Ample supplies of nutrients delivered to the Southern Chukchi Sea through Bering Strait fuel a high level of Chukchi shelf primary productivity during months in which water column light levels are sufficient to maintain phytoplankton blooms. Portions of the region likely exist in a near perpetual state of patchy phytoplankton blooms from the spring ice retreat all the way into the fall. Export fluxes to the benthos are large because large-celled diatoms sink rapidly to the shallow seafloor and because mesozoo plankton often are unable to constrain the phytoplankton bloom by grazing. Arctic marine mammals occur more frequently to the west of Saint Lawrence Island than to the east and the overall biodiversity of vocal marine mammals is higher to the west. Further subarctic species were heard well into winter months at all locations. Together, these findings suggest that the future Pacific Arctic ecosystem will adjust in species composition and species abundance in a bottom up response to environmental change. Arctic marine mammals are critical to the food security and cultural and spiritual health of coastal Arctic communities and understanding changes can be used to understand ecosystem-wide environmental changes.