At that time the only spawning I was able to find out
about was in the Soviet Union, in fact had some good
communications from members of their fisheries, and
also got a visit from an FBI agent :-)
Anyhow since then agency hatcherys have been
established in the US along with several private
hatcherys, all following artificial propagation
methods. I think it would be quite difficult to
replicate natural spawning conditions in a hatchery
for them. Or entirely impractical. Much easier to
mature brood stock and then use existing techniques to
artificially strip and fertilize/hatch and rear the
fry.
I had chatted with a couple other NANFA members over
the weekend ref sturgeon, do you think there would be
interest for a 'Sturgeon Study Group' ? You are the
fourth member who has written me on them.