What are the benefits of pond aeration and lake aeration?
The benefits of pond aeration and lake aeration are numerous. The overall extent of improving water quality will largely depend upon how eutrophic your pond or lake originally was prior to aeration. Pond aeration and lake aeration are used to artificially circulate ponds and lakes in order to increase dissolved oxygen concentrations in deeper waters. Ponds and lakes that thermally stratify during the summer will completely mix when aerated. This will result in nearly uniform water temperatures from the surface to the bottom of the pond or lake.
One benefit of pond aeration and lake aeration is the reduction of iron and manganese problems for drinking water supplies. Iron and manganese can be released from lake sediments under anoxic conditions in stratified ponds and lakes and artificial circulation via aeration can reduce this phenomenon.
Another potential benefit of pond aeration and lake aeration is to improve water transparency(clarity) by reducing the amount of phytoplankton(free-floating microscopic aquatic plants or algae). Lastly, aeration may even reduce the amount of accumulated muck in ponds and lakes. This may occur by oxygenating deeper waters near the sediments. Under such conditions, bacteria metabolize(break down) organic matter much more quickly.
Phytoplankton reductions resulting from aeration are based upon a series of complex physical, chemical and biological reactions. Some of the current theories are as follows:
A. Increased dissolved oxygen concentrations in deeper pond and lake waters will decrease the release of phosphorus (and metals) from sediments. Lower phosphorus concentrations provide less food for algae growth.
B. When the water column is mixed, phytoplankton are pushed into the deeper water. This may result in lower growth and reproduction rates for the phytoplankton due to lower rates of photosynthesis in darker waters.
C. Zooplankton (barely visible to the naked eye, tiny aquatic animals that feed upon algae or phytoplankton) are pushed into deeper waters due to pond and lake mixing. In darker waters, they are less vulnerable to sight feeding fish such as, juvenile bass, bluegill and crappie. Under such conditions, zooplankton survival rates are expected to increase, which in turn translates into higher predation rates on phytoplankton (algae).
D. Rapid circulation of carbon dioxide-enriched bottom waters with surface waters and contact with the atmosphere may increase the carbon dioxide content and lower the pH of the surface waters. This encourages the growth of less noxious green algae as opposed to blue-green algae.