show Abstracthide AbstractSingle-cell genome sequencing to explore relationships between physiological succession, ecotype partitioning, and taxonomic replacement under changing levels of water column O2-deficiency. Samples were taken from an ongoing time-series program monitoring microbial community responses in seasonally anoxic coastal, transition, and open-ocean OMZs (oxygen minimum zones). The focus will be on samples from the northeastern subarctic Pacific Ocean (NESAP), which contains the largest and least-studied permanent OMZ in the global ocean.