From what I’ve read, even if salmon numbers remain low for the foreseeable future, the alewife may not come back to anywhere near the levels that they were at in the past. Invasive species like zebra mussels are competing for the same zooplankton that the alewife feed on. If the various state and federal agencies that manage the lakes want to maintain their multi-billion dollar sport fishing industry, they may have to think outside the box and re-evaluate the fisheries in the Great Lakes. Rainbows have adapted and eat other forage where the salmon have not. The kings and cohos are hard-wired to feed in the open water where the alewife are (or were). Perhaps there are opportunities for other species besides salmon that will take advantage of other forage.
There was a creek behind our house where I grew up that flowed into Lake Michigan. One of our neighbors was an older gentleman who had lived there most of his life. Probably since the early 1900’s. He said that the creek was stacked with pike at ice-out and with walleyes shortly thereafter. Maybe the walleye from the Bay will expand their territory into the main basin. I guess that depends on whether or not they have something to eat.