# Mysterious 'rock snot' algae threatens Michigan's coldwater trout streams



## Steve (Jan 15, 2000)

Mysterious 'rock snot' algae threatens Michigan's coldwater trout streams


A mysterious algae that could devastate Michigan waterways was spotted in the Lower Peninsula for the first time last month, which worries biologists.



www.detroitnews.com


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## PunyTrout (Mar 23, 2007)

Bummer.


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## Fishndude (Feb 22, 2003)

And that's _*exactly*_ why felt soles on waders are banned in Alaska, and some other States. In the Upper Big, eh? Not hard to imagine it will end up in the Little, and Betsie, and PM, from there. Lots of people hit a couple/few of those rivers in any given weekend.


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## Hunters Edge (May 15, 2009)

It would appear if it will effect fish in rivers, it will ultimately effect the great lakes fishery. If spawning fish coming into rivers to spawn their young will have a dramatic low survival rate. In effect lowering fish numbers in both the rivers and ultimately in the great lakes. I hope they figure out how to eliminate or reduce this threat to the state, neighboring states and Canada.


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## Steve (Jan 15, 2000)

Seems strange. Not an invasive. What is making it pop up now if it was always here.


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## VetHuntRookie (Sep 18, 2021)

Fishndude said:


> And that's _*exactly*_ why felt soles on waders are banned in Alaska, and some other States. In the Upper Big, eh? Not hard to imagine it will end up in the Little, and Betsie, and PM, from there. Lots of people hit a couple/few of those rivers in any given weekend.


I’m confused why felt sole waders are the issue. Is it because the algae stick to it?


-VHR


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## Steve (Jan 15, 2000)

VetHuntRookie said:


> I’m confused why felt sole waders are the issue. Is it because the algae stick to it?
> 
> 
> -VHR


Sure and move it from water to water.


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## Shoeman (Aug 26, 2000)

I've fished waters with the snot, mostly down South. During high water events (down there several times a week) one had to look for out of current spots in order to get a clean drift.


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## B.Jarvinen (Jul 12, 2014)

I experienced it fishing on the St Mary’s, in mid-June, the first year of the pandemic. That was concerning but when I read up on it things only became more mysterious, not less. Because it seems to be a native species in the Lake Superior basin. It either blooms, or it doesn’t. Maybe it has some odd water chemistry niche they haven’t been able to figure out yet, I sure don’t know.


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## Boardman Brookies (Dec 20, 2007)

VetHuntRookie said:


> I’m confused why felt sole waders are the issue. Is it because the algae stick to it?
> 
> 
> -VHR


All kinds of stuff gets stuck in felt. Many states have banned them. With the stream beds here being mainly sand I dont see the need to use felt. Out west is a different story with the slippery rocks, but again, a lot of places they are banned.


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## VetHuntRookie (Sep 18, 2021)

Boardman Brookies said:


> All kinds of stuff gets stuck in felt. Many states have banned them. With the stream beds here being mainly sand I dont see the need to use felt. Out west is a different story with the slippery rocks, but again, a lot of places they are banned.


Interesting. I have only done wet wading so I didn’t know that about felt soles. I need to change my Cabela’s wish list then.


-VHR


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## Cork Dust (Nov 26, 2012)

Boardman Brookies said:


> All kinds of stuff gets stuck in felt. Many states have banned them. With the stream beds here being mainly sand I dont see the need to use felt. Out west is a different story with the slippery rocks, but again, a lot of places they are banned.


The issue regarding source and spread is broader than felt soled wader boots.:
The primary way for didymo to be spread is unknowingly by anglers, kayakers, canoeists, tubers, boaters and others engaging in water-based recreation. The microscopic algae can cling to waders, boots, boats, clothing, lures, hooks, fishing line and other equipment and remain viable for several weeks, even in seemingly dry conditions.

There are currently no known methods for controlling or eradicating didymo once it infests a water body.

Felt sole wading boots are a principal "culprit" because they just happen to take a long time to dry their core material completely. Diatoms as a class are high on the nutrient content scale for the invertebrates that feed on them. Concentrations of silicon dioxide SiO2 play a key role in diatom bloom longevity since this compound has very low solubility in water and composes much of their cell membraine structure. However, in streams with steady flow rates and high nutrient content runoff sources, other than groundwater inflows as water recharge sources within the watershed, this diatom can be quite detrimental largely because it displaces other attached algae and micro-invertebrates that are far more beneficial and nutritious to members of the food web. There are a whole array of aquatic insects in the stonefly, mayfly and some caddis fly members that wander around grazing on the attached algae and aquatic fungus clusters on these rocky substrates.


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## Cork Dust (Nov 26, 2012)

Boardman Brookies said:


> All kinds of stuff gets stuck in felt. Many states have banned them. With the stream beds here being mainly sand I dont see the need to use felt. Out west is a different story with the slippery rocks, but again, a lot of places they are banned.


A good soak, post use, in a bath of 10% chlorine bleach will kill rock snot and many other microscopic invasives, along with snail and invasie mussel and snail larvae (glochidia). Sun exposure, due to the effect of UV light bands, is good for smooth surface items like waders, rods and lines, but avoid long interval exposure.


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## Boardman Brookies (Dec 20, 2007)

Cork Dust said:


> A good soak, post use, in a bath of 10% chlorine bleach will kill rock snot and many other microscopic invasives, along with snail and invasie mussel and snail larvae (glochidia). Sun exposure, due to the effect of UV light bands, is good for smooth surface items like waders, rods and lines, but avoid long interval exposure.


That is a great reminder. We all need to do out part. Thanks for posting that


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## Cork Dust (Nov 26, 2012)

Here is a good summary of its spread history:



https://sdleastwanted.sd.gov/docs/conservationdigest/Didymo.pdf


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## riverbob (Jan 11, 2011)

thanks cort dust, thats good to know, i'm on my way to go fishing (lucky me) now i'll get this off my chest, alot of people don't care/ give a ****, it's all about them, there going to do what they want n the hell with the rest of us,,,,,,,,,,,,,,,,, just like the 19 shot ,,,,,,,, i hope i'm wrong


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## METTLEFISH (Jan 31, 2009)

Steve said:


> Sure and move it from water to water.


What makes you think it’s not already there? (Everywhere) Organism lay dormant for years awaiting conducive conditions to grow.


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## Steve (Jan 15, 2000)

METTLEFISH said:


> What makes you think it’s not already there? (Everywhere) Organism lay dormant for years awaiting conducive conditions to grow.


Sounds like that is the case in many places, but why transfer it to new places if we can take measures not to.


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## Shoeman (Aug 26, 2000)

I'm sure certain conditions can create a larger bloom


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## METTLEFISH (Jan 31, 2009)

I would definitely prefer to not spread it. However, is that at all possible?


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## Steve (Jan 15, 2000)

Boardman Brookies said:


> It is really bad in the upper Manistee. I was tossing weighted streamers and a sink tip this weekend and was picking up chunks of this crap constantly.
> 
> 
> Sent from my iPhone using Michigan Sportsman


Not good.


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## BMARKS (Nov 6, 2017)

It is def the felt boots, not the thousands of people with swimwear all summer, the boats and trailers, the waterfowl, the aquatic mammals. nope def only spread from felt boots.


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## M. Tonello (Sep 20, 2002)

Some good news at least so far. EGLE has conducted surveys on the Au Sable, Betsie, Boardman, and Platte Rivers, and hasn't found any more Didymo. They're planning to survey the PM and Muskegon Rivers next week, followed by other rivers as time allows. Also- EGLE has new signs printed up and they're working with our Parks and Rec folks to get the signs posted at Upper Manistee access sites.


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## AdamBradley (Mar 13, 2008)

BMARKS said:


> It is def the felt boots, not the thousands of people with swimwear all summer, the boats and trailers, the waterfowl, the aquatic mammals. nope def only spread from felt boots.


All those are potential contributors as well… just saying, IMO they are not needed in any Michigan water I have fished. Comparable to the recent steelhead reduction as a “net zero negative impact on the population, but rather a precautionary action”, why not apply the same logic here?

I may be in the minority on this one from the sounds of it, but, alas, just a personal opinion.


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## Botiz (Oct 21, 2010)

BMARKS said:


> It is def the felt boots, not the thousands of people with swimwear all summer, the boats and trailers, the waterfowl, the aquatic mammals. nope def only spread from felt boots.


The swimmers and boaters should also take steps to minimize their risk of spreading but that in no way relieves you or your responsibility to do the same.


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## BMARKS (Nov 6, 2017)

Botiz said:


> The swimmers and boaters should also take steps to minimize their risk of spreading but that in no way relieves you or your responsibility to do the same.


I am at zero risk of spreading any invasive species because all of my current gear has only ever been in the water of one river. the point is, guys buying different boots is not the answer to stopping invasive species.


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## DumpsterDiver99 (8 mo ago)

I've fished the Savage in western Maryland pretty extensively. It's a hell of a river but it's full of rock snot. Makes wading suck more than it should, half the time it feels like you're walking across a slip 'n slide lol. However, the Savage still has about 1000 wild browns and about 250 native brookies per river mile so I'm skeptical on the notion that it inhibits significant spawning habitat. It mainly clings onto larger rocks, rather than the gravel that trout require to spawn in. However, it absolutely sucks to get around. Maryland has banned felt soles for a reason. Algae species are spread by spores, and they are far smaller than seeds and virtually invisible to the naked eye, especially against felt soles. Those things might as well be gill nets for algae spores.


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## riverbob (Jan 11, 2011)

DumpsterDiver99 said:


> I've fished the Savage in western Maryland pretty extensively. It's a hell of a river but it's full of rock snot. Makes wading suck more than it should, half the time it feels like you're walking across a slip 'n slide lol. However, the Savage still has about 1000 wild browns and about 250 native brookies per river mile so I'm skeptical on the notion that it inhibits significant spawning habitat. It mainly clings onto larger rocks, rather than the gravel that trout require to spawn in. However, it absolutely sucks to get around. Maryland has banned felt soles for a reason. Algae species are spread by spores, and they are far smaller than seeds and virtually invisible to the naked eye, especially against felt soles. Those things might as well be gill nets for algae spores.


 that's good to hear n welcome


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