The GLA embraces a policy of “early detection, early response” when it comes to invasive species—both plant and animal invasives alike. This includes removing Japanese koi fish from the watershed.
As part of a three-year plan which began in 2024, the GLA will once again partner with a team from Thundering Aspens Sportsman Club of Mesick, Michigan, to reduce the invasive koi population. Last year, this team removed four koi in total, including three pre-spawn females carrying thousands of eggs. One female in particular set a world bowfishing record at 24.5 pounds.
If you see bowfishing activity on Little Glen, Big Glen, or Fisher Lake in early May, please do not be alarmed, as the methodology can appear quite unusual. There will be four or five sessions over the next month, and they may take place during the day or at night. The team will be using bows and arrows in their efforts. Day sessions will be combined with drone work, and night sessions will use high-intensity lights. Most of the activity will take place in shallow, nearshore areas where the fish tend to congregate. This removal plan is approved by the regional Michigan Department of Natural Resources (MDNR) fish biologist and the local sheriff’s office has been notified of the scheduled activity.
Commonly used in landscaped water features, Japanese koi have been spotted by Little Glen residents for a number of years. If allowed to remain in the lake, they can cause great harm to the ecosystem, promote algal blooms, and lead to diminished water clarity. Their tendency to “root” on lake bottoms is not only detrimental to the growth of native plants but can promote invasive plants. Invasive fish also take food resources away from native fish, which are critically important to the food web and fishery in Glen Lake. Finally, koi are prolific spawners which can cause food web disruption for years to come.
These fish are quite difficult to catch using traditional netting or electrofishing equipment. However, bowfishing anglers, who have studied koi fish patterns and behaviors, can safely and effectively remove the fish using bows and arrows.
Please share this important information with others to help us get the word out. If you have any questions or concerns about the process, you may contact the GLA office at 231-334-7645 or send us an email at contact@glenlakeassociation.org.