2025-09-08 ワシントン大学(UW)
<関連情報>
- https://www.washington.edu/news/2025/09/08/ocean-warming-puts-vital-marine-microbe-at-risk/
- https://www.nature.com/articles/s41564-025-02106-4
将来の海洋温暖化はプロクロロコッカス属のバイオマスと生産性を大幅に減少させる可能性がある Future ocean warming may cause large reductions in Prochlorococcus biomass and productivity
François Ribalet,Stephanie Dutkiewicz,Erwan Monier & E. Virginia Armbrust
Nature Microbiology Published:08 September 2025
DOI:https://doi.org/10.1038/s41564-025-02106-4
Abstract
The cyanobacterium Prochlorococcus is Earth’s most abundant photosynthetic organism and crucial to oceanic ecosystems. However, its sensitivity to a changing climate remains unclear. Here we analysed decade-long field measurements using continuous-flow cytometry from our SeaFlow instrument, collecting per-cell chlorophyll fluorescence and size data for ~800 billion phytoplankton cells across the tropical and subtropical Pacific Ocean to quantify the temperature dependence of cell division. Prochlorococcus division rates appear primarily determined by temperature, increasing exponentially to 28 °C, then sharply declining. Regional surface water temperatures may exceed this range by the end of the century under both moderate and high warming scenarios. Under these future conditions, our global ocean ecosystem model suggests a possible 17–51% reduction in Prochlorococcus production in tropical oceans. Even with the inclusion of hypothetical warm-adapted strains, models show significant production declines in the warmest regions, suggesting that thermal adaptation may not prevent negative impacts. These results highlight the potential vulnerability of Prochlorococcus-dependent marine ecosystems to future warming.
