Climate change affects Antarctic phytoplankton

MARE researchers Afonso Ferreira, Vanda Brotas, Catarina Guerreiro and Ana Brito are co-authors of the scientific article ‘Climate change is associated with higher phytoplankton biomass and longer blooms in the West Antarctic Peninsula’. The article was recently published in the scientific journal Nature Communications, and talks about how phytoplankton biomass and the different phases of the bloom in the West Antarctic Peninsula are changing in response to climate change.

The marine ecosystems along the coast of the Western Antarctic Peninsula have undergone significant changes in recent decades as a result of anthropogenic activities. Among the most significant changes is the increase in atmospheric and oceanic temperatures due to global warming, particularly during the winter, which has led to the generalised retreat of glaciers, ice shelves and a decrease in the extent, thickness and volume of sea ice. These changes affect all levels of the trophic chains, including primary producers, where there have already been changes in the biomass, composition and size of phytoplankton cells, impacting the other elements of the chain.

In this context, a team of Portuguese and Brazilian researchers, including several members of MARE, sought to observe these changes in order to understand their implications for marine ecosystems. To do this, they used satellite data collected over 25 years (1998-2022), which showed that phytoplankton biomass and bloom phenology in the Western Antarctic Peninsula are changing significantly as a response to climate change.

The data collected showed longer blooms and an increase in phytoplankton production over the years, especially in early spring and autumn.  According to the researchers, these changes are mainly due to the long-term decline of sea ice, in parallel with a recent intensification of the Southern Annular Mode (or Antarctic Oscillation), the main mode of atmospheric variability in the southern hemisphere.

This study is therefore extremely important for understanding the complex interaction between environmental changes and phytoplankton responses in this climatic region, and raises important questions about the long-term consequences that these ecological changes may have on global carbon sequestration and on Antarctic food webs.

To access the article click HERE

To access the interview in Expresso click HERE