‘No single cause’ to blame for White River algae bloom

RBC | Concerns over recent algae blooms in the White River prompted an informational meeting Tuesday in Meeker.
“We’ve had an issue in the river (algae blooms) we’ve all seen evolving over the last couple of years that’s affecting some of the fishing and having impacts on water quality,” said CPW District Wildlife Manager Director Bill deVergie. “We are not saying there is one source of the problem, and this is not catastrophic at this point. We are not blaming any one person or industry. I think we’re all striving for the same goal: the health of the river.”
deVergie introduced Mindi May, CPW water quality specialist, who shared research done last year in 15 different locations in the White River watershed in and east of Meeker.
From March through October 2016, May’s team examined water samples in the White River, Coal Creek and Little Beaver for nutrients, major ions, suspended solids, macroinvertebrates (insects) and chlorophyll A. They performed algae identification at the Wakara Ranch testing site, where the worst of the algae blooms occurred.
While algae are a normal part of a stream system, the species of algae identified last year is of particular concern: cladophora glomerata, aka green algae, forms long filaments and is “difficult to get rid of,” May said. “It’s one of the problem children out here,” in terms of algae. “It’s a species that’s really good at taking up nutrients and storing nutrients for later use.”
Clark Fork near Missoula, Mont., has also experienced an infestation of green algae, prompting landowners, recreationalists and industry to form a coalition to reduce mitigating factors that cause the algae to grow.
Algae feeds on nitrogen and phosphorus, found naturally in soil, commercial fertilizer, manure, septic tanks and water treatment plants. The main byproducts of feeding fish are nitrogen and phosphorus, which has led to international concerns about fish farming causing water pollution and algae blooms.
“There’s lots of little sources spread all around. If everybody can do a little bit maybe we can get it under control. It’s going to be tough. This (kind of) algae is difficult to control,” May said.
The Montana coalition lists soil erosion and/or disruption along the riverbank, removal of natural riparian vegetation, buildings and septic systems placed too close to streams and application of fertilizer too close to streams or at the wrong time of year, among other items, as potential sources of nitrogen/phosphorus contamination. (bit.ly/2nIiu8M)
While May’s research was limited to areas in and east of Meeker, Alden Vanden Brink of the Rio Blanco Water Conservancy District said the problems are occurring all along the river.
“Something happened overnight that wasn’t there in 2013 that was there in 2014. It’s affecting the water chemistry. That tells me that it’s not necessarily a non-point source of pollution,” he said.
Meeker science teacher Dr. Bob Dorsett, who has performed water sampling as part of his students’ studies for years, said the problem has become more obvious in the last two years.
“The water temperature is historically not different, but the algae blooms have been the most noticeable in the last two years. It’s been so thick at our Fifth Street sampling site it’s hard to get around in the river, and the macroinvertebrate counts are a lot lower. The best correlation we can see in our data is there are nutrient loads coming down from upstream.”
May said it’s possible the changes in the river have been taking place for several years and the algae has just reached a “breaking point.”
deVergie reiterated that CPW is “not a regulatory agency.” Its primary concern is protecting the fishery resources.
“From a big picture, this is something we need to work on. It’s a multi-year problem,” deVergie said, adding that CPW will continue to seek information to locate possible sources and solutions, and asking individuals to “speak up” if they are aware of potential causes of the problem.