This three-year, $390,357 National Science Foundation project grant under the Geosciences program (CFDA 47.050) will support research investigating marine diatom-parasite relationships in upwelling systems. The principal investigator at Princeton University will analyze archived samples from diatom-dominated upwelling regions using tag sequencing, metagenomics, and quantitative PCR to identify diatom-parasite pairs and examine their abundance, diversity, and dynamics over the course of blooms. Network and time series analysis will explore links among hosts and parasites. The funding also supports hands-on research experience for students. By furthering understanding of biological interactions like parasitism that influence primary production, this research aims to advance knowledge of the integrated Earth system, in line with NSF's mission to strengthen the national scientific enterprise through basic research in geosciences.