The presence of the
invasive alga didymo (a.k.a. rock snot) has been confirmed by ANR just
downstream of Warren Village (for more info about didymo in general
visit the Vermont Agency of Natural Resources (ANR) website)
This of course has many implications for the river--we will keep you
posted as we
learn more. Caitrin Noel, Watershed Coordinator for Friends of the Mad River, has observed Didymo in several locations including near the Park and Ride in Warren Village, at Riverside park, and at Lareau swimhole. It is important to keep in mind that Didymo has specific habitat requirements, and will not be found in all locations in the river. Didymo can grow in sunny areas of fast moving, clean water. It does not grow in sandy, slow moving or excessively shady areas.
The Friends of the Mad River Board and others from the community and
the Agency of Natural Resources are planning an
outreach campaign to educate folks
about how to prevent the spread of this invasive algae upstream and into
Here are some things to keep in mind about Didymo (from the VT ANR
While didymo cannot be removed from the river, we can work to stop the
spread of this pest into the tributaries if it is not already there.
- Didymo can have negative ecological, economic and aesthetic
impacts in infested areas, but how it will affect Vermont waters is
- There are many examples of rivers where Didymo does not form nuisance blooms or mats. Surveys can locate viable cells
but, for some reason, they do not undergo rapid growth and excess
production of stalk material. Scientists around the world are still
attempting to determine what factors limit or support this bloom
- Scientific studies conducted around the globe
have yet to show conclusively that Didymo has significant impacts to
trout fisheries. However, it remains a priority of the Agency of
Natural Resources to limit the algaís spread throughout the region, as
- Spread prevention is the only effective management tool. There
are no known methods of eradicating Didymo once established.
ANR is cooperating with a number of federal, state and other entities
to monitor and reduce the spread of Didymo in the Northeast.
can do your part to minimize the spread of Didymo by following best
practices and disinfecting your gear when using Vermont waters (for
specific suggestions see below).
- Disinfection and best practices not only help to reduce the
spread of Didymo, but other invasive species and pathogens such as VHS
septicemia) or whirling disease as well. Itís simply good
- Didymo is not considered a significant human health concern (from
the Taieri Trust website)
BEST PRACTICES for minimizing
the spread of
Didymo, other aquatic invasive species, and fish and wildlife pathogens
while using Vermontís waters:
There will be more information coming out about this in the Valley
Reporter and through other channels. Please share this info with
friends and neighbors. While this is an unfortunate situation, it
also an opportunity to ramp up our efforts to protect the Mad River in
- All Users - Disinfect your gear and boat before traveling
between different bodies of water or watersheds (see below).
- All Users - If you move around to fish, boat, play or work,
construct and use a simple, portable disinfection kit.
Users - When possible, fish, boat, play or work in a single waterbody
in a single day, rather than traveling between multiple watersheds
without appropriate precautions.
- All Users - 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.
- Anglers - When
practical, fish in a downstream direction. This doesnít mean you canít
wade upstream a bit to fish that nice run upstream Ė 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, youíve potentially spread Didymo upstream to
the whole stream, which may not have been previously infected. Most
algae and aquatic invasives/pathogens canít swim upstream.
- 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.
Kayakers, Boaters, Tubers - Remove drain plug and drain any water prior
to leaving boat loading/unloading area. Donít move water between