The Ecology Center’s annual Fish ‘n’ Fun Day fishing tournament on Coan Lake, originally scheduled for May 10, is being postponed.

The water quality at Coan Lake, located in Heritage Park, has been degraded by several recent factors. Each year before Fish ‘n’ Fish Day, the Ecology Center restocks Coan Lake with various fish species, but both parks and Ecology Center officials agree that restocking the pond at the present time would not be a good idea.

A relatively small body of water, Coan Lake has been heavily hit by several different factors recently and it has a major carp problem. Carp are not recommended for a small body of water like Coan Lake, and over the past couple of years, the large fish have literally eaten their way through the waterway’s ecosystem, destroying other species by eating their eggs, as well as much of the vegetation. 

“Any system that is out of balance with and over-abundance of once species puts the entire aquatic system at risk,” Liz Hay-Chmielewski of the Michigan Department of Natural Resources wrote in a letter to Golf, Parks and Recreation Executive Director Jeff Dobek in April. “This is especially true in a closed system such as Coan Lake. An overabundance of carp, a non-native fish species, is particularly damaging as carp feed by rooting around the bottom of the pond, stirring up sediment and food items … (making) it more difficult for native panfish species, which prefer clear water to survive. It also contributes to low oxygen levels …”

The carp problem was so profound that Ecology Center experts, along with the Michigan Department of Natural Resources, recommended a “carp kill” and the city and the organizations scheduled the Michigan fish bow hunting tournament team take boats out on Coan Lake and harvest as many carp as possible late last month.

That harvest, however, was cancelled after winter kill resulted in hundreds of dead fish surfacing on the waterway. Those fish deaths were likely the result of the record-setting low winter temperatures  this year, as well as the vast and sudden changes in temperature.

Since the evidence of the winter kill, there has been very little visible fish activity in the lake. A preliminary water sample test done by officials of the Ecology Center recorded low oxygen levels, high mineral content and some high chemical content in the water, after which city officials, after consulting with the DNR, planned another water test to confirm the findings and decide a course of action.

Preliminary discussions appear to agree that additional aeration of the water (through fountains and a reactivated water wheel, which is currently in planning thanks to a grant from Wayne County Community College District to the Ecology Center), should upgrade the quality of the water, along with possibly adding city water to the pond and some chemicals to balance the quality issues.

Neither the city or the Ecology Center wants to risk restocking the pond with new fish until the current problems are eliminated. Unfortunately, that means that the annual fishing tournament has to be postponed. There is no guarantee that it will be rescheduled later this year, although city and Ecology Center officials are researching the possibility of doing another tournament later in the spring or summer.