Might be typical. I remeber a massive alewive kill washing up on the east shores of Lake Michigan - not sure what the cause was back in the 60's, but don't remember a huge alarm over the event.
Ecology: Alewife Explosion - TIME (Friday, Jul. 07, 1967)
alwive kill lake michigan - Google Search
I also remember that. My parents used to take us kids to a rental cottage on Lake Huron back then, for summer vacation. (Back in those olden days, it was something like $50/week, and they were very nice little cottages, maybe 100 yards from shore). And I remember one summer, the alewives piled up on shore like cordwood. It stunk to high heaven.
IIRC the thought was that they were overpopulated, and had simply run out of food, so they died.
Not many years after that, the Coho and Chinook salmon were introduced, which produced a great sport fishery for the Great Lakes.
But then in the 90s (?) there was the massive die-off of the salmon population, because they ran out of alewives to eat.