1 November 2019 — 1256 mdt

Environment Montana releases document on its
study of waterborne plastics at 50 fishing access sites

Environment Montana, which is part of Environment America, yesterday released a document, Microplastic in Montana: A Study of Fifty River Access Sites, that’s partly a report and partly an advocacy brief for the organizations’ campaigns to outlaw single-use plastics such as straws, grocery bags, and foamed polystyrene fast food containers.

Tomorrow, Skye Borden, Environment Montana’s executive director, will deliver a presentation on the subject at the plastics symposium at Flathead Valley Community College.

Several sites in the Flathead were sampled. Only one, Ducharme on Flathead Lake, yielded plastics. That’s probably because upstream of the sites on the Flathead River, Polebridge on the North Fork, and Paola on the Middle Fork, there’s not much human habitation.

The study did not draw samples from the Flathead River just upstream from Flathead Lake, or from Ashley Creek, or the Whitefish and Stillwater Rivers downstream from Whitefish and Kalispell.

The document does not report the dates and times of days when the samples were drawn (that information probably is stored in the study’s database), and it is not clear who analyzed the samples.

Dates and times are important for the river sampling sites as they can be correlated with streamflow and water quality data. There are, for example, streamflow gauging stations above and below Polebridge, and downstream from Paola. A sample of clear water taken in late summer might contain fewer pieces of plastic than a sample of sediment filled water taken during the peak of spring runoff.

I’m not sure how useful this document is. It strikes me as being designed to be printed and distributed to elected officials, opinion leaders, and allies. It will not have the authority of an independent, peer reviewed, report written by independent scientists.

Nor will it have the authority of a study that drew samples at daybreak, meridian transit, and sundown, every day or every other day, over the course of a year, or at least from spring through fall. It provides only a snapshot of a body of water. But it’s a start.