As temperatures warm during summer, Idahoans flock to the shores of Idaho’s spectacular rivers, lakes, and reservoirs. Whether it’s boating, swimming, fishing, picnicking with family and friends, or just strolling along the banks—Idaho’s abundant waters provide a respite from the heat and a chance to cool our toes. With over 2,000 lakes and 93,000 miles of rivers and streams in the Gem State, Idahoans have a lot of options.
Unfortunately, these water bodies are not always safe for recreation due to recurring outbreaks of toxic algae. These impacts are felt across the state, with 35 health advisories issued on Idaho’s lakes and reservoirs in the last two years, from Priest Lake in the panhandle all the way to Henrys Lake in eastern Idaho.
In 2022, a horse died after drinking contaminated water, toxic algae is the presumed cause of deaths for two dogs as well. No doubt, these are tragic outcomes—made even more tragic because these deaths are preventable.
What is toxic algae?
Blue-green algae or cyanobacteria naturally occur at background levels in many freshwater ecosystems. But when conditions are right (or wrong…), populations of toxic algae have the potential to explode, producing potentially fatal cyanotoxins that can cause severe illness or death from direct contact, ingestion, and even exposure to wind-borne spray. These outbreaks are also referred to as HABs—harmful algal blooms.
Symptoms can include abdominal pain, vomiting, blistering around the mouth, fever, headache, diarrhea, cough, hives, rashes, and respiratory paralysis, and even lead to death. Dogs, cattle, and other livestock can be especially susceptible to toxic algae.
How do these outbreaks occur?
Outbreaks generally occur when there is a combination of high water temperatures and excessive phosphorus and nitrogen, which feed these bacteria. In many cases, it can be difficult to control water temperature, but there are steps that can be taken to reduce the nitrogen and phosphorus pollution that contribute to these outbreaks.
The primary sources of this pollution are wastewater systems and treatment plants, runoff from over-fertilized crops and lawns that drain to surface or groundwater, beef and dairy feedlots, fish farms, and other industrial discharges. Disturbed soils from construction sites can also contribute to this pollution.
Health Districts and other partners rely upon citizen reports to monitor potential outbreaks. Currently, the Idaho Department of Health and Welfare is responsible for issuing health advisories when IDEQ’s water sampling indicates a toxic algae outbreak. We will dive deeper into how to identify and report toxic algae as well as how this system can be improved in our next blogs in this series, but you don’t have to wait until then to take action to protect public health. Click the button below to take action and let Governor Little and IDEQ know that you care about keeping our waters safe and clean for pets, livestock, and people. Specifically, we are advocating for dedicated funding for our state agencies to monitor and combat the problem of toxic algae outbreaks—something you’ll hear more about later in this blog series.
Plus, dive deeper into the world of toxic algae in Idaho by attending our upcoming Toxic Algae Webinar on May 30 from 6-7pm. ICL will be joined by Dr. Amie Parris of IDEQ for a presentation on toxic algae outbreaks, what causes them, what the risks are, how you can stay safe, and what we’re doing to help. Toxic algae affects waterways and Idahoans all over the state, so make sure to tune in! Register here: https://us02web.zoom.us/webinar/register/WN_8Wl_wUj8Rm2EGnLpEAfQHg#/registration