HELENA – If you’re out on the water this summer and you spot some odd, blue-green substances on the surface of a lake or pond, the state of Montana wants to know about it.
The Montana Department of Public Health and Human Services and the Montana Department of Environmental Quality are asking for the public’s help to identify possible harmful algal blooms, or HABs.
Unlike other types of algae, harmful algal blooms consist of cyanobacteria, naturally found in many bodies of water. A bloom occurs when those bacteria quickly multiply and form a visible discoloration in the water.
“What they want to look for is some water that might look like pea soup, like maybe some grass clippings are floating in the water, like green latex paint,” said Matt Ferguson, state toxicologist for DPHHS.
Many cyanobacteria blooms aren’t dangerous. In some cases, though, the bacteria can produce cyanotoxins. Drinking or swallowing water contaminated with those toxins can cause nausea, vomiting, diarrhea, headaches or liver or kidney damage. Touching or inhaling the blue-green algae can lead to irritation of the skin, eyes, nose, throat or respiratory system.
If you do come into contact with something you suspect may be an HAB, authorities recommend rinsing off with fresh water as soon as possible and keeping children and pets out of the water.
So far, experts do not believe any human deaths have been caused by HAB exposure, but some animal deaths have been linked to it. Ferguson said there have not yet been any human exposures in Montana.
State leaders want to investigate all potential harmful algal blooms. They have a website, www.hab.mt.gov, and a 24-hour hotline, 1 (888) 849-2938, for anyone to report if they believe they’ve spotted one.
“We recommend that you do it; it’s very easy,” said Ferguson.
If you report a potential bloom on the state website, you can highlight the specific location and attach a photo, to help investigators determine whether it is likely to be harmful. The website also includes a map with previously reported blooms.
Once a possible bloom is reported, DEQ will investigate to determine whether it is producing cyanotoxins at levels of concern. If so, they could decide to issue a warning, or even close the body of water in extreme cases.
Ferguson said harmful algal blooms are becoming more common nationwide, including in Montana. Last year, authorities verified 41 citizen reports of HABs around the state. Many were on Canyon Ferry Reservoir, Holter Lake and Hauser Lake.
Blooms are most common in the summer, when warm, stagnant water interacts with high levels of nutrients, like excess nitrogen and phosphorus. Ferguson said, in many cases, those nutrients come from fertilizer runoff.