Didymo

What it is, where it is, prevention, sample collection and reports.To identify didymo you must be a professional, or at least have a high-powered microscope and an identification book. If you do find mats that fit the didymo description, you can mail a sample to the U.S. Geological Survey for positive identification Source; Patagonia.

Collecting Samples:   
Send reports and samples to: Dr. Sarah Spaulding; U.S. Geological Survey; 999 18th St., Suite 300; Denver, Colorado 80202 USA; Email: sarah.spaulding@usgs.gov. Source; PatagoniaDidymosphenia geminata, commonly known as didymo or rock snot, is a species of diatom that grows in warm and shallow water. If it overgrows, it can form large mats on the bottom of lakes, rivers and streams. It is not considered a significant human health risk, but it can affect stream habitats and sources of food for fish and make recreational activities unpleasant. It is considered a nuisance organism or invasive species. The microscopic algae can be spread in a single drop of water. Source wikipedia

Basic Biology :Didymo is a versatile alga. It’s found at temperatures between 32 degrees and 80 degrees F, and can grow in slow moving, shallow waters as well as waters with greater depth and swift currents. The nutrients in the water also determine where you will find didymo. The puzzling thing about didymo is it doesn’t act like most algae; it blooms in waters with very low levels of nutrients. Most algae blooms, like red tide for example, bloom with excessive amounts of fertilizers and high nutrients. Max Bothwell of Environment Canada has made some interesting observations of didymo in some Vancouver Island streams. In upstream reaches with low nutrients, didymo growth was plentiful, but in reaches downstream from water treatment discharge (i.e. high nutrients) didymo growth was less and included a more diverse algae community. Source Leah C. Elwell From the Federation of Fly Fishers

Where it’s been found Locations across North America have experienced excessive algal growth, but not of the same magnitude as locations in New Zealand.

Places in North America that have experienced blooms of didymo include:
South Fork of the American River, California
Kootenai River, Montana
Rapid Creek, South Dakota
White River, Arkansas
Deer River, Alberta, Canada; and numerous rivers on Vancouver Island, British Columbia, Canada.

British Columbia: It has been spotted as part of plant species surveys in 2004. Other than this there has been no attempt in Canada to document its extent.

South Dakota: It has been present in Rapid Creek in South Dakota since at least 2005, and is blamed for a significant decline in the brown trout population. It is also present to lesser extents in other nearby locations.[5]

Tennessee: Didymo was found in the tailwaters of the Norris, Cherokee, Wilbur and South Holston hydroelectric dams in 2005. It is the first U.S. finding east of the Mississippi River.[6]
Virginia: Didymo was identified in western Virginia in the summer of 2006 in the Smith River, the Jackson River, and the Pound River.[7]

West Virginia:

Identified in three western Virginia rivers (Jackson, Pound and Smith). “In West Virginia, the DNR will work with other state and federal agencies, and anglers to monitor Didymo in the Elk River and other locations. http://www.wvdnr.gov/2008news/08news118.shtm

Vermont: In June 2007, didymo was discovered in the Connecticut River, near Bloomfield, Vermont, its first recorded discovery in the northeastern United States. The sighting was reported by a fishing guide and confirmed by Dr. Sarah Spaulding, a didymo expert from Denver, Colorado.[8]

Vermont: Identified during the summers of 2006 and 2007 in the Batten Kill (NY/VT), in 2007 in the Connecticut River (NH/VT), the White River (VT), and the Delaware River system (NY/PA), and in 2008 in the Gunpowder River (MD) and the Mad River (VT).

http://www.vtwaterquality.org/lakes/htm/ans/lp_didymo.htm

New Hampshire: Also during the summer of 2007, didymo was discovered for the first time in New Hampshire in the Connecticut River near Pittsburg.[9]

New York: In August 2007, didymo was first discovered in New York State in a section of the Battenkill River in Washington County.[10]
 

Maryland: In May 2008, didymo was found in the Gunpowder River in Baltimore County.[11]
Didymo was found in early 2008 in Gunpowder Falls below Prettyboy Reservoir in Baltimore County. Since July 2008, DNR and Baltimore County/DEPRM have been monitoring Didymo occurrence monthly in the Gunpowder Falls between Prettyboy and Loch Raven reservoirs. Source DNR Maryland

Below are maps containing Didymo locations and survey sites by month.
http://www.dnr.state.md.us/invasives/didymo_maps.asp

Preventing the spread

The following methods have been recommended to prevent the spread of didymo:

Check: Before leaving the river, remove all obvious clumps of algae and look for hidden clumps. Leave them at the site. If you find clumps later don’t wash them down the drain, treat them with the approved methods below, dry them and put them in a rubbish bin.

Clean: Soak and scrub all items for at least one minute in either hot (60°C) water, a 2% solution of household bleach or a 5% solution of salt, antiseptic hand cleaner or dishwashing detergent.

Dry: If cleaning is not practical (e.g. livestock, pets), after the item is completely dry wait an additional 48 hours before contact or use in any other waterway.

http://en.wikipedia.org/wiki/Didymosphenia_geminata

Note: Wired will continue updating information in an effort to inform our readers. We invite our readers to contact us with any additional factual information that will help us to do so. Thank you

If you think you’ve found Didymo; Report suspected growths of didymo by collecting a small sample (put a pinch of the material in a vial with ethanol or dried in a folded business card). Label samples with the date, latitude and longitude (accurate site information).