Marine ecologists warn of coral extinction by the end of the century

As global temperatures rise, coral reefs in the Caribbean are diminishing. Barriers for coastal communities from storms, flooding and sea level rise, as well as attractions for tourism, can be found on coral reefs. Their net economic value is estimated to be tens of billions of dollars. Coral reefs face extinction by the end of this century if atmospheric and ocean temperatures continue to rise.

The reefs that I used to dive and snorkel on are gone. There are some species you don't see anymore. Dan Holstein is an assistant professor at the LSU Department of Oceanography.

He and his team have developed a model that is the first to predict how warming seas will affect coral populations in the Western Atlantic. The model uses projections of ocean warming to calculate how coral populations will be affected by rising ocean temperatures.

The model predicts that ocean warming will reduce the ability for coral to migrate. The model doesn't seal the fate of coral reefs, but it is a big wake-up call, said Holstein, whose work is published in a new paper in the journal Coral Reefs.

As the ocean warms, it can cause imbalances similar to temperature and weather extremes experienced on land.

Holstein said that thermal stress is the biggest problem corals face. We can do something about it.

Corals rely on a healthy relationship with a small marinealgae to survive. The coral's tissue is home to the algae that produce sugars for the coral. Coral may die from starvation if the ocean becomes too hot.

Holstein's model looks at how coral populations are able to adapt to temperature changes in the Caribbean.

"Coral reef connectivity through sexual reproduction and planktonic larvae remains a critical process to track during climate change," said co-author Paris.

The new model uses information from the open-source Connectivity Modeling System.

Holstein doesn't believe coral reef extinction is inevitable, despite the model suggesting a dire outcome for coral reefs and specifically for the boulder star coral used in the model.

Consumers and policymakers can change how much carbon is released into the atmosphere. The countries with the most at stake need to work together to reverse course.

The management of coral reefs requires cooperation across borders and scales. It is one of the obvious conclusions. Holstein said that if we fail to do that, all of our effort is at risk.

The study, titled Predicting coral metapopulation decline in a changing thermal environment, was published online on April 12 in the journal Coral Reefs. The authors of the paper are Holstein, University of Virgin Islands Associate Research Professor of Marine Science Tyler Smith, assistant scientist Ruben van Hooidonk at the Atlantic Oceanographic and Meteorological Laboratory, and Paris.

More information: Daniel M. Holstein et al, Predicting coral metapopulation decline in a changing thermal environment, Coral Reefs (2022). DOI: 10.1007/s00338-022-02252-9 Journal information: Coral Reefs Citation: Marine ecologists warn of coral extinction by the end of the century (2022, May 17) retrieved 17 May 2022 from https://phys.org/news/2022-05-marine-ecologists-coral-extinction-century.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.