The lower Kennebec holds the southernmost population of wild Atlantic salmon in North America. Stripers in Maine have reached up to 67 lbs. They feed voraciously on river herring and eels in the Kennebec from spring to late fall. The largest member of the river herring family, shad can grow to 10 pounds and over two feet in length. The Kennebec once hosted a run of a million or more shad, which spawned throughout the drainage in June.
Adults spend up to five years at sea before returning to their home river to spawn.
Dam construction and pollution nearly destroyed the Kennebec's shad population, which is now being restored. They grow to be three to four feet long. One of the most abundant fish of the Kennebec River. Alewives are born in upriver lakes and ponds, migrate to sea after a few months in freshwater and return three to five years later in May and June as 10-14 inch adults. They are eagerly devoured by striped bass, eagles, osprey and great blue heron.