A group of scientists has provided new evidence of the phenomenon of « Atlanticization » of the Arctic Ocean, a process linked to climate change that involves the gradual encroachment of Atlantic waters into the Arctic polar 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 « Atlanticization » of the Arctic Ocean, a process linked to climate change that involves the gradual invasion of Atlantic waters into the Arctic polar ocean.
The « Atlanticization » of the Arctic: Growing Development and Its Impacts
The campaign allowed for the collection of samples to study the evolution of marine biodiversity through the analysis of calcifying planktonic organisms. These organisms contribute to regulating atmospheric CO2 and the chemistry of seawater. They form calcium carbonate shells and are particularly sensitive to ocean acidification and climate change.
In August and September, the oceanographic research vessel Sarmiento de Gamboa sailed from Vigo (Spain) to Reykjavik (Iceland), after sampling the archipelagos of the Azores (subtropical) and Svalbard (polar), and analyzing the North Atlantic and Southern Arctic Oceans.
During this voyage, water and sediment samples were collected, and in situ experiments were conducted to assess marine biodiversity and biogeography, as well as their role in the carbon cycle, with particular attention to calcifying plankton. The research conducted in regions at different latitudes—from the warmer parts of the Atlantic to the coldest waters of the Arctic—enabled the scientific team to gather evidence of the impact of « Atlanticization » on the physicochemical properties of the water and pelagic ecosystems.
« The intrusion of Atlantic waters is transforming the Arctic into an ocean that is increasingly warmer and less salty due to accelerated melting. Moreover, this intrusion is rapidly altering marine ecosystems and the distribution of Arctic species, » explains Patrizia Ziveri, oceanographer at ICTA-UAB and scientific leader of the campaign.
This phenomenon is modifying both primary and secondary productivity and allowing species from more temperate latitudes to expand their habitats northward, creating food competition and predation on Arctic species.
Ever Warmer Temperatures
In the Svalbard archipelago, scientists observed calcifying plankton species such as coccolithophores, shelled pteropods, and foraminifera (the three main calcifying groups) at the edge of their usual geographic range, as well as surface temperatures higher than the average of the last 22 years in August and September. The vast area studied during the campaign, from subtropical to polar regions, allowed scientists to observe the global impact of climate change on the biogeography of the most common calcifying plankton species.
This project is based on the evidence that the loss of marine biodiversity represents one of the greatest threats to the oceans, but most of the knowledge comes from macro-groups and large animals.
Anthropogenic climate change and environmental degradation are producing alarming effects such as warming, acidification, stratification, and deoxygenation of the oceans, which affect both small plankton and fish.
Source: tameteo
