Primary productivity, phytoplankton and limiting nutrient factors in labrador lakes

Abstract The primary productivity of some lakes and reservoirs in western Labrador was measured by the 14C method in order to determine the range of productivities and the effects of impoundment. No primary productivity data previously existed for this part of Canada. Both the primary productivity and standing crops of phytoplankton were found to be low in a newly impounded lake but later rose to levels greater than in surrounding natural lakes. In nutrient enrichment experiments, carbon was never found to be limiting but phosphorus stimulated primary productivity when added alone or in combination with nitrogen.