'Rock snot' prompts Missouri to consider ban on felt-soled boots

Sunday, October 24, 2010 | 8:32 p.m. CDT; updated 7:50 a.m. CDT, Tuesday, October 4, 2011
Felt-soled boots are still for sale at Bass Pro Shops in Columbia. The Missouri Department of Conservation could soon ban felt-soled boots because of the alga "rock snot," which can be spread after anglers wearing the boots tread through infected waters. Fragments of the alga become embedded in the boot soles.

COLUMBIA — An invasive goo dubbed "rock snot" that is encroaching on southern Missouri’s cool-water streams has prompted consideration of a ban on felt-soled boots in state waters.

The ecological threat, commonly known as Didymo, is an invasive alga recently found in the tail waters of Bull Shoals Dam in northern Arkansas, about 10 miles south of the Missouri border. Legs of Bull Shoals Lake stretch into Missouri.



  • A proposal is made to the Department of Conservation’s Regulations Committee.
  • If the committee approves, Department of Conservation Director Bob Zeihmer is notified, and he makes a proposal to the Missouri Conservation Commission, which governs the department.
  • Approval by the Conservation Commission means the regulation is adopted in the wildlife code.

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Tim Banek, invasive species coordinator for the Missouri Department of Conservation, said the muck has prompted his agency to begin developing regulations that would prohibit felt-soled boots and waders in public waters. Felt soles are the most likely avenue of transport and contamination, he said.

Fragments of the alga easily transport via felt soles because the alga embeds into the spongelike material after anglers walk on it, Banek said. The process is known as fragmentation, and the department recommends that any fishing equipment, not just felt soles, be allowed at least 48 hours to dry before being used again.

The threat of the alga, according to the Conservation Department's website, is it "can overwhelm native species and disrupt the food chain," which supports fish, such as bass and trout, as well as salamanders, frogs, birds and mammals.

The website said people have reported eye inflammation after swimming in waterways infested with the alga.

Only one cell of rock snot is needed for it to eventually take over cold, spring-fed streams that are abundant in the Ozarks, Banek said, and "it gets so thick, you can't fish."

Although Arkansas has yet to take action on felt soles, many other states, as well as New Zealand, have passed regulations.

Vermont passed a statewide ban on felt-soled boots for all waters, public and private, effective April 1, said John Hall of the Vermont Department of Fish and Wildlife.

"It's going to be interesting," he said. "It's a major concern for fish habitats. We're going to have to get the word out, so retailers can be prepared."

Jim Marcotte, executive director of Alaska's Board of Fisheries, said the state passed a regulation on felt soles that takes effect in 2012. The regulation only applies to felt soles while fishing, both commercial and recreational.

New Zealand, according to its government website, has banned felt soles, and the crime of knowingly spreading the algae carries a sentence of up to five years in prison and a $100,000 fine.

Banek offered no timeline for any felt-sole regulations in Missouri. The first step is education, he said.

“We have to do our homework, “ he said. “We want to make sure the public is behind this.”

The regulation of felt soles in Missouri would be limited to public waters; owners of private land would have to make their own decision, Banek said.

Larry Whiteley, manager of communications for Bass Pro Shops based in Springfield, said the retailer developed Eco-Clear boots that make use of crushed walnut shells for traction. The crushed shells are embedded in a rubber compound designed to keep the alga from attaching.

Whiteley said the chain also offers boots with detachable felt soles and boots with metal cleats. If necessary, Bass Pro Shops would eliminate felt-soled boots from its product line, which he doesn’t suspect would hurt revenue.

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Ray Shapiro October 25, 2010 | 1:32 p.m.

Better to ban felt-soled boots than currently legal dog kennels which will be destroyed if Proposition B gets passed and HSUS, the spawn of PETA becomes the new Didymo Rock Snot of Missouri's dog, animal, livestock and agricultural industries.
Give Proposition B the boot!

(Report Comment)
Chris Cady October 25, 2010 | 2:48 p.m.

Your off-topic rant is not going to change anyone's mind, and just makes you look ignernt.

As for the topic, one thing that would have made a better story would have been something about where this algae came from and how it got to Arkansas. Inquiring minds want to know that sort of thing. I don't think it's been talked about so much that most everyone knows this already, like they do with the Asian carp for example.

(Report Comment)
Ray Shapiro October 25, 2010 | 3:31 p.m.

"Ignernt" enough to get you to post a comment on Rock snot, thank you very much...

(Report Comment)
Moian Reader34 October 26, 2010 | 12:34 p.m.
This comment has been removed.
John McLaughlin October 26, 2010 | 3:08 p.m.

Hello, this is John McLaughlin, the reporter who wrote the article.
Chris, thank you for reading. I agree some background information would have helped this story, and I'm gathering additional information for a later update. For this story, I focused mostly on the regulation aspect, as I thought it would be the best avenue for breaking the topic. I'm continuing my coverage and appreciate your input. Thanks.

Moian, thank you too for reading. I am unaware of other Missouri coverage on this topic, aside from the Missouri Conservationist's September issue. To clarify, the soles are the most likely way the alga transports, not the only one. Thank you for bringing that to attention. The conservation department recommends all equipment making contact with infested waters be allowed to dry completely for at least 48 hours. Thank you for the input.

(Report Comment)
L Williams November 3, 2010 | 9:17 a.m.

In theory, everything in the food chain has a natural predator or eater, no? So usually I wonder what organism(s) would feast on any identified "problem" species. In other words, what is Mom Nature's natural answer to the problem of the Didymo Rock Snot alga banquet table? If that's not a compounding problematic factor, then introduction of either rock snot eaters or über-competitor species would be worth reading about, if not actual lab & field testing, methinks.

Thanks for a good, informative article. I was unaware of this issue, and would hate to encounter the problem in the wilds.

(Report Comment)

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