Great Barrier Reef sees sharpest annual coral decline in nearly four decades
The Australian Institute of Marine Science, or Aims, said that two of the three areas monitored by researchers since 1986 have suffered coral losses this year.
The hard coral cover on the reef has declined largely due to heat stress from climate change. This heat stress has sparked mass bleaching events, which have been worsened by cyclones, flooding, and outbreaks of crown-of-thorns starfish.
The latest findings are a warning that the Great Barrier Reef faces a "volatile" future and may reach a 'point from which it cannot recover'.
The Great Barrier Reef, located off the northeast coast of Australia, is the world's largest living coral reef system and one of the most biodiverse ecosystems on the planet.
Stretching across 2,400km off the Queensland coast, it comprises thousands of individual reefs and hundreds of islands made of over 600 types of hard and soft corals.
Aims surveyed 124 coral reefs between August 2024 and May 2025 and found that coral cover had dropped sharply after a record-breaking marine heatwave in 2024, 'prompting grave fears over the trajectory of the natural wonder'.
"We are now seeing increased volatility in the levels of hard coral cover," said Mike Emslie, head of the institute's long-term monitoring programme.
"This is a phenomenon that emerged over the last 15 years and points to an ecosystem under stress."
Aims says repeated mass coral bleaching is becoming more frequent as the world warms.
Coral bleaching is a stress response in which corals expel the algae that give them colour and energy, turning white because the water it lives in is too hot and risking death if conditions don't improve.
Mass bleaching was extremely rare before the 1990s. The first two major mass bleaching events weren't recorded until 1998 and 2002.
In the years since, Aims noted, the Great Barrier Reef has "experienced unprecedented levels of heat stress, which caused the most spatially extensive and severe bleaching recorded to date'.
This was 'the first time we have seen substantial bleaching impacts in the southern region, leading to the largest annual decline since monitoring began', Dr Emslie said.
In the wake of the latest mass bleaching event in 2024, aerial surveys showed around three quarters of the 1,080 reefs assessed had some bleaching. And on 40 per cent of those reefs, over half the corals had turned white.
It was the fifth mass bleaching event on the Great Barrier Reef since 2016 and had the largest spatial footprint recorded, with high to extreme bleaching prevalence across the three regions, Aims CEO Professor Selina Stead said.
Despite the significant losses, Aims said the Great Barrier Reef still had more coral than many other reefs worldwide and remained a major tourist attraction.
'It's possible to find areas that still look good in an ecosystem this huge,' Aims said, 'but that doesn't mean the large-scale average hasn't dropped.'
The Great Barrier Reef is not on Unesco's list of endangered world heritage sites, though the UN recommends it should be added.
Australia has lobbied for years to keep the reef, which contributes billions of dollars a year to the economy, off the list as it could damage tourism.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Gizmodo
an hour ago
- Gizmodo
Monarch Butterflies Are Losing Their Navigational Abilities. You Can Guess Why
Each fall, millions of eastern North American monarch butterflies migrate up to 3,000 miles south to the mountains of central Mexico, then return to their northern range in the spring. These winged insects rely on a complex navigation system to go to and from their overwintering sites, and new research suggests climate change may be messing with it. Monarch butterflies have two distinct biological 'compasses.' The primary one infers direction based on their circadian rhythm and the position of the Sun, but on overcast days, they switch to a backup compass that infers direction from Earth's magnetic field. Scientists already knew seasonal temperatures play a critical role in calibrating these navigational biomechanisms during the fall migration, but they weren't sure if the same rules apply to the spring migration. A new study published Wednesday, August 13, in the journal PLOS One confirmed that they do, suggesting that rising winter temperatures in Mexico could prevent monarchs from returning to their northern range. 'The question was, if they use the Sun compass or the magnetic compass to go southwards, do they use the same kind of compass mechanisms to fly back north? And we weren't sure what triggered that,' co-author Patrick Guerra, an independent neuroecology researcher based in North Carolina, told Gizmodo. He participated in this research while working as an assistant professor at the University of Cincinnati. When temperatures drop in the fall, this shift calibrates both of the butterflies' biological compasses to point south, guiding them toward their overwintering sites in Mexico. 'Once they get there, they're basically overwintering in a fridge,' Guerra explained. His previous research showed that this long period of exposure to cool temperatures recalibrates the Sun compass to point north so that it can guide monarchs back to their summer range in the spring. In this new study, he and his colleagues investigated whether this is also true for the magnetic compass. To that end, the researchers conducted a series of righting response trials with migratory and non-migratory monarchs. During these trials, the butterflies were exposed to artificial magnetic fields that mimic geographic conditions south of their overwintering sites, then positioned so they were upside down. Upon righting themselves, non-migrating monarchs faced magnetic north, whereas migrating monarchs faced magnetic south. This indicated that monarchs exhibit something akin to migratory restlessness—a compulsion to go toward the direction their migratory instincts are telling them to follow even if they can't actually fly there. With this established, Guerra and his colleagues chilled the monarchs to trick their bodies into thinking they had gone through an overwintering period. When they performed the righting response trials again, the migrating monarchs pointed toward magnetic north. The non-migrating monarchs, however, still pointed toward magnetic south. 'That told us that, just like the Sun compass, the magnetic compass is recalibrated by the cold conditions that are consistent with being in Mexico while they're overwintering,' Guerra explained. 'So that kind of hammers home that their whole ability to navigate is really tuned to the environmental conditions that they're experiencing.' Greenhouse gas emissions are increasing average temperatures around the world, including in the overwintering range of monarch butterflies. Guerra and his colleagues already knew that this threatened their primary navigation mechanism, but their new study indicates that their backup mechanism is at risk too. If temperatures get too warm, monarchs may lose the ability to return to their northern range in the spring. Determining the minimum temperature monarchs need to recalibrate their biological compasses for spring migration will require further research, but these findings underscore the threat that climate change poses to this species.
CBS News
an hour ago
- CBS News
Reindeer populations could plummet by up to 80% by 2100, researchers say
Reindeer populations across the Arctic will likely decline substantially due to future climate change with the North American population facing the highest risk, researchers predict. While the species has survived multiple periods of Arctic warming, climate change has already contributed to the loss of nearly two-thirds of the global populations of reindeer in the last three decades, according to the research team, led by the University of Adelaide in Australia and the University of Copenhagen in Denmark. There are about 9 million reindeer globally, including those that are domesticated, according to the World Population Review. The North American wild reindeer, also called caribou and estimated at around 3.5 million by the World Population Review, are most at risk from a warming climate, the researchers said. Caribou are found in Alaska and Canada. The caribou populations could decline by up to 80% by 2100, "unless there are major cuts to greenhouse gas emissions and increased investment in wildlife management and conservation," Damien Fordham, an associate professor and deputy director of the Environment Institute at the University of Adelaide, said in a statement. The researchers came to their conclusion by examining how reindeer have responded to past climate events. "Using fossils, ancient DNA and computer models, we reconstructed changes in the abundance and distribution of reindeer over the past 21,000 years at resolutions never done before, and we directly compared these to future predictions," lead researcher Elisabetta Canteri said in a statement. They found that populations of reindeer have declined during past periods of "rapid climate warming." "But the losses expected in the coming decades due to future climate change are likely to be even more severe than those in the past," Canteri said. A decline in reindeer populations also could have wider ecological implications because the animals help maintain plant diversity in the tundra. "A reduction in tundra plant diversity resulting from the loss of reindeer and caribou will have many cascading effects, including reduction of carbon storage in Arctic soils," said Eric Post, a professor at the University of California Davis who contributed to the research. "Continued losses will likely further exacerbate climatic warming through release of soil carbon to the atmosphere, which of course would further threaten reindeer and caribou as well as ourselves."
Yahoo
5 hours ago
- Yahoo
A Pilot Is Pretty Sure He Found Amelia Earhart's Plane
Here's what you'll learn when you read this article: A pilot perusing Google Earth may have stumbled across the remnants of Amelia Earhart's plane. Inspired by a documentary on the Earhart's final flight, Justin Myers compared the measurements of anomalies in a Google Earth image to the components of her plane. So far, no major institutions have made any effort to investigate his claims. This story is a collaboration with Popular Mechanics. What would you do if you thought you'd cracked an unsolved mystery, but nobody wanted to listen? That's the predicament pilot Justin Myers currently finds himself in. With nearly a quarter-century in the air himself, he believes he's uncovered the answer to one of aviation's most enduring mysteries: Where is the wreckage of Amelia Earhart's Lockheed Electra 10E, the final plane she ever flew? All it took was Google Earth and a little curiosity. Unlike some who have tried to find the wreckage from Earhart and Fred Noonan's ill-fated final flight in 1937, Myers was not a life-long Earhart obsessive. 'To be totally honest,' Myers told Popular Mechanics, 'my interest started after watching a documentary on the National Geographic Channel. It was the next day when curiosity about Nikumaroro Island took me to looking on Google Earth.' Nikumaroro Island is often posited as a final resting place for, if not Earhart and Noonan themselves, than at least the Electra they were flying in. As Biography previously noted, 'This theory is based on several on-site investigations that have turned up artifacts such as improvised tools, bits of clothing, an aluminum panel and a piece of Plexiglas the exact width and curvature of an Electra window.' When Myers first looked up Nikumaroro, he wasn't initially looking for a plane at all. 'I was just putting myself in Amelia and Fred's shoes,' he told PopMech. But as he stared at those overhead images, he started to employ his own experience as a pilot, to think about 'where I would have force landed a light twin aircraft in their position, lost and low on fuel.' That's when Myers noticed what he felt were some anomalies on the map. He detailed his observations in a blog post: 'I picked an area which would probably have been what I thought to be best considering the circumstances. I zoomed in and there was a long sandy-looking shape... I measured the sandy section, which was over 50ft long, looked up the specifications of the Electra, and that measured 39ft.' Next to the sandy section, however, was a dark, straight object that was exactly 39 feet long. 'It looked man-made,' Myers noted as he continued to examine the object, 'it looked like a section of aircraft fuselage.' As Myers poured over the images more, he made out what appeared to him to be even more airplane debris, including what looked like a partially exposed radial engine, and his approximate measurements all aligned with the dimensions of the corresponding parts of the Lockheed Electra 10E that Earhart and Noonan had flown. But if these airplane parts could be seen from Google Earth images, why hadn't anyone seen them before? Myers suggested to PopMech that 'there was an element of luck in spotting that aircraft debris, as Mother Nature had revealed what had been buried on the reef for a long time. I managed to catch some photos before being covered over again by passing weather systems.' So, Myers assembled his images and his measurements, and was ready to present his findings. But just who do you present such a case to? 'I didn't know really where to go with this,' Myers wrote in his blog post. 'I wrote to the NTSB in the U.S., and they emailed me back saying it was not there [sic] jurisdiction, it was the ATSB, Australian Transport Safety Bureau. So, I filed an official report with the air crash investigation team in Brisbane.' But in the years since, there has been no real movement to take Myers' theory beyond the theoretical. 'I did have some communication with an expedition company in California,' Myers said to PopMech. 'However, I haven't heard anything in a long time. I also contacted Purdue University a few years ago and recently, but unfortunately they never responded.' So if Myers has found the solution to an enduring aeronautical quandary, why isn't anyone inquiring further? Well, in the case of Purdue University, it's not as though they're not pursuing answers to Earhart's disappearance at all. PopMech reported in July that they had announced their own expedition to investigate an anomaly known as the Taraia Object, often speculated to be the downed Electra. But it's also an impediment to Myers' outreach efforts that he is hardly alone in thinking he has found the final piece of the proverbial puzzle. If you had a dollar for every person who claimed to have found Amelia Earhart's plane, you'd probably have enough money to fund an expedition to try and find it. Hopes for answers have hinged on everything from old photographs to the promise of modern-day technology. In the process, some people with wildly different theories have become prominent figures in the aircraft recovery community, which has resulted in bitter feuds and sometimes even lawsuits. And of course, there's the risk of getting it wrong. In 2024, images from underwater drones operated by Tony Romeo's Deep Sea Vision showed 'contours that mirror the unique dual tails and scale' of the Lockheed Electra. At the time, Romeo had confidently stated that 'you'd be hard-pressed to convince me that this is not an airplane and not Amelia's plane.' But after another expedition was launched to more closely examine that anomaly, Romeo discovered that it was not an airplane but rather an ordinary rock formation. 'I'm super disappointed out here,' Romeo remarked after the fact, 'but you know, I guess that's life.' For his part, Myers isn't challenging others to convince him he's wrong, though he does feel confident, based on his measurements, that what he's found is more than just a naturally occurring phenomenon. 'The bottom line is,' he told PopMech, 'from my interests from a child in vintage aircraft and air crash investigation, I can say that is what was once a 12-metre, 2-engine vintage aircraft. What I can't say is that is definitely Amelia's Electra.' And if it isn't Amelia's place, PopMech asked, would Myers be disappointed? 'If this is not Amelia's Electra 10 E,' he said, 'then it's the answer to another mystery that has never been answered. This finding could answer some questions to someone who disappeared many years ago.' If Myers found Amelia Earhart's plane, it could bring him acclaim. But if it's a different downed plane he's found, it could at least bring closure to the family of whoever piloted it. Only time will tell if anyone with the funds to launch a search will take the leap of faith to see if there truly is a plane there at all. You Might Also Like Nicole Richie's Surprising Adoption Story The Story of Gypsy Rose Blanchard and Her Mother Queen Camilla's Life in Photos Solve the daily Crossword
