Knowing your limits: evaluating aquatic metabolism in a subtropical treatment wetland

Changes in dissolved oxygen (DO) within aquatic ecosystems integrate dynamic biological, physical, and chemical processes that control the rate of ecosystem metabolism. Aquatic ecosystem metabolism can be characterized by the diel change in DO changes over time and is expressed as the net aquatic productivity (NAP) based on the balance of gross primary productivity (GPP) and ecosystem respiration (ER). This study investigated aquatic metabolism of dominant emergent and submerged aquatic vegetation (EAV and SAV, respectively) within two treatment flow-ways of Stormwater Treatment Area 2 (STA-2) in the Everglades ecosystem. This study hypothesizes that aquatic metabolism will differ between aquatic vegetation communities with SAV communities having a greater GPP and ER rate than EAV communities driven by biophysical, hydrodynamic, and biogeochemical differences between systems. Aquatic metabolism observed in this study varied spatially (along flow-ways) and temporally (diel to days) controlled by different factors related to biological, physical, and chemical processes. This study suggests that ecosystem metabolism is controlled differently across flow-ways with varying levels of response to loading/transport and water quality resulting in differences in organic matter accumulation, C turnover, and P cycling. The relationship between GPP and TP concentrations could be an indicator of P-removal efficiency and ecosystem function.