How does the oxygen status of lake sediments affect phosphor

How does the oxygen status of lake sediments affect phosphorus availability? What is the role of iron?

Solution

under aerobic condition iron immobilises phospherous and anaerobic condition releases phospherous. when oxygen is present in the sediments the iron (Fe2+) is oxidised(Fe3+) and it will precipitates phospherous. Due to this the concentration of phospherous in the lake water will be very less. if the microorganisms in the lake is utilising oxyygen in the lake , the iron will get reduced and the phospherous will be released.