In the good news for coral reefs, scientists point to where they are strongest
It’s rare to find good news about coral reefs.
Consider most of the world’s rocks that have just gone through more than two years of extreme heat from the great eclipse event, which just passed. announced. And the relief will likely be short-lived, as the Pacific warming phenomenon El Niño it’s here now – and it looks powerful.
But new research presented at this week’s Our Ocean Conference in Mombasa, Kenya, says they have a surprising effect on these insects, as climate change and other factors increase ocean temperatures.
“Coral reefs are often framed as ecosystems that cannot be conserved,” said study co-author Emily Darling, director of coral conservation at the Wildlife Conservation Society. “This study shows otherwise.”
Currently under peer review, the analysis found around 166,000 square kilometers of the world’s reefs are potentially climate-resilient – meaning they can withstand those hot temperatures for a variety of reasons.
In collaboration with the technology non-profit SkyTruth, the researcher mapped these strong reefs, many of which were located on the coasts of five countries: the Bahamas, Cuba, Australia, Indonesia and the Philippines. Analysis based on a 2018 study, which focused on 50 reefs, which, if properly protected, have the best chance of survival.
In identifying the exact areas that should be supported, experts say that research can serve as a focus for conservation efforts in communities that rely on water as a means of livelihood and economy.
“It gives hope,” said Craig Dahlgren, executive director of the Perry Institute for Marine Science, who was not involved in the analysis.
“Things are bad, but we have places [where] there is something about them and corals that we can learn from, build upon, and help ensure that there is a future for coral reefs,” he said.
New research shows that more than 150,000 square kilometers of coral reefs are more resilient to the effects of climate change than previously thought.
Avoid, resist, recover
For corals, bleaching looks like death, but it’s just the beginning. Environmental stress, such as heat, causes the coral to expel the algae that live inside it – turning them ghostly white. This makes it easier to get sick and eventually, die.
Looking at resilience is not just about finding out whether reef regions have survived, but finding out – by using tens of thousands of field observations over decades and machine learning – what drives survival.
For some reefs, it’s as easy as the location.
“These are places where coral reefs naturally avoid the effects of heat and climate change,” Darling said, giving the example of corals he studied off the coast of Mozambique, where upwelling of cold water prevents the water from getting too hot.
But in some reefs, like Kenya, there is no avoiding it.
“They live in the tub where the hot water comes in, they stay there,” Darling said of Kenya’s coastal corals. But this is also where you can find durability, as some corals are resistant and resistant to heat, allowing the entire plate to survive the bleaching event.
Dahlgren, with the Perry Institute, saw this up close in the Bahamas during the extreme heat of 2023.
“Two colonies of corals, the same species, are very similar in size, shape, configuration. One of them is white, the other is completely healthy,” he said, attesting to this strength in individual characteristics such as certain bacteria and algae inside.
The ultimate mode of fitness is those that get hit hard – but bounce back. Stacy Jupiter, executive director of the Global Marine Program at WCS, saw this firsthand in Fiji following Hurricane Winston in 2016.
“When we did the survey four years later, we saw juvenile corals that were the same size,” Jupiter said at a press conference. So the reefs multiplied according to their coral cover.
Focusing on protection efforts
Intergovernmental Panel on Climate Change 2019 special report on oceans and cryosphere he said the risk of losing a stone includes losing food, tourism and coastal protection from storms. But making all reefs off limits will prevent it one billion people who use the services they provide.
The challenge for many countries is to know exactly where to invest what little they can – as many island countries with marine habitats often do not have the resources or economic freedom to protect these often large areas from the effects of climate change or fishing.
“Climate-resistant reefs are not evenly distributed,” said Joseph Maina, co-author of the coral study and a scientist at Macquarie University in Sydney, Australia. “And countries need to understand … those differences so that when they plan where future savings investments should go, they take this uneven distribution into account.”
Dahlgren sees the project as helping to provide “a lot of money” for conservation funding – such as establishing marine protected areas or active coral reef regeneration.
What on Earth23:40Can baby coral nurseries save reefs from climate change?
Coral reefs support marine life – and livelihoods. But the dimming caused by ocean warming puts both at risk. Fishing communities in Mauritius and Seychelles feel it more than anywhere else. But there are ambitious efforts underway in these island nations to restore some of what has been lost, to protect natural health and local economies.
Threats to come
Although climate change, fueled by human burning of fossil fuels, is accelerating ocean warming and thus the intensity of these bleaching events, Dahlgren warns that it is not the only threat corals face.
“In the Caribbean right now, we’re seeing coral diseases that are acting outside of climate stress that are also having devastating effects,” Dahlgren told Vermont’s CBC News.
And with El Niño threatening to trigger more bleaching around the world, experts worry that even those hardy corals are being hit too often.
Oceans around the world are experiencing a major coral bleaching event, according to the US National Oceanic and Atmospheric Administration. That means that corals in all the great oceans turn white, or even die, because the water they live in is too hot.
“The shrinking recovery windows between slip events scares me,” Darling said, adding that nature needs time to adapt and change, whether it’s resilient or resilient.
But it’s also important to protect corals that show varying degrees of resilience within the reef, Darling said, as it helps balance the risk in the event that one form of energy fails.
“It’s like a fundraiser,” he said. “It’s better to have a lot of redundancy in the same place.”
