Max Bothwell, a research scientist for Environment Canada, who wrote an influential article that linked angler’s felt soled boots to dydimo spread has now reversed himself and said that anglers are not responsible.
Here is his original article, On the Boots of Fishermen:
He now believes that dydimo has been in North American waters and that it is a change in water chemistry, specifically lower phosphorus levels that has caused dydimo blooms.
Read the article in the current issue of American Angler, July-August, 2013, pp 8-9.
“‘I no longer believe the problem is North American streams is the result of it (dydimo) being moved around.’ ?. Scientists are now convinced that dydimo lives in many streams, but blooms only when the water has far less than the normal amount of phosphorus?? The most damaging dydimo episode in the US seems to have been on Rapid Creek in South Dakota, where a six-mile bloom dramatically impacted a blue ribbon brown trout fishery. In 2007 and 2008, Bothwell and other scientists added phosphorus to sections of Rapid Creek. Sure enough, the dydimo mats shrank.”
If you go directly from stream to stream without the boots drying, you’re correct. Drying, however, kills didymo (unlike whirling disease spores), so those areas will be ok if you just dry the boots. The problem with felt soles is that they stay wet inside for weeks, making it much more likely that you’re going to transport didymo for the stream you fished this weekend to the one you’re going to fish next weekend.
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”
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.
Whether it is spread or not spread by fisherman to me doesn’t matter. If nothing else it made us more aware of didymo and it’s impact.
For me personally is that the thought that it was spread by felt soled boots led to the developement and improvement of rubber non slip soles. Which I like. For years I fished spring creeks (wet grass & mud banks) wearing felt soled boots and cannot begin to count the times I have slipped and almost busted my back side. So I for one am glad that rubber soles came along. I still have a pair of felt soled boots, just in case I ever book a trip in a drift boat. But that is not likely to happen.
I’m always leery of reports & “studies”, especially of environmental matters. Not to say that a red flag cannot be raised on an issue, but there are those who can make a profit from some bogus claim. There’s also some pseudo intellectual who might get a paper published for some far reaching claim that might enhance him/her getting tenure at some “higher learning” institution.
Quite often the culprits for the spread of aquatic vegetation and micro organisms are birds (not to mention species of fish!) - from ducks to blue Heron.
“That” water in SD has the beginning of another bloom of dydimo, as recently as three weeks ago. Other waters will follow suit. Birds? Sure, there’s ducks and herons, and osprey … but there’s also idiots who won’t follow “suggestions” about controlling the spread, and tramp right in to every water source they can find, with no regard to where they’ve been, what’s in the water, and how much of that cr*p they have on their boots/waters/laces/gloves/lines.
Some people will say absolutely anything to not have to accept the blame for the damage they’ve done.
All due respect…and no disrespect to anybody intended…in reality, there has never been a single study done that I have seen that has shown proof of Dydimo being spread by felt-soled boots, or any other boots for that matter. Nobody knows how it is spread. There are alot of WAG’s flying around out there…from boots, to canoe paddles and wildlife. But no proof. When in fact the study pointed out could be spot-on. Maybe it’s an organism that is in most waters, but one that needs a specific water condition in which to bloom? Maybe it’s spread by goose crap? Maybe muskrats? Can’t say no…because “nobody” knows. So why is everybody so certain that felt-soles are to blame? It’s always easier to blame somoebody for something that they can’t “prove” they didn’t do.
Right on the mark. It’s the time-honored “We must do SOMETHING, even if it won’t make any difference” approach taken by folks who don’t want to be bothered by facts, but only want to FEEL better.
BTW I’ve only ever owned one set of felt-soles in my life, and I hated them.
I am one who believes we should take any reasonable precaution we can so as not to do damage to the streams we love.
If you don’t believe the studies that say boots help spread a stream disease, why would you believe a study that says it doesn’t?
Why not play it safe if is easy to do so rather than being sorry later?
Thinking you have very limited wading experience. When we went to non-felt last year the ADF&G thought they would be exempt. For some reason they are not “hip” on breaking legs, ankles, wrists, and more. They were told emphatically they would NOT be exempt. It did not make them happy. I am beyond disgusted with the latest and greatest rubber soles. For rocky, cobble type streams anything will work. I have only found a few of those in my time in AK. The rest have been killers in those useless rubber-soled boots! -------------------------------- For some reason my enter key has stopped working on FAOL only so I am trying to break things into paragraphs in spite of the glitch. ---------------------------------------------------------------------- I met a fellow last year that was putting on felt soles at about the most popular stream in AK. I politely informed him (yeah, I can be that way sometimes!) they were illegal. He lit into me like a rented mule! He was tired of falling; down, in, and about any way you can imagine and he welcomed the chance to go to court and tear them a new one! He was already looking at filing a suit for damages he suffered as a result of the ban. Compared to the rubber, felt allows one to walk up underwater walls. Felt sucks on snow and mud. I tend to avoid fishing those areas…
