Predation on Listed Fishes at Reclamation Facilities and Ways to Reduce its Impact

Project ID: 7432
Principal Investigator: Cathy Karp
Research Topic: Ecosystem Needs
Funded Fiscal Years: 2008, 2009, 2010 and 2011
Keywords: None

Research Question

Predation on fish at Reclamation facilities is widespread and is an issue of great concern to State and Federal agencies (both sport and native fish populations can be adversely impacted by established predator populations). Our questions are:

* How widespread is predation at Reclamation facilities?

* Does predation significantly impact Reclamation operations?

* What are some methods (for example, fish behavioral barriers, flushing flows, habitat manipulation to move predators out) Reclamation can employ to reduce such predation?

Need and Benefit

Predation on threatened and endangered fish at Reclamation facilities is widespread throughout the Western United States. This is due, in part, to construction and operation of the facility and to the introduction and establishment of non-native fishes. Often, the altered environment is more suitable to introduced fishes, rather than the native species, and many of the introduced species consume the sensitive native forms. This is a huge legal and costly issue for Reclamation. Individual offices deal with losses to predation differently. We propose to review this issue, Reclamation wide, and offer guidelines to reduce impacts of predation on Reclamation's ability to deliver water.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Summary of Predation Issue Conversations at Reclamation Facilities and Operations (final, PDF, 99KB)
By Cathy Karp
Report completed on May 14, 2014

Predation on fish at Reclamation dams and diversion structures is widespread and significant. It is one of many stresses contributing to the decline of native freshwater fish in the western US.

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Last Updated: 6/22/20