An expedition led by Spanish scientists studies a worrying ocean process: the atlantification of the Arctic

The Arctic is changing. We have been hearing for a long time about how the polar ice melts, turning the immense frozen desert into an open ocean. However, the transformation of the northernmost region of the planet also occurs in deeper layers. It is the “Atlantification” of the Arctic.

New clues. We have new clues about this Atlanticification process of the Arctic Ocean. All thanks to the expedition led by the ICTA-UAB (Institute of Environmental Science and Technology) that has revealed new changes in ecosystems in the region where the two oceans intersect.

“Atlantification”. Experts call the process of change experienced by the waters of the Arctic Ocean Atlanticification. As ICTA-UAB itself points out, to “the progressive invasion of Atlantic waters in the Arctic Ocean.”

Although this phenomenon is linked to climate change, it is not only related to water temperatures in different areas of the ocean, but also encompasses a series of chemical changes in the water, which have to do with the relative concentration of salt or carbonate. calcic.

From Vigo to Reykjavik. To study these changes, the ICTA-UAB and other institutions launched the international expedition Global Biodiversity of Marine Planktonic Calcifiers (BIOCAL). The expedition left the port of Vigo in the direction of Reykjavik, Iceland, passing through two Atlantic archipelagos, the Azores, in the subtropical zone; and that of Svalbard, in the polar zone.

The objective was to collect samples at different latitudes of the North Atlantic from which changes in marine biodiversity could be studied. The team thoroughly studied calcifying planktonic organisms, small organisms that contribute to the regulation of both atmospheric carbon dioxide (CO2) and seawater chemistry, they note.

This plankton, capable of forming calcium carbonate shells, is key to understanding chemical changes in water since it is particularly vulnerable to changes in the acidity level of the water, as well as climate change, they add.

Studying the changes. The BIOCAL expedition studied the three predominant types of this calcifying plankton: coccolithophores, pteropods with shells and foraminifera in their journey; as well as the conditions in which he lived. They thus observed that, in places such as the Svalbard archipelago, these species were “at the limit of their usual geographical distribution area.” They also found temperatures higher than the average of recent decades during the months of August and September of this year.

“The intrusion of Atlantic waters is turning the Arctic into an increasingly warmer and less saline ocean due to accelerated melting. Furthermore, this intrusion is rapidly changing marine ecosystems and the distribution of species in the Arctic,” indicated in a press release Patrizia Ziveri, chief scientist of the campaign.

Changes in biodiversity. We will have to wait before having definitive results from the study of the samples collected. Its study could offer us valuable information about the loss of biodiversity in the area, especially with regard to smaller species, often overlooked in previous studies.

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Image | NASA Earth Observatory, Lauren Dauphin, based on data from the National Snow and Ice Data Center