Alewife
A small, silvery herring native to the Atlantic Coast of North America, the alewife is rarely the target but almost always the key.
Its spring spawning runs shaped coastal ecosystems for centuries, and in the Great Lakes — where it arrived as an invasive species — it became the foundational forage that entire sportfisheries were built around.
For anglers, understanding alewives means understanding what the predators are eating.
Scientific Name: Alosa pseudoharengus
Also known as River Herring, Branch Herring, Sawbelly, Gaspereau, Big-eye Herring
- Silvery body with a grayish-green back and a single dark shoulder spot behind the head, visible on fish over about 4 inches.
- The eye is notably large — wider than the snout length — which separates it from the closely related blueback herring; the belly cavity lining is pale grayish or pinkish white (dusky or black in bluebacks).
- Sharp, serrated scales run along the midline of the belly, giving the fish a saw-edged keel; no teeth on the roof of the mouth, unlike sea herring.
- Most fish run 11–12 inches and weigh under half a pound; maximum size is around 16 inches.
What to know
Habitat Distribution
- Native anadromous range spans the Atlantic Coast from Labrador south to South Carolina — ocean-dwelling most of the year, entering rivers and streams each spring to spawn.
- Landlocked populations exist naturally and through introduction across the northeastern interior, including the Great Lakes, where the species arrived via canals and is now an established invasive.
- Marine adults hold at depths of roughly 56–110 meters in coastal waters; landlocked fish spend most of the year in the deepest, coolest parts of lakes.
- A cool-water species, adults tolerate temperatures up to about 25°C (77°F) but gravitate toward colder water when available.
Specific Spots
- In lakes, alewives suspend in open, deep water rather than relating to bottom structure — they follow zooplankton concentrations up and down the water column, often rising toward the surface at night and dropping deep during daylight.
- During spring spawning runs, anadromous fish concentrate in river mouths, tidal pools, and the shallow lake margins and pond inlets connected to river systems — these are the spots where cast nets and dip nets do their work.
- Landlocked populations push into shallower water and tributary mouths to spawn, then retreat to deep-water refuges for the rest of the year.
Alewife FAQ
Answers from onWater's species guide.
What are the best lures and bait for Alewife?
Live or fresh-dead alewives are among the most effective baits for striped bass, largemouth and smallmouth bass, walleye, and other predators, rig them with a circle hook through the back just behind the dorsal fin to keep them swimming naturally.
What do Alewife eat?
Zooplankton, particularly calanoid copepods and small crustaceans, make up the bulk of the diet; alewives are filter-style planktivores, not pursuit predators, which is why lures that imitate them work better than lures that imitate their prey.
Where do Alewife live?
Native anadromous range spans the Atlantic Coast from Labrador south to South Carolina, ocean-dwelling most of the year, entering rivers and streams each spring to spawn.
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