Re: Rock Roller Dams
Ron May wrote:
Tim,

You mean those grisly old fish have been holding back on spawning for
100
years?

Ron May

This is actually a very interesting question, to which I do not know the 
answer. Apparently, the fish expert that I asked knows as much about this as 
some of us do about stratigraphy. When we blew the dam, the Rockfish 
hastened upstream in large numbers to do their duty. But those fish hadn't 
been born up there, and in fact were several generations descended from 
their last ancestor that DID spawn up there. I've heard it said that in 
general they go by smell -  In this case the smell of someplace they'd never 
smelt before (a little fishy humor).

Maybe they follow lines  of (ever shifting) geo-magnetic declination. AT 
least some of them didn't wait for the hole in the dam to go forth and 
multiply, because there were plenty there, waiting at the gate.

Maybe some biopolymath on this list can offer an explanation.

Tim T.