Physical controls and ecological implications of the timing of the spring phytoplankton bloom on the Newfoundland and Labrador shelf

The timing of spring phytoplankton blooms is crucial to many species that have adapted their development to benefit from the enhanced feeding opportunity they offer. Any change to their timing may affect the productivity of an entire ecosystem. This study explores the relationship between the ocean climate, the timing of the spring bloom and the secondary production on the Newfoundland and Labrador shelf. It is found that over interannual cycles, the ocean climate is significantly correlated with the timing of the bloom and the abundance of Calanus finmarchicus, a key zooplankton species for the ecosystem. It also appears that the spring bloom is initiated by the onset of ocean re-stratification following winter mixing. Understanding how annual variation in climate relates to the timing of the spring bloom and zooplankton abundance, that is, the base of the marine food web, can inform the development of ecosystem-informed models for higher trophic levels.