It is way too soon to assess this years hatch, the alewives haven't even spawned yet. They would be looking to reinforce the belief that last years hatch didn't do well. As for hydro acoustic monitoring, it is still very limited in being able to measure yoy. We cause schools to skirt away when in the top 20, a large vessel is even more of a disturbance.
On a positive note the emeralds are back and smelt are in the river.