Rock snot!

Just about a decade ago, I started noticing more green muck on the Delaware riverbed than ever before. It was sudden, and dangerously slippery; a slimy algae had spread throughout the watersheds of the northeast, covering rocks and making wading frighteningly perilous, and it was as if it had come out of nowhere.

We called it rock snot.

You couldn’t drift a nymph without getting your fly covered in rock snot. The shit was everywhere, and nobody knew where it came from.

It was so sudden, and perhaps for that reason most of us never questioned the narrative that it was an invasive species. Nothing like the bloom of rock snot, or didymo, had been witnessed before in the Delaware system. So naturally the narrative that rock snot was an invasive species was embraced nearly universally by anglers; and also by fishing industry insiders, who told us to give up our felt soled wading boots, and to buy a new pair of boots with vibram soles, which were marketed as an environmentally friendly alternative to felt, and technological fix for the problem of rock snot.

State legislatures across the nation banned felt soled wading boots to solve the problem of the rock snot.

So, anglers were expected to buy a new pair of vibram soled wading boots, and to throw out their disease spreading felt.

This seemed so ridiculous that I remember wondering why, at the time, the rock snot wasn’t gonna be spread by birds, no matter whether we wore felt boots or not. The millions of heron, mergansers, ducks and geese, that travel from river to river, all presumably spread didymo faster and more efficiently than the few thousands of anglers that were targeted with legislation banning felt soled boots in the aftermath of the discovery of didymo in our waterways.

But state legislatures everywhere decided to ban felt soled wading boots. Nearly every angler, including me, bought a pair of vibram soled wading boots to help solve the problem of the rock snot.

How is it that such ridiculous narratives are spread, leading to legislation banning gear with decades of history and use, but ignoring the obvious cause of the problem that every angler should have recognized and inferred when we first noticed the river bottom was covered in green slime, aka rock snot?

Why weren’t we talking about climate change?

The U.S. House of Representatives passed a rule a few years back suppressing scientific testimony at EPA hearings and elevating the testimony of financially motivated industry lobbyists. Suppression of science is the law of the land in the United States, if the truth interferes with capitalism.

The narratives that emerge, and the actions we take to solve problems, evolve in a context of suppression of science. They are delusional, or perhaps even psychotic, in their insistence upon “truths” that are disseminated deliberately to the public, consistent with the agenda of industry lobbyists and corporate insiders.

So let’s recap the rock snot story: just a few years back, we were told to throw away our felt soled wading boots.


Because anglers were said to be spreading an invasive species of algae called didymo.

The story was elaborate, and local anglers all knew it:

Didymo got on to the felt soles of our wading boots, and, if we didn’t treat our boots with an herbicidal bleach solution, then we would be the cause of the spreading of rock snot.

It was best to just buy a new pair of wading boots, without felt soles, and better still to buy a new pair of wading boots for every river system you fished, just to be sure you weren’t cross pollinating your favorite streams with the rock snot. Buying lots of boots was the angler’s way of protecting the environment, or so we were told or otherwise required to do by law.


Well, it turns out didymo isn’t an invasive species after all. It’s a “sentinel” species of algae that blooms in warm water conditions. It warns us of changes occurring within the environment. Scientists are discouraged from talking about it, at least before government agencies, both in the United States and Canada.

Please see

What’s changing? Well, water temperatures are getting warmer.


Climate change, of course.

Now before we start considering conspiracy theories, just keep in mind that, the average fisherperson sees changes in the aquatic environment before anyone else does. We were the first to see the rock snot blooming all over the Delaware River. Our flies were covered in it.

And instead of telling the world that we were observing changes to the ecosystem that might be related to climate change, we embraced a narrative that the rock snot was somehow our fault, and that we needed to buy new wading boots, from the big corporations that manufacture them.

At about the time this shit was all going down, Simms (America’s number one manufacturer of wading boots), announced it was no longer making felt soled boots.

That was about 2012, and let me guess that since then, profits from the sale of boots are up considerably…

Please read the comments below for helpful fact checking…

4 responses on “Rock snot!

  1. avid reader

    Yep. A couple of small corrections though. Rock snot is not really green but kind of a brownish gray. Do they have a name for that color? It’s not khaki but close. And it’s not caused by warm water temperatures – at least not directly – but by a decrease in phosphorous levels in water. Which might be caused by climate change. I’m just basing this on the article you linked to. I don’t actually know shit about rock snot. But I have noticed that it doesn’t correspond to water temperature, or else the lower Mainstem would have a lot more of it than say the Esopus, which is often so choked with rock snot it’s unfishable. All of this is to say that you should really choose one of your more talented contributors to this site and pay him say $40/hour to factcheck your articles, now that you’ve laid off your entire unpaid writing staff and chosen to go solo. I won’t say who you should hire, but the choice really should be obvious.

    1. goldenbeetle Post author

      Yes. I need a fact checker.

      I actually didn’t read the article that I linked to…


      You’re (re)hired.

  2. goldenbeetle Post author

    Here’s a comment from JK:

    Good article.
    I think it lacks emphasis on the corporations who gain from silencing scientists, a little, I think, and the political party who is their payed subsidiary. And the laws they create. A minor problem. I’d recommend checking out the links to see just how nefarious this is.
    Bitter much about buying new boots? Ahahaha. I couldn’t tell from the article. You hardly mentioned it.
    And it gave absolutely no credit to me, you scammer.
    Big problem.
    The delusion of consuming one’s way out of a problem created by consumption is pure capitalist bunk, which I hope people are coming to see creates a lot of serious problems.
    Particularly when we choose to ban scientific knowledge to perpetuate our delusional social system. This has happened in the past. We call it now the Dark Ages. Remarkable the myths we believe and continue to want to believe.

    To satisfy our desire to do “right”, at least we’ve progressed from self-flagellation to more comfortable boots.
    But the delusional system is the same.

    1. goldenbeetle Post author

      I think there’s something very complex going on, that is also very very simple, if that makes sense .

      We’re all very happy with problems that can be solved by buying new gear. Even the cheap environmentalists amongst us. So I wasn’t bothered at all by the new rules. I was happy to buy new boots.

      I was especially happy to know it was for a good cause.

      The dynamic that interests me is the general effect of suppression of science, to give voice to commercial advertisements that purport to solve problems that are within the domain of science. Scientists should be identifying and solving these problems, but they’re not.

      Simms and Orvis publish ads that tell us how to solve the problem. Scientists aren’t consulted at all.

      The House Rules on EPA Testimony were from 2014. The rock snot event basically culminated in 2012, when Simms declared it was no longer manufacturing felt soled boots. So there is no direct causation, no identifiable actors in a conspiracy, but instead a culture that has existed for some time now, where science is suppressed, and corporate narratives, and commercial solutions (buy boots) are sort of the cultural reflex. As you said, the delusion of capitalism; consume more to solve a problem of consumption. But again, my interest is also in our complicity with this narrative. We want to buy the boots, just give us a reason. You should look at the article again – I added an Orvis ad that I think is interesting…

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