Biogeography and Diversity of Marine Plankton

Marine plankton encompass a vast array of organisms, from viruses and bacteria to single-celled eukaryotes and metazoans, that drift in ocean currents and underpin global food webs and biogeochemical cycles. Their distributions are governed by a complex interplay of temperature, nutrient availability, light regimes and ocean circulation, creating distinct community assemblages across latitudinal gradients and depth zones. Patterns of diversity range from high species richness in tropical surface waters to specialised, low-diversity assemblages in polar and deep environments.

Advances in molecular methods, imaging technologies and ecological modelling have refined our understanding of how plankton communities respond to environmental change. Genetic surveys paired with functional trait analyses reveal how shifts in community composition alter carbon fixation, nutrient cycling and trophic interactions. These insights inform predictions of how climate-driven warming, acidification and deoxygenation may restructure plankton biogeography and affect ecosystem services such as fisheries productivity and carbon sequestration.

Global significance lies in the sensitivity of plankton to anthropogenic pressures and their role in planetary health. Practical applications of this research include the development of early-warning indicators of ecosystem shifts, the optimisation of marine protected area placement and the integration of plankton dynamics into climate mitigation strategies.

Research from Nature Portfolio

Recent studies have proposed a classification of ocean microbial communities into discrete ecological statuses that reflect diversity, taxonomic composition and biogeochemical potential, and have used machine-learning projections to forecast poleward shifts in key taxa, increases in photosynthetic carbon fixation and declines in nutrient metabolism under high-emission scenarios. Complementing this, ensemble species distribution models for hundreds of phytoplankton and zooplankton species predict a general rise in phytoplankton richness, a slight tropical decline in zooplankton diversity and a median poleward redistribution of species at 35 km per decade, with major implications for regional carbon export. Metatranscriptomic surveys across a pole-to-pole transect have revealed sharp breaks in algal microbiome beta diversity around 14 °C, delineating cold and warm regimes, and project that these biogeographic boundaries will migrate towards the poles as upper-ocean temperatures rise, indicating potential abrupt regime shifts in microbial community structure.

Biogeography and Diversity of Marine Plankton publication trend

The graph below shows the total number of articles in biogeography and diversity of marine plankton across all publications each year (not limited to Nature Index journals).

Technical terms

Plankton: Passively drifting organisms in aquatic environments, including viruses, microbes, algae and small animals.

Biogeography: Study of the spatial distribution of organisms and the processes shaping these patterns.

Species distribution model: Computational approach to predict geographic ranges of species based on environmental variables.

Beta diversity: Measure of variation in species composition between different communities or regions.

Metagenome-assembled genome (MAG): Genome sequence reconstructed from environmental DNA without prior cultivation.

Species richness: Number of distinct species present in a given community or region.

References

1. Global biogeography of microbes driving ocean ecological status under climate change. Nature Communications (2024).
2. Eukaryotic genomes from a global metagenomic data set illuminate trophic modes and biogeography of ocean plankton. mBio (2023).
3. Global Trends in Marine Plankton Diversity across Kingdoms of Life. Cell (2019).
4. Global pattern of phytoplankton diversity driven by temperature and environmental variability. Science Advances (2019).
5. Major restructuring of marine plankton assemblages under global warming. Nature Communications (2021).
6. The biogeographic differentiation of algal microbiomes in the upper ocean from pole to pole. Nature Communications (2021).