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Fish Passage Improvements on the Hudson River Coming Soon

By Sean McDermott, Northeast Regional Office Habitat Conservation Division

Fisheries have long been an important resource on the Hudson River.  Absent any manmade obstructions, migrating fish were historically able to ascend up to Glen Falls, approximately 40 river miles upstream of the Federal Dam, the first dam on the river.  On the Mohawk River, the first major tributary to the Hudson, migrating fish could reach Cohoes Falls, a natural barrier approximately 3 miles upstream of where the rivers come together.  Under these natural conditions, the Albany, NY area was identified as important spawning grounds for alewife, blueback herring, shad, sturgeon, and other fish.  

The Green Island Project (aka the "Federal Dam") is located at river mile 152 on the Hudson River, 5 miles north of Albany, NY.  The project is the first dam on the Hudson River and is the head of tide.  There are 12 dams upstream of Green Island; the Mechanicville Dam is the second dam on the river approx. 10 miles upstream of Green Island.  The Mohawk River empties into the Hudson River 1 mile upstream of the Project.  The Cohoes Dam lies 2 miles upstream on the Mohawk River in Cohoes, NY. (Photo: Green Island Power Authority)

 Fish distributions throughout the Hudson River were significantly changed by the construction of dams and the canal system in the 1800s.  During that time, American shad, Atlantic sturgeon and shortnose sturgeon were heavily exploited.  Shad were of great commercial value during this era, on par with larger rivers such as the Potomac and Susquehanna.  Sturgeon also was once a significant fishery on the Hudson River during the1880 and 1900s, captured for caviar.  During the height of the sturgeon fishery, Albany was the chief market and sturgeon eventually became known as "Albany beef.”  Alewife and blueback herring were also historically harvested on the Hudson River.  Typically, these fish were salted for consumption and brought to market inland, where they were sold for a low price.

The Hudson River still supports these and other sea run migratory fish.  Decreases in their populations, however, have been attributed to dam construction, over harvesting, pollutants from sewage, refuse and factory operations.  Presently, shortnose and Atlantic sturgeon are protected under the Endangered Species Act.  Petitions have been filed with the U.S. Fish and Wildlife Service and NOAA Fisheries to consider similar protections under the Act for alewife, blueback herring and American eel.

The Green Island Power Authority plans to increase the overall power generation at the Green Island Project.  The existing dam (Photo Credits:  NOAA)

Improvements in water quality over recent decades have enhanced fish habitat.  Though some habitat in the upper Hudson River has been lost due to development, significant water quality improvements around Albany now provide suitable spawning habitat supporting a number of sea run fish.  Though some fish can occasionally navigate the lock system, man-made barriers preventing fish passage still account for a significant loss of habitat on the Hudson River and its tributaries.  NOAA Fisheries Habitat Conservation staff is working with our Protected Resources Division, the U.S. Fish and Wildlife Service and New York State fisheries biologists to enhance fish passage past the Federal Dam on the Hudson River.  We were actively involved in the relicensing of the hydro powerhouse facility at this dam.  The powerhouse typically is where the water falls with force on turbines causing them to turn and generate energy which is then converted into electricity.  Our focus in the relicensing process was to help improve access to spawning habitat for migratory fish.  

 Changes to the Federal Dam will include re-aligning the dam, installing a downstream fish passage screening system and expanding the powerhouse.  (Photo: Green Island Power Authority)

In 2009, the resource agencies and the Green Island Power Authority, the license holder for the powerhouse on the Federal Dam, signed a settlement agreement to address fish passage.  In 2013, improvements to the powerhouse and the dam will take place.  Our primary objective is to protect habitat and restore migratory fish, including endangered and threatened species, while allowing businesses like this hydroelectric facility to continue to operate.