Didymo

jrp11948

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Several years ago the fly fishing world was forever changed by Didymo. From felt soles to washing waders, fly lines, etc. the end of the world was near. Besides the signs that say to your waders before entering the waters, Didymo has disappeared from print.
I've heard that the spring runoffs take care of it for us, but that sounds too easy.
Felt is still allowed in many states and I'm tired of busting my butt using the slippery rubber soled wading boots.
Anyone have any news?
 

Ard

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Welcome to the forum :)

If you are having difficulties with Vibram or other types of rubber soles perhaps look into some traction aids for them. I've been using Vibram since the early 1990's and have not had a in river fall to date. I used them fishing mountain streams in Pennsylvania - Virginia - New York - Maine - Colorado and of course here in Alaska for 14 seasons. From raging rivers like New York's Salmon River to Maine's Ragged and many here at home now I remain stable.

It deserves saying that if we kick into an unseen obstruction or catch a submerged tree limb those will give us trouble regardless of foot gear. I safe guard against those instances by using a wading staff for additional balance assistance. When the day comes that I fall in it may likely be a result of age and ability not my shoes.

On the Didymo question my view is / has always been one of caution in the vein of better safe than sorry. I'm not just on a creek or river to use the resource, I am there to enjoy the resource and to do any small thing possible to protect it from my presence. Here and back when I resided in the North East protecting means little things like not destroying vegetation, not walking through spawning beds, handling fish with care and of course careful or zero use of fire even when camping. The list can go on but we use rubber here in AK. and I have no complaints.
 

silver creek

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Several years ago the fly fishing world was forever changed by Didymo. From felt soles to washing waders, fly lines, etc. the end of the world was near. Besides the signs that say to your waders before entering the waters, Didymo has disappeared from print.
I've heard that the spring runoffs take care of it for us, but that sounds too easy.
Felt is still allowed in many states and I'm tired of busting my butt using the slippery rubber soled wading boots.
Anyone have any news?
Yes, I have news that you have not heard. You might just be the last person who has not heard that felt boots are NOT causing dydimo blooms. The dydimo blooms are caused by low phosphorus in the water.

Dydimo has been it the North America for hundreds of years. Dydimo was present in North America in as early as 1218 AD, in the sediment at the bottom of Naknet Lake dated by a volcanic eruption. So who brought didymo to Alaska well before any Europeans even know it existed?

'We found no statistically significant change in the numerical presence of D. geminata or D. clavaherculis, as a group, in Naknek Lake between the years 1218 and 2003."

Historical abundance and morphology of Didymosphenia species in Naknek Lake, Alaska

The dydimo blooms are caused by low phosphorus in the water.

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:

https://www.tandfonline.com/doi/abs/10.1577/1548-8446-34.8.382

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"

He published his findings in Freshwater Biology (2012) 57, 641–653 in an article titled:

Didymosphenia geminata growth rates and bloom formation in relation to ambient dissolved phosphorus concentration

"The blooms were present only in rivers where average dissolved P was very low. Didymo in higher nutrient waters had higher cell division rates, shorter stalks, and did not form blooms.

…. the blooms are caused by low nutrients in the overlying water, which promotes excessive stalk production. Subsequent surveys, experiments and observations in New Zealand have all been consistent with low nutrients (specifically low P) driving the blooms."


What causes didymo blooms

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 laundry 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. We allow the addition of some phosphorus into fertilizers in the river drainage of these dydimo affected rivers.

Secondly, there is no single chemical decontamination method that will kill all invasives WITHOUT damaging the waders and boots. Now that it has been established that felt soles are not responsible for dydimo blooms, the worst invasive is the New Zealand Mud Snails. They are resistant to chemicals and felt is NOT where they hide. They hide IN the boot, under the footbed and any crevice.

A study by the California Department of Fish and Game found hundreds of NZ Mud snails lodged inside the crevices of individual test boots. Over 50% of them were less than 1 mm in diameter. Replacing felt with rubber is not going to stop them.

"The majority of NZMS recovered were associated with wading boots. NZMS were observed on the tongue area of wading boots, associated with the laces or the area of the tongue that was tucked beneath the lacing eyelets. Large numbers of small NZMS were present inside of the boots, having worked down between the boot and the neoprene bootie of the wader. If the boots contained padded insole inserts, NZMS were also found underneath the inserts, associated with sand grains. NZMS were recovered from every treated set of wading gear. Numbers of NZMS per sample ranged from 1 to 227 with a mean of 33 (Appendix 2). Over 50% of NZMS recovered were < 1 mm in size (Table 4)."

http://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=3867

Finally, New Zealand has the most rigid laws (The fine for spreading invasives is 5 years in Prison and/or a $100,000.00 fine). Yet this has not stopped the spread of invasives.

We have 300 times the population of New Zealand, small fines and no jail time; and yet there are those that believe that rubber soles will stop the spread of invasives. Clearly that ignores the evidence.
 
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dharkin

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Sometimes when I read Silver's replies I can't help but think about the movie "Good Will Hunting"

"My boy's wicked smart."

YouTube
 

redietz

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Felt is still allowed in many states and I'm tired of busting my butt using the slippery rubber soled wading boots.
Anyone have any news?
Yes. Some rubber soled boots are better than others. I haven't slipped since I switched from felt (well before it was mandated.) I used to slip with felt regularly.
 

jrp11948

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Thanks for all the info. Some states have not outlawed felt, it would be a great study to see if it has affected the streams in those states.
I do use Vibram soles, with and without cleats and for me at least it all depends on the stream. Large rocks drive me crazy, slippery no matter what I'm wearing. Yes, I have moved to a wading stick, Im now of an age that I don't need to fall anywhere.
I dont think well ever know if banning felt was an over reaction or not. In Maryland I haven't seen didymo and hope I don't.
 

JoJer

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I bought a pair of rubber soled Caddis shoes (mostly for PC) and I've been surprised at how well they grip on stuff where I would have expected the felt to slip. All my boots have 8 large hex-head, slotted sheet metal screws in the sole. I plan to pack an appropriate combination wrench in my gear for easy removal even though the slots make it easy to remove the screws with a coin or Leatherman.
 

jrp11948

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Just got back from a trip to the Western Branch in Hancock, NY. On several retrieves I found a fluffy blob of white stuff on the fly. Didymo!! Thought it was a piece of tissue paper. It wasn't a large amount, but there it was. First time I've seen it, the guide says its present , but doesn't seem to last long.
 

LePetomane

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Didn't Simms quit making felt soled boots for a period of time in response to the allegation that they were responsible for the spread of invasives?
 

silver creek

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No, it doesn't. However, it's a good way to spread whirling disease, New Zealand mud snails, and other invasives.
You are correct in that theoretically felt probably does retain more microscopic invasives than rubber soles. However, for an organism that propagates asexually, even a single live invasive that survives decontamination will spread the invasive.

Even for non microscopic invasives like NZ mud snails, hard soled boots are significant spreaders as found by a study by the State of California, The Resources Agency DEPARTMENT OF FISH AND GAME, titled: CONTROLLING THE SPREAD OF NEW ZEALAND MUD SNAILS ON WADING GEAR.

Download the study here: http://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=3867

They found that the New Zealand Mud Snails work their way into locations well away from hard soles and into areas not normally inspected like under the insoles of wading boots.

However, the most disturbing finding is that to really kill NZMS, the decontamination process will also destroy wading boots and the waders. I submit that no fisherman will perform the level of decontamination necessary to stop the spread of this invasive.

"The majority of NZMS recovered were associated with wading boots. NZMS were observed on the tongue area of wading boots, associated with the laces or the area of the tongue that was tucked beneath the lacing eyelets. Large numbers of small NZMS were present inside of the boots, having worked down between the boot and the neoprene bootie of the wader. If the boots contained padded insole inserts, NZMS were also found underneath the inserts, associated with sand grains. NZMS were recovered from every treated set of wading gear. Numbers of NZMS per sample ranged from 1 to 227 with a mean of 33 (Appendix 2). Over 50% of NZMS recovered were < 1 mm in size (Table 4)."

They found that the New Zealand Mud Snails work their way into locations well away from felt soles and into areas not normally inspected like under the insoles of wading boots.

The same California study found that chemical decontamination eventually destroyed the waders and boots. Bleach for example is an oxidizer and damages gear. Any spill or drips in your vehicle will damage upholstery and carpets. That is why manufacturers recommend rinsing and drying gear without the use of chemicals. HOWEVER washing and rinsing with water alone does NOT KILL NZ Mud Snail and other invasives.

Here are some photos gear that has been chemically decontaminated. They were treated ONLY 7 TIMES and the gear looks like this. That is why I say there is no single treatment that will kill all invasives and won't damage wading gear excessively.

Bleach





Pine Sol



Bezethonium Chloride



The bottom line is that for invasives, there is no magic bullet. In the end, hard soled boots vs felt will make little difference. It will reduce the number of invasives that are transferred but that is like reducing the load of Ebola virus that infects you. You are still infected and it will take you a bit longer to die. These are asexual organisms that will "infect" a watershed with just a single transferred organism.

There is no single safe chemical treatment that will kill or remove all invasives. “NZMS were recovered from every treated set of wading gear“ even after treatment.

The science of invasives indicates to me that the ultimate result will be that these organisms will spread to whatever watersheds that are suitable for their biology. Not all watersheds are suitable for Whirling disease and that will decide whether they get infected just like didymo will not form mats in all watersheds.
 
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