A few years back most of the major fly fishing apparel companies, led primarily by Simms, got heavily onto the rubber soled boot bandwagon. They explained (correctly) that transmission of exotic invasive species like didymo and whirling disease were seriously threatening the health of our nations’ waterways. Their argument was that anglers had to do something, even if it was only of minimal effectiveness, to help prevent this spread. Simms and its fellow manufacturers absolutely had pure motives here (their boots cost the same regardless of the type of sole used), but as time has passed the rubber soled boot movement has failed to gain as much traction with anglers as Simms would have liked.
All puns aside, traction is the key issue. Felt-soled boots were originally made way back in the day using the same felt that is used on the inside of pianos. This is a heavy, dense substance which holds up to a shocking amount of abuse and also provides terrific grip on almost all underwater surfaces. Simms touted its development, along with the Vibram sole company, of a new rubber which supposedly improved upon the older Aquastealth rubber boot sole technology, and the new material probably did. The problem is, no rubber boot made to date can match (or frankly even come close to matching) felt soles for traction. Consequently, slips and falls with rubber soled boots are absolutely more common than they would be if everyone used felt.
This is a tradeoff, then. Do we, as anglers, have an obligation to elevate our levels of personal risk via wearing rubber-soled boots in exchange for minimizing our negative impacts on the environment?
Whirling Disease Pathogen
Simms argues that felt soles on boots are the last surfaces to dry, and thus the most likely vectors to spread exotics from waterway to waterway. This argument presupposes that the primary way exotics are vectored is via anglers who almost-but-not-quite dry their gear before changing rivers. I respectfully disagree.
The primary vectors for exotic invasives are not wading anglers at all. They are birds, boat bilges, boat trailers, and plain old waterway interchanges. If a didymo spore hitches a ride on a bird’s feather, and finds itself in the headwaters of a favorable watershed a few miles away, that spore can colonize everything downriver from that point. And even when anglers are to blame, is it really likely that the felt soles of the boots, versus the soft material inside the boot, or the neoprene of the wader booties, or the mophead of that wool fly, were the mechanism by which the spore traveled? Anglers are covered in porous materials. The better question is: why? Why do diseases seemingly vector more easily today than they once did? What can we as anglers do about it?
There are a lot of answers why invasives transfer more today than historically, including angler affluence (including boat anglers), ease of transport (superior roads, airlines), greater numbers of humans using the water, and more. All of those factors impact how invasives get spread around. But the key factor, and this is especially true of fish pathogens like whirling disease, is homogenization.
By introducing the same closely-related species of fish (primarily McLeod River Rainbow Trout) across a huge swath of the continent, fisheries managers have made the same mistake as forestry officials who allow blanket planting of one kind of oak tree (currently undergoing a nationwide assault by the red oak borer pest). It’s the same mistake cotton farmers made in the years before the boll weevil. And it’s the same mistake banana farmers are dealing with as their single-line crops come under assault. At the end of the day, when millions of fish are all the same, you only need one very successful pest to square off against that homogeneous mass of fish, and that pest is primed to mow them all down.
“Healthy” Pellet-Fed Rainbow
versus Whirling Disease-Infected Rainbows
The solution to the problem is diversity. Diversity of species, diversity of types of watershed, diversity in what we as anglers consider to be acceptable species to fish for. Trout anglers in Georgia lamented the demise of the Chattahoochee River rainbow trout fishery below Morgan Falls Dam (a result of Atlanta’s expansion and subsequent runoff) for several years, until the Department of Natural Resources adapted by stocking Gulf-strain striped bass, a native species, in the river. Today Georgia fly anglers are as likely to target striped bass as trout, and the stripers are thriving.
Similarly, the stocking of California rainbow trout throughout the West, thereby supplanting native cutthroats in most of the watersheds east of the Rockies (including in Montana), created the disease pathway by which whirling disease was able to gain a foothold. Although native cutties are susceptible to whirling disease just like rainbows, one has to ask, would whirling disease have attained the critical mass needed to expand into native trout zones if not for the “breeding pool” it enjoyed in the form of all those stocked homogeneous rainbows?
Throwing out felt soled boots in an effort to support millions of stocked exotic invasive rainbow trout is wrongheaded and reflects anglers’ misplaced priorities. It is a band-aid, and a very small one at that, for a problem which starts with what we, as anglers, consider to be a proper target. In our quest to catch a fish native to California in every state in the Union, we have created pathogen highways that fall, like dominoes, with just one push. The solution is not to abandon felt and risk our personal safety, but instead to ask ourselves why we are trying to catch fish we can buy at a Kroger store in the first place. Reassess the priorities, and management will follow suit with more diversity of experience. And with diversity comes protection from exotic invasives.