Phosphorus sources for phytoplankton and bacteria in Lake Michigan

Abstract

Size-fractionation experiments on the uptake of phosphate and recently excreted dissolved organic phosphorus (E-DOP)from phytoplankton suggest that algae and bacteria rely on different forms of phosphorus in the epilimnion of P-limited Lake Michigan. Rate constants for PO 4 uptake in 0-1 μm fractions generally were low relative to those measured in wholewater, suggesting that most of the uptake was by algae. Uptake of 33 E-DOP in 0-1 μm fractions approximated uptake in wholewater, indicating uptake principally by bacteria (...)