The recent development of biological sensors has extended marine plankton studies from conducting laboratory bench work to in vivo and real-time observations. Flow cytometry (FCM) has shed new light on marine microorganisms since the 1980s through its single-cell approach and robust detection of the smallest cells. FCM records valuable optical properties of light scattering and fluorescence from cells passing in a single file...

Photosynthesis acts as a fundamental control in the cycling of biologically reactive elements in the ocean. Modeling photosynthesis requires an understanding of its response to light, specifically the maximum rate of photosynthesis per photon absorbed and the irradiance level at which it becomes light‐saturated ( E k ), though field measurements of these parameters are both time and labor intensive. As absorbed light either dr...

In the North Pacific Subtropical Gyre, the daily pulse of photosynthetic carbon (C) fixation is closely balanced by losses. This concert of growth and loss is driven by a diverse assemblage of plankton, including the diazotroph Crocosphaera sp. While primary production is relatively well characterized in this ecosystem, the extent of C transfer to secondary producers is poorly constrained. Here, we use automated imaging flow c...