The Newfoundland and Labrador (NL) shelf and the Grand Banks of Newfoundland have been known as iconic fishing areas for centuries. In such areas with seasonal sea ice coverage, the timing of the spring bloom has been linked to sea ice melting, which stratifies the water column and promotes favorable conditions for phytoplankton to grow and accumulate. With sea ice gradually disappearing, we revisited the physical drivers controlling the initiation of the spring bloom in the region. We found that the timing of the phytoplankton bloom on the Grand Banks corresponds to the timing of ocean re-stratification following winter mixing. We also found that large-scale climate indicators are good proxies for the timing of the bloom and the abundance of Calanus finmarchicus, a key zooplankton species for the ecosystem. By revealing links between physical and biological processes, this work paves the way for an improved ecosystem approach to fisheries management.