Sustained ocean observations provide the foundation for much of what we understand about the ocean. Collected over the years, and sometimes decades, these observations give scientists insight into global cycles, seasonal trends, and long-term changes in the physics and chemistry of the ocean.

In a groundbreaking study published in a special issue of the journal Oceanography, a team of researchers led by Professor Nicholas Bates, Senior Research Scientist and Associate Director of Research at BIOS, used data from seven independent ocean time-series to look at how the chemistry of the ocean is responding to the uptake of human produced [anthropogenic] carbon dioxide [CO2].

The Bermuda Atlantic Time-series Study [BATS] site, located 50 nautical miles southeast of Bermuda, was one of the study locations. BATS is the longest running ocean time-series of its kind and provided researchers with more than 25 years of data about the ocean surrounding Bermuda.

In a unique collaboration with researchers from the United States, Venezuela, Spain, Iceland, and New Zealand, the study also looked at data from the Caribbean Sea, the North and South Pacific Ocean, and the Eastern and North Atlantic Ocean.

In looking at data from the seven time-series, the team found that, despite their different geographic locations, each of the time-series sites exhibited similar changes in ocean chemistry in response to the release of anthropogenic CO2 into the atmosphere and its subsequent uptake by the ocean.

The study also confirmed what many scientists have been saying for years: the surface waters of the ocean are slowly becoming less alkaline in a process called “ocean acidification.” The decades of time-series data showed a long-term decrease in pH and saturation states for calcium carbonate minerals, such as aragonite, meaning that it is becoming more difficult for calcifying marine organisms to build their shells and skeletons.

“Such sustained, long-term observations are vitally important to show changes in the chemistry of the global ocean,” said lead study author Nicholas Bates.

“Scientific data collected in the seas around Bermuda provide very important information and act as a bellweather for governments and policymakers to respond to the global issue of climate change.”