A couple of random points to add to this thread.
-NH Audubon's Amoskeag Fishways fishladder,located on the Merrimack in Manchester NH reported for 1997:
American Shad- 22,486
River Herring- 403
Atlantic Salmon- 57
STRIPED BASS- APPROX 2,000
This might add a new twist to the whether or not bass are breeding in the Merrimack.
-For what's its worth, there are published anecdotal accounts of large "rocks"(presumably of reproductive proportions being taken through the ice on a fairly regular basis from the Parker River 30-40 years ago. Resident non-breeders, breeders?
Why would an adult fish live somewhere it wouldn't, couldn't reproduce?