An Update on Didymo

Following up on an earlier post, Brian Marotz, of Montana Fish, Wildlife & Parks has been working with Dr. Jack Stanford at the University of Montana Biological Station and other didymo experts to better understand this diatom that's growing below Libby and Hungry Horse dams.

According to Marotz, "Some researchers aren't very concerned about didymo because it's believed to be cyclical." Montana fish and wildlife managers thought so, too, over 11 years ago when the dense blooms began to grow in the Kootenai.

"The diatom does have annual growth and death cycles, but it hasn't dissipated, and it's getting worse, even when we attempted to flush the river with planned dam discharges," notes Marotz.

"We're now documenting the widespread loss of most aquatic insect species where these nuisance blooms occur in the Kootenai and South Fork Flathead." Although there are a number of factors involved, Marotz says that fish populations have apparently declined or moved elsewhere for food.

"Like others, I hope these blooms simply disappear, but they haven't to date. We need to learn what makes didymo flourish and how we might control it."