Scientists Track Live Corals Before and After Heat Wave in the Ocean

Scientists have discovered that various corals and habitats alter their chances of survival as ocean temperatures increase.

The findings also showed that improved remote sensing technologies enable unprecedented scale-up of reef monitoring.

Mapping corals in the past

(Photo : GLENN NICHOLLS/AFP via Getty Images)

As ocean temperatures rise, more occurrences of coral bleaching will occur.

When corals bleach, organisms remained much more exposed to additional stresses such as water pollution.

Many reefs, however, are home to corals that have survived amid warmer waters.

Unraveling the complicated issue of coral bleaching and its influence on their survival or death may be critical to maintaining coastal and marine ecosystems on which more than half a billion people worldwide rely for food, jobs, recreation, and shoreline security.

Scientists have traced the position of live corals before and after a large marine heatwave for the first time.

The latest study demonstrates where coral reefs are thriving despite the rising sea surface temperatures driven by climate change.

The study also discovered that coastal growth and water pollution had a detrimental impact on coral reefs.

Arizona State University scientists with the Julie Ann Wrigley Global Futures Laboratory explain in a study published today in Proceedings of the National Academy of Sciences that various corals and surroundings alter the chance of their survivability as ocean temperature increases.

The findings also show that improved remote sensing technologies enable unprecedented scale-up of reef monitoring.

According to Greg Asner, principal author of the study and director of the ASU Center for Global Discovery and Conservation Science, repeat coral mapping with the GAO revealed how Hawaii's coral reefs responded to the 2019 catastrophic bleaching event.

"We identified coral 'winners' and 'losers,' and these winning corals are connected with usable water and less coastal development, despite rising sea temperatures," he added, as per ScienceDaily.

When the Hawaiian Islands experienced widespread bleaching in 2019, the GAO surveyed living coral cover along with eight islands before the arrival of the maritime heatwave.

Using this information, the researchers discovered more than 10 possible coral refugia ecosystems that may provide a safe refuge for corals threatened by climate change.

Despite identical heat stress, there has been up to 40% less coral mortality in possible refugia than on nearby reefs.

The findings also revealed that reefs along densely populated coastlines are more vulnerable to death during heat waves.

When land development happens, the quantity of pollution entering the reef ecosystem rises, producing an adverse condition for coral reefs that are already struggling to thrive in warmer waters.

Also Read: Scientists are Weeding Coral Reefs to Help Lessen the Impacts of Climate Change

Status of coral reefs around the world

Coral reefs may be found in over 100 nations and territories, and while they comprise just 0.2% of the seabed, they support at least 25% of marine species and provide safety, coastal protection, well-being, food, and economic independence to hundreds of millions of people, as per UN Environmental Programme.

Coral reefs, on the other hand, are among the most susceptible ecosystems on earth to anthropogenic sources, including environmental challenges from climate change and acidification of the oceans, as well as local effects from soil pollution, such as agricultural input of nutrients and sediments, marine pollution, and overexploitation and catastrophic fisheries management.

The Holomua 30x30 plan intends to create marine management zones in 30% of Hawaii's nearshore seas.

Coral reefs are an important part of life in the Hawaiian islands, as they are linked to cultures and economy.

Understanding which corals are surviving is critical to ensuring focused and effective protection.

ASU's Center for Global Discovery and Conservation Science worked with the Hawaii Division of Aquatic Resources and the National Oceanic and Atmospheric Administration's Pacific Islands Fisheries Science Center on this project.