Climate change is causing significant shifts in the phenology of phytoplankton communities, but current Earth System Models (ESMs) do not take into account the various phenotypes and trait groups that result from evolutionary strategies. A new study has used a species-based modelling approach, combined with large-scale plankton observations, to investigate past, contemporary, and future phenological shifts in diatoms and dinoflagellates in three key areas of the North Atlantic Ocean. The study found that the three phytoplanktonic groups exhibit coherent and different shifts in phenology and abundance. Large flattened diatoms are predicted to decline in abundance, while slow-sinking elongated diatoms and dinoflagellates are expected to increase in abundance. This may alter carbon export in this important sink region. The increase in prolates and dinoflagellates, two groups currently not considered in ESMs, may alleviate the negative influence of global climate change on oblates, which are responsible for massive peaks of biomass and carbon export in spring. The study suggests that including prolates and dinoflagellates in models may improve our understanding of the influence of global climate change on the biological carbon cycle in the oceans.
More information: Kléparski, L., Beaugrand, G., Edwards, M., & Ostle, C. (2023). Phytoplankton life strategies, phenological shifts and climate change in the North Atlantic Ocean from 1850 to 2100. Global Change Biology, 00, 1– 17. https://doi.org/10.1111/gcb.16709
Pelasphere 