By Marne Hayes EBS COLUMNIST
The work to improve the health of the Gallatin River cannot be done through a solitary lens. Our understanding of the challenges and the available solutions can only be made stronger by paying attention to similarities we see on other rivers around Montana. Findings from a recent study on the Smith River algae blooms, for example, offer helpful insight into identifying the conditions that cause blooms on the Gallatin, the solutions to address them, and the practices that will mitigate them moving forward.
Since the first algae bloom on the Gallatin in 2018, the Gallatin River Task Force and the Montana Department of Environmental Quality have ramped up monitoring efforts to understand the primary drivers of the algae blooms that have re-occurred in 2020 and 2022. The results suggest that the blooms are caused by a combination of nutrients, warm water temperatures, low streamflows and an abundance of sunlight. But a recent report released by the Montana DEQ regarding algae blooms on the Smith River might actually hold equally important information for what we know is happening here at home.
Every river system is different, though similarities between them can help us figure out what causes excess algae. Study results on the Smith point to increasing temperatures in spring and early summer as the primary driver of excessive algae growth. Specifically, the DEQ’s report on the Smith showed that minimum daily air and water temperatures are trending warmer in the Smith River basin during the spring and early summer. These increasing air temperatures have influenced water temperatures, so that the Smith’s water is now in the preferred temperature range for algae growth.
So, why do the findings on the Smith River matter to the Gallatin? Because similarities—and differences—in their conditions provide clues in identifying causes, finding solutions, and understanding how we can promote better health, more mindful use, and improve conditions for our waters and fisheries. That there was no algae bloom on the mainstem Gallatin in 2024 was surprising because the conditions seemed to be set up perfectly: ample nutrients, a warm and sunny July and low streamflows—though algae blooms were observed on the Taylor Fork, Beaver Creek and sections of the West Fork.
These circumstances are key to understanding the similarities and differences in each river’s water health, and the recurrence of algae due to varying conditions, according to Gabrielle Metzner, senior water quality specialist with the DEQ. “The Gallatin and Smith rivers both experience undesirable algae growth, however there are some notable differences between the two rivers related to the timing of the blooms, availability of data, and the landscape and land use near the rivers that we can learn from.”
The recent report on the Smith stemmed from concerns of algae blooms on that river, starting with public reports to the DEQ and Montana Fish, Wildlife, and Parks, regarding the observation and growing concern of algae growth visible in excess along stretches of the river. This prompted the DEQ to develop a project team to answer the overarching question: “Why are algae growing to undesirable levels in the Smith River, and why now?” The project team spent 2018-2020 collecting data along the entire float reach of the Smith and discovered the same kind of algae that we’ve seen along the Gallatin: Cladophora Glomerata.
The release of the DEQ’s report on the Smith River has put in motion exactly what is needed; a newly published Smith River Restoration Plan released by FWP that identifies projects and practices that, when implemented most effectively, will have the greatest impact on mitigating recurrent algae blooms on the Smith. It allows us to understand how to address the pieces we actually can control; nutrient pollution, streamside vegetation, responsible recreation and sustainable access.
Fortunately, the Gallatin River Task Force is also implementing plans and executing projects that address these pieces. Examples include restoration projects outlined in the Gallatin River Restoration Strategy, like the current project at Greek Creek, and expanding centralized sewer to Gallatin Canyon.
While the projects may vary river to river, what we know is that implementing projects and practices in similar and relevant ways will put us on the right path to helping improve water quality, quantity, and wildlife habitat right here at home on the Gallatin. When we opt out of the silo and take a broader and more universal approach to how we support better health and stewardship across Montana’s rivers, the whole becomes greater than the sum of its parts, as the saying goes.
Marne Hayes writes for the Gallatin River Task Force.
