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Learn about the importance of oxygen concentration and velocity in ice-covered lakes, and how reverse aeration techniques can prevent winterkill by increasing oxygen levels. Find out about equipment needs and safety precautions for lake aeration projects.
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Oxygen Demand in Ice Covered Lakes as It Pertains to Winter Aeration Christopher R. Ellis and Heinz G. Stefan
Oxygen consumption and thus depletion is a function of oxygen concentration and velocity of near sediment water
Winterkill Lake Facts • Stratify quickly after ice cover. • Oxygen consumption is greater than production. • Oxygen production slows or ceases as light penetration decreases. • Oxygen consumption is greatest at the water sediment interface. • Oxygen consumption decreases as oxygen concentrations fall below 3.8 ppm.
How to cause a winterkill • We need to destratify the lake/wetland. • We need to create currents that cause the oxygenated water on the top to go to and move along the bottom. • Need to make sure our actions are not increasing the amount of oxygen in the system.
REVERSE AERATION Reverse aeration is the use of lake aeration techniques that increase the oxygen concentration and velocity of near sediment water which increases oxygen consumption and depletion
Water currents (convection) Diagram of water flow during aeration operation
Equipment Needs • Two complete systems ($5,000)
Equipment Needs • Two complete systems ($5,000) • Generator ($1,300)
Additional Equipment • Do meter • Hand held depth finder • 8-inch ice auger • Ice chisel • Snow shovel • Repair tools for the poly tubing • Mud motors
Safety Equipment • Floatcoat or life jacket • A throwable flotation device • Life guard spikes • Ice creepers • Rope • Ice chisel or board for probing the ice