This dataset includes biological, chemical and environmental data associated with phytoplankton biomass and productivity collected on eight oceanographic cruises in the Pacific Arctic Region onboard the Canadian Coast Guard Service Sir Wilfrid Laurier. Samples were collected on cruises that occurred in July of 2006, 2008 and yearly from 2011 to 2016. Seawater sampling was conducted throughout the euphotic zone within (or near) five biological ‘hotspots’ in the northern Bering and Chukchi Seas, as identified by the Distributed Biological Observatory (DBO). Data includes concentrations of nutrients (Nitrate+Nitrite, Phosphate), total (>0.7 micron) and size-fractionated (>5 micron) chlorophyll-a, and particulate carbon and nitrogen. Also included are measurements of carbon and nitrate uptake rates from 24-hr dual-tracer carbon-13 and nitrogen-15 incubation experiments. Data are organized by row, with each row representing a single sampling depth, or the euphotic zone depth-integrated value.