i've read articles about the shad moving up shallow in the fall and the bass following them in.What happens in northeast  natural lakes that have perch and bluegill for a forage base,no shad.Do the perch and bluegill move shallow?Do the bass move shallow?

It's my understanding that the bass do move shallow as the water starts to cool in the fall regardless of the forage.  Why "shad migration" is talked about so much is the they tend to school up which makes it easier to see them moving.

Think of this years spawn growing up to be young bluegill, crappie, carp, silver sides, chubs and perch that have been hiding in weed beds that act like nurseries. The young fish are now looking for larger aquatic critters that are also leaving the dieing weeds as the days get shorter and water cools. Deep water is death for small fish, unless they school tightly together and move in mass....the fall migration.

WRB

Think of this years spawn growing up to be young bluegill, crappie, carp, silver sides, chubs and perch that have been hiding in weed beds that act like nurseries. The young fish are now looking for larger aquatic critters that are also leaving the dieing weeds as the days get shorter and water cools. Deep water is death for small fish, unless they school tightly together and move in mass....the fall migration.

WRB

I agree in the northeast the bass will move shallow. After the weeds start to die the baby bluegill,perch, crappie etc go to the shallows as a safe haven in deep water with no/dieing weeds there easy pray.

Some fish will move shallow, but some also stay with the deeper weed, as long as its green. You can catch bass in the deeper green grass (10-12ft) well into late October. After that, the water tends to get too cold and a lot (not all) the fish move to the deeper humps and stucture in 18-30ft. That's when the spoons and blade baits come out. At certain times, shad and baitfish ball up on the offshore structure and the fishing can be phenominal.