A health advisory prompted by high algae levels found in Haystack Reservoir, 10 miles from Madras on the Crooked River National Grassland in Jefferson County, was issued Wednesday by Oregon Public Health.

Water monitoring has confirmed the presence of blue-green algae that can produce toxins harmful to humans and animals. These algae levels are likely to be associated with dangerous toxin concentrations in the water, according to World Health Organization guidelines.

Swallowing or inhaling water droplets should be avoided, as well as skin contact with water by humans or animals.

Drinking water from Haystack Reservoir is especially dangerous. Oregon Public Health officials advise campers and other Haystack Reservoir visitors that toxins cannot be removed by boiling, filtering or treating the water with camping-style filters.

People who draw in-home water directly from Haystack Reservoir are advised to use an alternative water source because private treatment systems are not proven effective in removing algae toxins.

However, public drinking water systems can reduce algae toxins through proper filtration and disinfection. If people on public water systems have questions about treatment and testing, they should contact their water supplier.

Oregon Public Health recommends that people who choose to eat fish from waters where algae blooms are present should remove all fat, skin and organs before cooking since toxins are more likely to collect in these tissues.

Additionally, public health officials advise that people should not eat crayfish or freshwater shellfish harvested from Haystack Reservoir while this advisory is in effect.

Exposure to toxins can produce symptoms of numbness, tingling and dizziness that can lead to difficulty breathing or heart problems and require immediate medical attention.  Symptoms of skin irritation, weakness, diarrhea, nausea, cramps and fainting should also receive medical attention if they persist or worsen. Children and pets are particularly susceptible.

With proper precautions to avoid water contact, people are encouraged to visit Haystack Reservoir and enjoy activities such as camping, hiking, biking, picnicking, catch-and-release fishing and bird watching. Boating is safe as long as speeds do not create excessive water spray, which could lead to inhalation risk.

Meanwhile, a health advisory prompted by high algae levels found in Diamond Lake, seven miles north of Crater Lake National Park on Highway 138, was lifted Tuesday by Oregon Public Health and Jackson County Health Department officials.