ADVENTURE SPORTS OUTDOORS “THE VOICE OF THE AMERICAN SPORTSMAN”
May 2004
117
one can keep the debris from entering the pond, one can make headway on what is in the pond. Several watershed management techniques that accomplish this task and enhance aeration’s ability to reduce organic sediment include • Leaving an uncut buffer zone of vegetation around the pond • Limiting yard and garden wastes from entering the pond • Discouraging waterfowl to congregate in or around the pond • Removing debris/organic materials from the pond Physically removing organic debris such as branches or leaves from a pond can enhance aeration’s effect. This type of debris eventually breaks down There is no doubt that properly aerating a pond or lake provides many beneadding to muck accumulation. If branches or trees have been added for fish fits important for supporting fish, regulating nutrients, and for increasing the structure, consider replacing them as they age with strucgeneral health of the aquatic environment. However, tures created from plastic drain tile or other substances there are some misconceptions concerning aeration’s that do not undergo organic decay. Dredging is an immeactual effect on the bottom “muck”. Contrary to some diate way to reduce soft sediments and debris, but such claims of being a “magic bullet” aeration cannot on its projects are limited due to suitable sediment disposal own solve all of a pond’s soft sediment or “muck” probsites and significant costs. lems. Aeration can, however, be a key component in If good watershed management practices are put in accelerating the natural or enhanced digestion of soft place, aeration can be expected to reduce muck of a perisediment if certain watershed controls are put into place. od of several years. Bioaugmentation accelerates this process, but its impacts will not be seen until a few years Muck is basically a complex mixture of organic comafter its implementation. In three test ponds serviced by pounds originating from erosion, run-off debris, windMarine Biochemists - Wisconsin where watershed manblown “dusts”, leaf litter, plant decay and animal wastes. agement was enhanced and bioaugmentation implementAnything from grass clippings to goose droppings add to ed, measured soft sediment levels were noticeably the loading of organic soft sediment. The levels of the reduced by several inches during the first season. In the build-up of organic muck depend on the age of the pond, second and third years of the program, soft sediment was erosion, drainage patterns into the pond, disruptive activities around the pond including development of shoreline Twister TA-22 Diffuser. This is one of visibly reduced along shoreline areas. In all three of the the diffusers that we would use to do ponds, hard bottom was achieved along near shore areas or drainage areas, fertilizer use in drainage areas, waterwhat we talked about in this article. after the fourth and fifth year. fowl populations, etc. The successful results in these test ponds can be attributed to the cooperation In almost every pond, organisms that feed upon organic sediment are initialof the surrounding landowners and the continuation of programs over several ly aerobic or oxygen-requiring bacteria. In ponds without aeration, aerobic bacseasons. Unfortunately, other ponds with aeration introduction showed few teria thrive until dissolved oxygen levels near the bottom sediment water intersigns of soft sediment improvements largely due to continual organic influxes face (SWI or “where the muck meets the water”) become depleted. Once conoutside of adjacent landowners’ direct control. Aeration can definitely make a ditions turn anaerobic (devoid of oxygen), anaerobic bacteria take over the SWI dent in the amount of muck in a pond, but expectations have to be tempered niche. Anaerobic bacteria are far less efficient at breaking down organic matter with patience and the importance of long-term control of surrounding influthan aerobic strains, and lead to the production of noxious decay gases such as ences. Aeration alone cannot magically eliminate a pond’s “mucky” problems, hydrogen sulfide and methane. but it is an essential step in halting or reversing soft sediment accumulation. The addition of aeration aids in maintaining dissolved oxygen levels near the If you have questions or would like to find out more about your pond, you can SWI. Ideally, the dissolved oxygen level near this interface should be maincall Marine Biochemists at 309/452-0461. tained 2 ppm or higher at any given time, thus allowing sustainable aerobic decay of the muck. Proper aeration accomplishes this task by circulating a pond’s entire water column over a relatively short period of time allowing oxygen to dissolve into moving surface waters exposed to the atmosphere, and then distributes these oxygen-enriched waters to bottom areas. This circulation pattern also allows organic decay gases to “gas-off” into the atmosphere. The overall effect of proper aeration on the bottom muck is going to depend on several influencing factors. First, if the input of organic debris exceeds the consumption of the existing muck, muck will continue to accumulate. The converse is also true. If organic debris inputs are less than the consumption of muck, then levels of muck in the pond will begin to decrease. In other words, if
Aeration and Its Benefits to Your Pond Bottom By Bill Hancock, Marine Biochemists.com
247 Broadway • Quincy, IL HOURS: MON-FRI 8am-5pm SAT 9am-1pm
217/222-6006 www.aquatechmarine.net
Come check out our new line of Sylvan Pontoons & Deep-V’s!
Call Bill at 1.309.452.0571 Don't assume were overpriced… If pricing a quality boat, check with us before you buy!
