Ok, here we stand on the threshold of another environmental
disaster. Here in West Virginia we have deep mines, strip mines,
poor logging practices, silt and now didymo. Seems like every time
you turn around there's another problem with something hurting our
This new or not so new invader is an algae that was reported as
much as ten years ago, but lately is spreading at a rate that is
very alarming. And not only in here but in many eastern and
western trout streams and what is reported about it appears to
be off by as much as 50% on the low side.
'Rock-Snot' they call it, didymo is an invasive algae that harms
the stream environs in many ways, everything from water
chemistry to fish and insect size. Mayflies, caddis flies and
stone flies numbers decrease as the stalks of the didymo
algae spreads. The stalks left don't degrade very fast and
trap silt and other debris, so although species like midges
can actually benefit by that, any critter that requires clean
cobble type stream bottoms suffer.
Unfortunately the research and facts for this invader is very
lacking. New Zealand is probably the front runner in research
and control on the subject but early tests are not very promising
on any solution to this growing problem.
It can spread in water that was previously thought not to
support it. The idea that it could only thrive in cold low
nutrient waters is turning out to be a wishful pipe dream.
First thought to spread best in stable tail waters, it is now
being found in much more diverse waters, everything from
drainage ditches to municipal water systems.
Something that may help, as far as West Virginia water
ways is concerned, is fluctuating water and temperature
levels. Water that is subject to floods seems to scrub the
cobble-stones and low water dries out the stream beds,
so this may help to control the growth and spread of didymo.
The best prevention at this time seems to be to clean and
dry your gear, especially your felt soled waders or wading
boots. There are a number of web sites and bulletins that
explain this process. ~ T_Loop