Coral Expert: They are Tough and Will Surprise Us

29 May, 2024

They have been blown up in nuclear tests and poisoned when people fished with cyanide. However, the absolute biggest threat to the future of coral reefs is global warming, according to researcher Fredrik Moberg.

– But I think they will surprise us, he says.

“It is worth fighting for every tenth of a degree of warming that we can avoid and for every coral reef that we can protect,” says coral researcher Fredrik Moberg. Photo: Claudio Bresciani/TT

The victim is hundreds of millions of years old and already half dead. The forecast is that the killing will be completed sometime in the last half of the century if emissions continue at the current rate. And you don’t have to be the master detective Sherlock Holmes to find out who is the culprit in the drama, states the coral researcher and environmental communicator Fredrik Moberg in his new book “The Planet of the Corals”.

– Some examples of how we have killed coral reefs are by fishing with dynamite, fishing with cyanide and blowing entire coral atolls to pieces to test nuclear weapons, he says.

“Coral reefs are a charismatic ecosystem,” says author Fredrik Moberg. Photo: Jim Maragos/AP/TT Archive image.

But the big threat in the long term is global warming. In that, many of us are complicit, even if we did not have that intention from the beginning. We live in societies that are dependent on fossil fuels and emit a lot of carbon dioxide and other greenhouse gases.

Mass bleaching

Record temperatures in the oceans have led to a global mass bleaching of coral reefs. Corals live in symbiosis with algae, but if the water gets too warm, the algae leave the coral animal – whereupon the coral loses its color and risks starving to death.

The world is already about 1.2 degrees warmer than in pre-industrial times and the emissions that warm the planet continue to increase. More than 99 percent of coral reefs are at risk of dying if the global average temperature rises by 2 degrees by the end of the century, according to the UN climate panel IPCC. If the warming were limited to 1.5 degrees, the assessment is that up to 90 percent of the reefs could be lost.

Fredrik Moberg is “extremely worried” but believes that the IPCC’s scenarios are quite pessimistic.

– It has been shown that coral reefs are somewhat adaptable after all. They may be found in areas where there are cold water currents or may move slightly north or south, he says.

– The situation is bad, but I think they will surprise us and be tougher than the worst forecasts suggest. But if the warming goes towards 3 degrees, it will be difficult.

The sun shines on a coral showing signs of bleaching off the coast of Florida. Photo: Andrew Ibarra/NOAA/TT Archive image.

A tribute

The book is not only a true crime story that gets to the bottom of who the killer is, it is also a tribute to the reefs that tower like skyscrapers below the surface. As recently as 2020, a previously unknown 500 meter high reef was discovered off the coast of Australia – bigger than the Empire State Building in New York.

The nearest tropical reef is in Egypt, about 400 miles from Sweden. But there is still reason for Swedes to care about the future of the corals, says Moberg.

– Coral reefs are extremely important for biodiversity. Less than 1 percent of the ocean floor has coral reefs, but they are habitat for 25 percent of all marine species, he says.

Then, an estimated 500 million people directly or indirectly depend on coral reefs for their livelihoods via tourism, fishing and others.

Corals belong to the earth’s most species-rich environments. Photo: David Wood/TT Archive image.

Swedish corals

The colorful reefs have become a poster name for the victims of climate change, a canary in the coal mine. But even in Sweden there are corals that fight against ocean acidification, bottom trawling and warmer waters.

– I don’t think that many Swedes know that we have corals, the cold water reefs off the west coast are hidden, says Moberg.

– The reef-building cold-water corals we still have some of in Swedish waters are eye corals, not the same type that build up the tropical reefs. Cold water corals have incredible diversity, but are quite pale and dull even when they are healthy.

There are still cold water corals in Sweden. Photo: Adam Ihse/TT Archive image

Perhaps not everyone knows that Gotland, the biggest island in Sweden, largely consists of fossil coral reefs. Over 400 million years ago, what would become Sweden’s largest island lay in tropical waters at the equator, but the reefs were converted into fossils that slowly moved north.

– Some of the limestone quarries we use to make cement in Sweden are old coral reefs. And the production of cement is a major source of greenhouse gases, says Moberg.

Ironically, this means that when roughly 420-million-year-old coral reefs crumble and heat up to become cement, it releases a lot of carbon dioxide that is devastating to today’s coral reefs.

Price tag

One way to boost the corals’ stock is to try to put a price tag on them.

– It is really difficult. As an ecologist, you can say that they are invaluable, because they are so very important, says Moberg.

But it is a pretty good Trojan horse to show that they also have an economic value for them to be taken seriously in political discussions. When you do that, you come up with many different kinds of numbers, one being hundreds of billions of dollars every year. According to those calculations, a football field of coral reef is worth roughly $1-2 million annually.

Moberg hopes that his book will not be an obituary, but rather a time document of a period when humanity changed to rein in global warming.

Every tenth of a degree of warming we can avoid and every coral reef we can protect is worth fighting for.

The map shows where the world’s coral reefs in warm waters are located. Graphics: Anders Humlebo/TT

Text: Sofia Eriksson/TT
Photo: Claudio Bresciani/TT, Jim Maragos/AP/TT, Andrew Ibarra/NOAA/TT, David Wood/TT, Adam Ihse/TT
Graphics: Anders Humlebo/TT

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