Thanks for the comments.
I have both small and large Gams in the shallows with the water primrose but the small ones may already be that 5/8" you mention.
I'll try to pay a little more attention to their behavior in the future.
John the average length of a GAM at birth is 8-9 mm which is a little under 3/8". That's pretty small and may be why I don't see them. In late June there was a good number of large females in one BOW. They were decimated. The first to go were the 2 inchers and then 1 1/2 and so on. I wondered whether I was seeing the beginning of a big decline. Then a couple weeks later there were utterly tens of thousands of 5/8" gams that seemed to show up all at once. These are now declining as they grow. I figure there will be one more good showing of small GAMs before the season ends. I definitely could be wrong about the small ones utilizing habitat beyond the shallows but it seemed compatible with these observations.
