St. Lawrence species

Alewife

Alosa pseudoharengus

Type of resource

  • Fish
  • Pelagic fish

Status of the resource

  • Not determined

In season

Fresh from March to June.

SIZE : Generally less than 30 cm.

LIFE EXPECTANCY : Up to 10 years.

LIFE CYCLE : Sexual maturity around 4 or 5 years.

Alewives are born in lakes or the calm stretches of rivers in late spring. Juvenile fish remain in freshwater until the autumn, during which they swim to the ocean or deeper waters. Adults will return to freshwater in the spring to spawn, and then head back out to sea.

The alewife is silvery in color, sometimes with golden highlights. Its back is grayish-green, and it has a black spot at the back of its head. The body is slender, and its head is triangular with large eyes.

In the water column, generally between 56 m and 110 m deep; but it can go to depths of up to 145 m. As an adult, it can withstand water temperatures of up to 25°C.

Its habitat varies throughout its life. The alewife lives in saltwater and migrates to freshwater to spawn. It is an anadromous fish.

PREYS : 

Zooplanktons
Shrimps
Small fishes
PREDATORS : 

Eels
Striped bass
Sea lampreys
Monkfishes
Rainbow truits
Spiny dogfishes
Salmons
Seabirds

Harmful species?

In the Great Lakes, the alewife once considered a nuisance, led to the introduction of coho salmon to control it. This in turn stimulated sport salmon fishing.

MACHINES : Traps, gillnets, weirs, landing nets.

REGULATIONS : 

Management of the type of the fishing effort :

  • Specified fishing seasons
  • Limited number of fishing permits

Alewives and blueback herring (Alosa aestivalis) are so similar that statistics combine these two species and permits are managed together.

Did you know that?

Since at least the 1980s, the alewife has experienced local decline due to habitat loss and degradation, dams, over-fishing, and increased predation by striped bass. Management organizations are working to restore populations through measures such as the construction of fish passageways and restrictions on the type of fishing.

BENEFITS :
A source of protein and Omega-3, its flesh is lean and free of significant levels of contaminants.

LET’S COOK :
Rich, and slightly sweet taste. Tender, and rather firm white flesh.

Although tasty, alewives contain many bones. They are preferred smoked, marinated, or salted. This type of fish can also be used to make fishmeal or be used for pet food.