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Algae blooms detected at Ennis Lake

Posted at 4:00 PM, Sep 01, 2022

ENNIS — Experts are recommending people not swim or play in some areas of Ennis Lake.

According to a press release from NorthWestern Energy, the Madison County Health Department and the Montana Department of Environmental Quality, Watershed Protection Section, harmful algae blooms (HAB) are present along the Kobayashi Beach and other areas of the north shore of Ennis Lake, west of Madison Dam. Routine monitoring and field testing in the Kobayashi Beach and Meadow Lake Campground areas have detected the presence of an algal toxin, Anatoxin-a, that poses a risk to people, pets, and livestock.

Ingestion or prolonged contact with the algal bloom may result in illness, with signs such as muscle twitching, staggering, convulsions, paralysis and death. Importantly, children and pets are more likely to ingest HAB-infested waters because they spend most of their time wading in shallow waters where algae can accumulate, and they have less control over how much water they ingest. Animals and livestock that drink large amounts of contaminated water, and pets that collect scum on their fur and then ingest it by licking, are at high risk of toxin exposure. Toxin exposure can occur in humans from recreational activities where water might be ingested such as swimming, windsurfing, jet skiing, and water skiing.

Health experts recommend people not swim or take part in activities likely to result in exposure to the toxin in areas where the algal bloom is present. Additionally, pets and livestock should be prevented from entering the water in that area.

HABs are caused by blue-green algae that are native to Montana’s freshwater lakes and reservoirs. Not all varieties of blue-green algae are harmful, but some can produce dangerous toxins. Bluegreen algal blooms often look like pea soup, grass clippings or green latex paint. The algae are usually suspended in the water or appear as floating mats.

Advisory signs are at the Clute’s Landing, Meadow Lake Campground, and Kobayashi Beach public access points warning the public that toxic algae has been identified in the water in these areas. NorthWestern Energy and the Montana Department of Environmental Quality (DEQ) are monitoring the blooms and will provide updates if additional restrictions are implemented for public safety.

From the release:

"Suspect a HAB? When in doubt, stay out. Do not drink, swallow, or swim in water that shows signs of a HAB and be sure to keep kids, pets, and livestock out too. If you suspect a HAB-related illness in a person or animal call Poison Control 1-800-222-1222 and seek medical attention.

Report a suspected HAB at [] or call 1-888-849-2938. You may also report a suspected HAB by calling the Madison County Health Department at 406- 465-7339. Follow NWE on Facebook or on Twitter (@NWEinfo) and the Madison County Health Department (@madisoncountypublichealthdept)."