Collaborative Research: Large-scale nutritional ecology of diverse phytoplankton

This project addresses how marine phytoplankton — microscopic algae that fuel ocean food webs and contribute to global nutrient cycling — respond to differences in resource availability across the ocean. Nutrient supply in surface waters plays a central role in determining phytoplankton growth and overall ocean productivity. However, the ocean harbors a wide variety of phytoplankton species, and their varied nutritional demands may influence ecosystem responses in complex ways. This research provides a novel technical ability to diagnose the nutritional state of diverse phytoplankton communities using genomic tools while also advancing our understanding of large-scale patterns in marine productivity. The project also contributes to public understanding of marine ecosystems through science outreach and education activities, including hands-on events in collaboration with a state park that welcomes a broad public audience. Additionally, all genomic data and analysis tools are being shared openly, supporting further research and educational use. The research investigates whether different phytoplankton species experience distinct nutrient stress conditions even when living in the same environment. To do so, the team is leveraging a funded GO-SHIP cruise and combining comparative genomics, laboratory experiments, field-based nutrient bioassays, and analyses of existing large-scale DNA and RNA datasets from across the global ocean. A key focus is identifying biomarkers — specific genes or gene expression patterns — that indicate stress from limited nitrogen, phosphorus, or iron. These biomarkers are used to map nutrient stress states across multiple phytoplankton groups and geographic regions. The project compares patterns observed in field samples with predictions from Earth system models to improve scientific understanding of how nutrient conditions shape marine ecosystems. The results provide valuable insight into the relationships between environmental conditions, phytoplankton diversity, and the nutritional balance of ocean ecosystems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.