Fish die off at Como Lake likely due to low oxygen in water

Capitol Region Watershed District shared the following on June 4, 2026 regarding the large fish die-off that occurred in Como Lake this week:

"Como Lake recently had a fish die-off that is likely due to low oxygen 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. Capitol Region Watershed District (CRWD) staff investigated and confirmed the die-off of around 1,000 bluegill sunfish and crappies earlier this week.

"Fish die-offs are a natural occurrence in lakes under low oxygen conditions. Following last week’s heat wave, CRWD observed a sudden shift in the lake’s oxygen levels at continuous monitoring stations in the lake. 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 Capitol Region Watershed District, Ramsey County, and the Minnesota Department of Natural Resources."

Removal of the dead fish will began Friday morning, June 5, 2026. 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.

Related: In Minneapolis, there were about 150 dead fish in Lake Nokomis on June 1.