Alewives historically occurred in all major and minor coastal watersheds in the state. Declines in these populations were caused by the construction of dams and heavy industrial pollution, which rendered many waters unsuitable for their migration into freshwater spawning areas.
Alewives can be found in the Western North Atlantic Ocean, from Nova Scotia to North Carolina, and blueback herring extend further south to South Carolina.
The alewife, a pelagic planktivore native to the Atlantic Ocean, entered the Great Lakes through canals. First seen in Lake Ontario in 1873, and bypassing Niagara Falls through the Welland Canal, the species became widespread in the basin by 1960.