Dynamic Coupling of Iron, Manganese, and Phosphorus Behavior in Water and Sediment of Shallow Ice-Covered Eutrophic Lakes

• DOI: 10.1021/acs.est.5b02057
• Publication Date: 2015-07-24T11:51:25Z
• Authors: Andrew W. Schroth; Courtney D. Giles; Peter D. F. Isles; Yaoyang Xu; Zachary Perzan; Gregory K. Druschel
• Keywords: 0106 biological sciences; Geologic Sediments; Manganese; Geography; Climate; Iron; Temperature; Water; Phosphorus; Eutrophication; 01 natural sciences; Trace Elements; Oxygen; Lakes; 13. Climate action; Hydrodynamics; Ice Cover; 14. Life underwater; Water Pollutants, Chemical

Decreasing duration and occurrence of northern hemisphere ice cover due to recent climate warming is well-documented; however, biogeochemical dynamics underneath the are poorly understood. We couple time-series analyses water column sediment interface (SWI) geochemistry with hydrodynamic data develop a holistic model iron (Fe), manganese (Mn), phosphorus (P) behavior shallow eutrophic freshwater bay. During periods persistent subfreezing temperatures, highly reactive pool dissolved colloidal Fe, Mn, P develops over time in surface sediments bottom waters reductive dissolution Fe/Mn(oxy)hydroxides below SWI. Redox driven by benthic O2 consumption, limited air–water exchange oxygen cover, minimal circulation. thaw events, concentration, distribution size partitioning all species changes, highest concentrations "truly dissolved" Fe near surface, relatively well-mixed Mn "colloidal" profile influx geochemically distinct river increased The flux trace metals beneath dynamic, heavily influenced climate-dependent physical processes that vary both space.