Many residents have noticed the recent blue-green algae (cyanobacteria) bloom on Gun Lake. While these blooms can be alarming, they are a natural part of many lakes and are very common during the summer months. This is not a problem unique to Gun Lake. Blue-green algae blooms have been reported on numerous lakes throughout West Michigan and across the state this summer as a result of favorable environmental conditions. This year’s bloom is likely the result of several environmental factors coming together, including the heavy spring rains, warm summer temperatures, and nutrients that fuel algae growth. The busy holiday weekend may have also contributed by stirring up bottom sediments in shallow areas, releasing additional nutrients into the water.

Blue-green algae blooms can be frustrating because they are very difficult to manage. Unlike rooted aquatic plants, these algae are suspended throughout the water column and are constantly moved by the wind and waves. One day a bloom may be concentrated along one shoreline or in a canal, and the next day it may be blown to a completely different part of the lake. When algae become concentrated along a shoreline or in a canal, localized treatments may be possible under the right conditions. However, Michigan EGLE regulations do not allow treating large offshore areas or the entire lake for these types of blooms. Even if an area is treated, new algae can quickly be blown back in from other parts of the lake.

If you see areas where the water looks bright green, resembles spilled paint, or has thick surface scum, it is best to avoid swimming or wading in those areas. Pets should also be kept out of blooms, as they may drink the water or ingest algae while grooming themselves afterward.

Unfortunately, there is no quick fix once a widespread blue-green algae bloom develops. These blooms typically run their course and gradually decline as weather conditions change. The Gun Lake Improvement Board and its lake management consultant will continue monitoring conditions and will take appropriate action where practical and permitted.

We appreciate everyone’s patience and understanding as we work through these natural summer conditions.

Thank you,

Jaimee Desjardins, Environmental Scientist