Linking oceans, rivers and lakes

Linking oceans, rivers and lakes. . , A Part of History , Both Native Americans and early settlers enjoyed abundant harvests along this coastal shore. Each spring, thousands of adult alewives made an upstream pilgrimage, moving from salt water into the Mill Pond and up Somes Brook to Somes Pond and Long Pond to spawn (reproduce) in fresh water. The large populations of diadromous (sea-run) fish were welcomed by all, and the catch was smoked or salted for year-round consumption or used as bait by fishermen. The Mill Pond Dam, located just across the road, traces its roots back to 1763, when Abraham Somes erected a sawmill to produce lumber for a growing local industry. It was the first of several dams constructed along this brook. A grist mill and a woolen mill operated a short distance upstream from here (see map for directions)., Bridging the Gap , Dams present obstacles for sea-run fish and destroy their natural habitat. Where dams are essential, fish passage can be enhanced for some species by providing fishways. In the early 20th century, fishways were constructed between Somes Sound and Long Pond. Over time, the fishways fell into disrepair, dramatically reducing the local sea-run fish populations. In 2006, fishway restoration work began in order to help rebuild the populations of native sea-run fish species such as alewife, sea lamprey and American eel., Nature's Way , Imagine sea-run fish that swim in huge schools, back and forth, from the Gulf of Maine into Maine's inland lakes, ponds, rivers and streams. During this cyclic journey, both juveniles and adults are a food source for nearly everything, including striped bass, haddock, salmon, osprey, eagles, herons, cormorants, loons and otter. By restoring access to their habitat, we give sea-run fish a chance to flourish again. With more sea-run fish throughout the Gulf of Maine, our rivers, lakes, estuaries and ocean will reward us with more biological bounty than any of us have experienced in our lifetime., How it works , Fishways, most commonly referred to as fish ladders, are structures placed on or around human-made barriers (such as dams) to assist the natural migration of diadromous fishes. A pool-and-weir (seen in this sketch) is one of the oldest styles of fish ladders. It uses a series of small dams and pools of regular length to create a sloping channel for fish to travel around the obstruction. Effectively, the channel acts as a fixed lock to gradually step down the water level; to head upstream, fish must pass from box to box in the ladder., [photo captions:] , Old saw mill and wooden dam, extending from the shore near the present Library to beyond the present fishway., Fishway at old Woolen Mill site (third dam) along Somes Brook. This fish ladder is a pool-and-weir type, hand built using local granite blocks held together by mortar.