written by therockyriver.com staff

By now, most serious fly anglers know all about the bans on felt soles. However, plenty of people have never heard them or know why they are happening, especially if the issue has not yet hit home.

The quick history of the origination of the felt bans begins in September of 2008, when Trout Unlimited called for the complete elimination of felt soles on all shoes, boots and wading gear. Their goal was to send felt soles into extinction by 2011. Just days later, Simms Fishing released a product line of wading gear and shoes that were completely felt-free. Weeks later, New Zealand announced a ban on all felt soles beginning on the first day of October in 2008. By 2010, Simms stopped selling felt soles altogether. Fast-forward to today, and you will find alternatives to felt in nearly every wader company’s catalog. Felt is now officially banned in Alaska, Vermont, Maryland and New Zealand, and Oregon and Montana are next in line. So, the question is – what is the big deal over felt?

The reason Trout Unlimited pushed this great American crusade, and the reason so many have joined the cause, is over the concern that felt is providing the perfect habitat to house and transport invasive aquatic species, particularly a nasty alga called didymo, or more commonly, “rock snot.”

Didymo, (didymosphenia geminataidymosphenia geminata) is a single-celled alga originally native to northern Europe, Asia and Scotland, and is historically found in cold, clear streams that are coincidentally the habitats of nearly all species of trout. It grows in strands up to 8 inches in length, that block sunlight from hitting the river floor and choke out the organisms in the system that rely on sunlight for photosynthesis. The impact on an ecosystem is substantial, and can be irreversible if the organism spreads wildly out of control.

Didymo was first found in the U.S. in 2007, and has since spread to Pennsylvania, West Virginia, New York, Maryland, Virginia, Vermont, New Hampshire, and most recently, Connecticut.

In 2006, the Federation of Fly Fishers held an international conference in which experts from around the world discussed the known and potential unknown consequences of didymo, as well as how it is spread. The conclusion was that anglers most commonly spread the invasive alga, but at the time experts believed other parts of boots were more to blame then felt. While the conference was being held, research was being conducted that held the scientific answers to the questions about the spreading of didymo.

A graduate student at Montana State University, Kiza Gates published her 2007 study on the effects of anglers in the transport of Whirling Disease. You can see the study in its entirety here. Gates found that the average angler who does not clean boots after a trip transports 0.59 ounces of sediment from one site to the next. By her careful calculations, anglers in Southwestern Montana alone relocated over 3 tons of sediment in 2005. She also found that anglers from other states carried 1,600 pounds of sediment to and from Montana. In the course of her work, she even found one boot with a mud snail from New Zealand trapped in it.

Gates later did follow-up research on her Whirling Disease study, and found that felt trapped 100% of the spores that the material was exposed to. On the contrary, the rubber soled boots that were tested trapped 0% of those same spores.

Many other studies have been conducted since Gates’ 2007 research, and scientific evidence proves that not only are anglers the main cause for the transport of invasive species, including didymo, but that the biggest offender is felt. The reason is because of the structure of felt itself, which is basically a dense carpet of spaces between interwoven fibers. This material not only provides the perfect trap for aquatic species, but it stays moist for a very long time after it has been removed from the water. This means aquatic species can live in the felt for weeks in the truck or garage, until the gear is again used in the water.

There are guidelines in the U.S. for cleaning felt soles after a trip, but the methods are inconvenient and involved, and the reality is most people are not going to take the time to perform this ritual religiously. Furthermore, unless you heat your boots up to 113 degrees (F) for a half an hour after each trip, there really is no way to guarantee the complete disinfection of didymo from felt. So, this leaves an all-out ban as the inevitable option, and that is what we are starting to see across North America.

There are select groups of anglers that will voice strong opinions against the felt bans, but the reasoning is based on conclusive scientific evidence that felt is a major enabler – albeit not the only one – of the spreading of invasive species and diseases in water systems. Outfitters, organizations and companies recognize this and are working toward providing legitimate alternatives to older products like felt, and better products – for the angler and the environment – will continue to come out each year.

To the people who hate the fact that felt will ultimately be banned across the United States, please keep in mind that the reason for it is so that we all can continue fishing in the beautiful places that we love… even if it is a little less convenient or different for a while.