We received an email from a dog owner that frequently uses Twin Lakes and in a recent visit, found several dead bait fish along the banks of the large lake. The owner was concerned that we may be using chemicals to treat the water or weeds along the shoreline.
Our department prides itself on being an eco-friendly, green operation. We try to maintain water quality through natural means whenever possible. Stephens Lake Park lake is a great example. We used to rely on chemicals such as Cutrine-Plus, an algicide to kill the blue/green algae (an algae that could be fatal to animals such as dogs) and AquaShade, a dye used to prevent growth of algae. However through management plans that included planting of aquatic shoreline plants; reducing the nutrients provided by geese feces; and the continued use of our aerators and fountains, we have not had to use any chemicals this year. We anticipate that the Stephens water quality will further improve once the construction of our water fall is completed.
The same goes for Twin Lakes. Our volunteer Columbia Aquatic Restoration Program (CARP) has planted over $10,000 worth of plants that we received from a grant. This and the continued use of the aerators, have enabled us to not use any chemicals.
I might also add that the Missouri Department of Conservation and the Environmental Protection Agency, both recognize the value of using Curtine-Plus to manage algae. MDC has a publication on algae control, Algae Control in Lakes and Ponds, that we use as a basis for our own program. They recognize that algae is a greater threat and must be controlled. Cutrine-Plus is a very safe product for both humans, pets and wildlife. It's one of the few products where you may swim immediately after application without any risk. Cutrine is widely used in drinking, irrigation, fishing and stock lakes as it has no restrictions. AquaShade, approved by the EPA, is a harmless, simple "blue" color dye used to prevent the growth of algae. We have only used AquaShade at Stephens Lake Park.
I mention this as should we ever encounter a significant blue/green algae bloom, we may need to use Cutrine or AquaShade to handle the problem. Hopefully, we won't ever have that situation arise.
We do not use chemicals for weed/shoreline management either, so any source of chemicals would have to come from the resident's yards located above the lake. With the amount of turf between the lake and the homes, I doubt many if any fertilizer or chemicals reach our lake.
The dead fish you see are Gizzard Shad. Gizzard Shad are known to have a weak system and can't tolerate low oxygen levels or changes in water temperatures. The week of Sept 22-26, 2008 was unseasonably warm and I'm sure that was part of the problem. The nervous systems of these fish are so sensitive, that even when caught by a net for bait, they will quickly die in the bait bucket. In fact, MO Dept of Conservation has actually posted a sign at the lake to inform park users that the dead fish is Gizzard Shad and not a sign of problems. This sign states:
"This lake contains a species of fish call Gizzard Shad. Gizzard Shad, by nature, are very fragile fish and prone to early spring die-offs. They stress easily and die from natural environmental factors that normally have little effect on other fish species. Some of the factors which help promote these die-offs include water temperature extremes and fluctuations, overpopulation and disease. Don't be alarmed if you see dead shad scattered around the shoreline during late spring or summer. It's a natural occurrence for lakes containing Gizzard Shad to experience these periodic die-offs. These fish will eventually be recycled through the aquatic ecosystem by natural processes."
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