Nearly All Coral Reefs Will Disappear Over The Next 20 Years, Scientists Say

Nearly All Coral Reefs Will Disappear Over The Next 20 Years, Scientists Say

SOURCE: Forbes DATE: February 24, 2020 SNIP: Over the next 20 years, scientists estimate about 70 to 90% of all coral reefs will disappear primarily as a result of warming ocean waters, ocean acidity, and pollution. Expand that out to 2100 and it’s “looking quite grim,” says Renee Setter, a marine scientist at the University of Hawaii in Manoa. By 2100 there will be nearly zero suitable coral habitats remaining, eliminating nearly all living coral reef habitats. Recent research, presented at the Ocean Sciences Meeting 2020, is focused on transplanting lab-grown corals into dying reef ecosystems in hopes that it will revive the reefs. While there have been promising results in the short term, by 2100 ocean environment will be too harsh for corals to survive. In recent decades scientists have become increasingly alarmed at what looks like the inevitable fate of coral reefs. Scientists have tried to use underwater speakers to play continuous sounds of healthy coral reefs in hopes this entices marine life to return. While this, along with other artificial means to encourage coral reef growth has been successful to some degree, the increasingly harsh environment will lead to coral reef die-off. Corals live in a mutually symbiotic relationship with photosynthetic algae, called zooxanthellae. Corals make up the hard calcium carbonate structure of coral reefs and provide protection and a home for zooxanthellae. In return, the zooxanthellae provide nutrients to the coral. When surface ocean temperatures warm beyond a narrow livable range, the coral kicks out the zooxanthellae, causing “coral bleaching” and often times the eventual death of the coral. A similar process occurs when corals...
Gulf Coast Coral Likely To Face Widespread Destruction By The End Of The Century

Gulf Coast Coral Likely To Face Widespread Destruction By The End Of The Century

SOURCE: Kera News DATE: December 26, 2019 SNIP: Without a significant reduction in greenhouse gas emissions, coral reefs throughout the Gulf of Mexico are likely to face widespread bleaching and collapse by the end of the century, according to a new report from several research universities. Researchers from Rice University, the University of Texas at Austin and Louisiana State University used climate models to project future changes in the Gulf’s waters, from Texas to Florida. Specifically, they looked at factors that stress coral reefs, such as temperature rise and acidification. “All of the trends are negative in that we find that the oceans are warming; the ocean is becoming more acidic. Everything that is conducive to coral health is being degraded rapidly,” said Sylvia Dee, an assistant professor of Earth, environmental and planetary sciences at Rice. “What we can say with certainty is that by the end of the 21st century it is highly likely, and almost certain, that many of the coral reef communities in the Gulf of Mexico will be undergoing heating conditions and acidification conditions that are likely to destroy them.” The Gulf Coast is home to numerous coral reef systems, many of which are inside protected areas such as Florida’s John Pennekamp state park and the Flower Banks National Marine Sanctuary off the coast of Galveston. The reefs support fisheries, help protect coastlines and contribute to tourism, Dee said. The researchers also looked at other factors contributing to poor coral health, such as runoff pollution, coral mining and over-fishing. “Those are problems that could be eradicated now, those things could be stopped immediately,” she...
Climate change: Marine heatwaves kill coral instantly

Climate change: Marine heatwaves kill coral instantly

SOURCE: BBC DATE: August 9, 2019 SNIP: Increasingly frequent marine heatwaves can lead to the almost instant death of corals, scientists working on the Great Barrier Reef have found. These episodes of unusually high water temperatures are – like heatwaves on land – associated with climate change. Scientists studying coral after a heat event discovered that extreme temperature rises decayed reefs much more rapidly than previously thought. The study revealed that corals became up to 15% weaker after an extreme heat event, causing some fragments to actually break off from the reef. Dr Tracy Ainsworth, from the University of New South Wales in Australia, worked on the study. She told BBC News that her whole research team, made up of scientists who have worked on corals for more than a decade, was shocked to find them to be “really brittle”. More typically, temperature rises cause something called coral bleaching – when the coral expels vital algae that lives in its tissues. In those events, the coral itself remains intact. “But what we’re seeing here is that – when the coral tissue dies – it falls and breaks away from the skeleton,” Dr Ainsworth explained. Commenting on the paper, Dr Laura Richardson, from the School of Ocean Sciences at Bangor University, UK, said that the really significant discovery was “the rapidity with which the reef skeleton breaks down when you have these severe heatwaves”. Dr Richardson added that the team had documented, for the first time, that severe heatwaves were causing “almost instant mortality of corals”. Dr Ainsworth said the researchers referred to the resulting, heat-damaged skeletons as “ghost corals,...
Lord Howe Island coral bleaching ‘most severe we’ve ever seen’, scientists say

Lord Howe Island coral bleaching ‘most severe we’ve ever seen’, scientists say

SOURCE: The Guardian DATE: April 1, 2019 SNIP: Researchers have documented what they are describing as the most severe coral bleaching to hit the world’s southern-most reef at Lord Howe Island. Scientists from Newcastle University, James Cook University and the National Oceanic and Atmospheric Administration have spent the past two weeks surveying corals around the island in the far south Pacific Ocean after they were alerted to bleaching in isolated areas. Bill Leggat, a coral biologist at Newcastle University, said the worst of the bleaching was in shallow water closer to the shoreline. “It’s quite variable but where it’s severe it is actually quite severe,” he said. “Some of the sites are looking at 80-90% bleaching going very close inshore.” The bleaching has occurred over the past summer, with March the peak month of the year for coral bleaching due to warmer ocean temperatures. While much of Australia’s focus on coral bleaching has been centred on the Great Barrier Reef, it is a worldwide occurrence due to climate change. “We’re starting to see beaching in sites where wouldn’t have previously expected to see...
Great Barrier Reef authority gives green light to dump dredging sludge

Great Barrier Reef authority gives green light to dump dredging sludge

SOURCE: The Guardian DATE: February 20, 2019 SNIP: The Great Barrier Reef Marine Park Authority has approved the dumping of more than 1m tonnes of dredge spoil near the reef, using a loophole in federal laws that were supposed to protect the marine park. Acting on concerns from environmentalists, the federal government banned the disposal of dredge spoil near the reef in 2015. But the ban applied only to capital dredging. Maintenance work at ports – designed to remove sediment from shipping lanes as it accumulates – is not subject to it. On 29 January the marine park authority granted conditional approval for North Queensland Bulk Ports to continue to dump maintenance dredge spoil within the park’s boundaries. The permit was issued just days before extensive flooding hit north and central Queensland, spilling large amounts of sediment into the marine...