Fig. 1: Study area and oceanographic conditions.

a Location of moored Remote Access Samplers in the East Greenland Current (EGC) and the West Spitsbergen Current (WSC) of Fram Strait, indicated in blue and red respectively. The small red arrows illustrate recirculation of Atlantic Water in central Fram Strait. The grayscale gradient indicates the fraction of days with average sea ice cover of >20%. b Water temperature (°C), concentrations of oxygen (µmol L−1) and nitrate (µM), the proportion of Atlantic Water (%), sea ice cover (%), and daylight hours.