I pulled this video about the effects of Didymo off the Orvis News blog, as it really is an important issue for everyone that enjoys the use of our rivers and streams - fishermen, boaters, hikers, etc. Even those with dogs can spread Didymo. All the dog has to do is swim in one stream and then another shortly thereafter, and that can spread it, as it can get stuck in their paws and/or fur just as easily as it can a wading boot.
From Phil Monahan, the Orvis News editor: "Anyone who cares about rivers needs to watch this 25-minute film that follows the progression of a Didymo bloom in the Gunpowder River in Maryland. You'll be astounded by how quickly the river is transformed as the bloom progresses, and a once-clear freestone stream becomes a gunked-up, brown mess. If you ever needed a reason to take personal measures that halt the spread of aquatic nuisance species, this ought to do it. Didymo is no longer "someone else's problem." Thanks to guide Jason du Pont for his dedication to this project."
Nice job Jason, thank you. And to you, too, Phil.