Didymo

jrp11948

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After all the hoopla and banning of felt waders, has anyone seen Rock snot lately? I heard some talk that it washes out in the spring melt or dies with the heat. Any of that true or more internet inaccuracies?
Im not a fan of the rubber bottom boots and just bought a set of Rock Treads, haven't used them yet, with the lock down.
 

Ard

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When it comes to invasive species I tend to trust more in what agencies who have training and expertise with the spread and or avoidance of them recommend more than any other source. The rubber? You'll get used to Vibram soles I've been using them since the mid 1990's. Think of them like a PPE mask, better safe than sorry maybe.....
 

silver creek

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Much of the early reports on didymo were wrong. Fishermen and fishing tackle and boats do not spread didymo. It has always been present. Unfortunately, most of the wrong information is still out there and has not been corrected.

What has changed is the phosphorus level in the water that then causes didymo to produce didymo blooms of fibrous mats.

BBC Earth has updated information.

BBC - Earth - The brown snot taking over the world’s rivers

https://www.concordmonitor.com/didymo-rock-snot-felt-wader-3007790
 

trev

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If I recall correctly we banned phosphorus in some uses and by cleaning up the phosphorus in the water created the problem.
I don't think any agency in the states that banned felt actually did a study, they just with an abundance of caution reacted to Max Bothwell's first report; and I also doubt that they ever did any follow up research or they would have removed the bans by now after reading the discoverer of the problem refute his own previous paper.
Didymo, it turns out, only turns malignant when waters are very low in phosphorus, a nutrient often associated with pollution by detergents and fertilisers.
I think this is Bothwell giving the complete story- YouTube
 

satyr

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I thought that the felt bans were more for mud snail larvae than for snot. Isn't that why Yellowstone banned them last year?
 

silver creek

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I thought that the felt bans were more for mud snail larvae than for snot. Isn't that why Yellowstone banned them last year?
If you will check the history of felt soled wading boot bans, they occured right after Max Bothwell published an article title "On the Boots of Fishermen" on this page which has since been taken down:

http://www.env.gov.bc.ca/wat/wq/studies/didymo-blooms.pdf

He then followed that up with the formal publication of this article in the scientific literature. Note that he states ENVIRONMENTAL CHANGES are NOT to blame and FISHERMEN ARE TO BLAME and GOVERNMENT AGENCIES SHOULD OUTLAW FELT SOLES!!!!!

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

On the Boots of Fishermen: The History of Didymo Blooms on Vancouver Island, British Columbia
Max L. Bothwell,Donovan R. Lynch,Harlan Wright &John Deniseger

Abstract:

"In 1989 blooms of the river benthic diatom Didymosphenia geminata (didymo) first appeared and rapidly spread among rivers on central Vancouver Island, covering the bottoms with thick, woolly-looking mats. Although didymo is native to North America, extensive field surveys of rivers on Vancouver Island and other data indicate that didymo blooms are new. No known environmental changes were associated with the onset of didymo blooms. However the pattern of didymo spread among rivers on Vancouver Island correlates with the activity of fishermen and the commercial introduction and widespread use of felt-soled waders in the late 1980s. Since 1994 nuisance blooms of didymo have appeared in numerous other places in the Northern Hemisphere and South Island, New Zealand, all areas frequented by fishermen. Actions by government agencies to educate the public and restrict the use of felt-soled waders have been undertaken in some jurisdictions and at least one commercial manufacturer of waders will discontinue production of felt-soled models in the near future."

Then Bothwell reversed himself in this publication. Now he blames it on ENVIRONMENTAL CHANGES THAT IS HE DENIED WERE THE CAUSE IN HIS FIRST PAPER!

https://www.tandfonline.com/doi/pdf/10.1080/0269249X.2014.889041

The Didymo story: the role of low dissolved phosphorus in the formation of Didymosphenia geminata blooms

MAX L. BOTHWELL1∗, BRAD W. TAYLOR2,3 & CATHY KILROY4

Abstract:

"We outline, in chronological sequence, the events and findings over 25 years that have shaped our understanding of Didymosphenia geminata

(Lyngbye) M. Schmidt blooms. Starting with the first appearance of D. geminata mats in streams on Vancouver Island in the late 1980s
and followed years later by blooms in Iceland, South Dakota and Poland, D. geminata blooms were enigmatic for nearly 20 years. Early
papers exploring whether blooms were caused by environmental change consistently failed to identify any specific factor(s) associated
with their onset. Following the D. geminata outbreak in New Zealand in 2004 that seemed to result from an introduction of the species,
the possibility that blooms that had previously occurred elsewhere in the world might also be explained by the introduction and movement
among watersheds of a new variant with a bloom-forming tendency was touted and widely accepted. Now, however, the identification
of very low soluble reactive phosphorus (SRP; below ∼2 ppb) as the proximate cause of bloom formation, has led to the more likely
explanation that D. geminata blooms are the result of large-scale human intervention in climatic, atmospheric and edaphic processes that
favour this ultra-oligotrophic species.
In this new view, blooms of D. geminata are not simply due to the introduction of cells into new
areas. Rather, bloom formation occurs when the SRP concentration is low, or is reduced to low levels by the process of oligotrophication.
Mechanisms that potentially cause oligotrophication on global and regional scales are identified."
 

silver creek

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In a rush to judgement states proposed outlawing felt soled boots and waders BUT, get this...... allowing state and federal employees to continue to wear them!

Check this out:

http://www.leg.state.vt.us/docs/2010/bills/Passed/H-488.pdf

In Vermont:

"Sec. 1. 10 V.S.A. § 4616 is added to read: § 4616. FELT-SOLED BOOTS AND WADERS; USE PROHIBITED

It is unlawful to use external felt-soled boots or external felt-soled waders in the waters of Vermont, except that a state or federal employee or emergency personnel, including fire, law enforcement, and EMT personnel, may use external felt-soled boots or external felt-soled waders in the discharge of official duties."

http://www.leg.state.vt.us/docs/2010/bills/Passed/H-488.pdf


Proposed Montana legislation that never left committee.

"NEW SECTION.**Section 2.**Use of felt-soled boots and waders prohibited.

(1) A person may not use external felt-soled boots or external felt-soled waders in the waters of the state.

(2) The possession of external felt-soled boots or external felt-soled waders on the banks or shores of a stream or lake or in a boat, raft, canoe, or other water vessel is prima facie evidence that the person or persons in whose possession the boots or waders are found were using the boots or waders in the waters of the state.

(3) The provisions of this section do not apply to a state or federal employee or emergency personnel, including fire, law enforcement, and emergency medical technicians, using external felt-soled boots or external felt-soled waders when acting within the scope of duty."
 

redietz

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After all the hoopla and banning of felt waders, has anyone seen Rock snot lately? I heard some talk that it washes out in the spring melt or dies with the heat. Any of that true or more internet inaccuracies?
Im not a fan of the rubber bottom boots and just bought a set of Rock Treads, haven't used them yet, with the lock down.
Yep. There was a bloom in the Gunpowder this year, mostly above Falls Road (i see you're from Maryland, so I assume this means something to you.) There wasn't one last year because of the high flows. Generally, you only see it from about mid-February through mid-April.
 

redietz

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I thought that the felt bans were more for mud snail larvae than for snot. Isn't that why Yellowstone banned them last year?
The ban on felt soles is to prevent the spread of all sorts of invasive species, not just didymo. (Whirling disease comes to mind.)
 

JDR

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The Clean Water Act was changed a few weeks ago. The old standards and regulations no longer apply. Virtually all of the standards have been downgraded or eliminated.
 

silver creek

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The ban on felt soles is to prevent the spread of all sorts of invasive species, not just didymo. (Whirling disease comes to mind.)
Forgive me for this long post but the history of WD is full of twists and turns, including states purposely spreading the parasite!

If you research the spread of whirling disease in several states, especially Colorado, you will find that it was the state fisheries and NOT fishermen that seeded the entire state with whirling disease.

WD was endemic in some Colorado hatcheries and instead of closing the hatcheries and decontaminating them, the fisheries departments continued to use the hatcheries because they needed the trout stocking to continue to keep the put and take fishermen happy. No fish, no license sales - no license sales, budget cuts - budget cuts, fisheries job losses!

This is a previous post of mine. The links are dead but the information and quotes are legitimate.

The State of Colorado stocked infected fish for years from it's own infected hatcheries. Maryland also has infected fish hatcheries but the fish are being destroyed "at two facilities in Garrett County"

Colorado's policy was that:

"Trout from positive hatcheries will be stocked into waters where the parasite has been found to minimize the risk of contaminating other watersheds. Only trout from negative testing hatcheries can be stocked into waters where the parasite has not been found. "

http://wildlife.state.co.us/Fishing/Management/WhirlingDisease.htm

"A disease that attacks the bone structure of young fish has wiped out 90% of Colorado's wild rainbow trout in six of the state's best trout streams, a state study shows. The study by the Colorado Division of Wildlife also found that Whirling disease has reached 12 of the state's 15 trout hatcheries, threatening the state's $420 million-a-year fishing industry."

Pacific Regional Aquaculture Information Service for Education (PRAISE)

Subsequent research showed that parasite dose exposure in the environment increases infection rates and decreases survival. The Colorado Div of Wildlife stocking increased the infection rate.

"Parasite dose strongly determines the severity of whirling disease, which generally increases with the number of triactinomyxons the fish encounters (Hoffman 1974; O’Grodnick 1979; Markiw 1991, 1992a, 1992b; Hedrick et al. 1999a; Thompson et al. 1999; Densmore et al. 2001; Ryce et al. 2001; Ryce et al. 2004; Ryce et al. 2005)."

http://fwpiis.mt.gov/content/getItem.aspx?id=40473

Even after WD was found in the Colorado hatcheries, the state continued to breed fish in its infected hatcheries and continued to stock infected fish.

"A policy implemented in spring 1995 prevents the stocking of trout from hatcheries testing positive into waters where whirling disease has not been found. This includes wilderness areas and streams where native trout may be restored. Trout from positive hatcheries will be stocked into waters where the parasite has been found to minimize the risk of contaminating other watersheds. Only trout from negative testing hatcheries can be stocked into waters where the parasite has not been found.

Subsequently, the Division of Wildlife released new research suggesting that the stocking of infected fish in WD+ reservoirs was increasing the level of infection in brown trout populations downstream (for highlights from the research, see the whirling disease page). CTU believes this research offers further evidence that the stocking of infected fish (even in habitats that already have the WD parasite present) can harm the resource. There have been many questions about how the DOW will – or will not – respond to these important new findings in their management programs, where "lightly" infected trout continue to be stocked in numerous waters around the state (the so-called "B waters").
"

http://parks.state.co.us/SiteCollec...eStewardship/Whirling Disease Information.pdf

I understand that few fisheries departments act with such disregard. Maryland, for example, has an aggressive testing policy and they did the right thing and closed the Bear Creek hatchery when WD was found.

"The discovery of whirling disease (Myxobolus cerebralis) at Bear Creek Hatchery in late 2006 led to the eventual closing of that facility. It has remained closed since early 2007."

http://www.dnr.state.md.us/fisheries/recreational/whirlingd/BCH08plan.pdf

Nevertheless, when a state such as Colorado with its many miles of trout habitat acts in such a way, is there any wonder that I dig into the the actual bills that are passed to see if the rules apply equally to the state employees and the fishing public?

Can we not agree that the fishing public and the state employees should be treated equally under the law? How can anyone, in this time in our history, say that a public employee carving out a privilege for himself over the public is acceptable?

Of course this does NOT excuse fly fishers from spreading the parasite.

However, there are two pieces of good news about whirling disease.

The first is that WD can ONLY occur where the intermediate host Tubifex worm (or sludge worm) exists. Trout become infected when they eat the worm and the Tubifex worm does not inhabit all waters.

Secondly, even highly infected waters like the Madison River which had its rainbow population devastated had recovered. This is the second piece of good news since rainbow are most susceptible to WD.

The answer to WD may be the DeSmet Rainbow Trout which is responsible for the recovery of the Madison River. 95% of the Rainbows in the Madison were resistant to WD in 2009. That answer is the DeSmet Rainbow Trout.

Vincent was Montana Fish Biologist responsible for turning the Madison River into an all natural reproduction River in 1974 and he is credited with saving Montana's wild fish.

http://fwp.mt.gov/mtoutdoors/HTML/articles/2004/DickVincent.htm

http://www.outdoorlife.com/blogs/gone-fishin/2014/04/montana-trout-fishery

Vincent, now retired, was the whirling disease coordinator at the Montana Dept of Fish, Wildlife and Parks.

See Vincent's explanation of how the Madison River recovered from WD and how he was the original biologist who saved the DeSmet Rainbow from extinction in the Intermountain West. And read carefully why he urges caution and further study before stocking these fish in other watersheds.

http://missoulian.com/lifestyles/re...cle_a5585588-acbc-5528-a2f0-f24caea09f59.html


"It's truly remarkable," said Vincent. "A decade ago, whirling disease had wiped out 90 percent of the Madison's rainbow trout. Today, we have a population that's highly resistant and bouncing back quite nicely." Vincent is recently retired from his longtime post of whirling disease coordinator at the Montana Department of Fish, Wildlife and Parks. Never in his wildest dreams did he imagine that before he stepped down he'd see Madison River rainbow populations at 70 percent of their historic numbers....

Vincent was an FWP biologist back in 1991 when he first noticed that the Madison's young rainbow trout seemed to be dying off. He scratched his head a bit, nursed some quiet suspicions, kept careful track of the numbers.

But years passed, and it wasn't until 1994 when he finally put a name to the problem - whirling disease. That's what they called it down in Colorado, where rainbows and other salmonid fish were circling the evolutionary drain....

Rainbow trout are not native to Montana. They came from California, a century ago and more, sloshing along the rails in water-filled milk jugs. At the time, a rainbow was a rainbow was a rainbow, despite the fact that distinct sub-species came from distinct watersheds.

One of those coastal watersheds - no one now knows which one - provided the rainbow trout that arrived at Wyoming's DeSmet Reservoir, out near Sheridan, back in the early 1890s.

Eventually Wyoming's fishery biologists killed off the DeSmet strain, in favor of a rainbow easier to catch, but not before Vincent got his hands on a few.

In 1977, Vincent trucked a load of Wyoming's DeSmet rainbows into Montana's Willow Creek Reservoir, near the tiny town of Harrison. That was long before the disease, and Vincent just wanted some good sport fish for the lake.

But the whirling disease parasite eventually arrived at the reservoir, too, "and it did wreak a bit of havoc, but not nearly as much as we expected."

That's because 30 percent of those wild DeSmet rainbows tested naturally resistant to the parasite. Everywhere else - including the Madison - only 1 percent of fish showed any resistance; which is why, in some Colorado rivers, some 98 percent of rainbows have been wiped out by whirling disease.

Today - what with the California roots lost to history and the Wyoming fish killed off - Montana remains the last known home of DeSmet rainbows. They persist only in Willow Creek Reservoir, and in a single high-mountain wilderness lake - and in both places they have proved highly resistant to whirling disease, killing the parasite before it burrows through the skin.

And although he has no definite proof as yet, Vincent is convinced their genetic heritage survives in one other river - the Madison. Perhaps, he said, they arrived by way of Hebgen or Ennis lakes, where a few Harrison fish were later stocked.

"Personally," he said, "I'm pretty sure some of those DeSmet fish escaped from Harrison and ended up in the Madison. Then evolution went to work, and selected out the ones that can handle the disease."

At Willow Creek Reservoir, where a solid DeSmet population initially proved 30 percent resistant, many rainbows died. But those that survived passed their resistance on to their offspring, and now some 98 percent have resistance.

Down in the Madison, where only a few escaped DeSmet fish are thought to have lived among other rainbows, just 1 percent of the fishery showed initial resistance. The fishery collapsed, with whirling disease claiming all but 10 percent of the river's rainbows. But again, with the presumed help of a few DeSmet genes, the survivors passed on their good fortune and now 95 percent test resistant.

"They're very well recovered from the darkest depths of the whirling disease," Vincent said. "The Madison is a surprising success story."

It is, he said, the only Western river known to have recovered on its own.

Vincent has tried to track the genetic history of those DeSmet rainbows, hoping to unlock the clues of disease resistance, but historic records are incomplete at best. He's not sure where in California they came from, for instance, or even if they survive there today.

"It's a real puzzle, actually."

He's also not sure how the DeSmet rainbows will fare in the long run, as they obviously are not evolved for the particulars of the Madison. How will they deal with seasonal water level changes, for instance, or warm water flows?

"That's one area we'll need to look at," he said. "Just who are these new Madison River rainbows? Because genetically, they sure aren't the same fish that were there 20 years ago. There's been a genetic bottleneck. Will evolution iron things out? I guess only time will tell."

That's why he's still advising caution, before biologists rush out to stock Montana streams with Harrison's DeSmet fish. Down in Colorado, and in Utah, where whirling disease has hit so hard, they've already started introducing Harrison's fish in hopes of also introducing parasite resistance.

In Montana, however, "it's not that bad, yet," Vincent said. "We know we have the stock, and we know it's not going anywhere, so let's not be hasty. Let's do some basic research before we go moving fish around willy-nilly."

After all, he said, it was moving species around that got us into this mess in the first place.

"The Madison is coming back," Vincent said. "Let's see how that turns out over time, before we take any drastic steps."


I wrote the above several years ago and the DeSmet Rainbows continue to thrive in the Madison River. I believe that is why there is very little written about Whirling Disease currently.
 
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fq13

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If temperature isn't an issue and you are wading wet? I I would recommend Chacho Z2 sandals and neoprene booties. They have a 5.10 climbing sole. It is sticky as heck and straps down tight enough to take a rapid swim. I have worn mine in the Grand Canyon, the Snake River and Yellowstone. They are awesome. Down side is that aren't a quick on and off. You have to cinch them down. Plus the rock climbing soles are soft and will mark up your boat and wear down if you use them on your daily walks on side walks, so save them for the river. They are not as sticky as felt, but they work.
 

silver creek

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It has now been 20 years since whirling disease devastated the Madison River.

Of all the invasive species that can be spread, WD seems to have already spread to most watersheds that can support it. If you read the articles on WD published in the last 5 years, very few address stopping the spread. There is acknowledgment that the proverbial "cat is already out of the bag." These articles address how the fisheries have adapted to WD, some with resistant rainbows like the Madison and others like Rock Creek becoming brown trout fisheries.

Here are two articles, one about Montana and the other about Colorado which was responsible in my opinion for spreading WD throughout the west by seeding its rivers with WD.


Whirling doom, gloom gone: Fish, biologists living with disease | Outdoors | ravallirepublic.com

"Officials called whirling disease the "single-largest threat to wild, naturally reproducing trout populations in the Rocky Mountain Region." Within a year of its discovery in Montana, the disease had spread to 14 streams, and people feared it would kill nearly all of Montana's prized rainbow trout population. A rapidly assembled task force asked for a crash research program. State biologists harvested nearly 1 million trout eggs from Canyon Ferry Lake to keep the state's fish hatcheries free from the disease.

But today, some fish biologists believe the crisis never materialized, in part because the fish adapted their behaviors."



Wild rainbow trout make a comeback 20 years after disease outbreak - UPI.com


"Wild rainbow trout are returning to the mountain rivers of Colorado for the first time in more than 20 years after an invasive parasite eradicated them and some other species in the Rocky Mountain West.

In 2015, wild rainbow trout were discovered in the Gunnison River in southwestern Colorado. These trout had a resistance to 'whirling disease,' a parasite called Myxobolus cerebralis, carried by tube worms, that attacks the cartilage of developing young fish. In salmonid fish, especially rainbow and native cutthroat trout, the disease attacks balance centers in the "fingerling" fish's skull and causes the fish to develop a bizarre tail-chasing whirling behavior."
 

jrp11948

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Yes, the Gunpowder is a the major trout stream in Central Maryland, a tailwater from a reservoir.
Wow, I just read some of the latest article, and even though I was a biology major (a long time ago) it's heavy reading. But one possible reason for low outbreak is "water activity or scouring". This was a factor in Western Maryland where we do have a heavy melt in the spring and very high, fast running water due to rain. Again, just a rumor from a state biologist in that area, who believes that the high water washes it out in the spring. It sounds like a mechanical action rather than chemical or biological. I would also think that very warm and slow moving water would be more susceptible.
Either way, I have not seen it in the rivers where I fish the most, thank goodness, and hope that it's main method for transmission is not fishermen.
 

JoJer

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It's good to have all this info collected in one spot. Might deserve a sticky so new anglers can get the history and science behind the marketing.
 

redietz

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I would also think that very warm and slow moving water would be more susceptible.
Oddly enough, that isn't the case. Didymo doesn't compete very well with other alagae, and seems to only bloom where the water is both too cold and too nutrient poor for other algae to bloom. That's why the most affected rivers are tailwaters. IN Gunpowder specifically the blooms are always in later winter, and diminish in size the further below Prettyboy you go. There's never a bloom of any consequence below Little Falls -- the largest tributary.
 

trev

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Reckon that scouring releases some phosphorus? Isn't that the climate connection, that reduced snowmelt results in less phosphorus leeching/washing into the streams? It's been a long time since I read up on it, so maybe I have forgotten.
I've wondered for many years why they don't just treat it with a dump truck load of phosphate whenever wherever it becomes a problem.
 
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