Study shows there’s still hope for coral reefs amid record-warm sea surface temperatures

For decades, biologists have been trying to figure out how coral reefs can survive record-breaking warmth. sea ​​surface temperature and a changing climate.

Corals have survived temperature changes for millions of years, but the next few decades will be crucial for determining which species will survive the next stage on Earth.

relies on microalgae, known as symbionts, to provide food and energy, coral reef A few degrees above average sea surface temperature could trigger massive bleaching events around the world. Most coral symbionts do poorly in warm waters and begin to die off. In response, the coral begins to excrete the symbionts and the coral loses its color. Some reefs can survive and recover from bleaching, while others cannot. It’s an evolutionary game of survival of the fittest.

Several recently published studies have investigated how corals can withstand rising sea surface temperatures.

Corals associated with D. glynnii (right) are advantageous during extreme heat compared to corals associated with C. latusorum (left). (Image credit: David A. Paz-García/State of Pennsylvania)

One idea is to use symbiotic algae, which are highly tolerant to warm water, to help corals adapt. However, using different symbionts was thought to sacrifice coral nutrients and produce harmful side effects.a Newly published study in Royal Society Bulletin B It turns out that corals with heat-tolerant symbionts grow and reproduce without problems.

Study co-author Todd Lajeunes, a professor of biology at Pennsylvania State University, explained why coral bleaching would have far-reaching effects.

“Severe bleaching events often lead to mass mortality, with cascading effects across ecosystems,” Lajeunes says. ”The corals will begin to decay, and then all the habitat and food they provided to many other animals will disappear. It has a big impact. ”

Abnormally high Florida sea surface temperature causes large-scale coral bleaching

The research team focused on the thriving Posilopora coral in the eastern Pacific.

“There are a lot of fields there, thriving and growing. It’s like you’re on steroids,” Lajeunes said. “They are in an environment that cannot contribute to healthy growth at all.

Studies show that the thermotolerant D. glynnii symbionts distinguish these climate-tolerant corals. To test this theory, biologists used the D. glynnii symbiont present in Pocillopora corals and the more susceptible C. latusorum symbiont.

The research team measured coral mass gain, skeletal growth and reproduction.

The researchers studied measured skeletal growth, total mass gain, mineralization rate, or calcium carbonate production rate, which is a measure of coral growth, in controlled aquaria environments under different temperature regimes. (Image credit: Matthew Aschaffenburg/Penn State University)

“We found that D. glynnii has the ability to withstand water temperatures that compromise the mating relationship of most corals and dinoflagellates without significant trade-offs,” said lead study author Kira Turnham. “This combination of partners will grow and reproduce similarly to more temperature-sensitive partnerships.”

Previously, LaJeunesse said, it was thought that these microalgae were using too much energy to cope with physiological stresses and could not release as much energy for corals. He said the difference is due to evolution.

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“In our case, we were studying heat-tolerant symbionts and animals that have co-evolved over millions of years,” Lajeunes said. “Evolution can solve many things.”

The researchers continue the next chapter of their research on Palau’s diverse coral reefs in the western Pacific.

The group’s work in the eastern Pacific can also be applied to more common and abundant coral ecosystems, Lajeunes said.

A global effort to protect coral reefs

I. Care divers work to restore and maintain corals off the coast of Florida. (Image: Brandy Campbell/FOX Weather)

(FOX Weather)

Corals became an early “climate change child” when coral bleaching made headlines in the early 1980s, Lajeunes said.

Various efforts are underway to protect coral reefs around the world.

of floridawhere the sea surface temperature exceeds the maximum value 95 degrees near Key Largo, with a diver I care They are trying to move parts of the reef to survive what is expected to be a bad year for coral bleaching.

in another studyResearchers from the Italian Institute of Technology and the University of Milano-Bicocca tested a natural antioxidant extracted from turmeric, a coral found in the Genoa Aquarium in the Indian Ocean. The researchers said they were able to demonstrate that using the biomaterial in seawater up to 33 degrees Celsius (91.4 degrees Fahrenheit), which can cause coral bleaching, could help stop the bleaching process.

“This technology has already been patented and is actually, Next steps in this research will focus on large-scale applications in nature,” study co-author Marco Contaldi said in a release.

Human efforts could save coral reefs, but it could also be that “life finds a way,” Lajeunes said, citing “Jurassic Park.”

It is unknown what form these coral reefs will take. The demise of these ecosystems will ultimately affect the humans who depend on coral reefs for fishing, the economy, and hurricane barrier protection.

“Life will survive somehow,” Mr. Lajeunes said. “I don’t know how well it will work. Will it offer goods and services like what healthy reefs do today, or decades ago? Who knows.”