Pacific Southwest Region
California, Nevada and Klamath Basin

Service Releases Pacific Lamprey Conservation Recommendations

Apr 29, 2010


For Idaho, Oregon, Washington: David Patte, (503) 231-6121

For California: Erica Szlosek, (916) 978-6159

For the Klamath Basin: Matt Baun, (530) 842-5763


Service Releases Pacific Lamprey Conservation Recommendations

Best Management Practices Guidelines Now Available

As part of the U.S. Fish and Wildlife Service’s commitment to fisheries resources and in response to requests from tribes, federal agencies and others, the Service today released the Best Management Practices to Minimize Adverse Effects to Pacific Lamprey.  The document focuses on recommended practices for Pacific lamprey conservation in upstream and upriver habitat. They are voluntary but important due to significant declines of Pacific lamprey throughout its range over the past three decades. 

“This compilation of conservation practices for lamprey serves as a call to action to address the growing impacts to lamprey,” said Robyn Thorson, Director of the Service’s Pacific Region. “We are also planning to release a conservation plan for lamprey later this spring for public review.  Together, these two efforts, along with tribal restoration plans and the U.S. Army Corps of Engineers’ ten-year passage plan, provide a solid platform for coordinated and strategic conservation actions that can help stem the population declines of one of the most unique and oldest aquatic species in the West.”

The document describes the primary factors that contribute to lamprey population declines in upstream and upriver habitat. These are: impeded passage at dams, culverts and irrigation diversions; altered management of water flows and dewatering of stream reaches; dredging; chemical poisoning; poor water quality; and stream and floodplain degradation. Many of these factors vary depending on location.

 Recommended best management practices described in the report include:

  • Consulting with local biologists to obtain information on known lamprey populations during project planning;
  • Providing passage over irrigation diversions or dams that currently block upstream migration of Pacific lampreys;
  • Timing in-stream activities to avoid adversely affecting lampreys;
  • Avoiding the dewatering of areas important to lampreys;
  • Timing and conducting temporary dewatering events in ways that avoid adverse affects to lampreys;
  • Salvaging and relocating larvae that are found in stream or river substrates when dewatering events or in-stream activities cannot be changed; and
  • Evaluating screens installed to prevent juvenile salmonids from moving into ditches, canals and hydropower turbines to ensure they do not trap or harm lampreys.

Lampreys are eel-like fish that can reach two to three feet in length as adults. Hatched in fresh water, lampreys spend the first three to seven years of life as larvae buried in the bottom of streams in slow- moving water. As juveniles, they migrate to sea to mature and feed parasitically for one to three years then return as adults to freshwater streams, where they live for about a year before spawning.  Lampreys occupy many of the same streams as Pacific salmon and are a food source for many fish, birds and mammals. To many Indian tribes along the Pacific Coast, the Pacific lamprey is culturally significant and has value as a food source and medicine.  Pacific lampreys range from the Pacific Northwest to Baja California, Mexico, and around the Pacific Rim to Japan. They have been caught as far as 62 miles offshore and at depths up to 2,600 feet.

The Best Management Practices document was developed with the U.S. Forest Service and the Bureau of Land Management for use in planning activities on their lands that have potential impacts to lamprey streams. 

 “We in the Service thank these two agencies for their interest and initiative to conserve lamprey,” Thorson said. “This science-based guidance is now available for use by other federal, state and local agencies, tribes, conservation organizations and private land managers – anyone with a project that might affect lamprey.”

 For a copy of the document and for more information about the Pacific lamprey and the U.S. Fish and Wildlife Service’s Pacific Lamprey Conservation Initiative, visit the Service’s web site at: 

The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people. We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service. For more information on our work and the people who make it happen, visit