News from the DNR Office of Communications

Felt Sole Ban In The Works For Maryland Streams

Proposed regulation will help stop spread of didymo

Annapolis, MD (May 24, 2010) — Based on scientific advice from the Maryland Department of Natural Resources (DNR) Invasive Species Matrix Team, DNR is moving forward with a regulation to ban the use of felt-soled boots and waders in Maryland waters. The ban on felt soles was introduced at the May 17 public scoping meeting in Annapolis, and would help to prevent further spread of microorganisms that infest the State’s waters and, when overgrown, damage water quality and impair fishing and boating opportunities.

“You couldn’t find a more effective method for transporting microscopic species from one place to another than the felt soles used by anglers,” said Jonathan McKnight, Associate Director of DNR’s Wildlife & Heritage Service. “Felt is an excellent collection material, and it stays wet over time between locations, which allows organisms to survive.”

One of the most damaging microorganisms transported by felt soles is didymo, also known as rock snot, an alga that thrives in cold-flowing fresh water. Individual didymo organisms are microscopic, but infestations can include enormous numbers. The resulting mass is an unsightly, yellow-brown slime layer that makes streams and rivers unattractive and nearly impossible to enjoy. DNR scientists and anglers have found seasonal infestations of didymo in the Gunpowder River and traces of the organism in the Savage River.

Numerous other diseases and harmful species can be carried on felt soles, including whirling disease, which is fatal for trout.

This regulation to prohibit the use of felt-soled boots and waders in Maryland may become effective in January 2011. Alaska and Vermont have already moved to prohibit felt soles, and felt has been banned in New Zealand streams since 2008. Many anglers are aware of the risk and have switched from felt soles to rubber soled waders, and some manufacturers have discontinued felt-soled boots and waders.

Concerned citizens are encouraged to send in their thoughts on banning the use of felt-soled boots and waders in Maryland to

DNR will be reaching out to the angling community over the summer to seek comment and input. The next public scoping meeting will occur in September prior to the submission of the felt-sole ban regulation. Information about this regulation initiative and the schedule for next public scoping event can be found at

   May 24, 201000

Contact: Josh Davidsburg
410-260-8002 office I 410-507-7526 cell

The Maryland Department of Natural Resources (DNR), which celebrated its 40th anniversary in 2009, is the state agency responsible for providing natural and living resource-related services to citizens and visitors. DNR manages more than 467,000 acres of public lands and 17,000 miles of waterways, along with Maryland's forests, fisheries, and wildlife for maximum environmental, economic and quality of life benefits. A national leader in land conservation, DNR-managed parks and natural, historic, and cultural resources attract 12 million visitors annually. DNR is the lead agency in Maryland's effort to restore the Chesapeake Bay, the state's number one environmental priority. Learn more at