Climate played a key role in shifting ancient coral reefs

An international team of scientists has pioneered a new method to determine where prehistoric warm-water coral reefs existed. The results of the analysis show that climate can significantly affect where corals grow. 

Study co-author Dr. Alex Farnsworth of the University of Bristol explained why this was not an easy topic to explore. “Climate has changed significantly throughout geological time, however understanding how it has impacted coral reef ecosystems has been difficult due to a lack of quantifiable data which has significant gaps.”

Some of these gaps can be attributed to an incomplete fossil record, while other gaps can be attributed to biased research practices – since most previous coral studies have occurred near wealthy nations. 

However, researchers from Spain and the UK found a way to fill in these gaps. By modeling habitats and reconstructing past climates, the researchers were able to predict where corals lived from 250 million to 35 million years ago. They found that corals extended farther from the equator in warmer periods. 

“Our work demonstrates that warm-water coral reefs track tropical-to-subtropical climatic conditions over geological timescales. In warmer intervals, coral reefs expanded poleward. However, in colder intervals, they became constrained to tropical and subtropical latitudes,” explained study first author Dr. Lewis Jones.

This information may cause some people to assume that global warming benefits warm-water corals, but this is not necessarily the case. “Current anthropogenic climate change will result in the poleward expansion of suitable habitat for coral reefs,” said Dr. Jones. “In fact, we are already witnessing the expansion of some tropical reef corals. However, whether coral reef ecosystems – and all the biodiversity they support – can keep pace with the current rapid rate of anthropogenic climate change is another question.” 

Based on their findings, the researchers believe it is possible that decreasing the acceleration of global warming is more necessary for tropical coral systems than preventing global warming. 

The findings are clear evidence that climate and corals have been linked for millions of years. The researchers hope this knowledge will guide further learning. 

“Using this new combined data-model approach we can start to better understand reef ecosystems evolution and behavior,” said study co-author Dr. Alex Farnsworth. 

We can also expect that this research will play a role in preserving these magical rainforests of the ocean.

The study is published in the journal Nature Communications.

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By Erin Moody , Earth.com Staff Writer