Created on Thursday, 24 July 2008 06:09
Last Updated on Thursday, 24 July 2008 06:09
Friends of the Mad River is urging local residents and visitors to do their part in preventing the spread of the invasive alga didymo.
Didymo, or "rock snot," is an invasive nuisance alga now known to be present in the main stem of the Mad River. It can be easily spread on fishing gear, clothing and other recreational, scientific or construction equipment that contacts the water. In addition to didymo, there are many other invasive species that can "hitchhike" on gear or people and move between water bodies.
"We are all responsible as stewards of the waters of Vermont to clean any gear or equipment used in any river before moving to another water body. Please help get the word out about didymo: The Friends of the Mad River (FMR) have didymo warning signs available for riverside landowners to post along sections of the river which might get some use from the public," explained Caitrin Noel, FMR watershed coordinator.
The public access locations on the Mad River have been posted with signs, although unfortunately several have been removed at least once. The signs can be picked up at the General Wait House (next to the Waitsfield Elementary School), or at the didymo information table at the Waitsfield Farmers' Market on July 26 or August 9.
The State of Vermont Department of Environmental Conservation suggests users take the following steps to prevent the spread of didymo and other invasive species upstream in the Mad River, to tributaries, or to other water bodies:
• Disinfect your gear and boat before traveling between different bodies of water or watersheds (see below).
• If you move around to fish, boat, play or work, construct and use a simple, portable disinfection kit.
• When possible, fish, boat, play or work in a single water body in a single day, rather than traveling between multiple watersheds without appropriate precautions.
• Visually inspect your boat, gear and equipment before entering and leaving the water. Remove all plants, plant fragments, animals, mud or other debris and discard in the trash.
• When practical, fish in a downstream direction. This doesn't mean you can't wade upstream a bit to fish that nice run upstream -- think on a watershed scale. By fishing at the mouth of a large river in the morning, then going to the headwaters in the afternoon without disinfecting your gear, you've potentially spread didymo upstream to the whole stream, which may not have been previously infected. Most algae and aquatic invasives/pathogens can't swim upstream.
• Anglers: Consider the use of easily disinfected wading gear. For example, rubber-soled wading boots with cleats are easier to disinfect quickly than felt-soled boots.
• Anglers, guides, outfitters: Designate waders/boots/canoes/tubes for different watersheds or have multiple sets available for same-day travel, when needed.
• Canoeists, kayakers, boaters, tubers: Remove drain plug and drain any water prior to leaving boat loading/unloading area. Don't move water between water bodies.
There are a number of disinfection techniques that will kill most aquatic invasive species and fish and wildlife pathogens, including didymo. Solutions of bleach or dishwashing detergent products are suggested as they provide the best combination of availability, cost and effectiveness against didymo as well as other aquatic invasive species and fish and wildlife pathogens, such as whirling disease. Choose the appropriate agent based on the actual items requiring disinfection (i.e., bleach solutions will destroy some items). It is recommended that all disinfected equipment be rinsed on dry land, away from state waters. It is preferable to drain used solutions into treated wastewater (e.g., pour down a sink drain).
• Using dishwashing detergent: soak and scrub for at least one minute in 5 percent solution (add 6.5 ounces of detergent with water to make one gallon). 'Green' products are less effective and not recommended for disinfecting.
• Using bleach: soak or spray all surfaces for at least one minute in 2 percent household bleach (2.5 ounces with water added to make one gallon). Bleach solutions must be replaced daily to remain effective.
• Using hot water: soak for at least one minute in very hot water (above 140 degrees F -- hotter than most tap water) OR for at least 20 minutes in hot water kept above 120 degrees F (hot tap water, uncomfortable to touch).
• Drying: Drying will kill didymo, but slightly moist environments will support some organisms for months. This approach should only be used for gear that can be left in the sun for extended periods of time (i.e., a canoe that's left in the yard for several days between uses).
Cleaning recommendations for absorbent items (felt-soled waders, clothing, wetsuits, sandals with fabric straps, or anything else that takes time to dry out).
These items require longer soaking times to allow thorough penetration into the materials. The thicker and denser a material, the longer it will require for adequate disinfection. Err on the side of caution. Bleach solutions are not recommended for absorbent materials.
• Hot water: Soak items for at least 40 minutes in very hot water kept above 140 degrees F (hotter than most tap water).
• Dishwashing detergent and hot water: ("Green" products are less effective and not recommended for disinfecting): Soak for 30 minutes in a hot 5 percent detergent/water solution kept above 120 degrees F.
Contact the Friends of the Mad River with questions or suggestions about outreach around preventing the spread of didymo and other invasive aquatic species: (802) 496-9127, www.FriendsoftheMadRiver.org.
Source: VT DEC website: www.vtwaterquality.org/lakes/htm/ans/lp_didymo.htm