New data suggests angler's felt soled boots NOT responsible for dydimo spread

[Silver Creek]

Actually, nothing in what you quoted supports your thread title. He said that he no longer believe that didymo spread is the major threat, but nothing that you quoted indicates he no longer believes that didymo is not spread by felt soles and other angler's clothing. Rather, he said that the didymo has largely been spread already, and now it's just a matter of stream conditions which determine how active it is. Maybe there's something else in the article that supports the title (I haven't read it), but what you quoted does not.

I think you are correct. The point being made is that dydimo is already endemic and pervasive in North America. Dydimo has already spread and banning felt is not a solution to preventing further spread.

I think this recent discovery makes more sense than the old theory that all of a sudden dydimo sprang due to anglers boots when anglers have been using these same rivers for over a century with no dydimo blooms.

What is causing the dydimo blooms, I surmise, is the current trend of reducing phosphorus in detergents and lawn fertilizer. So as we get rid of phosphorus to prevent algae blooms we get dydimo blooms.

Ever wonder why NZ has such a problem with dydimo? They have lots of crystal clear streams and rivers with low phosphorus because there is little run off from agriculture and lawns.

Basic epidemiology 101 states that we cannot stop the spread of what has already spread. How we then prevent disease is to make the target population less receptive to the disease.

In rivers that have dydimo blooms, I suggest we need to monitor phosphorus and experiment by allowing some phosphorus back into lawn fertilizers in dydimo prone watersheds. Perhaps there is a phosphorus level that is too high to allow dydimo to bloom and too low to allow algae to bloom. In science we call this the "Goldilocks effect"

http://en.wikipedia.org/wiki/Goldilocks_principle

A similar phenomenom to the dydimo bloom was the increase in sea lamprey in Lake Superior a few decades ago. Biologist discovered that as the rivers flowing into Lake Superior were cleaner due to EPA monitoring of industrial waste, sea lamprey began to use them for spawning. So barriers were installed. Since we cannot install a mechanical barrier to dydimo, perhaps phosphorus can serve as a chemical barrier.