Didymo along the Gore Creek in Vail | VailDaily.com

Didymo along the Gore Creek in Vail

Daily Staff Report
Special to the DailyAquatic diatoms like "didymo" can foul up rivers in a host of ways.

VAIL ” In Vail, didymo comes in the fall, but anglers need to be aware of its presence and potential for damage to the river.

Didymosphenia geminata (“Didymo” for short) is a rare and beautiful diatom (a type of algae) restricted to pristine lakes and streams of northern latitudes.

Recently, “didymo” now forms excessive growths in many streams and rivers of North America. This algae is now showing up in and around the Vail area. Anglers are reputedly the main carrier and distributor of this aggressive diatom. Throughout North America, “Didymo” is expanding its geographical range and forming massive growths in streams.

This nuisance organism (in some regions, it is an invasive species) grows attached in streambeds and may impact freshwater fish, aquatic plants, and important aquatic insects.

Didymosphenia geminata is a single-celled alga, within the group of algae called diatoms (Bacillariophyta). The cells grow on stalks and form large colonies. The stalks are responsible for the negative impacts of this species and are composed of a complex slimy substance(mucopolysaccaride). Colonies of cells are visible as white to light brown tufts attached to rocks. As the colonies develop, they smother rocks and trap fine sediment.

Didymo forms long strands that resemble wet, green toilet paper flowing downstream. The strands get caught up on logs and rocks in the river, further choking out river insects vital to survival in river fish.

Impact to humans is no more than eye irritation in swimmers. The economic impact of the algae comes from fouling prime fishing waters and potentially clogging water intake pipes along the river.

Reportedly, the alga can live for up to 40 days out of the water and on wading shoes and waders.

Vail Colorado

Support Local Journalism