Marine research provides evidence of ‘Atlanticization’ of the Arctic Ocean

The international BIOCAL expedition, led by the Institute of Environmental Science and Technology of the Autonomous University of Barcelona (ICTA-UAB), has provided new evidence of the phenomenon of the “Atlanticization” of the Arctic Ocean. Gradual invasion of the polar Arctic Ocean from the Atlantic Ocean.

The campaign collected samples to study changes in marine biodiversity through analysis of calcifying planktonic organisms. Calcifying planktonic organisms contribute to the control of atmospheric CO2 and seawater chemistry. These organisms form shells of calcium carbonate and are particularly sensitive to ocean acidification and climate change.

This August and September, the marine research vessel Sarmiento de Gamboa will sample the islands of the Azores (subtropical) and Svalbard (polar) before sailing from Vigo (Spain) to Reykjavik (Iceland). It sailed and analyzed the North Atlantic and South Pole. Oceans.

Water and sediment samples will be collected during the journey, and field experiments will be conducted to assess marine biodiversity and biogeography, and their role in the carbon cycle, with a particular focus on calcified plankton. I did. Studies in different latitudes, from the warmest parts of the Atlantic Ocean to the colder waters of the Arctic, have allowed the scientific team to gather evidence of the effects of ‘Atlanticization’ on water’s physicochemical properties and pelagic ecosystems. I did.

“The invasion of the Atlantic Ocean is turning the Arctic into an ocean, with accelerating ice melt, leading to warming and decreasing salinity.Furthermore, this invasion is changing the Arctic marine ecosystem and species distribution. is changing rapidly,” explains Patrizia Givelli. , an oceanographer at ICTA-UAB and the campaign’s lead scientist.

This phenomenon changes primary and secondary productivity, allowing species from more temperate latitudes to expand their range northward, and causing food competition and predation against arctic species.

In addition to surface temperatures in Svalbard being higher than the average for the past 22 years, scientists also found that at the edge of their normal geographic range, calcifying plankton species, the coccolithophytes, shed their shells. observed pteropods and foraminifera (three major calcified groups). And September. The wide range of regions surveyed in this campaign, from the subtropics to the polar regions, allowed scientists to observe global signs of climate change in the biogeography of common calcifying planktic species.

The project is based on evidence that marine biodiversity loss is one of the biggest threats to the ocean, but most of the knowledge comes from large macrogroups and animals. Anthropogenic climate change and environmental degradation are causing alarming effects such as ocean warming, acidification, stratification, and deoxygenation, affecting both small plankton and fish species.

Despite humanity’s clear dependence on the ocean, the impact of these changes on biodiversity is still not fully understood, especially at the food web level.

The expedition included an interdisciplinary team of scientists (ICTA-UAB, Scripps Institution of Oceanography, Oxford University, and Rowan University) including oceanographers, biologists, geologists, and environmental and social science experts from multiple countries. I did.