In recent decades, we’ve been able to accurately measure temperature changes in the world’s oceans. But how do we know what they were like hundreds of years ago? Well, one way to do that is to analyze structures from that time—mainly living organisms, but few of them are here to tell stories. That’s why this 600-year-old coral from Fiji could be so important.
Recent research suggests that the Pacific Ocean has warmed dramatically in recent centuries, exacerbated by climate change. But understanding temperature changes over the years is essential to trying to predict what might happen in the future.
We know, for example, that there have been cooler years (and even decades), but what exactly were these periods? This is what was recently published in research Science advances Want to reply. The study analyzes a single sample of coral. Diplostria helioporaalso known as “honey coral”. The specimen was discovered in 1998 and sampled.
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The researchers then used the sample and compared it to other records of coral reefs in Fiji to create a timeline of what happened to the waters in the area before the 1990s, since it is from this period onwards that we have accurate records of the site's waters.
The research has created a record that spans from 1370 to 1997, covering 627 years of history. This is the longest temperature record ever recorded anywhere in the world in the Pacific Ocean.
Giant coral in the Pacific Ocean
This giant coral species lives for hundreds of years. According to the research, it “continuously forms a calcium carbonate skeleton that builds up in layers on top of the older skeleton.” As a result, newer layers are pushed out and the older skeleton is left behind, creating a trace of history.
These coral skeletons reveal the ocean's past. The research analyzed strontium and calcium, two elements found in these samples, which indicate seawater conditions at the time the corals “occupied” these skeletons.
Ocean temperatures have been rising in recent years.
Among the data that has been revealed, for example, there was a very warm period between 1370 and 1553. Other periods were cooler. By comparing the skeletal data with present-day data, researchers can understand the chronology of the oceans.
“When we do this, we find that the warming of the Pacific Ocean over the past century, largely due to human-induced global warming, represents a significant departure from the natural variability recorded in previous centuries,” says lead researcher Juan Pablo Dolevo, a fellow at the Institute of Marine Sciences and Limnology, National Autonomous University of Mexico (UNAM). Conversation.
The conclusion is that the ocean in the Fiji region is warmer than it has been in the past 653 years. These changes could lead to more extreme weather, such as longer droughts or more intense tropical cyclones, with significant impacts for the millions of people living in the region. The study shows how important it is to preserve and analyse this type of coral reef.
