Search

Beyond the Barrier Reef: Australia’s 3 other World Heritage reefs are also in trouble

<div class="theconversation-article-body"><a href="https://theconversation.com/profiles/kate-marie-quigley-1400512">Kate Marie Quigley</a>, <a href="https://theconversation.com/institutions/james-cook-university-1167">James Cook University</a> and <a href="https://theconversation.com/profiles/andrew-hamilton-baird-11285">Andrew Hamilton Baird</a>, <a href="https://theconversation.com/institutions/james-cook-university-1167">James Cook University</a> The Great Barrier Reef is world famous – it’s the largest coral reef system in the world and home to tens of thousands of species. No wonder it is World Heritage listed. But Australia has three lower profile reefs which are also World Heritage listed – Ningaloo and Shark Bay in Western Australia, and Lord Howe Island, 600 kilometres off the New South Wales coast, the <a href="https://www.guinnessworldrecords.com/world-records/612288-most-southerly-coral-reef">southernmost coral</a> in the world. Ningaloo has 260km of coral reef, while the reefs of Shark Bay have less coral but are home to ancient stromatolites, vast seagrass beds and iconic species such as dugongs. This month, the World Heritage Committee will meet in New Delhi. On the agenda will be how the world’s natural World Heritage sites are faring. The Australian government will be under increased scrutiny to prove it has upheld its <a href="https://www.dcceew.gov.au/parks-heritage/heritage/about/world/management-australias-world-heritage-listed/managing-world-heritage-australia/protecting-world-heritage#regulation">international commitments</a> to protecting these reefs. Our <a href="https://onlinelibrary.wiley.com/doi/10.1111/gcb.17407">new research</a> has found all four of these reefs are in greater danger than we thought – even those in subtropical waters, such as Lord Howe Island. Our two Indian Ocean reefs at <a href="https://whc.unesco.org/en/list/578/">Shark Bay</a> and Ningaloo actually face more species and function loss than the Great Barrier Reef. At 1.5°C of warming, we are likely to lose about 20% of the 400-odd coral species which currently live across these four reefs (equating to about 70 extinctions). At 2°C warming, our modelling of species abundance and ecosystem functions predict an almost complete collapse in reef ecosystems – even for the subtropical reefs. This aligns with <a href="https://www.annualreviews.org/docserver/fulltext/animal/12/1/annurev-animal-021122-093315.pdf?expires=1721002489&id=id&accname=guest&checksum=A9A203CC0F3AEB7D1FE9420F50EDF69A,%20https://backend.orbit.dtu.dk/ws/files/238807594/AGR2020.pdf">predictions</a> by the Intergovernmental Panel on Climate Change for the future of coral reefs. We believe our work adds to the need to consider whether Australia’s four iconic reefs should be <a href="https://whc.unesco.org/en/danger/">on the list</a> of World Heritage sites in danger. <h2>What does it mean when a reef is World Heritage listed?</h2> Declaring a natural or cultural site as World Heritage is done to encourage the preservation of locations of immense ecological and cultural value. Nations have to <a href="https://whc.unesco.org/en/nominations/">nominate sites</a> they think are worthy of protection. Australia has 20 World Heritage sites, <a href="https://www.dcceew.gov.au/parks-heritage/heritage/places/world-heritage-list">of which</a> 12 are natural. When sites are formally listed, the United Nations Educational, Scientific and Cultural Organization (UNESCO) requires the country’s government to look after it. If the site is degrading, it can be listed as in danger. UNESCO has considered listing the Great Barrier Reef as in danger twice, in 2021 and again in <a href="https://www.theguardian.com/environment/article/2024/jun/24/set-more-ambitious-climate-targets-to-save-great-barrier-reef-unesco-urges-australia">June this year</a>. For the reef to keep its World Heritage status, the government must prove its policies are sufficient to keep the reefs in <a href="https://www.dcceew.gov.au/parks-heritage/heritage/about/world-heritage/outstanding-universal-value">good health</a>. In the debate over the Great Barrier Reef, two things have been missed – first, any mention of Australia’s other World Heritage reefs, and second, whether the federal government’s current policies to cut greenhouse gases are enough to protect the reefs into the future. <h2>What did we find?</h2> Our new results suggest all four reefs are in trouble. Given current warming trends, they will only deteriorate further in the future if we stay on this course. While the Barrier Reef has drawn a great deal of attention, it’s actually the ecosystems at Ningaloo, Shark Bay and Lord Howe Island which are projected to warm the most. When standardised to park boundaries, temperatures here are projected to increase by up to 1.3°C by the end of the century. (This temperature estimate is for sea temperatures, not the overall surface temperature which we use as shorthand when we talk about 1.5°C or 2°C of warming). While that might not sound like much, it will be enough to push many corals to potential extinction. Many coral species already exist within 1-2°C of the maximum temperature they can tolerate. Our modelling shows Shark Bay and Ningaloo actually face a greater risk of species and function loss than the Barrier Reef. It also suggests the ability of our reefs to bounce back will be overcome when warming tips over 1.5°C globally. While these models incorporate the baseline heat tolerance of coral species on these reefs, they don’t yet include their <a href="https://www.annualreviews.org/content/journals/10.1146/annurev-animal-021122-093315;jsessionid=mfIBuwjZ-ru5bkBMhWXDjumNnsvZgxkl02fPAg63.annurevlive-10-241-10-101">potential for genetic adaptation</a>. The question of whether some corals could adapt to this rapid warming is still open. A lot is riding on their ability to do so. <h2>Looming danger</h2> This year, the <a href="https://theconversation.com/sentinels-of-the-sea-ancient-boulder-corals-are-key-to-reef-survival-in-a-warmer-world-223207">Great Barrier Reef</a> and <a href="https://www.theguardian.com/australia-news/2024/mar/06/lord-howe-island-coral-bleaching-moving-south-fears-ocean-temperatures">Lord Howe Island</a> have suffered intense stress from high sea temperatures – the direct result of burning fossil fuels and producing heat-trapping greenhouse gases. This year is <a href="https://www.reuters.com/business/environment/2024-could-be-worlds-hottest-year-june-breaks-records-2024-07-08/#:%7E:text=The%20latest%20data%20suggest%202024,so%20far%2C%20some%20scientists%20said.">on track</a> to again be the hottest year on record, overtaking the previous record holder of 2023. Australia is already in the midst of an extinction crisis. Australia has one of the worst track records for extinctions. Since European colonisation, 34-38 mammal species have <a href="https://www.science.org/doi/abs/10.1126/science.adg7870">gone extinct</a> compared to just one from the contiguous United States, which covers a similar area. You might have read that coral cover – a measure of how much coral there is in an area – <a href="https://link.springer.com/article/10.1007/s00338-024-02498-5">hit historic highs</a> on the Great Barrier Reef last year. Coral cover is a helpful and important metric, but it’s <a href="https://theconversation.com/record-coral-cover-doesnt-necessarily-mean-the-great-barrier-reef-is-in-good-health-despite-what-you-may-have-heard-188233">not perfect</a>. For instance, fast-growing heat tolerant coral species might expand as less heat tolerant species die off. Importantly, relying on coral cover alone can mask significant changes in how the <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2019.2628">reef is functioning</a>. It’s hard to assess how species in our oceans are doing, given the difficulty of access and the large number of species, including many <a href="https://theconversation.com/the-first-step-to-conserving-the-great-barrier-reef-is-understanding-what-lives-there-146097">unknown to science</a>. If warming continues unabated, we will likely start to lose species before we have even documented them. Our results are based on “moderate” climate models of global surface temperature changes. Australia has committed to cutting emissions by 43% below 2005 levels by 2030. While that sounds good, it’s not enough – this decrease is compatible with <a href="https://environment.govt.nz/what-you-can-do/climate-scenarios-toolkit/climate-scenarios-list/ipccs-ssp-rcp-scenarios/">hitting 3.2ºC by 2100</a>. To limit warming to 1.5ºC or below by 2050, we would need to commit to much greater cuts in emissions – 90% below 2005 levels by 2030. Our results clearly suggest Australia’s four World Heritage reefs will be dramatically affected by warming in the near future. They will no longer qualify as being maintained under “conditions of integrity”. It’s hard to see how they can avoid being added to the in danger list.<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;" src="https://counter.theconversation.com/content/234268/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /> <a href="https://theconversation.com/profiles/kate-marie-quigley-1400512">Kate Marie Quigley</a>, DECRA Research Fellow in molecular ecology, <a href="https://theconversation.com/institutions/james-cook-university-1167">James Cook University</a> and <a href="https://theconversation.com/profiles/andrew-hamilton-baird-11285">Andrew Hamilton Baird</a>, Professorial fellow in coral reef ecology, <a href="https://theconversation.com/institutions/james-cook-university-1167">James Cook University</a> Image credits: Shutterstock 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/beyond-the-barrier-reef-australias-3-other-world-heritage-reefs-are-also-in-trouble-234268">original article</a>. </div>

Domestic Travel

"Why is the water so salty?" and other priceless questions from clueless tourists

In the heart of the stunning intersection where the Daintree Rainforest kisses the Great Barrier Reef, you’ll find <a href="https://www.tripadvisor.com.au/Attraction_Review-g499639-d1045292-Reviews-Ocean_Safari-Cape_Tribulation_Daintree_Region_Queensland.html" target="_blank" rel="noopener">Ocean Safari</a> – a top-notch, eco-certified tour company. Brooke Nikola, one of their delightful tour guides, has been guiding wide-eyed adventurers through this paradise for years. With thousands of tourists coming from all corners of the globe, she’s accumulated a treasure trove of amusing anecdotes that could rival the size of the reef itself. Let’s dive right into the deep end with some classic moments <a href="https://www.news.com.au/travel/australian-holidays/queensland/hilarious-comments-from-clueless-tourists/news-story/ad90a419cbf4fed9d454d3edef0cb096" target="_blank" rel="noopener">per news.com.au</a>. One sunny day, while marvelling at the endless blue expanse, a curious tourist asked Brooke, “Why does the water taste so salty?” “Well, it’s the ocean,” Brooke gently reminded them. Ah, the wonders of seawater – still a mystery to some. Then there was the time aboard the Ocean Safari vessel, cruising serenely over the waves, when a perplexed guest inquired, “How far above sea level are we?” And who could forget the would-be scientist who attempted to bottle the stunning blue ocean water, only to be baffled when it turned out clear. We can only imagine Brooke explaining the tricky science of light refraction and how the ocean's mesmerising blue doesn't quite fit into a bottle. No doubt their holiday turned into an impromptu science lesson. The complaints Brooke hears are just as priceless. One guest, dripping after a snorkelling session, grumbled, “Ugh, snorkelling makes me so wet.” Then there was the revelation about the rainforest. As rain drizzled through the lush canopy, a bewildered tourist remarked, “It’s so rainy in the rainforest!” Who knew that rain would be part of the rainforest experience? Certainly not that guest! Geography can be tricky, especially in a place as uniquely named as Cape Tribulation. As tourists boarded the Ocean Safari vessel from Cape Tribulation beach, one asked where the Daintree Rainforest was – oblivious to the verdant scenery they had driven through for the past hour. Brooke had to kindly point out that they had been in it this whole time. Another classic came from a guest who thought Cape Tribulation was an island. They earnestly asked, “So, how big is the whole island?” To which Brooke replied, “It’s pretty big. So big, in fact, it’s known as Australia!” Through all of these delightful moments, no doubt Brooke remained a fountain of patience and good humour. So, next time you find yourself at Cape Tribulation, remember to bring your sense of wonder – and a good laugh. Because as Brooke can tell you, the Great Barrier Reef is full of surprises, both above and below the water! Images: Ocean Safari / Instagram

Travel Trouble

Tourists' narrow escape after Great Barrier Reef plane crash

Nine tourists and a pilot on board a plane that flipped and crashed while trying to land on Lizard Island in the Great Barrier Reef are "lucky to be alive". The light plane bound for Cairns, was carrying nine adults and one 14-year-old girl, when it crashed shortly after 7:30am on Monday morning. It is believed that the plane tried to return to the Island after a mechanical malfunction, colliding with trees as it came down. Queensland Ambulance operations sent two rescue helicopters to the Island, shortly after the accident, and four passengers were flown back to Cairns Hospital for treatment. Royal Flying Doctor Service nurse Stephanie Beatty said it was remarkable that they managed to come out of the crash relatively unharmed. "Minor injuries, minor head injury and a fractured arm, otherwise most shaken but okay," she said. "I think the people are very lucky to be alive." Queensland Ambulance Service Acting Assistant Commissioner Brina Keating also said that it was "incredible" they managed to walk out alive. "All were walking — they were able to get out of the aircraft," she told ABC News. "To walk away from something like that is incredible." Ms Keating also said that the cause of the crash was being investigated. Footage of the wreckage shared on <a href="https://twitter.com/AnnaRawlings_/status/1744170681749946773?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1744170681749946773%7Ctwgr%5E4bc69f9710cd8300d7b1080153bf7dc1e4e405d4%7Ctwcon%5Es1_&ref_url=https%3A%2F%2Fwww.9news.com.au%2Fnational%2Fplane-crash-lizard-island-great-barrier-reef%2F78af78a6-2df7-4ad3-86ce-57e724512856" target="_blank" rel="noopener">social media</a> show the mangled plane lying upside down with broken propellers, and emergency tape closing off the area. According to the Cairns Hospital and Health Service, all 10 people are in a stable condition. Images: Anna Rawlings/ X

Travel Trouble

Using a dental scanner on corals like a “magic wand”

Dr Kate Quigley’s trip to the dentist might have revolutionised coral reef research. The intra-oral dental scanner her dentist was using turned out to be the perfect thing for scanning baby corals and learning critical information about their growth. “Baby corals and teeth are actually not too different. They’re both wet,” says Quigley, now a senior research scientist at the Minderoo Foundation. “Which might not seem like a big deal – but if you’re scanning something, that creates diffraction. […] Having tech that can work in a wet environment and handle a texture that’s wet, is actually really important.” There are a few other things that bring dental scanners and coral together, too. “The properties of teeth and baby coral skeletons are very similar. They’re calcium-based, slightly different, but similar enough that the resolution of the laser was tailored to coral skeletons, just by accident,” says Quigley. While conducting research at the Australian Institute of Marine Science (AIMS) and James Cook University, Quigley managed to get one of the tooth-scanning devices she’d seen at the dentist (the ITero Element 5D Flex), and test it on corals. Quigley has published a description of the new method in Methods in Ecology and Evolution. Monitoring coral growth is key to restoring and preserving it. “Growth and survival are really the currency of any monitoring program. It doesn’t matter what organism you’re looking at,” says Quigley. But it’s very difficult to monitor the growth of corals – because of their shape and size. “How most coral growth studies are done is really just taking 2D flat images. And that works really well when the coral is really young, say a month or two months, because they’re like little flat pancakes,” says Quigley. As they grow, corals develop very complex three-dimensional structures. Scanning these structures is time-consuming, and often destructive: the coral has to be killed in order to be scanned. The dental scanner takes quick, harmless scans and uses AI to combine the images into a 3D picture almost immediately. “Instead of taking all day and into the night, it takes two minutes,” says Quigley. It also provides better detail. “Baby corals start off really small. They’re almost invisible,” says Quigley. “Being able to measure those really fine scale differences, smaller than a millimetre, was also really important.” Quigley describes the scanner as “effectively a magic wand”. So far, the scanner’s been shown to work in a lab (at AIMS National Sea Simulator) and in the field – on a boat above the water. Unfortunately, it’s not waterproof enough to take diving. Yet. Quigley hopes it will become a regular tool used by coral researchers and restorers. “If we are thinking about scaling up reef restoration in the future we’re going to need a way to measure and monitor these individuals more effectively. It wouldn’t be sustainable if it’s one individual a day.” Quigley says that this discovery demonstrates the importance of thinking laterally. “In science I feel like there’s less and less room to just be creative anymore,” she says. “This has been a really interesting time for me – to dabble in dentistry and look at all the tech that’s available and may be useful in conservation.” This article originally appeared on <a href="https://cosmosmagazine.com/nature/coral-dental-scanner/" target="_blank" rel="noopener">cosmosmagazine.com</a> and was written by Ellen Phiddian. Images: Shutterstock

Travel Trouble

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

The Great Barrier Reef – what does a new Labor government mean for its future?

The Great Barrier Reef was inscribed on the UNESCO World Heritage list in 1981, and with good reason – it’s the world’s largest single structure made by living organisms. It’s an Australian icon intrinsically tied to our national identity, but the reef is in danger due to the effects of climate change. Just this past summer it experienced its fourth mass-bleaching event in seven years, with 91% of the reef experiencing some level of bleaching according to the summer 2021-22 Reef Snapshot report. Every Federal election, the Great Barrier Reef becomes a bit of a poster child for climate change, but what does the recent change in government actually mean for its future? The Labor government’s climate policies are more ambitious than those of the Coalition, but will it be enough to save the reef from devastation? Are we finally taking steps in the right direction? <h2>Climate change and its impact on the reef</h2> The effects of climate change are being felt majorly by the Great Barrier Reef already. Especially apparent are the mass coral-bleaching events caused by increasing ocean temperatures as a result of global warming. “Corals can (and frequently do) recover from bleaching, but just like forest recovery after a bushfire, they need time, and the speed of the recovery can vary depending on the severity of the heatwave and the types of corals growing on the reef,” explains Dr Emma Kennedy, a research scientist in Coral Reef Ecology at the Australian Institute of Marine Science (AIMS). But according to Dr Jodie Rummer, associate professor at the Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies at James Cook University, these events are only going to become more frequent. “With the trajectory that we’re on right now, what we’ll seeing by even the year 2044 is annual mass-bleaching events on the Great Barrier Reef, and coral reefs worldwide,” she says. “Even our more robust coral species require eight to 10 years to fully recover from these repeated heat waves. “We’re just losing that window of recovery for not only the coral reef and the coral organisms, but also all the other organisms that the coral reef supports.” Current greenhouse gas emissions trajectories indicate that globally we’re tracking towards an increase in global temperatures approaching 3°C above pre-industrial levels, by 2100. This is incompatible with healthy, thriving reefs. If warming exceeds 1.5°C “we would lose the reef altogether,” warns Rummer. <h2>Labor’s Great Barrier Reef policies</h2> With a new government comes new targets and policies that affect the reef. To start with, let’s look at the funding. The Labor government has promised to invest almost $1.2 billion in reef preservation and restoration by 2030 – that’s an extra $194.5 million on top of the LNP’s existing $1 billion reef package. This money will be used to tackle issues such as pollution from agricultural runoff, a more sustainable fishing sector, funding scientific research into thermal-tolerant corals, and funding protection and restoration work by Indigenous ranger organisations. The government also plans to continue and double the funding of the Reef 2050 Plan, which was initially released in 2015 to address the concerns of the World Heritage Committee. “It’s an awful lot of money, but it actually isn’t a lot of money when you think of it like $100 million each year,” says Dr Maxine Newlands, political scientist at James Cook University, Australia. “That’s not very much given the size of the Great Barrier Reef and what needs to be done.” It’s also important to keep in mind that the electorates that fringe the Great Barrier Reef in Queensland are Liberal seats. It remains to be seen whether there will be any opposition to funds being directed at the Great Barrier Reef – or calls for it to be redirected elsewhere, such as to farming, instead. But while it’s important to be mindful of these second and tertiary stressors to the reef, and to be acting on them, if we’re not addressing the number-one stressor that the Great Barrier Reef is facing – climate change – we’re not getting to the heart of the problem. “No more band aids on arterial wounds,” emphasises Rummer. “So, the money is great,” she adds. “And in terms of research, management and policy, we absolutely need it right now.” But the ideal is money being allocated toward reducing impacts of climate change – like the triple threat of global warming, ocean acidification and declining ocean oxygen levels. <h2>Emissions reductions targets must be increased</h2> Speaking of the reef’s number-one stressor, the outcome of this election has started Australia moving towards more action on climate change. The Labor government’s energy plan includes a target of a 43% reduction in greenhouse gas emissions from 2005 levels by 2030, which is far more ambitious than the previous 26% to 28% target set by the Coalition. The previous government’s policies were consistent with 3˚C of warming, whilst Labor’s policy is consistent with 2˚C, according to a report by Climate Analytics. It’s definitely a step in the right direction, but not enough to ensure the survival of the reef. Instead, the Greens’ target of a 74% emissions reduction, and teal independents’ targets of a 60% reduction, are consistent with limiting warming to 1.5°C. With an unprecedented number of Greens candidates and the “teal wave” of independents elected into the crossbench, it’s a sign of shifting public sentiment. “It’s put a bit of a magnifying glass onto the policies of the two major parties, because while I think climate change is always an issue, it’s become more prominent in this election,” says Newlands. According to Newlands, the presence of these climate-forward members is likely to “either expedite the current target of net zero by 2050, or at least have that conversation of ‘well, that’s not enough but what is?’ “Having those independents in will keep climate change on the political agenda. So, it puts pressure on particularly Labor, but Liberals as well, to address that.” The 2020s are a critical decade for climate and we’re already two years in. But we have the opportunity to catalyse action on climate change and take the necessary steps to ensure the continued survival of the Great Barrier Reef. “No other developed country in the world has more to lose from inaction on climate change than we do,” says Rummer. “But we also have the most to gain. “It’s important to look forward into the future with a lot of optimism.” This article originally appeared on <a href="https://cosmosmagazine.com/earth/great-barrier-reef-labor-government/" target="_blank" rel="noopener">cosmosmagazine.com</a> and was written by Imma Perfetto. Image: Shutterstock

Domestic Travel

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"> <form class="wpcf7-form mailchimp-ext-0.5.61 spai-bg-prepared init" action="/technology/artificial-intelligence-reef-song/#wpcf7-f6-p193163-o1" method="post" novalidate="novalidate" data-status="init"> <input class="wpcf7-form-control wpcf7-text referer-page spai-bg-prepared" name="referer-page" type="hidden" value="https://cosmosmagazine.com/technology/" data-value="https://cosmosmagazine.com/technology/" aria-invalid="false" /> </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

10 awe-inspiring UNESCO world heritage sites everyone needs to visit

Taj Mahal The Taj Mahal is universally recognised as the greatest masterpiece in Indo-Islamic architecture. The white marble mausoleum was commissioned in 1632 by Mughal emperor Shah Jahan to house the tomb of his favourite wife, Mumtaz Mahal. Spatial grandeur, arches, domes, relief work and precious stone inlay are among its defining characteristics. Angkor Wat Exploring the mysteries Angkor Wat in Siem Reap, Cambodia is an unforgettable bucket list trip. Part of one of the most significant archaeological sites in Southeast Asia (the ancient capital of the Khmer Empire, from the 9th to the 14th century), this massive temple complex was originally constructed as a Hindu place of worship for the god Vishnu and is the largest religious structure on the planet! Great Barrier Reef The Great Barrier Reef, off the coast of Queensland Australia, is the largest living thing on earth. It’s so huge that you can see it from outer space! Stretching for over 2,300 kilometres, this ecosystem is home to a diversity of marine line, including 400 types of coral, 1500 species of fish, and 4000 varieties of molluscs. Not surprisingly it’s a magnet for scuba divers. Plitvice Lakes National Park Plitvice Lakes National Park in Croatia is located halfway between Zagreb and Zadar. This idyllic oasis is renowned for its 16 crystalline lakes connected by a series of exquisite waterfalls, splendid caves and lush forests. Each year, more than one million visitors flock to this natural paradise, making it Croatia’s main tourist attraction. The Parthenon The Acropolis of Athens is an enduring symbol of Classical Greece. The crown jewel of this hilltop citadel is the Parthenon, a former temple dedicated to the goddess Athena. Built by Ictinus and Callicrates, beginning in 447 BCE, this Doric icon is regarded as the most important surviving ancient Greek monument. Grand Canyon Words don’t do even begin to do justice to the glory of the Grand Canyon. Formed by Colorado River activity over the past six million years, it’s one of the longest and deepest gorges (averaging 1,600m in depth) on earth. Its immense size and layered red rocks make it a must-see-before-you-die attraction. Want to bring your four-legged friend along? The Grand Canyon is also pet-friendly! Los Glaciares National Park Located in the southwest of Santa Cruz province of the Argentine part of Patagonia in a remote area known as the Austral Andes, Los Glaciares National Park is a rugged paradise of granite peaks, lakes and numerous glaciers that cover half the 600,000-hectare expanse. Traversing this spectacular scenery is a once-in-a-lifetime experience. Jeronimos Monastery Travel to the Belem district at the entrance to the port of Lisbon to find the Jeronimos Monastery, which dates back to the 15th century. This highly ornate religious building was constructed and donated to the monks of Saint Hieronymus to pray for sailors on their voyages. Its cloisters, columns, arcades and complex ornamentation are characteristic of Portuguese Gothic style. Old Québec Founded by the French explorer Samuel de Champlain in 1608, Québec is among the oldest settlements in North America (and one of the most popular travel destinations in Canada). Centuries-old charm is on full display in its impeccably preserved historic district, a shining example of a fortified colonial city with cobblestone lanes, churches, convents and landmarks like Château Frontenac and Place Royal. Iguazu Falls Stretching 2.7 kilometres across Argentina and Brazil, Iguazu Falls is the largest system of waterfalls in the world. The sheer size, thunderous sound and spectacle of these 275 individual cascades – including the 82-metre-tall Devil’s Throat – is truly jaw-dropping. The exotic flora and fauna of the surrounding rainforest add to the allure. Image credits: Getty Images This article originally appeared on <a rel="noopener" href="https://www.readersdigest.com.au/culture/10-awe-inspiring-unesco-world-heritage-sites-everyone-needs-to-visit" target="_blank">Reader's Digest</a>.

Travel Tips

Overcoming the barriers to reef recovery

<div> <div class="copy"> The Great Barrier Reef has been impacted by three mass bleaching events in the last five years. Foremost, it is being challenged by climate change, particularly ocean warming. There are still areas of the reef that are doing well and demonstrating quite a high level of resilience, but other areas are not. As the climate continues to warm, we predict that these bleaching events will continue to become more frequent and more severe, and this raises concerns about the reef’s long-term outlook. Most corals already live close to what we call their upper thermal limit – the upper temperature of what they can tolerate. When seawater temperatures rise just a degree or so above that upper limit, it begins to cause stress and damage to the coral. Corals also have symbiotic algae called zooxanthellae that live inside their tissues. When a higher water temperature is combined with a high irradiance stress on those days when it’s very calm and very sunny, those two factors together are detrimental to the algae that live in the coral tissues, and it causes a breakdown of that symbiosis. That’s what leads to coral bleaching – and if the water is hot enough, it impacts the coral animal tissue as well. <blockquote class="has-text-color has-weekly-blood-red-color"> When you dive below the surface, all of the noise from the world above is quietened, and it allows you to be completely immersed in an entirely different environment. </blockquote> That’s the mechanism by which temperature causes damage to the corals. If that persists for long enough those corals will often die. And of course, having fewer corals left on a reef impacts the ability of that reef to recover. Many people hear the word coral and think of colourful rocks. It’s important to understand that these are colonial animals. Hundreds or thousands of individual coral polyps make up the larger colony. Through time, as the animal grows, it lays down layers of limestone and that’s what builds the structure of the reef. The living part of the coral is actually the thin veneer of tissue covering the outside of what looks like rock. Since childhood, I’ve always wanted to immerse myself in the underwater world. I grew up in the state of Maryland, on the east coast of the USA, and spent quite a lot of time in the summers on the Chesapeake Bay. It’s certainly not tropical but I found it fascinating and enjoyed exploring my environment. Then I did a bit of travelling to some tropical locations, and I fell in love with reefs. They are so otherworldly, with all their incredible diversity and beauty and colour. They really are quite alien. When you dive below the surface, all of the noise from the world above is quietened, and it allows you to be completely immersed in an entirely different environment that is so fascinating, with so many behaviours and life forms to observe. I’ve been captivated by the connectedness of the reef ecosystem – how these organisms all rely on one another and work cohesively together. Of course, the flashy beautiful fish and charismatic creatures are attractive, but the corals have really enthralled me. I realised early in my studies that corals are the foundational species of the reef ecosystem. They are the giant sequoia, if you like – the massive trees that build the “forest” of the reef. I became very interested in understanding how the system works – how it changes, recovers and maintains its communities – and also wanted to ensure that it will be maintained for future generations. The more that I learned about these ecosystems, the more I saw the challenges that they faced. Many of the reefs in the Caribbean are degraded – I saw how they have been ravaged by diseases and bleaching in the last 15 years. Understanding the drivers of coral diseases became the focus of my dissertation work – and really prompted me to start thinking about how to apply my knowledge and skills to develop ways to help. <blockquote class="has-text-color has-weekly-blood-red-color"> [From] that early life history stage when the coral larvae have just settled onto the reef… it’s likely that fewer than one in a thousand survives to adulthood, maybe less. </blockquote> After my dissertation work in the Caribbean, I saw an opportunity for a postdoctoral position at the <a rel="noreferrer noopener" href="https://www.aims.gov.au/" target="_blank">Australian Institute of Marine Science (AIMS)</a> here in Australia. It’s been a dream to come here and study the corals of the Great Barrier Reef. One of the key things that we’re working on is trying to overcome the bottleneck in the survival of corals – that early life history stage when the coral larvae have just settled onto the reef. It’s likely that fewer than one in a thousand survives to adulthood, maybe less. In a joint reef resilience project with BHP in Woppaburra Sea Country (the Keppel Islands) I’m working towards identifying ways to overcome that bottleneck by reducing the high mortality during a coral’s first year of life. At a broader scale, we’re really trying to nail down the know-how for generating corals reliably and consistently at scale. Corals have a unique way of reproducing – at least from a human perspective. Obviously, they are attached to the sea floor. So, corals can’t go out and find mates. What most corals have evolved to do is synchronise the spawning of their gametes. They release their eggs and sperm into the sea in a highly synchronous event that only happens once a year for most species. These are animals, remember, and they reproduce like animals, with eggs and sperm released into the water. When the corals on the reef are healthy and densely populated, those eggs and sperm float and then mix at the surface of the ocean – the eggs become fertilised by sperm, and those fertilised eggs develop in the sea. Over the course of a few days to a few weeks, they develop into microscopic larvae that are less than a millimetre in size. Those larvae get moved around by currents, and hopefully get taken to a reef somewhere, where they’ll settle down, attach to the sea floor, and then grow into an adult coral. A single adult coral can release thousands to millions of eggs and sperm. They synchronise this release using a suite of cues from the environment, based on the lunar cycle, the tide and the time of sunset, down to the minute. Once they settle onto the reef they metamorphose into a single, tiny polyp. Over time, that single polyp divides, then divides again, and grows into a larger colony. So most colonies of corals have grown from a single tiny larva that settled into one polyp that grew over many years. At this time of year, the majority of the species of corals that live on the Great Barrier Reef will spawn. It’s interesting because they all spawn around the full moon, over several days, but they’re highly synchronous within a species. One species might spawn at 10 minutes after sunset. And then the next species will spawn 20 minutes after sunset. And then the next 30 minutes after, so that increases the likelihood that they’ll be able to fertilise eggs of the same species right around the same time. It’s not an exact science but we’ve become pretty good at predicting those times, and we expect them to go in a certain order. In general, the corals that we collect for the research we do are synchronised to their natural cycle, and we let them spawn naturally. But there’s a lot of interest in the research community at the moment in manipulating these spawning times. By adjusting the day length and the solar and lunar cycles, it will allow us to have a broader window of opportunity to do our work that is currently constrained to once per year. In my research, many of the corals that are generated from spawning go back out onto the reef. We then track how those corals perform through time and across different reef sites and environments. When a reef is supplied with trillions of larvae each year, then that reef can usually recover on its own. But problems exist when reefs are not getting adequate supplies of larvae because they don’t have adult populations producing them; the reefs may have been degraded, and there aren’t enough individuals spawning to generate the larvae required. Bleaching can also impact a coral’s ability to spawn. If a coral has severely bleached, even if it doesn’t die, it often won’t spawn, or if it does spawn, the eggs and sperm are of poor quality. <blockquote class="has-text-color has-weekly-blood-red-color"> A single adult coral can release thousands to millions of eggs and sperm. They synchronise this release using a suite of cues from the environment, based on the lunar cycle, the tide and the time of sunset, down to the minute. </blockquote> The newest research has suggested that those latent effects of bleaching can persist for several years. While it might seem that the coral has recovered, there can be lingering impacts on their ability to reproduce, which affects the recovery of the reef. What we can do is go out and identify where the adult corals are located, put them together, spawn them, and increase the odds that each larva that’s developed in that process can then settle and survive. That overcomes the bottleneck that would be found naturally that limits the recovery potential of the reefs. The tools that we have currently are insufficient to address the scale of coral decline globally. At AIMS, I’m involved in two big programs focused on developing new and innovative methods to improve the resilience of coral reefs affected by climate change: the Reef Restoration and Adaptation Program and the Australian Coral Reef Resilience Initiative. My hope is that we can develop a toolkit of strategies to implement on reefs that aren’t recovering naturally and that require accelerated adaptation to ocean warming, while we work to reduce greenhouse gas emissions.  <img id="cosmos-post-tracker" 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=171406&title=Overcoming+the+barriers+to+reef+recovery" alt="" width="1" height="1" /> </div> <div id="contributors"> <a href="https://cosmosmagazine.com/nature/marine-life/overcoming-barriers-to-coral-reef-recovery/">This article</a> was originally published on <a href="https://cosmosmagazine.com">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/dr-carly-randall">Dr Carly Randall</a>. Dr Carly Randall is a marine scientist with the Australian Institute of Marine Science specialising in coral ecology and reproductive biology. She is currently investigating drivers of post-settlement coral mortality to improve coral restoration methodologies. </div> </div>

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

Snorkellers discover rare, giant 400-year-old coral – one of the oldest on the Great Barrier Reef

Snorkellers on the Great Barrier Reef have discovered a huge coral more than 400 years old which is thought to have survived 80 major cyclones, numerous coral bleaching events and centuries of exposure to other threats. We describe the discovery in <a href="http://nature.com/articles/s41598-021-94818-w">research</a> published today. Our team surveyed the hemispherical structure, which comprises small marine animals and calcium carbonate, and found it’s the Great Barrier Reef’s widest coral, and one of the oldest. It was discovered off the coast of Goolboodi (Orpheus Island), part of Queensland’s Palm Island Group. Traditional custodians of the region, the Manbarra people, have called the structure Muga dhambi, meaning “big coral”. For now, Muga dhambi is in relatively good health. But climate change, declining water quality and other threats are taking a toll on the Great Barrier Reef. Scientists, Traditional Owners and others must keep a close eye on this remarkable, resilient structure to ensure it is preserved for future generations. <img src="https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="coral and snorkellers" /> <h2>Far older than European settlement</h2> Muga dhambi is located in a relatively remote, rarely visited and highly protected marine area. It was found during citizen science research in March this year, on a reef slope not far from shore. We conducted a literature review and consulted other scientists to compare the size, age and health of the structure with others in the Great Barrier Reef and internationally. We measured the structure at 5.3 metres tall and 10.4 metres wide. This makes it 2.4 metres wider than the widest Great Barrier Reef coral <a href="https://doi.org/10.1007/BF00345677">previously</a> measured by scientists. Muga dhambi is of the coral genus Porites and is one of a large group of corals known as “massive Porites”. It’s brown to cream in colour and made of small, stony polyps. These polyps secrete layers of calcium carbonate beneath their bodies as they grow, forming the foundations upon which reefs are built. Muga dhambi’s height suggests it is aged between 421 and 438 years old – far pre-dating European exploration and settlement of Australia. We made this calculation based on rock coral growth rates and annual sea surface temperatures. The Australian Institute of Marine Science has investigated more than 328 colonies of massive Porites corals along the Great Barrier Reef and has aged the oldest at 436 years. The institute has not investigated the age of Muga dhambi, however the structure is probably one of the oldest on the Great Barrier Reef. Other comparatively large massive Porites have previously been found throughout the Pacific. One exceptionally large colony in American Samoa measured 17m × 12m. Large Porites have also been found near Taiwan and Japan. <img src="https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="Mountainous island and blue sea" /> <h2>Resilient, but under threat</h2> We reviewed environmental events over the past 450 years and found Muga dhambi is unusually resilient. It has survived up to 80 major cyclones, numerous coral bleaching events and centuries of exposure to invasive species, low tides and human activity. About 70% of Muga dhambi consisted of live coral, but the remaining 30% was dead. This section, at the top of the structure, was covered with green boring sponge, turf algae and green algae. Coral tissue can die from exposure to sun at low tides or warm water. Dead coral can be quickly colonised by opportunistic, fast growing organisms, as is the case with Muga dhambi. Green boring sponge invades and excavates corals. The sponge’s advances will likely continue to compromise the structure’s size and health. We found marine debris at the base of Muga dhambi, comprising rope and three concrete blocks. Such debris is a threat to the marine environment and species such as corals. We found no evidence of disease or coral bleaching. <img src="https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="to come" /> <h2>‘Old man’ of the sea</h2> A Traditional Owner from outside the region took part in our citizen science training which included surveys of corals, invertebrates and fish. We also consulted the Manbarra Traditional Owners about and an appropriate cultural name for the structure. Before recommending Muga dhambi, the names the Traditional Owners considered included: <ul> <li>Muga (big)</li> <li>Wanga (home)</li> <li>Muugar (coral reef)</li> <li>Dhambi (coral)</li> <li>Anki/Gurgu (old)</li> <li>Gulula (old man)</li> <li>Gurgurbu (old person).</li> </ul> Indigenous languages are an integral part of Indigenous culture, spirituality, and connection to country. Traditional Owners suggested calling the structure Muga dhambi would communicate traditional knowledge, language and culture to other Indigenous people, tourists, scientists and students. <img src="https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" alt="coral rock under water with sky" /> <h2>A wonder for all generations</h2> No database exists for significant corals in Australia or globally. Cataloguing the location of massive and long-lived corals can be benefits. For example from a scientific perspective, it can allow analyses which can help understand century-scale changes in ocean events and can be used to verify climate models. Social and economic benefits can include diving tourism and citizen science, as well as engaging with Indigenous culture and stewardship. However, cataloguing the location of massive corals could lead to them being damaged by anchoring, research and pollution from visiting boats. Looking to the future, there is real concern for all corals in the Great Barrier Reef due to threats such as climate change, declining water quality, overfishing and coastal development. We recommend monitoring of Muga dhambi in case restoration is needed in future. We hope our research will mean current and future generations care for this wonder of nature, and respect the connections of Manbarra Traditional Owners to their Sea Country. <a href="https://theconversation.com/profiles/adam-smith-515741">Adam Smith</a>, Adjunct Associate Professor, <a href="https://theconversation.com/institutions/james-cook-university-1167">James Cook University</a>; <a href="https://theconversation.com/profiles/nathan-cook-1261134">Nathan Cook</a>, Marine Scientist , <a href="https://theconversation.com/institutions/james-cook-university-1167">James Cook University</a>, and <a href="https://theconversation.com/profiles/vicki-saylor-1261504">Vicki Saylor</a>, Manbarra Traditional Owner, <a href="https://theconversation.com/institutions/indigenous-knowledge-4846">Indigenous Knowledge</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/snorkellers-discover-rare-giant-400-year-old-coral-one-of-the-oldest-on-the-great-barrier-reef-166278">original article</a>. Image: Richard Woodgett/Shutterstock

Domestic Travel

Swimming With Whale Sharks

Snorkelling in the Indian Ocean just off Ningaloo Reef in Western Australia means blue infinity in every direction – but what’s that eerie pale oval approaching under the surface? Widening and narrowing and growing larger by the second, it resolves into the enormous gulping mouth of a whale shark. Stand by – or rather, swim by – for one of Australia’s grandest marine spectacles. Unsurpassed globally for regular, reliable and accessible whale shark encounters, World Heritage-listed Ningaloo Reef runs 260 km along Western Australia’s remote North West Cape, about 1300 km north of Perth. Every year – from April to July – these normally elusive filter-feeders arrive for an annual mass-spawning of coral, which, aided by fortuitous currents, turns the outer reef into a nutrient-rich soup of plankton and krill. A relatively recent addition to this prehistoric dinner engagement are gatecrashing, snorkelling Homo sapiens, drawn to feed their sense of wonder on sharing salt water with the largest of all shark species. The adventure begins on very dry land. Although flanked by vast tracts of water – Exmouth Gulf on one side, the Indian Ocean the other – North West Cape is an arid, baked wilderness bisected by the rocky heights of Cape Range, an extinct limestone reef from the region’s deeper past. Anchored off a lonely desert boat ramp 38 km from Exmouth township, the 17 m Draw Card is amid a tiny gaggle of whale-shark boats (there are eight Exmouth-based tour operators) ferrying their patrons aboard by inflatable Zodiac. First on the agenda is a morning snorkel on the reef, a handy acclimatisation and a superb experience in itself. Amid a kaleidoscope of colourful sea life, the crew’s two whale-shark ‘spotters’ – Ellece Nicholls and Emma Goodfellow – and videographer Meg Green, free-dive with mermaid-like agility, pointing out creatures of interest. Usual Ningaloo suspects include parrotfish in all hues of green and blue, frilly orange lionfish, giant clams, tawny nurse and leopard sharks, whitetip and blacktip reef sharks, barracuda and bull rays. The easily found sailfin catfish (small, black and fantailed) is one of 50 endemic species. The Draw Card cruises south through shallow turquoise waters, heading for one of only three navigable passages to the open ocean – soon revealed by a gap in the white line of offshore surf. The shark-spotting plane radios success and the deck ripples with excitement. As we power into position several kilometres out to sea, the 19 tourists aboard are divided into two snorkel groups and re-briefed on protocols – no touching, no duck-diving, keep 3 m clear of any whale shark (and 4 m from the tail). Whale-shark watching works for one simple reason. “They’re sun worshippers,” spotter and marine biologist Ellece Nicholls says. On clear days plankton rises to the light, attracting whale sharks to the surface where they linger to hoover up the bounty. The biggest enemy is heavy cloud cover, rarely a problem at Ningaloo. Think of it as a game of marine leap-frog. The boat stops ahead of a shark and the first snorkellers tag along as it passes, with the Zodiac deployed to aid any stragglers. Group two drops in further along the shark’s probable path. After the whale shark leaves its first escorts, the boat collects them and moves ahead of group two (now in shark conference) to repeat the process. Group one don fins and stride off the duckboard, looking for the spotter’s hand signal. Ellece points and faces go under – nothing. Then a casual over-shoulder, underwater glance reveals a blue-grey speckled bulk the size of a van. Veering before reaching us, the silent giant had almost slipped by unobserved behind our backs. Gentle titans Wondrous as it is, there’s no time to stop and wonder. Admiring a whale shark is not a passive activity. It’s time to snorkel as fast as humanly possible, which inevitably falls short of any whale shark in middle gear. But following its wake is unforgettable. The towering column of tail sweeps with effortless power, slowly shrinking and dissolving a gentle titan into the deep blue curtain of ocean ahead. Minutes later, adrift in the open sea, we regroup for pick-up. Ellece says we saw a juvenile male, “only” 4 m long but with a barrel-like girth. While 12-m whale sharks have been seen here, the typical Ningaloo visitor is a 4-7 m male. Far sooner than expected, we’re ready for another dip into his world. “This is what we call a blind drop,” Ellece says, meaning no-one knows exactly where the shark is. But in we go and there he is. Afterwards comes an unexpected bonus, a hefty green turtle flapping through the blue nearby, a marine bumblebee in flight. Leaving our teenage shark to another nearby boat – the industry here is amiably co-operative – we shift closer to the reef wall for whale shark number two. Here the seabed is dimly visible, with shadowy coral clusters far below, the length of a tall building away. Festooned with remoras and trailed by a retinue of golden trevallies, this slightly larger shark gives a clear view of its white-spotted, ridged back, the starlike pattern imitating sunlight dappling the surface. The day’s final shark is further out. Over the abyss again, a diffuse star of light beams from below, but it’s only a trick of the sun. Our largest (5 m-plus) specimen’s head-on approach is signalled by the flattened white oval of Exmouth’s biggest mouth. Dipping gently up and down, feeding at a leisurely cruising pace, it scoops invisible fare with every rise. From the corner of the sack-like maw, a much smaller eye watches its watchers keeping pace for those few precious minutes. Afterwards on deck, we’re treated to a topside view when it skirts the boat ahead of group two, its broad head emerging from the deep like a submarine milky way. Five swims with three individuals filled an hour of shark time (the maximum allowed). The exhilaration of eye contact with our planet’s biggest fish lingers throughout lunch and the post-shark reef snorkel. The lasting impression is one of great peace and beauty, the awe of approaching creation writ truly large. Endangered species Plenty of mystery accompanies this majesty. While Exmouth is a leading centre for tagging and research, the whale shark life-cycle remains largely unknown – and if they really do migrate north from Ningaloo to breed in Asian waters, as some experts contend, why do so many travel south along the reef? South is definitely the safer option for them right now, given their popularity as a soup garnish in several Asian countries – a single whale shark can fetch thousands of dollars for its fins. In March 2016 the species’ Red List conservation status was altered from vulnerable to endangered (a ‘very high’ risk of extinction). The example of Exmouth, however, gives hope that countries still slaughtering whale sharks will be inspired by the economics of ecotourism – and the sheer wonder of the creature itself – to spare the world’s biggest fish. For more info go to <a href="https://www.whalesharkdive.com/">www.whalesharkdive.com</a> or <a href="http://www.visitningaloo.com.au">www.visitningaloo.com.au</a> By David Levell Image: Reader’s Digest This article originally appeared on <a href="mailto:https://www.readersdigest.com.au/travel/activities/swimming-whale-sharks">Reader’s Digest</a>

Domestic Travel

Did you know these 5 places could disappear in your lifetime?

When places are well-known and popular – historical and modern alike – we might take it for granted that they’ll be around forever. But sadly, many of the world’s best known and culturally significant landmarks are in jeopardy. Human activity has had a devastating effect on many valued places, including massive milestones of human achievement. And many of these are so much more than just tourist attractions – they’re unique, valuable remnants of ancient times and civilizations. The Great Barrier Reef This massive, once-thriving coral reef has suffered enormously over recent years, with coral bleaching – caused by climate change – stripping the coral of its nutrients. This, in turn, harms the rich marine life that calls the reef home. And, of course, this also depletes it of the dazzling colours that once were a hallmark of the Great Barrier Reef’s underwater wonder. The reef remains the largest coral reef ecosystem in the world, but projections have warned that the damage to it could become irreversible in the next 10 years. Old City of Jerusalem One of the world’s most spiritually significant places, the Old City of Jerusalem, is in danger of disappearing, UNESCO has found. The walls of the Old City are one of its trademark features. Most famously, the Western Wall, also known as the Wailing Wall, is a valuable pilgrimage site for people of the Jewish faith, one that dates back to around 20 BCE. The Wall is the only remnant of the city’s Second Temple. The city was actually listed on UNESCO’s list of endangered cultural sites in the 1980s. Widespread urbanisation has been found to pose a significant threat to the city. Everglades National Park This stunning Floridian wildlife sanctuary has sadly found itself fighting for its life in recent years. As ‘the largest designated subtropical wilderness reserve’ in North America, according to UNESCO, it’s been a beloved travel destination for American citizens for decades, but the ravages of time and human activity have not been kind to it. Its survival first came into question after it was battered by Hurricane Andrew in 1993. But it’s human influence that has posed the primary threat, as water flow to the site has decreased and the impacts of pollution have increased, resulting in harmful algal blooms. Its vast, diverse wildlife is more threatened than ever before. The Taj Mahal It’s hard to imagine this monolithic structure, located in Agra, India, being in danger. The structure itself is in some jeopardy from the elements, but the primary reason for concern is that the Indian Supreme Court could potentially close the attraction. The court has butted heads with the government, claiming that unless the government does a better job of preserving it, they’ll have to shut it down. Pollution is visibly altering the Taj’s pristine surface. It’s also experienced insect infestations. Flies of the genus Geoldichironomus, which breed in the heavily polluted Yamuna River, neighbouring the Taj, have encroached upon the structure in recent years. Mount Kilimanjaro’s peak This revered mountain, one of the Seven Summits, proves that even giants can fall to climate change. While the mountain itself, located in Tanzania, isn’t in imminent danger, its iconic snow cap might vanish – and shockingly soon. Research found that the snow cap had lost 85 per cent of the total area of its ice fields between 1912 and 2007, and the remaining ice could be history as early as 2030. Written by Meghan Jones. This article first appeared in <a href="https://www.readersdigest.com.au/travel/travel-hints-tips/10-top-tourist-attractions-that-could-disappear-in-your-lifetime">Reader’s Digest</a>. For more of what you love from the world’s best-loved magazine, <a href="http://readersdigest.innovations.com.au/c/readersdigestemailsubscribe?utm_source=over60&utm_medium=articles&utm_campaign=RDSUB&keycode=WRA87V">here’s our best subscription offer.</a> <img style="width: 100px !important; height: 100px !important;" src="https://oversixtydev.blob.core.windows.net/media/7820640/1.png" alt="" data-udi="umb://media/f30947086c8e47b89cb076eb5bb9b3e2" />

Travel Tips

Foreign ship convicted of dumping garbage on Great Barrier Reef

<div class="post_body_wrapper"> <div class="post_body"> <div class="body_text redactor-styles redactor-in"> A foreign shipping company and the chief officer of one of its vessels have been convicted for dumping food scraps on the World-Heritage listed Great Barrier Reef. The Liberian bulk carrier Iron Gate dumped the equivalent of 120-litres of a garbage bin filled with food waste into the reef in 2018. The chief officer approved the discharge of garbage between Brisbane and Gladstone. Fines against both parties totalled $6,600 and were persecuted by the Australian Maritime Safety Authority (AMSA). “Australians and tourists alike visit Lady Elliot Island to swim with manta rays and turtles – not blended food waste from merchant ships,” ASMA general manager of operations Allan Schwartz said. “We take a zero-tolerance approach to pollution from shipping and that is why, after detecting this breach during a routine inspection of Iron Gate in 2018, we detained the ship and later charged the chief officer and company, Kairasu Shipping S.A.” He said the conviction would impact the company's reputation. “Dumping garbage into the World Heritage-listed Great Barrier Reef isn’t something you want on your professional record,” he said. “These convictions should serve as a reminder to other industry operators that in Australia, we make sure polluters pay.” </div> </div> </div>

Travel Trouble

Incredible private island on Great Barrier Reef for sale

If you've ever dreamed of owning a private island, now could be your chance. Victor Island on the Great Barrier Reef has hit the market at $5.5 million, and it's more affordable than some waterfront homes in Brisbane and Sydney. The eight-acre oasis offers incredible views of the Coral Sea, along with a four-bedroom solar powered house and caretakers cottage. Also included are two boats to help residents make the ride into mainland Mackay. "It's very rare," Barbara Wolveridge from Sotheby's International Realty told 9News. "I've been in the business for 30 years and this is the first time I've actually had an opportunity to sell an island. Owner Meg Sullivan has decided now is the time to part ways with the island after owning it for five years. She's hoping someone else can experience the life she's lived. "It's the freedom of living on the island where you can do what you want, when you want," she said. "If you want to catch a fish for dinner you go and throw a line in." If you're interested you might need to act quickly with the property generating interest from buyers across the country and around the world. "We've got people lining up to come and see it," Ms Wolveridge said. Victor Island is for sale for $5.5 million.

Real Estate

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

Our Partners

Over 60

News

Shop

Catalogues

Contests

Entertainment

Travel

Health

Lifestyle

Finance

Property

Games

Information

Keep up to date

Search

Beyond the Barrier Reef: Australia’s 3 other World Heritage reefs are also in trouble

"Why is the water so salty?" and other priceless questions from clueless tourists

Tourists' narrow escape after Great Barrier Reef plane crash

Using a dental scanner on corals like a “magic wand”

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

The Great Barrier Reef – what does a new Labor government mean for its future?

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

No, sunscreen chemicals are not bleaching the Great Barrier Reef

10 awe-inspiring UNESCO world heritage sites everyone needs to visit

Overcoming the barriers to reef recovery

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

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

Snorkellers discover rare, giant 400-year-old coral – one of the oldest on the Great Barrier Reef

Swimming With Whale Sharks

Did you know these 5 places could disappear in your lifetime?

Foreign ship convicted of dumping garbage on Great Barrier Reef

Incredible private island on Great Barrier Reef for sale

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

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

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

Our Partners