To Prevent the Spread of Didymo:
1.Before coming to the park, clean all gear and equipment by:
• REMOVING debris and strands of alga from your gear
• CLEANING all gear in 2.5-5.0% solution of household bleach and hot water for 10 minutes. Hard to remove debris should be scrubbed with a biodegradable detergent.
• DRYING all gear to touch, and then continue drying time for at least 48 more hours.
2.Use only clean, thoroughly dried gear and equipment
3.Report sightings of suspect algae to Great Smoky Mountains National Park staff
From the National Park Service:
https://www.nps.gov/grsm/learn/nature/didymo.htm