3-27-08

[Looper Flies]

Hit the Clinch a few times this week, since I was in K-Town doing some work.  Had a little luck -- I only fished about 2 or 3 hours a day.  Caught one nice rainbow that was in full colors.  His fins looked very healthy despite all the rock snot everywhere.  I haven't been back to the Clinch since November, and it was much different than last I was there.  The water seems healthy, but the algae has got to have an effect on the life of the river.

[adamtn]

did you disinfect your snot boots?

[Looper Flies]

yep.  shot of clorox and water should take care of it.  no way am i bringing that junk to my local waters.

[grumpy]

It makes me shiver to think of those that don't disinfect their gear.

Grumpy

[Mike Hill]

did you disinfect your snot boots?

Now that's a statement to wake up to!!

[Mike Hill]

Is there a list somewhere of the infected rivers?  For safety sake, I was going to buy another pair of waders and boots to use in those rivers and those rivers only.

[troutwag]

Does anyone know much about this stuff, rock snot.....didymo?  I have heard it can wreak havoc on irrigation equipment, but have not heard of it hurting fish populations.  I have picked it up on the Clinch and it is full of bugs. 
Best,
John

[Looper Flies]

Didymosphenia geminata is a single-celled alga, within a group of algae called diatoms (Baccilariophyta).  The individual cells grow a stalk and can form large colonies.  The stalks, rather than individual cells, create negative impacts.  Colonies are visible as white to brown tufts attached to rocks.  As colonies develop and more stalk material is generated, growth will cover rock surfaces and trap fine sediment.

 

HABITATS for NUISANCE GROWTH
D. geminata tends to form excessive growths in
*Low, stable flow
*Water 3 inches to 6 feet deep
*Moderate to high current
*Below outlets of lakes and reservoirs
*Sunny open streams

 


PROBLEM
In North America, D. geminata is expanding its geographical range and forming massive growths in streams. This nuisance organism grows attached in streambeds and may impact freshwater fish, aquatic plants, and aquatic insects.
 
ECOLOGICAL IMPACTRock Creek
Didymo impacts other stream organisms, and impacts are greater when large masses are present.

·         Aquatic larval insects decline (caddisflies, stoneflies, and mayflies).

·         Other aquatic larval insects increase (midge larvae and worms).

·         Decline in large adult trout

·         Abundant young of the year trout

HUMAN IMPACT
Economic impacts include fouling of water intakes and a potential link to decline in fisheries. Impacts to aesthetics are common and recreationalists report unsightly masses that appear like strands of toilet paper or fiberglass. The growths become snagged in fishing gear and make swimming areas unappealing. Direct human health impacts are thought to be limited to eye irritation in swimmers.


REPORT
Didymo feels like wet wool to touch, and is not slimy. Please report suspected masses of didymo. Help us confirm your report by collecting a small sample (put a pinch of the material in a business card and fold). Send samples with the date, latitude, and longitude (or detailed accurate site information).