Atlantic salmon (Salmo salar) spawning migrations in a controlled river under two transport strategies

As part of the Penobscot River Restoration Project (PRRP) we examined spawning migration movements of Atlantic salmon (Salmo salar) through nine dams on the Penobscot River. All salmon passed upstream or transported were implanted with a Passive Integrated Transponder (PIT) at the lowest dam on the river (Veazie).  PIT readers were installed at nine dams on the Penobscot River with antenna arrays located at the entrance and exit of the dam fishways. Prior work (2002-2004) and the 2010 season represent different passage and transport strategies for salmon through the lowest three dams.  We compared fish that were released to migrate through the lower three fishways and fish that were transported above the third dam (Milford). In 2010 a subset of forty two salmon were also implanted with acoustic tags which provided transit time between dams and rates of fallback over them.  Initial data analysis will focus on the timing and speed of upstream migrations of salmon, passage efficiency at each fishway, and movements up through and downstream over dams. Subsequent years will provide observations of how PRRP removal of Great Works and Veazie Dams (the lowest two) influences salmon migration.