April 29, 2017

Sturgeon

Shortnose Sturgeon
(Acipenser brevirostrum) a living fossil predating the dinosaur, can be found in several Maine rivers. They are a primitive fish with rows of bony, armor-like plates on their sides and a skeleton of cartilage rather than bones. Sturgeon are bottom feeders–they suck plants and animals disturbed by their movement into their tube-like mouth. Smaller than their cousins the Atlantic sturgeon, which can grow to 7ft long, the shortnose sturgeon rarely reaches more than 3ft.

Like all anadromous fish, the shortnose sturgeon needs access to both freshwater rivers and rich estuaries. The species rarely migrates far into the ocean away from its native river. When ready to spawn, the sturgeon migrate upstream and deposit their eggs over gravelly or rocky river bottoms in moderately deep water with strong current.

Although the shortnose sturgeon is an endangered species, the Kennebec River has some of the best habitat for sturgeon in Maine. When Edwards Dam was removed last summer, the sturgeon regained access to their full historic range on the river. In time, these spawning grounds may help the fish to recover.