Como Lake Update – Fish Die-off

In early June 2026, Como Lake had a fish die-off likely caused by low oxygen levels in the water. Fish need oxygen in the water to breathe and can become stressed and die when oxygen levels in the lake drop quickly. CRWD staff investigated and confirmed the die-off of thousands of bluegills and crappies.

Following a heat wave during the last week of May, we observed a sudden shift in the lake’s oxygen levels at our continuous monitoring stations. Oxygen levels in the lake can drop quickly as the water surface warms. High temperatures can also cause rapid decomposition of algae and aquatic plants like curly-leaf pondweed, further reducing oxygen levels in the lake as they decompose, and giving off a foul odor.

We appreciate the concerned community members who reached out to us and our partners at Saint Paul Parks and Recreation, Ramsey County, Minnesota, and the Minnesota Department of Natural Resources.

Please note that we typically don’t remove dead fish and instead allow them to remain in the food chain for other species to consume. However, with the stench from this die-off, we worked with a contractor to remove some of the fish on Friday, June 5.

The fish die-off is not impacting Como Lake’s water quality for general use or posing a risk to humans or pets at the lake.

Above photo: Como Lake Fishing Pier. Photo by Ackerman + Gruber.