4. Predator management

Sub-strategy

Improve the survival of salmon and steelhead and other native focal fish species by managing and controlling predation rates.

Rationale

The construction and operation of the Columbia-Snake river hydrosystem, as well as disposal of dredge spoils in the lower Columbia River and estuary, have altered historical habitats and created new, hybrid habitats. These altered habitats support a wide range of predator species including native and non-native predatory fish species, predator birds such as Caspian terns, double-crested cormorants, several gull species, mergansers and pelicans, and marine mammals such as California and Steller sea lions.

Principles

  • In the altered habitat of the Columbia Basin, certain predators have expanded their range and adversely affected the focal fish species the program seeks to protect and enhance.
  • While predation is a natural, dynamic and complex process within the Columbia Basin ecosystem, predator-management actions, guided by best available science, are necessary to manage the level of predation on, and improve the survival of, salmon and steelhead, sturgeon, lamprey, and other native resident fish species in the basin. The biological opinions contain a number of predator-control actions.

General measures

  • The federal action agencies, in cooperation with the Council, state and federal fish and wildlife agencies, tribes, and others, should convene a technical work group to: (a) determine the effectiveness of predator-management actions; and (b) develop a common metric to measure the effects of predation on salmonids, such as salmon adult equivalents, to facilitate comparison and evaluation against other limiting factors. Once developed and agreed upon, future predator-management evaluations funded by the action agencies should include a determination of the effectiveness of such actions and the common predation metric in their reports.
  • The federal action agencies shall report to the Council annually on their respective predator-management efforts
  • The U.S. Army Corps of Engineers (the Corps) or Bonneville shall evaluate the extent of predation on lamprey at Bonneville and other upstream dams
  • Management of predator fish
    • Bonneville should continue to annually implement and evaluate the base predator-control program and, where warranted, expand northern pikeminnow removals to other mainstem dams in the lower Columbia River (for example: expand the program to include northern pikeminnow removals at McNary and Bonneville dams). The action agencies should evaluate annually the biological and cost effectiveness of focused pikeminnow removals for these expanded dam angling efforts and implement if warranted. Scoping of focused pikeminnow removals at other mainstem dams in the lower Columbia River will be based on evaluations and adaptive management principles with input from NOAA Fisheries and the fish and wildlife agencies and tribes and the Council.
    • The federal action agencies should work cooperatively with NOAA Fisheries, U.S. Fish and Wildlife Service, states, tribes, and the Council to develop and implement systemwide strategies to manage and reduce non-native fish species that compete and feed on native fish (both anadromous and resident species) in the basin.
  • Management of predator birds
    • The Council will encourage more aggressive efforts by the Corps and others to make the fullest possible use of their existing authority to remove or manage avian predation that is impacting wild fish populations.
    • The federal action agencies should, in collaboration with state and federal agencies, tribes, and other hydropower operators:
      • Continue efforts to reduce the number of Caspian terns on East Sand Island in the lower Columbia River and estuary by implementing the U.S. Fish and Wildlife Service Caspian Tern Management Plan
      • Develop a double-crested cormorant management plan encompassing additional research, development of a conceptual management plan, and implementation of warranted actions in the lower Columbia River and estuary
      • Implement the avian management plans (for double-crested cormorants, Caspian terns, and other bird species) for Corps-owned lands and associated shallow-water habitat areas in the mid-Columbia area that have been developed through the Corps and other processes for predatory bird species in the Columbia River estuary. The action agencies should also develop and implement any management plans developed for double-crested cormorants, Caspian terns, and other bird species in the mid-Columbia area and prioritize actions for implementation.
      • Implement predator-bird management actions in the Columbia River Basin in coordination with state and federal fish and wildlife agencies and tribes.
    • The Corps should continue to implement and improve avian-deterrent programs at all lower Snake and Columbia River dams.
  • Management of predator seals and sea lions
    • The Corps should:
      • Take actions to improve the exclusion of sea lions at all main adult fish ladder entrances and navigation locks at Bonneville Dam.
      • Continue to support land- and water-based harassment efforts by NOAA Fisheries, the Oregon and Washington departments of fish and wildlife, and tribes to keep sea lions away from the area immediately downstream of Bonneville Dam.
    • The federal action agencies should fund federal, tribal, and state agencies to evaluate the extent of seal and sea lion predation on salmonids, sturgeon, and lamprey in the lower Columbia River from below Bonneville Dam to the mouth of the river.
    • The federal action agencies, in collaboration with the region’s state and federal fish and wildlife agencies, tribes, and others, should identify opportunities and implement actions to reduce salmon, sturgeon, and lamprey losses through seal and sea lion management in the lower Columbia River and estuary.
    • When federal, state, or tribal managers determine that predation by seals and sea lions is causing significant adverse impacts to salmonids or other native fish, state and federal fish agencies employing lethal and non-lethal methods to manage predation shall continue the lethal methods if non-lethal methods are not successful.

Links to the subbasin plans

See the Council’s subbasin plans for subbasin-level information pertaining to predators.

Links to other parts of the program

Strategies: non-native and invasive species, strongholds, sturgeon, lamprey

← 3. Non-native and invasive species

5. Protected areas and hydroelectric development and licensing →

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