MONKTON, Md. – As an algae with a gross nickname invades pristine trout streams across the U.S., Maryland is about to become the first state to enforce a ban on a type of footgear the organism uses to hitchhike from stream to stream: felt-soled fishing boots.
The state Department of Natural Resources plans to prohibit wading with felt soles starting March 21 to curb the spread of invasive organisms that can get trapped in the damp fibers and carried from one body of water to another.
Similar bans will take effect April 1 in Vermont and next year in Alaska, aimed especially at didymo, a type of algae that coats riverbeds with thick mats of yellow-brown vegetation commonly called "rock snot."
Maryland fishery regulators say didymo, short for Didymosphenia geminata, can smother aquatic insect larvae such as mayflies, stoneflies and caddis flies that are favored food for trout.
"We've got to keep it from spreading," said Jonathan McKnight, associate director of the state Wildlife and Heritage Service in Maryland, where didymo was found in 2008 in the Gunpowder Falls north of Baltimore. A western Maryland stream, the Savage River, also has tested positive for the organism but hasn't had a rock snot bloom.
Didymo, pronounced DID-ee-moh, isn't a stream-killer like acid mine drainage. Fish have adapted in the northern rivers where it first appeared, but biologists can't say for sure how it will affect the ecology of Maryland waterways.
"I think the cautionary approach to that would be to assume it's going to have some adverse impacts and respond accordingly," said Ron Klauda, a Maryland freshwater fisheries biologist.
Maryland officials are taking public comments through Feb. 28 on their proposed ban. They say 2011 will be an "education year," with violators getting warnings and information cards instead of tickets. Fines and penalties haven't yet been determined and won't be effective until 2012.
A U.S. Agriculture Department map shows didymo in at least 18 states as of 2008. New Zealand has banned felt soles to protect its trout fishery.
Some anglers and policymakers, however, aren't sold on the felt-sole ban. Many anglers prefer felt to rubber — even newer, supposedly stickier rubber compounds — because they believe felt gives better traction on slippery, rock-strewn riverbeds where losing one's footing can be disastrous.
"We're going to have injuries. We're going to have people messing up their knees," said Mark Mayer, who traveled from Chattanooga, Tenn., to fly-fish the Gunpowder Falls in June.
A proposed felt ban introduced this year in the Oregon legislature is almost certainly doomed after a state Department of Fish and Wildlife official testified that the agency's own employees prefer felt soles.
"Certainly, going to no (felt) soles would reduce one vector of the spread of invasive species, but only one vector," said Oregon Department of Fish and Wildlife spokesman Rick Hargrave. Didymo and other organisms also cling to waders, shoelaces and boat hulls, experts say.
Hargrave said what's needed is "a very holistic, rigorous program" to address the bigger issue of invasive aquatic species.
Oregon state Rep. Brian Clem, Democratic co-chairman of a committee that held a hearing on felt soles in early February, said the cost of replacement gear is another problem. Simms Fishing Products, which voluntarily discontinued felt-soled wading boots last year, offers rubber-soled boots priced from about $100 to $220.
"We don't want to price out and potentially take safety risks on a huge number of people who love this sport, many of whom come to this state to enjoy it," Clem said.
The conservation group Trout Unlimited asked manufacturers in 2008 to stop producing felt-soled footwear by 2011 to curb the spread of didymo and other aquatic nuisances. Not all have complied, but most are working on alternate materials and designing boots that clean up easier and dry faster, making them less hospitable to microbes, said David Kumlien, who heads Trout Unlimited's Aquatic Invasive Species Program.
Kumlien testified in support of the Vermont felt ban but he said Trout Unlimited isn't lobbying for prohibition, partly because felt soles aren't the only culprits. Instead of seeking felt bans, Trout Unlimited is encouraging everyone who works or plays on the water to "inspect, clean and dry" their gear after use. Montana is promoting that approach with public service ads urging people to "Stop aquatic hitchhikers!"
Still, the felt-ban debate has been helpful, Kumlien said.
"While a ban on felt soles doesn't solve the invasive species problems, it's something that will reduce the risk of anglers moving invasive species," Kumlien said. "And quite clearly, it's gotten people's attention."