All posts tagged: bleaching

Corals that recover from bleaching still struggle to breed

Corals that recover from bleaching still struggle to breed

Published by skeptic

A marine biologist inspects bleached coral around Lizard Island on the Great Barrier Reef DAVID GRAY/AFP via Getty Images Although coral reefs can recover from bleaching, those subjected to heat stress have a lower reproductive output, researchers have found. This means reefs may take longer to bounce back than previously assumed and are more vulnerable to future stressors. Bleaching occurs when corals exposed to above-average ocean temperatures expel the symbiotic algae that live inside their tissues. These organisms give them their vibrant colours as well as providing most of their food via photosynthesis. Bleached coral remains… Source link

Great Barrier Reef’s worst bleaching leaves giant coral graveyard: ‘It looks as if it has been carpet bombed’ | Great Barrier Reef

Great Barrier Reef’s worst bleaching leaves giant coral graveyard: ‘It looks as if it has been carpet bombed’ | Great Barrier Reef

Published by skeptic

Beneath the turquoise waters off Heron Island lies a huge, brain-shaped Porites coral that, in health, would be a rude shade of purplish-brown. Today that coral outcrop, or bommie, shines snow white. Prof Terry Hughes, a coral bleaching expert at James Cook University, estimates this living boulder is at least 300 years old. “If that thing had eyes it could have looked up and watched Captain Cook sail past,” he says, back on the pristine beach of this speck of an island 80km offshore at the southern end of the Great Barrier Reef. It is not just Heron’s grand old bommie that is freshly bleached. The surrounding tangle of staghorn corals, or Acropora, are splashed in swathes of white, or painted a dappled mosaic of greens and browns that betray the algae and seaweeds growing over the freshly killed coral. Hughes estimates 90% of those branching corals are dead or dying. Terry Hughes inspects the coral around the Heron Island research station Snorkelling above these blighted coral thickets evokes the imagery of forests annihilated by …

Most of Australia’s Great Barrier Reef is suffering from coral bleaching

Most of Australia’s Great Barrier Reef is suffering from coral bleaching

Published by skeptic

Australia’s Great Barrier Reef is experiencing one of its worst bleaching events since monitoring began nearly four decades ago, authorities say, with much of the famed reef showing signs of damage as warming ocean temperatures blight reefs worldwide. Bleaching occurs when heat-stressed coral turn white after expelling symbiotic algae that provide food and color. It’s a result of abnormal ocean temperatures in the past year that scientists worry could represent a major change to Earth systems. In the Great Barrier Reef marine park, 73 percent of the reefs surveyed have prevalent bleaching — which means that more than 10 percent of the coral cover is bleached, the Great Barrier Reef Marine Park Authority, which manages the area, said Wednesday. Very high and extreme bleaching was observed across nearly 40 percent of the reef system. “Climate change is the greatest threat to the Great Barrier Reef, and coral reefs globally,” said Roger Beeden, the authority’s chief scientist. “The Great Barrier Reef is an incredible ecosystem, and while it has shown its resilience time and time again, …

Mayorkas impeachment trial; coral reef mass bleaching

Mayorkas impeachment trial; coral reef mass bleaching

Published by skeptic

Good morning. You’re reading the Up First newsletter. Subscribe here to get it delivered to your inbox, and listen to the Up First podcast for all the news you need to start your day. Today’s top news The Democratic-led Senate will kick off the impeachment trial of Homeland Security Secretary Alejandro Mayorkas today. He’s only the second Cabinet secretary to be impeached in U.S. history. Mayorkas is accused of allegedly failing to enforce immigration laws. Many Democrats have called for a motion to dismiss the trial. Senators could reach an agreement to debate the articles of impeachment tomorrow. Department of Homeland Security Secretary Alejandro Mayorkas is the first Cabinet secretary to be impeached in roughly 150 years. As House Republicans targeted him he was involved in Senate negotiations on a bipartisan bill to change administration border policies. Go Nakamura/Getty Images hide caption toggle caption Go Nakamura/Getty Images Department of Homeland Security Secretary Alejandro Mayorkas is the first Cabinet secretary to be impeached in roughly 150 years. As House Republicans targeted him he was involved in …

To help coral reefs survive bleaching, scientists speed evolution

To help coral reefs survive bleaching, scientists speed evolution

Published by skeptic

Record levels of heat in the ocean are causing a worldwide mass bleaching event on coral reefs, as seen here on the Great Barrier Reef. Scientists are working on creating more heat-resistant coral to help restore reefs. Veronique Mocellin /AIMS hide caption toggle caption Veronique Mocellin /AIMS Record levels of heat in the ocean are causing a worldwide mass bleaching event on coral reefs. It’s the second one this decade, where the delicate skeletons of corals turn a ghostly white. With mass bleaching only expected to get worse as the climate keeps warming, coral scientists are urgently searching for ways to help reefs endure. Bleaching can kill corals, putting some of the most diverse ecosystems in the world at risk. So scientists are homing in on how bleaching happens. It boils down to relationship drama between corals and a tiny organism that’s too small to see. Scientists estimate that a quarter of all marine species depend on coral reefs. Biologists say that’s a best guess and it’s very likely there are species yet to be …

Extreme coral bleaching could spell worst summer on record for Great Barrier Reef, authority says | Great Barrier Reef

Extreme coral bleaching could spell worst summer on record for Great Barrier Reef, authority says | Great Barrier Reef

Published by skeptic

The Great Barrier Reef is in the midst of what could be its worst summer on record with a widespread and extreme coral bleaching event coming on top of floods, two cyclones and outbreaks of coral-eating starfish, according to an official Australian government report. The “summer snapshot” report released by the Great Barrier Reef Marine Park Authority and the Australian Institute of Marine Science said: “Compared [with] previous summers, cumulative impacts have been much higher this summer and a widespread bleaching event is still unfolding.” The report says 39% of 1,080 individual reefs surveyed from the air had experienced either very high (61-90% coral cover bleached) or extreme (more than 90%) levels of bleaching. Such high levels had been observed on reefs in all three regions of the park, which is a world heritage-listed natural wonder, but the most heat stress had occurred in the south. The reef marine park, covering an area the size of Italy and including 3,000 individual reefs, is in the middle of a fifth mass bleaching in only eight years …

Aerial video shows mass coral bleaching on Great Barrier Reef amid global heat stress event – video | Environment

Aerial video shows mass coral bleaching on Great Barrier Reef amid global heat stress event – video | Environment

Published by skeptic

Scientists have recorded widespread bleaching on the Great Barrier Reef as global heating creates a fourth planet-wide bleaching event. According to the National Oceanic and Atmospheric Administration’s Coral Reef Watch, 54% of ocean waters containing coral reefs have been experiencing heat stress high enough to cause bleaching ► Subscribe to Guardian Australia on YouTube Source link

Australia’s Great Barrier Reef suffers most severe coral bleaching ever recorded

Australia’s Great Barrier Reef suffers most severe coral bleaching ever recorded

Published by skeptic

The Great Barrier Reef — a colorful and iconic natural wonder off the coast of Australia that spans an area of 133,000 square miles (344,400 square kilometres) — is suffering potentially unprecedented bleaching due to climate change. Bleaching occurs when coral become stressed due to high temperatures or lack of nutrients and expel the algae that live symbiotically within it. This causes it to turn a pale, bone-white color and eventually kills the coral. According to a report last week by the Great Barrier Reef Marine Park Authority, more than half of the 1,000 reefs analyzed (out of more than 2,900 in total) had either high, very high or extremely high levels of bleaching. Only a quarter were relatively unaffected. Perhaps most ominously, the bleaching in many regions stretched as far down as 18 meters (roughly 60 feet). Overall it is the fifth mass bleaching event to impact the reef in eight years. “I feel devastated,” Dr Selina Ward, a marine biologist and former academic director of the University of Queensland’s Heron Island Research Station, …

Coral reefs are experiencing mass bleaching amid record ocean heat, scientists warn

Coral reefs are experiencing mass bleaching amid record ocean heat, scientists warn

Published by Sam

The world is currently experiencing its second major coral bleaching event in 10 years, with reef systems from Australia to Florida teetering on the brink of disaster following months of record-breaking ocean heat, a US agency announced Monday. Issued on: 15/04/2024 – 17:45Modified: 15/04/2024 – 19:25 3 min The consequences of coral bleaching are far-reaching, affecting not only the health of oceans but also the livelihoods of people, food security, and local economies. Severe or prolonged heat stress leads to corals dying off, but there is hope for recovery if temperatures drop and other stressors such as overfishing and pollution are reduced. “As the world’s oceans continue to warm, coral bleaching is becoming more frequent and severe,” said Derek Manzello of the US National Oceanic and Atmospheric Administration (NOAA). “When these events are sufficiently severe or prolonged, they can cause coral mortality, which hurts the people who depend on the coral reefs for their livelihoods.” Read more‘Real estate’ for corals: Swiss organisation builds artificial reefs with art, tech NOAA’s heat-stress monitoring is based on satellite …

Global heating pushes coral reefs towards worst planet-wide mass bleaching on record | Climate crisis

Global heating pushes coral reefs towards worst planet-wide mass bleaching on record | Climate crisis

Published by skeptic

Global heating has pushed the world’s coral reefs to a fourth planet-wide mass bleaching event that is on track to be the most extensive on record, US government scientists have confirmed. Some 54% of ocean waters containing coral reefs have experienced heat stress high enough to cause bleaching, the National Oceanic and Atmospheric Administration’s Coral Reef Watch said. A global bleaching event is declared when at least 12% of corals in each of the main ocean basins – Pacific, Atlantic and Indian – experience bleaching-level heat stress within a 12-month period. The declaration also requires confirmed reports of bleaching. Coral Reef Watch also confirmed the world’s largest coral reef system – Australia’s Great Barrier Reef – had been through its most widespread heat stress event on record in 2024. The first global bleaching event happened in 1998 with 20% of the ocean’s reef corals exposed to a level of heat stress high enough to cause bleaching. The second event, in 2010, saw 35% reaching that threshold, and the third from 2014 to 2017 peaked at …