Twait shad Directive (1992) that list, respectively, species whose conservation requires the designation of special areas of conservation and that are subject to management measures." Twait shad The twait shad or twaite shad ("Alosa fallax") is a species of fish in the family Clupeidae. It is found in the eastern Atlantic Ocean and the Mediterranean Sea and is an anadromous fish which lives in the sea but migrates into fresh water to spawn. In appearance it resembles an Atlantic herring but has a row of six to ten distinctive spots on its silvery flanks. They become mature when three or more years
Assabet River followed by deliberate introduction into ponds near the Concord and Sudbury Rivers. This is now an invasive, habitat-destroying plant across many of the eastern states. On the Assabet River, OARS (Organization for the Assabet, Sudbury and Concord Rivers) organizes an annual plant pulling event in early July. Volunteers in canoes hand-pull the surface-floating rosettes of leaves and nuts before the nuts mature and fall to the bottom. Alewife, "Alosa pseudoharengus" is an anadromous species of herring found in North America, anadromous meaning that it mates and is born in fresh water, but live most of its life in saltwater. In