Tag Archives: Bleaching

The most severe bleaching event on record has affected 84% of the world’s coral reefs

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The harmful bleaching of corals around the world has increased to affect 84% of the ocean coral reefs, marking the most intense event in recorded history, as announced by the International Coral Reef Initiative on Wednesday.

This is the fourth global bleaching event since 1998, surpassing the 2014-17 bleaching that impacted two-thirds of the reefs during that time. The current crisis began in 2023, and it remains unclear when it will end, with ocean warming being criticized for the phenomenon.

Mark Eakin, the executive director of the International Coral Reef Association and former coral monitoring officer for the US National Marine and Atmospheric Administration, stated, “We’re witnessing a complete transformation of the planet and its impact on our oceans’ ability to sustain life and livelihoods.”

Last year was reported as the hottest year on record globally, with average sea surface temperatures for oceans away from the poles reaching 20.87 degrees Celsius (69.57 degrees Fahrenheit), which is detrimental to corals. These structures are vital for seafood production, tourism, and protecting coastlines from erosion and storms. Coral reefs are often referred to as “rainforests of the sea” because they host a significant amount of marine biodiversity, with approximately twenty five% of all marine species living in and around them.

Corals house colorful algae, which give them their vibrant hues and serve as a food source. However, prolonged warming causes the algae to release toxins, leading to coral bleaching where they expel the algae and turn white. Weakened corals are at an increased risk of death due to these events, prompting NOAA’s Coral Reef Watch program to introduce additional levels to the bleaching alert scale to convey the heightened risk of coral mortality.

Efforts to conserve coral reefs are underway, such as initiatives to restore coral populations. Dutch labs are working with coral fragments, including those sourced from the Seychelles, with the intention to propagate them in zoos for potential reintroduction to natural reef habitats. Similar projects, including those in Florida, aim to rescue at-risk corals from high temperatures and rehabilitate them before returning them to the sea.

Nevertheless, scientists stress the importance of reducing greenhouse gas emissions like carbon dioxide and methane to combat planet-warming effects and protect coral reefs.

Melanie Mcfield, co-chair of the Caribbean Steering Committee for the Global Coral Reef Surveillance Network, emphasized, “The most effective way to safeguard coral reefs is to address the root causes of climate change by reducing human emissions, primarily from fossil fuel combustion. Inaction poses a significant threat to coral reef ecosystems.”

This update coincides with President Donald Trump’s efforts to bolster fossil fuels and scale back clean energy initiatives as he enters a second term, prompting concerns about the future of coral reefs. Eakin remarked, “The current government is actively dismantling these ecosystems, and eliminating their protections would have catastrophic consequences.”

Source: www.nbcnews.com

NOAA Declares Fourth Mass Bleaching Event Imminent for World’s Coral Reefs

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Invertebrates are highly sensitive to heat stress, so coral health is closely linked to seawater temperature. Corals turn whitish when stressed. release symbiotic algae They live in organizations. Bleaching indicates that the health of the coral is at risk.

“When a coral bleaches, it doesn’t mean it’s dead. It means it’s weak and at risk of dying if conditions don’t improve,” says Ana Palacio, a scientific assistant at the Oceanic and Atmospheric Research Institute Collaborative Research Institute based at the University of Miami in partnership with NOAA.

Corals are important ecosystems that support a wide variety of fish and aquatic species, helping to nourish coastal communities and attract tourists. The economic value of coral reefs is estimated at $2.7 trillion annually. According to the 2020 report of the Global Coral Reef Monitoring Network.

“They protect our coastlines. They protect us from storms and hurricanes. They have great value to our economy and security,” said Palacio.

Coral ecosystems are among the ecosystems that scientists believe are most at risk from global warming. In 2018, the United Nations Intergovernmental Panel on Climate Change estimated that: 70% to 90% of the world’s coral reefs They will disappear if the average global temperature drops. exceeded the threshold of 1.5 degrees Celsius above the pre-industrial average.

Last year was the hottest year on record on Earth. The average global temperature has approached that threshold for the first time, but scientists believe 2023 was an anomaly, driven by El Niño.

Experts say bleaching began early in the season as sea surface temperatures soared in Florida.

“Typically, bleaching is observed around August to September in the Northern Hemisphere. We started observing the bleaching phenomenon in July last year,” said marine biologist Fanol Montoya Maya from the Coral Restoration Foundation, an organization that collects, restores, and replants coral.

Palacio said the area has seen widespread mortality of elkhorn and staghorn corals, two species that are the focus of restoration efforts.

“In some places, about 20 percent of those populations survived,” Palacio said of the restored corals. “We’re focusing our hopes on why those corals survived and what they can tell us about resistance, and how corals can become more resilient.”

The last global coral bleaching event occurred in 2014 and lasted until 2017. More than 56% of the world’s coral reef areas experienced temperatures that could cause bleaching during that period.

Bleached coral at Flower Garden Banks National Marine Sanctuary off the coast of Galveston, Texas, Gulf of Mexico, September 16, 2023.
LM Otero / AP

Manzello said in an email Monday that 54% of the world’s coral reef areas have experienced bleaching-level heat stress in the past year, and this event could be the worst bleaching event on record.

“The proportion of coral reef areas experiencing bleaching-level heat stress is increasing by about 1% every week,” Manzello said. “This event is likely to exceed the previous peak.”

Montoya-Maya said bleaching warnings were already issued in Florida earlier than last year. He said the Coral Restoration Foundation is preparing for a busy summer in response to new bleaching events.

The natural pattern of El Niño is beginning to disappear, and NOAA’s Climate Prediction Center estimates that an El Niño event is possible. There is a 60% chance of a La Niña event occurring this summer.This could cool the waters of the Atlantic Ocean and allow some corals to recover, at least temporarily.

“This is very heartbreaking and will cause damage to many coral reefs around the world,” Palacio said. “I hope this bleaching event creates some traction and people start to care more and pay attention to what’s happening to the climate.”

Source: www.nbcnews.com

The Great Barrier Reef in Australia experiences its fifth major bleaching event in just eight years

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Australia’s Great Barrier Reef is experiencing significant heat-induced coral bleaching once again, as confirmed by the country’s government on Friday.

The Great Barrier Reef Marine Park Authority, responsible for conservation and protection efforts for the reef, stated that widespread bleaching is occurring due to increased heat stress over the summer.

Scientists from the Australian Institute of Marine Science reported that this is the fifth major bleaching event on the Great Barrier Reef since 2016.

Coral bleaching poses a serious threat to coral reefs worldwide, triggered by abnormal conditions such as high or cold seawater temperatures and increased acidity. When corals expel photosynthetic algae, they turn white, making them more vulnerable to disease.

While corals can recover from bleaching events, frequent occurrences make it difficult for reefs to bounce back. Climate change is causing ocean temperatures to rise, leading to more frequent bleaching events globally.

The current mass bleaching event on the Great Barrier Reef is consistent with reports of bleaching in coral reefs in the Northern Hemisphere, exacerbated by El Niño and climate change, according to the Great Barrier Reef Marine Park Authority.

On March 5, researchers observed large-scale coral bleaching at a site in the southern Great Barrier Reef.Renata Ferrari / Australian Institute of Marine Science

The agency, in collaboration with scientists from the Australian Institute of Marine Science, conducted an aerial survey covering nearly two-thirds of the Great Barrier Reef Marine Park to assess the severity of the bleaching event.

Further research and underwater assessments are necessary to gauge the impact of the ongoing bleaching event, with plans for additional aerial surveys in other reef areas.

While heat stress has not affected the entire reef, variations exist in the extent of bleaching among different areas, as highlighted by Neil Cantin, a senior research scientist at the Australian Institute of Marine Science.

Coral affected by coral bleaching (left), Arlington Reef, Central Barrier Reef, February 27.Grace Frank / Australian Institute of Marine Science

Since the first recorded bleaching event in 1998, with subsequent events in 2002, 2016, 2017, 2020, and 2022, it is clear that coral bleaching incidents are becoming more frequent, posing a significant threat to the Great Barrier Reef.

Efforts are underway to understand the overall condition of the reef and implement effective restoration measures guided by aerial surveys and underwater observations.

David Wachenfeld, the Australian Institute of Marine Science’s research program director, emphasized the urgent need to address climate change to protect the Great Barrier Reef effectively.

“Protecting coral reefs like the Great Barrier Reef from climate change requires global emissions reductions, best practices in local management, interventions to increase climate and reef resilience, and ongoing research and development,” Wachenfeld stated.

Source: www.nbcnews.com