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NOAA Fisheries Releases Design Guidelines for Nature-like Fish Passages

May 23, 2016

Fish ladders and other types of fish passage for migratory sea-run fish have been constructed for more than 275 years, with an assortment of attempted designs. In the last 45 years or so, we have learned a great deal about what works and what doesn't when it comes to restoring access to upstream spawning and rearing habitats for our region's 14 diadromous fish species, including three which are listed under the Endangered Species Act.

Saw Mill Park step-pool fishway, Acushnet River, Acushnet, MA.Credit: NOAA.

For fish passage restoration sites where removal of dams and other barriers is not feasible, or dam removals are expected to change the upriver channel bed, nature-like fishways may be the best option for restoring migratory fish runs while protecting bridges, utility lines, and other upriver infrastructure.

NOAA Fisheries, together with the U.S. Geological Survey and the U.S. Fish and Wildlife Service, used body size, swim speed and behavioral data for 14 Atlantic Coast migratory fish species to develop a set of design guidelines for step-pool and other nature-like fishways.

This guidance, comprised of seven key parameters, provides important information to engineers in designing nature-like fishways for a range of streams and rivers and restoring runs for a single species or groups of migratory fishes such as alewife, blueback herring, and American shad.

The technical memo is available online.

Questions? Please contact Jennifer Goebel at 978-281-9175 or email