’s more, we forecast that this will increase 40% in the next seven years – equating to an estimated 15.7 billion plastic items by 2025. This increase is set to happen much faster in developing countries than industrialised ones. According to our projections, between 2010 and 2025 the amount of plastic debris on Australian coral reefs will increase by only about 1%, whereas for Myanmar it will almost double. How can plastic waste cause disease? Although the mechanisms are not yet clear, the influence of plastic debris on disease development may differ among the three main global diseases we observed to increase when plastic was present. Plastic debris can open wounds in coral tissues, potentially letting in pathogens such as Halofolliculina corallasia, the microbe that causes skeletal eroding band disease. Plastic debris could also introduce pathogens directly. Polyvinyl chloride (PVC) – a very common plastic used in children’s toys, building materials like pipes, and many other products – have been found carrying a family of bacteria called Rhodobacterales, which are associated with a suite of coral diseases. Similarly, polypropylene – which is used to make bottle caps and toothbrushes – can be colonised by Vibrio, a potential pathogen linked to a globally devastating group of coral diseases known as white syndromes. Finally, plastic debris overtopping corals can block out light and create low-oxygen conditions that favour the growth of microorganisms linked to black band disease. Structurally complex corals are eight times more likely to be affected by plastic, particularly branching and tabular species. This has potentially dire implications for the numerous marine species that shelter under or within these corals, and in turn the fisheries that depend on them. Our study shows that reducing the amount of plastic debris entering the ocean can directly prevent disease and death among corals. Once corals are already infected, it is logistically difficult to treat the resulting diseases. By far the easiest way to tackle the problem is by reducing the amount of mismanaged plastic on land that finds its way into the ocean. Do you think enough is being done to cope with this threat? Written by Joleah Lamb. Republished with permission of <a href="http://www.theconversation.com" target="_blank">The Conversation</a>.<img width="1" height="1" src="https://counter.theconversation.com/content/90694/count.gif?distributor=republish-lightbox-advanced" alt="The Conversation"/>

International Travel

10 things you didn't know about the Great Barrier Reef

The Great Barrier Reef might be one of Australia’s most instantly recognisable attractions, but that doesn’t mean it doesn’t have a secret (or two). Here are 10 things you never knew about the Great Barrier Reef. To see them all, scroll through the gallery above. Were you aware of these things?

International Travel

Great Barrier Reef valued at $56 billion

A new Deloitte Access Economics report has found the total asset value of the Great Barrier Reef to be $56 billion. The economists calculated the World Heritage site’s economic, social and iconic brand value to reach the staggering figure. Many Australians believe the reef is priceless but Deloitte arrived at the figure after a six-month analysis that drew on economic and scientific sources as well as international surveys. At $29 billion, tourism was found to be the greatest contributor to the overall value. $23.8 billion of the reef’s value came from “indirect or non-use value” which means people who haven’t yet visited the reef but value knowing it exists. $3.2 billion of its value was attributed to recreational users such as weekend divers. Commissioned by the Great Barrier Reef Foundation, the report found the reef added $6.4 billion of economic value to the Australian economy in 2015-16. The reef employs 39,000 people directly but there are also 64,000 jobs linked to it nationally. In comparison, National Australia Bank creates 34,000 direct jobs, Telstra 33,000 and Qantas 26,000. Great Barrier Reef Foundation director Steve Sargent said no other Australian asset contributed as much value to “Brand Australia”. "At $56 billion, the reef is valued at more than 12 Sydney Opera Houses," he said. "This report sends a clear message that the Great Barrier Reef – as an ecosystem, as an economic driver, as a global treasure – is too big to fail." Former US vice-president Al Gore deemed the report as a necessary look at the reef’s value. "Any failure to protect this indispensable natural resource would have profound impacts not only to Australia but around the world," he said. Deloitte Access Economics partner and report author John O’Mahony labelled the reef as irreplaceable. "With the reef under threat, our report is a major step in looking to value nature's significance in monetary terms and using this information to help inform what we do to protect and save important natural assets." The study used various economic techniques including input-output tables, econometrics, willingness to pay analysis, sensitivity and the Brand Asset Valuator. In the past two years, two-thirds of the reef have been impacted by unprecedented coral bleaching.

International Travel

Desperate plea for government to save the Great Barrier Reef

WWF Australia has issued a desperate plea for supporters to write to the government and urge Prime Minister Malcolm Turnbull to do more to <a href="http://www.oversixty.com.au/travel/domestic-travel/2016/10/5-australian-world-heritage-sites-everyone-should-visit/">save the Great Barrier Reef</a>. This follows research released in early April which suggest a “substantial loss” of coral was expected in 2017, with 90 per cent of the reef already covered in bleached coral. Professor Terry Hughes from the ARC Centre of Excellence for Coral Reef Studies at James Cook told Storyful, “Last year most of the severe bleaching was in the northern 700km stretch of the Great Barrier Reef. This year tragically, that damage has extended much further south. So in 2017 most of the bleaching is the central section of the Great Barrier Reef. “If we look at the last two years in combination, fully two-thirds of the Great Barrier Reef, the northern third and the middle third, is now severely damaged by global warming.” The video above depicts the incredible colourful ocean life on display in the reef, in comparison to the desolate bleached coral. It’s one thing to read about the damage to the reef, but seeing it makes you really understand the gravity of the situation. For more information on the damage to the reef and what you can do to help, <a href="http://www.wwf.org.au/what-we-do/oceans/great-barrier-reef#gs.T0dlAUY" target="_blank">click here</a>. Do you think Australia has done enough to protect the Great Barrier Reef? Video credit: WWF-Australia via Storyful

News

Coral expert debunks Great Barrier Reef myths

Perhaps you've heard that the epic, 2200km-long Great Barrier Reef in Australia has died. Perhaps you've read that on Thursday the Australian government released it's report card giving the state of the reef a D for the fifth year in a row. Perhaps you've read its obituary by writer Rowan Jacobsen on the website Outside Online. But before you start mourning the loss of what Jacobsen calls "one of the most spectacular features on the planet," the community of scientists that study coral reefs in the Pacific Ocean would like you to hold up, slow down, and take a deep breath. The news isn't good, but it may not be as dire as the obituary may have you believe. "For those of us in the business of studying and understanding what coral resilience means, the article very much misses the mark," said Kim Cobb, a professor in Georgia Tech's School of Earth and Atmospheric Sciences. "It's not too late for the Great Barrier Reef, and people who think that have a really profound misconception about what we know and don't know about coral resilience." Cobb spoke to us about the state of the world's largest reef system, and why there is reason for both concern and hope. Q: Is the Great Barrier Reef dead? No. It's not. We just had a massive bleaching event, but we know from past research that corals are able to recover from the brink of death. Q: So bleached corals aren't dead corals? That's right. There's lots of confusion about what bleaching means. Coral is an animal, and the animal exists in symbiosis with photosynthetic algae. The algae provides food for the coral in exchange for a great home. But when the water gets too warm, the algae become chemically destructive to the coral. When that happens, the coral convulses and spits out puffs of algae to protect itself. That removes all the colour from the coral tissue which is transparent, allowing you to see right through to the underlying skeleton. So you are not necessarily seeing dead coral, you're really just seeing clear coral without its algae. Q: But bleaching is still bad, right? Bleaching events are worrisome because if the coral misses this key food source from the algae for too long it will literally starve to death. But, if the water temperature comes back down, it will welcome the algae back. The key is that the water temperature change has to be relatively quick. When was the massive bleaching event? It started with the Hawaiian Islands bleaching in the early part of 2015 due to a moderate El Nino event in 2014-2015. After that there was the build up to the massive El Nino that culminated in the warmest ocean waters during the November 2015 time frame. Unfortunately, these warm waters didn't release their grip on many of the Pacific reefs until the spring of 2016, so that's nine months of pretty consistently high temperatures. That is a long time for a coral to be in a mode of starvation. Has the Great Barrier Reef been through anything like this before? It has had very severe bleaching events associated with large El Ninos like we had last year, but the problem is we are seeing baseline ocean temperatures getting warmer every year. When you pile a strong El Nino on top of this ever warming trend, you get more extreme and more prolonged bleaching episodes. What was striking about this year was the extent of the damage. It was staggering. By important metrics the '97-'98 El Nino was bigger, but the damage from this last one was far more extensive. So how can you remain hopeful about the fate of Great Barrier Reef and other reefs in the Pacific? I work on a research site in the Christmas Islands that is literally smack in the middle of the Pacific Ocean, and which was much more devastated than the Great Barrier Reef. It was worse off than any reef in the world with up to 85 per cent mortality. But even in the face of that whole-scale destruction, we saw individual corals that were still alive, looking like nothing had happened. I cling to that. I know from my own site that there is a lot more resilience baked into the system then we can hope to understand right now and that out of the rubble will come a reef that may not look exactly like it looked before, but may be better adapted for future temperature change. It kind of sounds like an awesome research opportunity. You better believe it. This is a window into the future of global reefs. It's a great natural laboratory. Written by Deborah Netburn. First appeared on <a href="http://www.stuff.co.nz/%20%20" target="_blank">Stuff.co.nz</a>. Related links: <a href="http://www.oversixty.com.au/news/news/2016/10/7-foods-to-lower-blood-pressure/">7 things to eat or avoid to lower your blood pressure</a> <a href="http://www.oversixty.com.au/lifestyle/relationships/2016/10/dorrie-jacobson-on-body-issues-and-intimacy/">How body image issues hold you back from intimacy</a> <a href="http://www.oversixty.com.au/lifestyle/home-garden/2016/10/the-healthiest-leanest-ways-to-cook/">5 of the healthiest, leanest ways to cook</a>

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Footage captures beauty of Great Barrier Reef

Last month we reported coral bleaching is putting the <a href="/news/news/2016/04/great-barrier-reef-coral-bleaching-concerns/" target="_blank">future of the Great Barrier Reef at risk</a>. This is why it’s so important to remind ourselves as to how spectacular reef was at its peak, and why it’s worth whatever effort it takes to keep it intact. This video was taken in 2011 at Ribbon Reef and features a selection of bright coral and inquisitive marine creatures, recorded by a diving crew exploring the area. If it doesn’t make you want to do something about the reef, we don’t know what will! The video is four minutes long but is worth watching the whole way through. It provides an enthralling look at one of the most beautiful natural wonders in the world. Video credit: Vimeo / Undersea Productions Related links: <a href="/news/news/2016/04/great-barrier-reef-coral-bleaching-concerns/">Coral beaching puts future of Great Barrier Reef at risk</a> <a href="http://www.oversixty.co.nz/travel/international/2016/04/time-lapse-video-ningaloo-marine-park/">Time-lapse video captures beauty of Ningaloo Marine Park</a> <a href="http://www.oversixty.co.nz/travel/international/2016/03/dive-of-discovery-off-the-great-barrier-reef/">Dive of discovery off the Great Barrier Reef</a>

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93 per cent of Great Barrier Reef hit by coral bleaching

A comprehensive, aerial and underwater survey of the Great Barrier Reef has suggested that 93 percent of the World Heritage site has been affected by coral bleaching. A review of more than 900 individual reefs showed the severe bleaching had occurred in the northern section of the reef, stretching 1,000 kilometres north of Port Douglas. Professor Terry Hughes from the National Coral Bleaching Taskforce told ABC News, "We've never seen bleaching on the Great Barrier Reef of that severity and when bleaching is that strong it affects virtually all coral species. We expect the central and southern corals to regain their colour and recover over the next few months.” "The southern third of the Great Barrier Reef fortunately cooled down late in summer due to ex-cyclone Winston. The 2016 footprint could have been much worse. "In 1998 and 2002, 40 per cent of the reefs had no bleaching — it's only 7 per cent this time," he said. We also know in 1998 and 2002 about 18 per cent of the reefs were severely bleaching — this time it's over half.” "So by those metrics this bleaching event is three or four times more severe." The aerial survey, which began last month, covered 911 individual reefs and found that only 68 had escape bleaching entirely. Of those that had been bleached, more than half had been severely bleached. If a coral remains bleached for an extended period it is likely to die, and Mr Hughes expects a mortality rate as high as 50 per cent in some parts of the reef. Professor Andrew Baird, from the ARC Centre of Excellence for Coral Reef Studies, spent over two weeks at sea recording the bleaching, and told ABC News, "Tragically, the northern section is the most remote part of the reef, and its remoteness has protected it from most human pressures but not climate change. North of Port Douglas, we're already measuring an average of close to 50 per cent mortality of bleached corals." Related links: <a href="/lifestyle/family-pets/2015/12/life-lessons-from-grandparents/">Top 10 life lessons kids learn from grandparents</a> <a href="/lifestyle/family-pets/2015/10/quotes-about-siblings/">9 heart-warming quotes about siblings</a> <a href="/lifestyle/family-pets/2015/09/kids-addicted-to-technology/">How kids have fun today is alarmingly different to the good old days</a>

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