>range of hydraulic forces. Paddlefish larvae, for example, can >survive
>frequent,low turbulence and entrainment at velocities up to 3 >m/s
Ow, that hurts just thinking about it...
>you have probably already thought of this, but can you correlate
>hydrographic peaks with first downstream record? I assume stage data >are
>available. Are collections pretty extensive?
Sort of. The first collections in the Potomac were in the upper South Branch
in WV during 1977, and the front moved downstream rapidly, even with normal
water levels. By 1984 they had been picked up downstream as far as
Moorefield, WV. In November 1985 the drainage was hit with a terrible flood
(100yr?). Not too surprisingly, by the next summer, rainbow darters were
picked up as far downstream as Harpers Ferry (a couple hundred rkm
downstream). Of course, in November it would have been adults being blasted
downstream rather than larvae. There's not enough collections to get at it
on a fine-scale level (ie., movement on a year-by-year basis), although we
have data from 1992-1995 for which we have good coverage which documents
upstream movement in Sideling Hill Creek, Washington Co., MD. I've collected
the upstream-most(Potomac at mouth of Wills Creek, Allegany Co., MD) and
downstream-most (Muddy Branch at Rt 190, Montgomery Co., MD) specimens that
I'm aware of- I'm still awaiting data from MBSS and Penn State that might
extend the range a bit more.
We're not so lucky for the Genesee drainage. Much of our data is based on
limited museum specimens and anecdotal reports from NYDEC folks. After C.L.
Smith retired (well, after he stopped making collections for his NY book),
not many people seem to have sampled the Genesee Basin...
Thanks again for your suggestions,
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