Research Document - 2011/074
Optical, chemical, and biological oceanographic conditions on the Newfoundland and Labrador Shelf during 2009 and 2010
By P. Pepin, G. Maillet, S. Fraser, T. Shears, and G. Redmond
We review seasonal and interannual variations in the concentrations of major nutrients, chlorophyll a, as well as the abundance of major taxa of zooplankton measured from Station 27 and along standard transects of the Atlantic Zone Monitoring Program (AZMP) in the Newfoundland region for 2009 and 2010. Across the region, annual nitrate inventories (shallow and deep) have declined since 2008 and appear to be continuing to decrease in 2010. Chlorophyll concentrations in 2009 were at their highest levels since the start of AZMP activities in the region but returned to near normal values in 2010. In 2009 and 2010, the principal zooplankton indices indicated that abundance was generally higher than average, with densities reaching their highest levels in 2010 along many of the oceanographic sections. The indices of inventories and abundances across trophic levels (nutrients, phytoplankton and zooplankton) generally exhibit weak associations (i.e., correlations) between adjacent trophic levels. There was no single physical environmental variable that demonstrated a widely consistent pattern of correlation with either nutrient inventories, phytoplankton abundance or with the wide diversity of zooplankton taxa. This may be the result that over the last decade the physical environment of the Newfoundland Shelf showed the lowest overall variability relative to previous decades going back to 1950.
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