The jungle of the sea is dying – this is how researchers summarize what they themselves can hardly understand. Whether off the US coast or in the Mediterranean, corals are in a dramatic situation.
As a result of the man-made climate crisis, the oceans continue to warm, the animals are helplessly exposed to the higher temperatures, because they cannot simply swim away. Scientists and coral conservationists therefore expect another mass extinction.
It’s about more than just the colorful reefs. These cover only 0.2 percent of the seabed. More importantly, they are home to about a quarter of all life in the oceans. Millions of people are also indirectly dependent on them: fish and other marine life that live in and on the reefs are the staple food in many regions, they serve as breakwaters for the coasts and as a source of income for local residents because they attract tourists.
In a joint 2020 report, the Global Reef Monitoring Network and the International Coral Reef Initiative estimated the value of goods and services related to coral reefs at $2.7 trillion (approximately CHF 2.2 trillion) per year.
But the reefs are under threat like never before. In 2018, scientists at the United Nations Intergovernmental Panel on Climate Change found that if the world warmed by 1.5 degrees – the more ambitious goal of the Paris Climate Protection Agreement – 70 to 90 percent of the world’s corals would die. At 2 degrees, the minimum climate target, that would be more than 99 percent. So far, the earth has warmed about 1.2 degrees and is heading for 2.7 degrees, because climate protection measures are not enough to meet the Paris goals.
For many corals this already means death. The average sea surface temperature is at record levels. Every day since mid-March has surpassed anything previously measured – and measurements have been taken since 1982. The global average sea surface temperature currently stands at 21.1 degrees; almost one degree more than the average for the years 1982 through 2011.
“The reason is human-induced global warming,” said climate researcher Mojib Latif of the Geomar Helmholtz Center for Ocean Research in early August. “The oceans store more than 90 percent of the heat generated by human-made greenhouse gases.” Add to that the natural weather phenomenon El Niño, which is raising the temperature of the oceans even more, but has only just begun.
The problem with all of this: Corals are sensitive creatures that can only thrive under specific conditions. If not, the animals become stressed and shed the colorful algae with which they live in symbiosis. But then they lack the nutrients that the algae provide them – and the color: you speak of coral bleaching. Since the 1980s, these have become more and more.
The effects of the heat at sea are currently becoming particularly apparent off the coast of Florida. At the end of July, a record water temperature of 38 degrees was measured in Manatee Bay – the best bath temperature. No corals live there in the murky water, but up to 36 degrees were also measured for the Florida Keys, a chain of offshore islands with coral reefs.
When Bailey Thomasson, who works for the conservation organization Coral Restoration Foundation, dived the Sombrero Reef, she was initially pleasantly surprised: the corals appeared brown, not white. But then came the shock, as she told the New York Times:
“The coral didn’t get a chance to bleach. They just died.” What was brown on the animals’ calcareous skeletons was dead tissue. “I just thought, oh my god, we’re in the apocalypse.”
Even the organization’s coral kindergarten on the Looe Key reef looked no better, she told the newspaper. For two years, she and her colleagues had put the offspring there, 5,400 pieces of coral would grow. When they went out in July, they could see all the white of the faded corals from the boat. After the turnout, she burst into tears, Thomasson said. “All is lost in Looe Key,” she reported afterwards.
Ian Enochs, head of the coral program at the Atlantic Oceanographic and Meteorological Laboratory (AOML) in Miami, says something similar. In early August, he dove off Cheeca Rocks Reef – in fact one of the most densely populated and stable reefs in Florida. But what he saw was “total devastation”: a shocking coral bleaching. He told the Miami Herald: “It was literally every coral. They just gave up.”
Coral conservationists on the US East Coast are now trying to save what can be saved, evacuating fragments of the coral to tanks on land where they can control the temperature. But it’s not just Florida that’s being affected: Corals are dying all over the Gulf of Mexico and the Caribbean, sometimes stretching hundreds of miles.
Researchers on the other side of the Atlantic are also concerned. The Mediterranean Sea is also home to corals – and mass extinctions are also feared here. At the end of July, the highest average surface temperature since measurements began in 1982 was reported: 28.7 degrees.
Temperatures are still two to three degrees higher than usual for the time of year – the highest values are usually not reached until August. As a result of the climate crisis, the Mediterranean Sea is warming up very quickly.
“25 years ago, marine heat waves were exceptional, now they are becoming the norm,” says Joachim Garrabou of the Institute of Marine Sciences (ICM) of the Spanish National Research Council (CSIC). The corals barely have time to recover.
Just last year, the western Mediterranean region experienced the worst heat wave ever recorded. A mass extinction took place – that is, the death of animals of various species. This year it is still too early to speak of a mass extinction again, says Garrabou.
The effects of the heat will not be seen until the end of August at the earliest. “Species can tolerate the heat for a while, but then they start to suffer.” But the outlook is bad. “The situation is even worse this year,” said the marine researcher. This time the heat is hitting the entire Mediterranean.
For example, the gorgonians, a type of soft coral, are under acute threat. Some of them can live for more than 100 years and grow slowly. They are therefore particularly vulnerable to the increasingly frequent marine heat waves. “Many gorgonian populations are on the verge of collapse,” says Garrabou.
And the gorgonians are just one example: all life in the Mediterranean suffers. “It’s like comparing a jungle with ancient trees to a meadow,” explains Garrabou. “We had very complex ecosystems with high biodiversity, and now we’re losing them, at least in the shallows.” These are the main habitats of the corals and are particularly affected by the marine heat waves.
The Spaniard demands that more protected areas are needed to at least mitigate the effects of the climate crisis in the sea. “While marine protected areas cannot cool the water, we see that strictly protected areas recover more quickly and better from human disturbance.” In addition to the impacts of the climate crisis, these include overfishing and pollution – additional stressors for ecosystems.
Florida coral conservationist Bailey Thomasson is also focusing on fighting the causes. It is now up to everyone to demand climate protection measures. “Not in a year, not tomorrow, but now,” she told the New York Times. “Actually yesterday.”
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Source: Blick
I am Ross William, a passionate and experienced news writer with more than four years of experience in the writing industry. I have been working as an author for 24 Instant News Reporters covering the Trending section. With a keen eye for detail, I am able to find stories that capture people’s interest and help them stay informed.
