Grazing by microzooplankton in the eastern Canadian arctic in summer 1983

Abstract

Grazing of microzooplankton on phytoplankton was studied in the eastern Canadian Arctic by the dilution method. In Jones Sound, significantly high growth and grazing coefficients on phytoplankton were observed even though the mixed layer nutnents were low. In Baffin Bay, growth and grazing coefficients could be observed only when excess nutnents (NOs) were added to the experimental bottles. The microzooplankton community grazed 8 to 15 % of initial standing stock and 40 to 114 % of potential primary production daily in Jones Sound, and 9 to 15 " ' 0 of initial standing stock and 37 to 88 % of potenbal production daily in Baffin Bay. If nanophytoplankton alone is considered as potential food for m~crozooplankton, then the grazing impact of this community on the standing stock and production of the total phytoplankton would be on average 5 to 31 % d-' in Jones Sound and 10 to 47 % d-' in Baffin Bay, respectively. The grazing of the high latitude microzooplankton community studied by the dilution method is comparable to that in the lower latitudes.