Skip to Content

When in doubt, stay out of the water: Protect yourself and pets from cyanobacterial blooms this summer

BOISE, Idaho (KIFI) – Summer is peak season for cyanobacterial blooms (previously called cyanobacterial harmful algal blooms), and Idahoans are reminded to protect themselves and their pets when recreating in and around water.

“It’s important for the public to take precautions,” said Brian Reese, DEQ’s water quality standards analyst. “Even without a visible bloom, algal or cyanobacteria toxins can be present at low concentrations. While toxin counts might not be high enough to trigger a health advisory, they can still pose a risk to people and animals.”

Cyanotoxin exposure primarily occurs from swimming in or swallowing water impacted by a bloom or consuming fish caught in affected waterbodies. Swallowing water impacted by a bloom can lead to stomach pain, nausea, and vomiting. Direct skin contact may also cause skin and eye irritation.

Pets, livestock and wildlife can get sick or even die after cyanobacteria exposure. Animals are often the first affected because they are more likely to swim in or drink affected water. Wash your pet with freshwater and soap after they swim, and do not let them lick their fur, which can act as a filter and deliver a concentrated dose. Seek veterinary care immediately if your pets or livestock seem sick after going in or near water.

You can protect yourself and your pets by:

  1. Checking the Idaho Department of Health and Welfare’s Recreational Water Health Advisories Map before visiting Idaho’s water bodies. Following health advisories will reduce your chance of exposure and potential illness.
  2. When in doubt, stay out and keep your pets and livestock out of the water. Avoid water that smells bad, looks discolored, or has foam, scum, mats, or paint-like streaks on the surface.
  3. Do not drink or cook with water containing a bloom. Boiling or filtering the water does not remove the toxins and can increase the risk.

Bloom conditions can change quickly and elements such as wind and rain can impact toxin concentrations and bloom location. The time of day and level of sun exposure can also push a bloom up or down within the water column.

DEQ, DHW, Idaho Department of Parks and Recreation, and local health officials are encouraging the public to keep an eye out for blooms this summer and take the following precautions when recreating in and around water.

Check for health advisories before you go

The Idaho Department of Health and Welfare maintains the Recreational Water Health Advisories Map, which displays health advisories for water bodies across Idaho.

The DHW map also includes advisories on fecal bacteria E. coli exceedances, gastrointestinal norovirus outbreaks, swimmer’s itch warnings, and fish consumption advisories.

Track potential blooms and sample results

DEQ manages the Potential Bloom and Water Quality Sampling Map, which displays sample results and remote sensing data (i.e., satellite data) collected from the Cyanobacteria Assessment Network (CyAN).

DEQ created the map to share which water bodies might be experiencing a potential bloom, document where staff collected samples, and upload sample results. The map is updated every 3 to 4 days.

Report a suspected bloom

It is not possible for DEQ to sample and monitor all of Idaho’s water bodies. Instead, DEQ often relies on citizen reports to determine where and when to sample. If you see a potential bloom, notify DEQ using the Harmful Algal Bloom Report form. Include location details and, if possible, pictures of the potential bloom. This will help DEQ locate and sample the site.

Toxic blooms can vary in appearance but can often look like pea soup, grass clippings, spilled paint, mats, green or blue-green foam, or dense surface scum. Some blooms may produce a foul odor.

Additional Resources

You can find answers to frequently asked HABs questions on DEQ’s FAQ page and DHW’s FAQ page. See DHW’s HABs fishing fact sheet for fish consumption information and the CDC’s Animal Safety Alert Fact Sheet for pet safety updates.

Article Topic Follows: Idaho

Jump to comments ↓

Author Profile Photo

Evan Thomason

Evan is the weekend meteorologist and reporter.


KIFI Local News 8 is committed to providing a forum for civil and constructive conversation.

Please keep your comments respectful and relevant. You can review our Community Guidelines by clicking here

If you would like to share a story idea, please submit it here.

Skip to content