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
Weymouth Back River Whitman's Pond was dammed to turn the machines which processed the natural bog iron for the Weymouth Iron Works. Later, the Commonwealth of Massachusetts installed a herring ladder to allow the herring to bypass the dam on their spawning runs. Historically the herring ran to Whitman's Pond, and beyond up Mill River and Swamp River, to Great Pond. River herring commonly refers to two species, Blueback herring ("Alosa aestivalis") and alewife ("(Alosa pseudoharengus)"). Today, 1/2 million river herring and Rainbow smelt ("Osmerus mordax") run up the river each year to spawn (although they are not able to ascend the fish