Last Friday, March 28, the Michigan Department of Natural Resources published a press release warning that due to the extreme weather conditions this winter, waterways around the state would likely fall victim to "winterkill," which is the most common type of fish kill. Just days later, City of Taylor maintenance workers were cleaning hundreds of dead fish out of Coan Lake in Heritage Park.
Taylor parks' staff said that fish deaths are a regular occurrence at the small lake, which is located near the Ecology Center and the Petting Farm. At times, the deaths come because of drastic changes in temperature, which can happen from fall to winter or winter to spring. This week's drastic uptick in temperature may have had something to do with the problem, but it is likely a combination of several factors, including the inclusion of large carp in the small lake, along with the extreme snow, ice and cold temperatures during the winter months. This winter was one of Michigan's most extreme ever, and certainly the most extreme in the past decade or so.
Taylor officials contacted the DNR, who confirmed the likely scenario. Given the small size of the lake and park visitors that often deposit unwanted fish and/or food deposits into the waterway, large carp and even ducks have become problematic in terms of harming the lake's ecosystem. Carp are just too large for the waterway and are eating away fish, fish eggs and other wildlife friendlier to the lake's environment. Combined that with a duck population that is too often fostered by passers-by feeding them (please do not feed the ducks at Coan Lake!). Ducks drop large amounts of unwanted feces in and around the waterways. All of these issues can create a troublesome lake environment.
But what is being seen at Coan Lake is not unlike what is being seen across the state, according to the DNR.
"Winterkill is the most common type of fishkill," DNR Fish Production Manager Gary Whelan said in a press release. "Given the harsh conditions this winter with the thick ice and deep snow cover, it will be particularly common in shallow lakes and streams and ponds. These kills are localize, and typically do not effect the overall health of the fish population or fishing quality."
Shallow lakes -- like Coan -- with excess vegetation and soft bottoms are particularly prone to this type of problem. Dissolved oxygen is required by fish and other forms of aquatic life. During these types of extreme weather conditions, the fish suffocate"