Variabilité à court terme des propriétés physiques,chimiques et biologiques du Saguenay,fjord subarctique du Quebec (Canada)

Tidal variability of water mass characteristics has been assessed in the upper 100 metres of the Saguenay, a subarctic fjord in Québec, Canada. Temperature and salinity show a maximum variability in the 5-15 m layer in which vertical oscillations of a very sharp pycnocline are observed. Phosphates, nitrates and chlorophyll a are highly variable above this pycnocline during a tidal cycle, but dissolved oxygen content is remarkably stable in the whole water column. It is concluded that fluctuations of many variables in the subsurface waters might be large enough to hinder high rates of primary production.