Learn about alewife

The alewife is a common sea-run (diadromous) fish in Massachusetts waters. Read on to learn everything there is to know about this fish.


  • The alewife's body is compressed laterally with a sharply forked tail. The shiny scales have varied metallic hues of silver, brass, and grayish green with darker shades on dorsally.
  • The alewife is the same genus as the closely related blueback herring that share the common name, river herring.
Alewife from shrimp survey

Alewife facts

  • Species name: Alosa pseudoharengus
  • The alewife preys on small fishes, copepods, and small shrimps. As a small schooling fish, it is preyed upon by many species of fish and wildlife, including species of high economic value such as striped bass.
  • Alewives are a diadromous species, meaning they migrate between fresh water and salt water to complete their life cycle. Females spawn in the spring and can lay up to 300,000 eggs. The eggs hatch in a few days and the juvenile herring occupy freshwater habitats for a few months before emigrating to the sea.
  • The alewife matures in the ocean and returns to spawn in natal streams at an age of 3-4 years and size of about 12 inches.
  • The spring migrations of adult alewives in our coastal rivers formerly supported important fisheries but remain popular symbols of the rebirth of spring and the natural struggle to survive.
  • Alewife populations are considered depleted on the east coast. Recreational and commercial harvest of alewives was prohibited by DMF in 2006 out of concern over their status. 
  • DMF manages alewives in state waters in cooperation with the Atlantic States Marine Fisheries Commission. NOAA Fisheries manages alewives in federal waters based on recommendations from the New England Fishery Management Council.
  •  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.
alewife distribution map

More info

To learn more about the alewife, contact Bradford Chase at (508) 990-2860 x 118 or brad.chase@mass.gov.

Additional Resources

Contact for Learn about alewife


DMF Staff Directory View 


(508) 990-0449


836 S Rodney French Blvd, New Bedford, MA 02744

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