Are felt soles spreading invasive species?
Here's an interesting development for anyone who is accustomed to wearing felt-soled waders and boots when they wade southeastern Minnesota trout streams.
Effective April 1, Vermont has banned felt-soled waders or boots in state waters. The goal is to help curb the spread of aquatic invasive species such as whirling disease of fish and didymo, a microscopic algae more commonly known as "rock snot."
Why the focus on felt? Aquatic invasive species can be spread in a number of ways, but felt-soled boots are a notable contributor to the problem, particularly with microscopic species that spread through cells and spores. Felt is especially problematic because it is difficult to dry, clean or disinfect. Felt's woven fibers create voids that remain damp for long periods of time, and didymo cells and other small material can penetrate and occupy these voids. Recommended treatments have often been found to be ineffective at disinfecting these spaces.
Information on the role of felt-soled waders in the spread of aquatic invasive species can be found on the Center for Aquatic Nuisance Species website ( http://stopans.org ) by clicking on "The Science of Felt" link.
There are many alternatives to felt-soled boots available on the market now, as well as "homemade" remedies for people who don't want to throw out their felt-soled gear. For example, you can cut the felt soles off the boots and use a studded sole product that straps onto your waders or boots.
Or, if you have rubber boots but want more traction, add your own "studs" by screwing in half-inch hex-head sheet metal screws. This is an inexpensive way of using your current waders and boots after removing the felt soles. Specialized, hardened screws are also commercially available.