"Rock snot" has turned up in Vermont streams

Category: MyView

Created on Wednesday, 15 August 2007 20:00

Last Updated on Wednesday, 15 August 2007 20:00

Published Date

08/16/07

By Clark Amadon

I live across from the Mad River, which is a source of great pleasure for its beauty, clean waters, and for me fishing, too.  I was out in it yesterday afternoon and early Tuesday morning. I love looking into its clear depths searching, sometimes in vain, for elusive trout. However, we have an unwanted and nasty intruder who may make an appearance and we have to do something about it!

Didymo <MI>(Didymosphenia geminata)<D>, or "rock snot," is an invasive alga that has recently turned up in Vermont streams. So far it's in the upper Connecticut, the White River and in the Battenkill. This alga enjoys clear, clean, largely infertile water which means most all of our trout streams in Vermont are prime candidates for didymo to take hold. The Mad River is an excellent example of this type of river! This alga forms a thick mat along the rocky streambed and chokes out most aquatic insects, which in turn reduces hatches and food for trout and makes the river a slimy mess. Didymo looks like brown wet wool or toilet paper in rivers. Soon thereafter, trout populations collapse -- not what we want to see in a state that already does not protect our wild trout populations! It's very bad for all river users such as fishers, canoeists, kayakers, swimmers and tubers.

If you fish, wade, float, or generally amble about anywhere in Vermont rivers you have to clean your gear (waders, boots, canoes, kayaks, shoes) in a two percent bleach or dishwashing detergent solution with hot tap water by soaking all your gear that comes in contact with the water for at least three minutes. Hose off those boats with the bleach solution in a safe area. "Rock Snot" could be anywhere!  

Felt soles require 30 minutes in hot water with dishwashing detergent five percent solution or flushing for a minute in a two percent bleach solution. Contrary to the recent articles, drying your gear for 48 hours is not enough time for felt-soled boots to dry.

In New Zealand, they have found didymo spores living in damp felt soles for weeks after they were last used. Clean them in the solution as directed above, and you should be fine to fish and otherwise recreate. "Check, clean, and dry" is the way to go. Getting rid of your felt soles also can help reduce transmission of didymo; try "aqua stealth" or "sticky" soles. Less than five minutes of our time can help keep our fisheries from turning into algae-laden graveyards; and folks, if you don't clean you'll only have yourselves to blame!

I plan to live here for a very long time along the Mad River and want to continue, sometimes in vain, to seek out trout in the Mad's clear depths. I don't want to stare into a brown slimy mess! Let's all do our part to keep out didymo!

Clark Amadon lives in Moretown and is president of MadDog Chapter Trout Unlimited.