Utilization of Phosphorus by Phytoplankton in Phosphorus-Rich Environments.

摘要

A study was made of the eutrophic Flat Creek embayment of Lake Sidney Lanier near Gainesville,Georgia,to determine to what degree phosphorus in luxury concentration could be utilized by various species of phytoplankton. Three prominant species of algae, Chlorococcum, Fragillaria and Nostoc,were grown under experimental conditions to determine their response to luxury amounts of phosphorus. Uptake of p32varied from less than 20% for Nostoc to greater than 80% of the p32added for Chlorococcum. However,if Nostoc was previously deprived of phosphorus,its subsequent uptake ability increased markedly. For the species studied, p32uptake was directly proportional to the surface-per-volume ratio,similar to results found in marine benthic algae. These results show that phytoplankton can uptake large amounts of phosphorus entering a lake through municipal or industrial waste discharges,but further research is needed to ascertain whether removal of phosphorus by this means retards eutrophication or whether the phosphorus continues up the food chain.