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
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