Lamprey River wide range of valuable wildlife habitats. Its anadromous fishery is one of the strongest in the Great Bay watershed. Anadromous fish species that use the Lamprey River include shad, river herring, smelt and even Atlantic salmon. These fish are hatched in the river, then spend most of their lives out at sea, returning to the river to spawn. The fish species will move up the river as far as Durham, where they are prevented from moving further upstream by Wiswall Dam. The river is also rich in species of freshwater mussels. The river is managed by the New Hampshire Fish
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