Photo: Dent Bridge Overlook on Dworshak Reservoir.  Photo:  USACE Facebook

OROFINO - In cooperation with the U.S. Army Corp of Engineers and Idaho Department of Environmental Quality (DEQ), the Idaho North Central District of Public Health has issued a health advisory for Dworshak Reservoir due to the presence of a harmful algal bloom. Recent samples taken indicate concentrations of toxin-producing blue-green algae (cyanobacteria) present that may cause illness to humans and animals.

Cyanobacteria occur naturally. Under certain conditions, some types of algae can release toxins into the water that are harmful to people, pets, and livestock. Recent tests indicate that algae that produce these toxins are present. The blooms are generally green, or blue-green, and may form thick mats along shorelines. These may look like a surface scum, resembling pea soup and can have an unpleasant odor or stench.

Public Health – Idaho North Central District, the Army Corp of Engineers and DEQ advise the following precautions be taken where harmful algal blooms are known to be present:

  • Humans, pets, and livestock should not drink the affected water.
  • Humans and animals should stay out of the affected water. Swimming, wading, or other activities with full body contact of water should be avoided.
  • Fish should be cleaned and rinsed with clean water. Only the fillet portion should be consumed. All other parts should be discarded.
  • Pets and livestock are vulnerable to cyanobacteria and their toxins and should stay out of water where blooms are visible. Pets and livestock can be exposed to cyanobacteria and their toxins through drinking, swimming, or self- grooming by licking their wet coat or paws. A reaction will likely require immediate veterinary attention.
  • Do not allow pets to eat dried algae.
  • If affected water contacts skin or pet fur, wash with clean potable water as soon as possible.
  • Areas of visible algae accumulation should be avoided.

Samples taken indicate unsafe algae cell counts, so everyone should heed these precautions and avoid contact with the water in the impacted area.

Symptoms of Exposure

People who are exposed to water with high concentrations of cyanobacteria or cyanotoxins may experience nausea, vomiting, diarrhea, difficulty breathing, skin irritation, allergic responses, liver damage, or neurotoxic reactions such as tingling fingers and toes. Anyone with symptoms should seek medical attention. Boiling or filtering the water will not remove cyanotoxins.