A medium-sized member of the herring family, the alewife travels in large schools. Alewives grow to a length of around 15 inches with 10 to 11 inches being a average length. Like many of the clupeids, they are an important food item for many larger fish species as well as an important commercial species.

According to Bigelow and Schroeder, the alewife, "like the shad and the salmon makes its growth in the sea, but enters fresh water streams to spawn. This "anadromous" habit, as it is called, forced itself on the early settlers on our coasts." Alewife spawn in ponds and sluggish stretches of streams. Each female lays 60,000 to 100,000 eggs or more, according to her size. Like shad and salmon, they tend to spawn in the waters they were born in.

Alewives feed on plankton primarily but are capable and will take larger prey such as sand lance, smaller herring (including their own species) and fish eggs. Their habit of feeding on floating fish eggs caused a catastrophe in Lake Michigan when they were introduced there. The eggs of many of the native planktivorous fish floated and were severely impacted by the alewife. The alewife populations, in turn, exploded and for many years, large alewife die-offs were a regular occurance.

Check our Fish Slides database for photos and catch records.

Robins, C. Richard, Ray, G. Carleton, Douglass, John, 1986, A Field Guide to Atlantic Coast Fishes of North America, Houghton Mifflin Company, Boston