Species Profile: Blueback Herring

Herring
Art by Duane Raver, courtesy USFWS

Herrings and their relatives are among the most important of commercial fishes worldwide and are very important as forage fish for a wide variety of predatory fish, birds, and other carnivores.

Blueback herring (Alosa aestivalis) are a favorite food of bass and other game species where they live in the same waters. Also known as river herring, they are an anadromous fish that migrate from saltwater into freshwater and have become established in many freshwater lakes.

Facts About Blueback Herring

  • Description: Blueback herring and alewife are very similar. They are flat-sided fish with rounded bellies and forked tails. Both are silvery with dark blue or bronze backs, and they have small spiny scales along their belly.
  • Typical size and lifespan:  Blueback herring reach a maximum length of 16 inches (40 cm) and weight of 7 oz. (200 g.) Their maximum age is about eight years.
  • Distribution: Blueback herring range along the Atlantic coast from Nova Scotia to northern Florida, and they migrate into inland rivers and lakes.
  • Feeding habits: These fish consume microscopic plants and animals (plankton), small insects, small fish, and the eggs of fish (including bass).
  • Spawning: In freshwater or brackish water, blueback herring spawn by depositing eggs that stick to hard objects such s gravel, rocks, plants, and wood. In lakes, they like hard bottoms composed of clay or gravel, where wind and wave action keep silt clear. They will also spawn on riprap, seawalls, and pilings.
  • Attraction to light: Blueback herring seem to come to the surface when the sun is shining, and to go deep on darker days. For that reason, the topwater bite for bass, which feed on blueblack herring, may be better on sunny days. Largemouth and spotted bass tend to feed better when the sun is shining.
  • Life cycle: In saltwater, adult blueback herring swim to fresh or brackish water to spawn. Herring in lakes spawn when the water reaches about 70°. Many adults die after the spawn but a few survive to return to the sea. The larval herring live for a few months in spawning areas, then move back to the sea. In freshwater, herring are more likely to survive the spawn. Female herring are fully mature at five years old and produce 60,000 to 100,000 eggs. Males are smaller and mature at three to five years of age.
  • Problems for freshwater lakes. Since blueback herring eat fish eggs and fry as well as the food that gamefish fry eat, they are direct predators and competitors with them. Because of this, they have caused problems with largemouth bass populations in certain lakes, among them Lakes Burton and Nottely in Georgia, and with the walleye population in Lake Hiwassee in North Carolina. State fisheries agencies work to limit their spread in freshwater lakes. It is illegal to use them as live bait in lakes where they don't already exist, and it is always illegal to stock them.

Blueback herring are a mixed blessing in lakes, and the long-term effects can be very bad. Follow your state's rules about stocking any species in any lake, especially those that are not native.

This article was edited and revised by our Freshwater Fishing expert, Ken Schultz.