The Gaspereau (or Alewife) is a small, bony fish found in North America from the Gulf of St. Lawrence to Florida. Adults are 20 to 30 centimeters long and weigh around 250 grams, with a lifespan of 3 to 5 years. Alewives are diadromous—they migrate between salt and freshwater to spawn. After two years at sea, they return to spawn between May and early July. Juvenile fish migrate back out to sea in August.