Along this coastal shore, Native Americans and early settlers relied on abundant runs of sea-run fish, especially alewives that each spring moved from salt water into Mill Pond and up Somes Brook to Somes Pond and Long Pond to spawn in fresh water. These fish were caught for food, preserved by smoking or salting for year-round use, and used as bait by fishermen. The Mill Pond Dam originated in 1763 when Abraham Somes built a sawmill for the growing local lumber industry, and it became the first of several dams along the brook, with a grist mill and a woolen mill operating farther upstream. Although dams obstruct sea-run fish and damage their habitat, fishways can help some species pass these barriers, and fishways were built between Somes Sound and Long Pond in the early 20th century. After those fishways fell into disrepair and local sea-run fish populations declined sharply, restoration work began in 2006 to help rebuild native species such as alewife, sea lamprey, and American eel. These migrations connect the Gulf of Maine with inland waters and provide food for many animals, including striped bass, haddock, salmon, osprey, eagles, herons, cormorants, loons, and otter. A fishway, often called a fish ladder, is a structure built on or around barriers such as dams to aid the migration of diadromous fish, and a pool-and-weir ladder uses a series of small dams and regular pools to form a sloping channel that lets fish move around an obstruction by passing from box to box upstream.