A recent expedition from Vigo, Spain, to Reykjavik, Iceland, has shed light on the profound effects of climate change on marine biodiversity, particularly among calcifying planktonic organisms. These organisms, crucial for regulating atmospheric CO2 and seawater chemistry, are increasingly threatened by ocean acidification.
Conducted from August to September, the research involved extensive sampling across the North Atlantic and South Arctic Oceans, including the Azores and Svalbard archipelagos. The team collected water and sediment samples, conducting in-situ experiments to evaluate marine biodiversity and the roles of various species in the carbon cycle.
Patrizia Ziveri, an oceanographer at ICTA-UAB and chief scientist of the campaign, noted that the intrusion of warmer Atlantic waters is transforming the Arctic into a less saline ocean, significantly impacting marine ecosystems. "The intrusion is rapidly changing the marine ecosystems and species distribution of the Arctic," Ziveri stated.
In Svalbard, researchers discovered calcifying plankton species, such as coccolithophores and foraminifera, at the northern limits of their typical ranges, coinciding with unusually high surface temperatures over the past two decades. This study underscores the urgent need to understand how climate change affects not only large marine species but also smaller organisms that underpin the food web.
The findings reveal that ocean warming, acidification, and deoxygenation are creating cascading effects on marine ecosystems, impacting everything from plankton to fish populations. The team also investigated biogeochemical processes altered by climate change and the spread of pollutants in marine environments.
This multidisciplinary effort involved oceanographers, biologists, geologists, and environmental scientists from various institutions, including ICTA-UAB, the Scripps Institution of Oceanography, and the University of Oxford. The campaign was spearheaded by ICTA-UAB's Marine and Environmental Biogeosciences Research Group (MERS).