Scott
Great post. I have very similiar questions. I tried to find some more info on the alewife since that was the only species I was moderately familiar with.
http://www.anr.state.vt.us/dec/waterq/ans/alewife.htm http://www.state.nj.us/dep/fgw/pdf/fishfact/alewife.pdf There is alot of useful information on those pages.
Previously I was considering stocking these fish, but after doing some more research I don't think I will. In one or more of the sites I looked at it said they underwent massive dieoffs, and competed directly with YOY fish such as your bass and bluegill.
Hope this helps
Chris
