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Idaho Algae

The visible algae of Idaho lakes, ponds and streams, most common first.

Oregon37 algaeIdaho37 algaeWyoming36 algae

Tap a state to open its algae database

Idaho at a glance

Algae in Idaho lakes, ponds and streams

37visible algae recorded
11with toxin risk
1listed or invasive

Harmful algae blooms

Advisory levels
Idaho Department of Environmental Quality runs the cyanobacteria harmful algal bloom program and works with Idaho Health and Welfare and local health districts on public notices.
  • Health Watch: A bloom may be present.
  • Health Alert: High risk to pets and livestock. Do not drink the water and keep children and animals out.
  • Health Advisory: Confirmed high risk to people. Do not drink, swim, wade or let animals in.
Report a bloom

How to reportUse the Idaho DEQ online form, call (866) 671-5385 or email algae@deq.idaho.gov.

Idaho DEQ bloom report form

Sick pets or livestock
If a pet or animal gets sick after contact, see a veterinarian right away. Poison Control is (800) 222-1222 and 911 for emergencies. Mention it when you report the bloom.

Invasive algae to report

Early detection1 SPECIES
On the Idaho noxious weed list. Not established in Idaho; the goal is to find and remove it.

How to reportA find must be reported to the Idaho State Department of Agriculture within 10 days: (877) 336-8676 or invasivespecies.idaho.gov.

Idaho algae database

NativeBelongs hereIntroducedNot nativeInvasiveListed noxious weed or aggressive non native

Cyanobacteria marked with toxin risk can produce toxins harmful to people, pets and livestock; a lab test is the only way to know. How common ratings are based on field records and our own surveys. Photos are from iNaturalist and Wikimedia Commons contributors under Creative Commons licenses; credits appear on each entry. Header photo: Andrew / CC0 (iNaturalist).

Not sure what is growing in your water?

Send us a photo for a free ID or send a sample. We will identify the algae, test for toxins when needed and tell you what it means for your water.

Contact usAlgae ID service

Idaho / Wyoming (208) 501-4531Oregon (541) 280-0596