Alewife and Blueback Herring
Our Scientific Name
Alosa pseudoharengus (alewife)
Alosa aestivalis (blueback herring)
By the Numbers
We both are 10 to 12 inches long, and weigh 0.5 pounds.
How to Identify Us
We look alike, and are often lumped together as “river herring” but we are really two different species. We are silvery in color with a single black spot just behind our eye, and alewife have a larger eye. We have sharply-angled bony scutes on our belly that feel like a saw. Alewives are grey-green and blueback herrings are blue-green on our dorsal (back) sides. We are thin or compressed from side to side, but long from our dorsal to ventral (belly) sides, and we both have a forked tail.
Why We Matter and What's Been Happening
Our numbers became so low we were almost endangered, but we are beginning to recover in a few rivers. Government agencies are working to prevent overfishing out at sea, and are removing obstacles, like dams, so we can migrate back to our home rivers to spawn new generations of alewife and blueback herring.