Comparison of phosphate uptake by epiphyton, metaphyton, and epipelon in the Everglades

Periphyton is an essential primary producer and is important to phosphorus dynamics in freshwater systems. Anthropogenic phosphorus enrichment disrupts the Everglades ecosystem. To gauge the response of periphyton to phosphorus enrichment, the rates of phosphate removal by epipelon, metaphyton, and epiphyton mats were measured in the laboratory in water that was 150,500, or 1000 µgL ^-1 above ambient levels of potassium phosphate. Phosphate removal rates were measured every 30 min for 150 min. A second experiment measured phosphate removal every 10 min for 1 h. In Experiment I, periphyton from the high concentration treatment removed phosphate 2.139 times faster than the intermediate treatment and 7.265 faster than the low concentration treatment. In Experiment II, the highest concentration treatment removed phosphate 2.277 and 5.079 times faster than the intermediate and low concentration treatments. Removal rates declined as P was removed from the water. Epiphyton removed phosphate fastest, averaging 27.37% greater than metaphyton and 118.0% greater than epipelon in Experiment I and 16.24% greater than metaphyton and 35.82% greater than epipelon in Experiment II. These findings can aid understanding effects of phosphorus pollution in nutrient-polluted waters, to model nutrient pollution after release events and in using periphyton to remediate nutrient enrichment.