Atlantic Ocean warmer and more acidic than ever before: study

By Isobel Williams via SWNS

The Atlantic Ocean is warmer and more acidic than ever before, reveals new research.

Data from 40 years of ocean testing shows that the Atlantic Ocean is changing in composition much more rapidly in the last four years than ever before.

At a site 80km (50 miles) southeast of the island of Bermuda, scientists take monthly samples of the physics, biology, and chemistry of the ocean’s surface and depths.

They have been taking these since 1988 in a project called the Bermuda Atlantic Time-series Study (BATS).

In a new paper published in Frontiers in Marine Science, researchers have now presented the latest findings from this monitoring effort.

Professor Nicholas Bates said: “We show that the surface ocean in the subtropical North Atlantic Ocean has warmed by around 1°C over the past 40 years.

“Furthermore, the salinity of the ocean has increased, and it has lost oxygen.

“In addition, ocean acidity has increased from the 1980s to the 2020s.”

The results, from the Bermuda Institute of Ocean Sciences, found that ocean surface temperatures have increased by around 0.24°C each decade since the 1980s.

In total, the ocean is around 1°C warmer now than it was 40 years ago, but temperatures have risen much more sharply in the last four years.

Not only have the monitored waters gotten warmer, but there is also more saline at the surface, meaning more salt is dissolved in the water.

Professor Bates explained: “We suspect this is part of the broader, more recent trends and changes in ocean temperatures and environmental changes, like atmospheric warming and having had the warmest years globally.

“These observations give a sense of the rate of change in the recent past of ocean warming and ocean chemistry. They provide key indications of future changes in the next decades.

“They also are proof of regional and global environmental change and the existential challenges we face as individuals and societies in the near future.”

At the same time, the data indicated that over the last 40 years the amount of oxygen available to living aquatic organisms has decreased by six percent and the acidity level of the water has increased by 30 percent, resulting in lower carbon concentrations.

This change in composition of the ocean could have a significant impact on the creatures that live there, particularly shelled organisms.

Professor Bates added: “The ocean chemistry of surface waters in the 2020s is now outside of the seasonal range observed in the 1980s and the ocean ecosystem now lives in a different chemical environment to that experienced a few decades ago.

“These changes are due to the uptake of anthropogenic CO2 from the atmosphere.”