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Alewife Facts

Alewife Facts
Alewife is a type of fish that belongs to the herring family. It can be found in the Atlantic Ocean (from Labrador to South Carolina), Connecticut River, Great Lakes and lakes along the eastern coast of the USA. Some groups of alewife live in the ocean and reproduce in the rivers (anadromous fish), while other spend their entire life in the rivers, ponds and lakes (non-migratory, landlocked fish). Chemical pollution of the water and construction of dams during the 19th and first half of the 20th century resulted in drastic decline in the number of anadromous alewives. Thanks to great conservation efforts, alewives are still not on the list of endangered species.
Interesting Alewife Facts:
Alewife can reach 9 to 15 inches in length and up to 0.5 pounds of weight. Non-migratory alewives are smaller.
Alewife has grayish green back, grayish-silver scales on the lateral sides of the body and white belly. Adults have black spot behind the gills.
Alewife can change color of the body (become darker or paler) to blend with the colors of the river bed during the spawning season.
Alewife has small mouth, large eyes and laterally compressed body. Central part of belly is serrated due to few rows of overlapped scales.
Scales of alewives were used in the manufacture of artificial pearls during the WWI.
Alewife migrates from deeper waters to the surface to find food at the evening.
Alewife is a carnivore (meat-eater). Its diet is based on zooplankton (mostly on copepods and amphipods), shrimps and small fish and their eggs.
Alewife lives and travels in large groups (schools) composed of thousands of fish.
Natural enemies of alewives are stripped bas, cod, salmon, haddock, sea birds, otters, seals and minks.
Anadromous alewives can travel up to 1200 miles from the ocean to the slow-moving streams and ponds to reproduce. Most alewives spawn in the same rivers and ponds where they were born.
Spawning of alewives takes place from March to June.
Females produce from 60.000 to 100.000 eggs per season. As soon as spawning is completed, alewives (both males and females) travel back to the ocean.
Eggs of alewives are pinkish colored. Incubation lasts 2 to 15 days, depending on the temperature. Only 1% of eggs will manage to survive that period (eggs represent important source of food for numerous freshwater creatures).
Juveniles inhabit watersheds until the autumn. At the age of 3 to 7 months (when they reach length of 2 to 4 inches), alewives become ready to travel to the ocean. They live in the salt water until the age of 3 to 4 years, when they reach sexual maturity and become ready to reproduce.
Alewife can survive up to 9 years in the wild (5 years is an average lifespan).


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