Coastal environments are vulnerable to land development due to human population growth that has increased nitrogen and phosphorus loading into receiving estuaries. As a result, phytoplankton blooms have proliferated as “bottom‐up” (resource) processes outweigh “top‐down” (removals). This study investigated phytoplankton biomass and assemblage regulation by both N‐form (ammonium, nitrate, urea) and zooplankton at two southeaste...