Phytoplankton biomass and primary productivity of of Lake Leake and Tooms Lake, Tasmania

Phytoplankton biomass and primary productivity were studied in 2 lakes in eastern Tasmania. Low standing crops (7-746 and 42-180 mm Super(3)m Super(-3) for Lake Leake and Tooms Lake respectively) and primary productivity (approx 9 g Cm Super(-2) yr Super(-1) for both lakes) indicate extreme oligotrophy. During a period when biomass remained constant in Lake Leake the hourly assimilation rate in constant light conditions varied seasonally, indicating physiological adjustment by the algae ('light adaptation').The relationships between plankton biomass and C assimilation are discussed.