ICL raises awareness about algal blooms

North Idaho is no stranger to harmful algal blooms affecting the surrounding lakes in the area, especially in late summer.

This year, the Idaho Conservation League partnered with the Idaho Department of Environmental Quality to help educate the public on how to spot algal blooms this summer before they cause harm to people or pets.

Harmful algal blooms, also known as HABs, are a rapid growth in algae or bacteria that produce toxins, or cyanotoxins, said Dr. Amie Parris of IDEQ. They can appear as a foam, scum or paint-like mat on the surface of lakes or reservoirs.

“They can vary in color from green to blue to red or even brown,” Parris said.

The presence of toxins from algae is not unusual, she said, as it is a common component of many algae’s life cycles. Most algae thrive in warm, stagnant waters where nutrients are abundant.

“As they multiply rapidly, they release toxins that can be devastating to fish, shellfish, mammals, birds and even humans,” she said. “The more stagnant the water, the higher the likelihood of a bloom, especially in lakes and ponds.”

In many drinking reservoirs, staff will use artificial mixing machines or mechanisms to keep the water constantly moving in an attempt to mitigate the risk of algal blooms popping up in the reservoir.

Not only can they cause illnesses, Parris said. HABs can also rapidly kill fish populations, contaminate seafood, disrupt entire water ecosystems and heavily deplete the oxygen levels in water.

Parris said HABs tend to pop up in the same bodies of water year after year because they require certain components to thrive. The clearer the water, the more likely a HAB is to spring up since the bacteria needs plenty of sunlight to photosynthesize and multiply. Algal blooms also need sustenance and do well in lakes containing large amounts of phosphorus and nitrogen. UV rays also play a big role in the likelihood of a harmful algal bloom.

“It’s believed that cyanobacteria and algae produce toxins as a defense mechanism against hydrogen peroxide,” Parris said.

Periods with little cloud cover and abundant direct sunlight can cause HABs to become more toxic as they work to fight off the higher levels of hydrogen peroxide developing in the water.

Algal blooms also like warmer water temperatures, which is why they tend to pop up in smaller bodies of water where the temperatures can rise more.

Symptoms that manifest in humans who are affected by cyanotoxin poisoning vary so greatly that Parris said it can be difficult for doctors to diagnose. People can experience anything from neurotoxic impacts to liver and kidney damage to dermal illnesses.

“The symptoms often mimic other illnesses like foodborne illness, gastrointestinal issues, so that can make it really challenging to diagnose at your doctor’s or at the hospital,” she said. “But this really shows the need for caution and to reach out to your healthcare provider if you feel like you’ve been exposed to a bloom or to some cyanotoxins.”

Symptoms can quickly arise in pets that have been exposed to HABs as well. Animals can experience vomiting, fatigue, breathing difficulties, coughing, liver failure and even death.

“It’s crucial for pet owners to avoid letting their pets into bodies of water that show signs of an algal scum,” Parris said.

Not only can blooms create illnesses in those who swim in them, but they can also have devastating economic effects on regions that struggle with frequent episodes. In 2015, Parris said that HABs cost the Pacific Northwest region roughly $97.5 million in fishery losses as well as $40 million in shellfish harvest closures.

While it may be assumed that only those who swim in contaminated waters can become ill, Parris said that is not the case. Drinking or ingestion, eating contaminated foods, and inhalation can also cause problems.

“Most people think that boiling their water will eliminate the cyanobacteria and their toxins, but boiling water does not destroy toxins,” she said. “That’s a big misconception. It can actually increase their concentration.”

Parris said that Idaho health advisories for toxic blooms have gone down in the past few years. There were 21 health advisories issued in 2021 while 2023 only saw 12 advisories.

“In Idaho, we do tend to see the same water bodies experiencing blooms and those blooms do tend to last for months at a time,” she said.

Other parts of the country tend to see smaller HABs in spring and then again in late summer or early fall. However, Idaho tends to see most of its blooms in August, with many lasting long into November.

IDEQ regularly looks at satellite images across the region to monitor bodies of water for potential blooms. Additionally, staff are always open to hearing from the public if they have recently visited a body of water they believe may be experiencing a bloom.

Josh Johnson, ICL central Idaho director, offered a few ways that individuals living near water bodies can mitigate the risk of those bodies developing an algal bloom. Since HABs thrive off rich sustenance, Johnson suggested buying fertilizers that do not contain phosphorus, as they can run off into nearby waters.

Additionally, routinely maintaining and pumping septic systems, as well as picking up dog poop, can ensure that these substances are not accumulating in nearby lakes and reservoirs.

“All these small things do add up,” Johnson said.

Right now, HAB research programs have no state or federal funding, so not as much research has been done on them as many agencies would like.

“We are not able to do as extensive of a monitoring program as we’d like,” she said. “But we are able to allocate funds and do a good amount of sampling and monitoring throughout the year.”

Johnson said ICL is working with legislators and other government agencies to advocate for dedicated funding to HAB research and mitigation programs. ICL staff are also hoping for more routine summer monitoring of high-risk water bodies so blooms can be caught early and the public can be kept safe.

“We’re doing a big push to make sure that there’s more education on this issue,” he said. “We really want to avoid any issues.”

Parris encouraged everyone to report potential blooms that are spotted this summer immediately. This way, testing can be done and if needed, the water can be closed to the public until the bloom has disappeared.

Report potential harmful algal blooms by email at algae@deq.idaho.gov. Parris encouraged the public to send photos with any potential algal bloom report.

“Pictures are really great,” she said. “Just a couple will give us a good idea to see if we need to go out.”

Potential HABs can also be reported via the IDEQ 24/7 hotline at 866-671-5383 or on the IDEQ website at deq.idaho.gov/report-a-potential-cyanobacteria-algal-bloom.