Predation of Juvenile Salmon and Steelhead in the Columbia Basin and Along the Oregon Coast
The importance of predation of juvenile salmon and steelhead in the decline and in the recovery of Pacific Northwest salmonids is controversial.
This web site links information about the predation of juvenile salmon and steelhead in the Columbia Basin and along the Oregon Coast. Predators of smolts include birds (e.g., Caspian terns, gulls, and cormorants), fish (e.g., northern pikeminnow [formerly northern squawfish], walleye, and bass), and marine mammals (harbor seals and sea lions).
*********************************************************************
Some of the files are PDF files that require the Adobe Acrobat Reader for viewing. It is available for free downloading at Adobe Acrobat Reader.
*********************************************************************
(Much of this Introduction is discussed in greater detail in my 2003 Review about bird predation at 14 Columbia Basin dams .)
The 4H's (Hydropower, Habitat, Harvest, and Hatcheries) are generally considered to be the causes of the decline in the abundance of salmon and steelhead in the Columbia Basin and along the Oregon Coast. However, predation is also considered to be a factor in the decline or in the recovery of salmonid populations, though its importance and its management are controversial.
Unacceptable Levels of Predation of Juvenile Salmon
The level of predation of juvenile salmon and steelhead that is unacceptable depends largely upon opinions. In general, any predation may be too much for some people, moderate predation may be acceptable to many, and all predation may be permissible to others.
The unacceptance of predation can depend upon the species of predator and prey:
- Salmon and steelhead are themselves predators of other fish (including juvenile salmonids) and Dungeness crab larvae, but this predation is usually considered acceptable. However, it has been pointed out that salmon predation could be important to the Dungeness crab fishery.
- Striped bass are predators of juvenile salmonids but are also popular for sportfishing. In Coos Bay, Oregon, the Oregon Fish and Wildlife Commission approved a plan in 1990 to enhance the striped bass population, in spite of their predation.
- Several species of warmwater gamefish (e.g., walleye and largemouth bass) sometimes prey on juvenile salmonids in the Columbia Basin or along the Oregon Coast but are also popular for sports anglers. In 1998, the Oregon Department of Fish and Wildlife proposed reducing warmwater gamefish predation of juvenile salmonids by ending fishing restrictions on warmwater gamefish. However, resistance from fishing groups was intense enough for the Oregon Department of Wildlife to quickly withdraw its proposal.
- Northern pikeminnows are predators of juvenile salmonids in the Columbia Basin and are controlled in several areas, but they are not popular with anglers. Walleyes also take some juvenile salmonids in the Columbia Basin, but are popular for sports fishing. Controlling walleyes appears to be less practical in reducing their predation of salmon, and an Oregon Department of Fish and Wildlife biologist also notes:
"A walleye removal program would be less acceptable than the pikeminnow program, especially to an active and vocal group of walleye anglers."
The level of acceptance of predation also depends upon whether predation is on private or public lands. Some groups have suggested that the unacceptable level of predation be higher on public than private property. In the Columbia Basin, predator control is usually done on public waters or on property owned by public entities to protect a publicly owned resource (salmon) by controlling a publicly owned resource (fish, birds, or marine mammals) and is financed by taxpayers or electric ratepayers. In this case, the level of predation that is unacceptable would be more open to public debate than control done on private property that is financed by the landowner.
The amount of predation that is unacceptable also varies with the type of control that is used. Public acceptance is higher for nonlethal methods of control than lethal means, and some groups and individuals believe that nonlethal methods of control should be tried first, with lethal methods used as a last resort. The acceptance of lethal control also seems to depend upon the species that is controlled. In general, lethal control is considered more acceptable for fish like the northern pikeminnow than for birds or marine mammals. Some of the concerns about lethal control are included in comments by the Oregon Department of Fish and Wildlife on p. 29-30 of their (1998 "Draft Predation Action Plan: Avian Species") about using lethal control for control of bird predators of juvenile salmonids in the Columbia River Estuary:
"The shooting of Caspian terns, double-crested cormorants, and/or gulls is the option that would likely be the most controversial with the public. The overall benefits of this option would be limited, at best, and at worst, might result in the disturbance or 'take' of nesting bald eagles or other non-target species [e.g., listed brown pelicans]. In order to be very effective, large numbers of birds would have to be killed. Even if that could be accomplished, it is likely that these individuals would be replaced over time with birds migrating into the area into 'vacated' territories. To be effective, this activity would have to take place on a continual basis. It is highly unlikely that this would be either cost-effective or publicly acceptable. Furthermore, this would be in violation of international, federal and state laws. Lethal shooting has been used to a limited extent to discourage birds from foraging in the tailrace of some mainstem dams. It has been an effective method for reducing avian predation at specific sites where smolts are particularly vulnerable, but would not be effective in eliminating or reducing breeding colonies of terns, cormorants or gulls."
Finally, the level of unacceptance of predation is influenced by one's self-interest. For example, individuals or groups who are advocates for predators are unlikely to blame predators for the decline of salmon; groups who are advocates for dams (hydropower) are more likely to emphasize the importance of predators than of dams. Accordingly, it is not surprising that some viewpoints about predation are self-serving. It may be helpful for a reader to use the following "Self-Interest Profile in Salmon Recovery" to help reveal if a group's or individual's viewpoint is self-serving and to look for its strategies in defending its position.
Self-Interest Profile in Salmon Recovery : 0=not important, 1=minor importance, 2=very important
|4 H's________________________ |Ocean
Group's or |Hydro- |Hab- |Hatch- | |Condit- |Pred-
Individual's |power |itat |eries |Harvest |ions |ators
-------------------------------------------------------------------
Self-Interest_______|_______|_____|_______|_________|________|______
Blame for Decline___|_______|_____|_______|_________|________|______
Factor(s) to Change_|_______|_____|_______|_________|________|______
---------------------------------------------------------------------
A group or individual may employ six strategies to promote its vision of what should or should not be done about predators. First, a group can be very selective and present evidence that only supports its position. Second, a group can try to discredit any evidence that it thinks may hurt its side. Third, a constituency can try to divert attention from changes that would affect its self-interest by blaming other factors for the salmon decline (e.g., hydropower advocates may blame fishermen or predators). Fourth, a group can try to delay actions by creating confusion about all the other possible factors that may be involved; confusion leads to indecision and continuation of the status quo. Fifth, a constituency can try to "divide and conquer" by publicizing wedge issues that may split an opposing coalition (e.g., a coalition of all fishermen could be split by focusing on conflicts between commercial and recreational fishermen or between nontribal and tribal fishermen). Finally, a group can present speculation to favor its side and try to masquerade it as science.
Establishing the Need for and Cost Effectiveness of Predator Control
Because predator control can be controversial, many wildlife management professionals and government agency staff recommend that the need for predator control be determined before conducting control. The need for predator management in the Columbia Basin has been carefully established for bird management in the Columbia River Estuary and for northern pikeminnow control in the Northern Pikeminnow Management Program (NPMP), but the need has only been assumed for control of birds by the U.S. Department of Agriculture's Wildlife Services (formerly Animal Damage Control) at several mainstem dams (my 2003 Review about bird predation at dams).
Wildlife and fisheries managers have also recommended that animal damage control be conducted only if control is cost effective (i.e., the cost of predation is less than the cost of predator control). Otherwise, the predation may not be significant enough to warrant the costs of predator control. The costs of control include not only the economic costs of conducting the control, but also biological, aesthetic, and/or social costs of conducting control. For example, a biological cost would be if it harms nontarget animals; a social cost could develop if control is very unpopular or controversial. However, Wildlife Services maintains that its control programs in the Columbia Basin do not have to be cost effective and that the cost of predation can be estimated by the cost of its control programs. With this circular logic, Wildlife Services could spend a considerable amount of taxpayer or electric ratepayer money controlling predators that may be taking an insignificant number of juvenile salmonids and justify doing so because it has spent so much money. Taxpayers and electric ratepayers can ask if their money is enhancing a bureaucracy rather than salmon. (This subject is also discussed in sections 4-E and 6-D-4 and in Appendix II-D in my 2003 Review about bird predation at dams.)
My Viewpoint about Predator Control in the Columbia Basin and Along the Oregon Coast
Because there is so much money and politics involved in salmon recovery issues, it is relevant for the reader to know the viewpoint of a web site because that may influence what information is presented and how it is presented.
I am an amateur, independent biologist. I am not a consultant nor am I employed by or a volunteer to work on salmon recovery issues for any governmental agency, educational institution, or nongovernmental group. Similarly to many wildlife managers, I believe that predator control can be justified when there is scientific evidence of the need for control and if control is cost effective.
Return to Table of Contents for Predation of Juvenile Salmon
*********************************************************************
This is only a sample of viewpoints about predation. The emphasis of this web site is on providing information about predation rather than in giving all viewpoints. The following links are for predators of adult as well as juvenile salmonids.
- Predators By T. Novak. 1998. In "A Snapshot of Salmon in Oregon" by Oregon State University Extension Service.
- Major Threats and Impacts to Pacific Salmonids by NOAA Fisheries of National
Marine Fisheries Service. 2000. (See 6th paragraph, part of which states:
"In general, predation rates on salmon are considered by most investigators to
be an insignificant contribution to the large declines observed in west coast
populations. However, predation may significantly influence salmonid abundance
in some local populations when other prey are absent and physical conditions,
such as narrow river mouths or human-made barriers such as fishing locks, lead
to the concentration of adult and juvenile salmonids."
- Factors Responsible for the Decline in Salmon Abundance and Distribution in the Pacific Northwest by D. Botkin, K. Cummins, T. Dunne, H. Regier, M. Sobel, L. Talbot, and L. Simpson. 1995. This is p. 152 in "Status and Future of Salmon of Western Oregon and Northern California: Findings and Options." Center for the Study of the Environment, Santa Barbara, California. Report No. 8. (Predation is not considered a major factor in the decline of Pacific Northwest salmonids.)
- Harvest, Ocean Conditions, and Predators Aren't to Blame by American Rivers. ("There is no scientific basis for claims that ocean conditions, harvest, or predators are the primary reason for the decline of Snake River salmon. Lower Snake River dam supporters often lay the blame for the demise of Snake River salmon and steelhead on factors other than the dams, such as ocean conditions, harvest, and predation. While these factors have contributed to salmon mortality, the scientific evidence clearly shows that they are not the primary problem.")
- The Introduced Fishes Workshop/Symposium by C. L. Lang, Environmental and Legislative Director for the Oregon B.A.S.S. State Federation. 1998?. (Bass fishermen are concerned about control of warmwater game fish that may prey on juvenile salmonids.)
- There have been many newspaper and newsletter articles that have expressed viewpoints about Caspian Tern, Northern Pikeminnow, seal, or sea lion predation of salmonids in the Pacific Northwest. These are accessible through searching Latest Viewpoints in Newspapers or Newsletters about Salmon Recovery in "A Sampling of Salmon Recovery Viewpoints for the Oregon Coast & Columbia River Basin."
Perspectives of Groups or Individuals that Feel that Predation is a Significant Factor in Salmon Recovery
- Welcome to SalmonJustice.com; Home of Common Sense Salmon Recovery. (Common Sense Salmon Recovery is a coalition of groups and individuals representing farmers, cattlemen, realtors, the building industry, and others. "Common Sense Salmon Recovery is a nonprofit organization that believes the National Marine Fisheries Service has failed in its responsibility to protect Northwest salmon resources by allowing overharvest and by failing to properly manage predators that feed on salmon.")
- Smith Leads Northwest Members in Urging Action to Protect Juvenile Salmon. 1998. (9 Pacific Northwest U.S. Congress Representatives urge the U.S. Fish and Wildlife Service to reduce bird predation of juvenile salmonids in the Columbia Basin.)
- Coalition Challenges Salmon Recovery Premises by Mike O'Bryant. Columbia Basin Bulletin - October 6, 2000 on Red Fish Blue Fish Web Site. ("The Save the Salmon Coalition says that ocean conditions and predation on salmon by other protected species, such as Caspian terns, cormorants and sea lions, have a far greater impact on the abundance of salmon than do inland habitat and hatcheries.")
- Save the Salmon Coalition's Approach to Salmon Issues by Oregonians In Action. (Their points are that there is little point in regulating river watersheds because of poor ocean conditions and uncontrolled predators.)
- Predators by Save Our Dams.
- See Comment 7 in Columbia River Alliance for Fish & Commerce All-H Plan Comments in
CRA Alliance Alert, Issue No. 317, March 17, 2000. (CRA membership includes
river dependent communities, navigation, electric utility, industries, agriculture, labor and forestry industries. Their Comment 7 includes "Predator population reduction must be included in recovery actions.")
- What We Can Do About Saving Salmon! By Don Dodds, President, North Pacific Research. (Predators and ocean conditions are more important than river conditions in salmon recovery.)
- See salmon predators and marine mammals in Buchal's "The Great Salmon Hoax."
Return to Table of Contents for Predation of Juvenile Salmon
*********************************************************************
Return to Table of Contents for Predation of Juvenile Salmon
*********************************************************************
Return to Table of Contents for Predation of Juvenile Salmon
*********************************************************************
- Reports of Researchers from the U.S. Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit at Oregon State University, Real Time Research, and Columbia River Inter-Tribal Fish Commission in the Columbia River Estuary and Lower Columbia River. Their research about bird predation is in the Columbia River Estuary as well as upstream to McNary Dam and at Solstice Island in Potholes Reservoir near Moses Lake.
- Current Updates: Avian Predation in the Columbia Estuary and Lower Columbia River.
- 1997 Annual Report: Avian Predation on Juvenile Salmonids in the Lower Columbia River by D. D. Roby, D. P. Craig, K. Collis, and S. L. Adamany. 1998. 1997 annual report to the Bonneville Power Administration and U.S. Army Corps of Engineers. Revised September 1998. (This is available as a PDF file, 442K)
- 1998 Annual Report: Avian Predation on Juvenile Salmonids in the Lower Columbia River by K. Collis, S. Adamany, D. D. Roby, D. P. Craig, and D. E. Lyons. 2000. Annual report for 1998 research to the Bonneville Power Administration, Portland, OR,
Contract No. 97BI33475, Project No. 97-024-00, 101 electronic pages (BPA Report DOE/BP-33475-2). (This is available as a PDF file, 509K)
- See 2000-2002 Season Summaries in "Reports" Menu of http://www.ColumbiaBirdResearch.org.
- Bird Predation on Salmon by National Marine Fisheries Service. 1999. (Caspian Terns in the lower Columbia River.)
- White Paper: Predation on Salmonids Relative to the Federal Columbia River Power System by National Marine Fisheries Service. 2000. (PDF file, 157K.)
- Caspian Tern Predation on Salmon and Steelhead Smolts in the Columbia River Estuary by National Marine Fisheries Service (NOAA Fisheries). (PDF file, 1,327K.)
- Draft Predator Control Program (Mainstem/Systemwide Province): Program
Summary by D. L. Ward, K. Collis, J. H. Petersen, D. D. Roby, and S. P. Barnes. October 24, 2002 draft prepared for the Northwest Power Planning Council. (PDF file, 509K.) (Predation by fish, birds, and marine mammals is partially reviewed for the Columbia Basin, but control programs of birds at dams and of northern pikeminnows at mainstem dams owned by the Chelan County Public Utility District are not mentioned, so this is not comprehensive of all mainstem dams.)
- Scroll down the Predation Links by Red Fish Blue Fish. (Has about 2 dozen newspaper articles about Caspian Tern predation in the Columbia River Estuary.)
*********************************************************************
- Environmental Assessments about Caspian Tern and Cormorant Management in the Columbia River Estuary by the U. S. Army Corps of Engineers. (This page has links to recent Environmental Assessments--some of which are too large to download without a broadband Internet connection.)
- Avian Predation in the Columbia River Estuary. 14 April 1998 letter from
National Marine Fisheries Service to Bob Willis of U.S. Army Corps of
Engineers. (The National Marine Fisheries Service urges action to reduce predation.)
- Action Alert: Caspian Tern Relocation Pilot Study by Black Hills Audubon Society. (Includes links to their 1998 letter.)
- Caspian Tern Management in Pacific Northwest: Letter to U.S. Fish and Wildlife
Service by Craig Harrison of Pacific Seabird Group. 1999.
- Caspian Terns Take Over, Chinook River Salmon Pay the Toll by L. Wirkkala. 2000. (Tern management in the Columbia Estuary has thus far been to move their nesting from Rice Island downstream to East Sand Island. Terns eat fewer juvenile salmonids when they nest at East Sand Island because other prey are available. However, Wirkkala points that the movement of the tern colony downstream increases the vulnerability to tern predation of juvenile salmon from a hatchery near East Sand Island.)
- U.S. Army Corps of Engineers' Environmental Assessment for Caspian Tern
Relocation FY 2000 Management Plan and
Pile Dike Modification. Comments by U.S. Fish and Wildlife Service. 2000.
- Comments about the FY 2000 U. S. Army Corps of Engineers' Caspian Tern Environmental Assessment by R. D. Bayer. 2000.
- Letter about U. S. Army Corps of Engineers 2001 (FONSI) and Environmental Assessment--Caspian Tern Relocation by Gerald W. Winegrad, American Bird Conservancy; Yvonne Borresen, Defenders of Wildlife; Herb Curl, Seattle Audubon Society; and Marlyn Twitchell, National Audubon Society.
- Wildlife Groups, Feds Agree on Terns by Eric Sorensen in 30 March 2002 Seattle Times (newspaper). (Agreement reached after a court case about bird management in the Columbia River Estuary.)
- Draft Review: Caspian Tern (Sterna caspia) Site Feasibility Study: A Preliminary
Assessment of Alternative Nesting Sites for Columbia River Terns by U.S. Fish and Wildlife Service. (PDF file, 1,676K)
- See "Hot Topics" for Status Assessment and Conservation Recommendations for the Caspian Tern (Sterna caspia) in North America by W. D. Shuford and D. P. Craig. 2002. U.S. Dept. of Interior, Fish and Wildlife Service. Portland, Oregon.
*********************************************************************
- Some of the papers for bird predation in the Columbia River Estuary also include some information for predation near lower Columbia River dams.
- Protecting Juvenile Salmonids from Gull Predation Using Wire Exclusion Below Hydroelectric Dams by J. E. Steuber, M. E. Pitzler, and J. G. Oldenburg. 1995. Proceedings of the Great Plains Wildlife Damage Control Workshop 12:38-41. (PDF file, 12K) (Bird control at Columbia Basin dams.)
- Importance of migrating salmon smolt in Ring-billed (Larus delawarensis) and California Gull (L. californicus) diets near Priest Rapids Dam, Washington by D. L. York, D. L., J. L. Cummings, J. E. Steuber, P. A. Pochop, and C. A. Yoder. 2000. Western North Am. Naturalist 60:216-220. (PDF file, 442K)
- Assessment of the Extent of Salmonid Predation by American White Pelicans in the Pool and Tailrace of McNary Dam 2002 by B. Tiller and I. Welch. 2002. Abstract in U.S. Army Corps of Engineers, Northwest Division, Annual Program Review of the Anadromous Fish Evaluation Program (AFEP), Nov. 18-21, 2002 in Portland, Oregon. (PDF file)
- Review: Bird Predation of Juvenile Salmonids and Management of Birds Near 14 Columbia Basin Dams by R. D. Bayer. 2003. Yaquina Studies in Natural History No. 10. (This was published on 28 February 2003; the same day that Wildlife Services sent out the following Environmental Assessment. The online version has been revised since this Review was originally published. Also see the previous links to bird predation and management at Columbia Basin dams.)
- On 28 February 2003, Wildlife Services mailed their
"Pre-Decisional Environmental Assessment: Piscivorous Bird Damage
Management for the Protection of Juvenile Salmonids on the
Mid-Columbia River." (This EA is for Wildlife Services bird control at the Wells, Rocky Reach, Rock Island, Wanapum, and Priest Rapids dams owned by the Chelan, Douglas, and Grant County Public Utility Districts as well as for the Wells and Priest Rapids hatcheries in the mid-Columbia Basin. This EA is not available on the Internet. It is 141 pages long plus
unnumbered appendices. Written comments must have been received by 7 April 2003. For questions, contact:
Michael Linnell (Phone: 360-753-9884 Fax: 360-753-9466)
Assistant State Director
USDA-APHIS-Wildlife Services
720 O'Leary St. NW
Olympia, WA 98502
*********************************************************************
*********************************************************************
- Cormorant Harassment to Protect Juvenile Salmonids in Tillamook County, Oregon by R. D. Bayer. 2000. Studies in Oregon Ornithology No. 9. (SOO 9 is an update of the following SOO 6.)(Files: Total of about 303K, start with
Table of Contents & Summary (s9_cnt.htm, 9K);
Sections A-H (s9a.htm, 138K);
Section I-end (s9b.htm, 148K);
Figure 1 (s9_fig-1.gif, 8K).
- The Cormorant/Fisherman Conflict in Tillamook County, Oregon by R. D. Bayer. 1989. Studies in Oregon Ornithology No. 6.
(Files: Total of about 540K, start with
Table of Contents & Abstract (s6_cnt.htm, 25K);
Chap. 1-2 (s6a.htm, 170K);
Chaps. 3-6 (s6b.htm, 148K);
Appendices (s6c.htm, 171K);
Index (s6_index.htm, 21K);
Map (s6_map.gif, 5K).
- Tagging Smolt on the Nehalem River and A Shining Star in Salmon Recovery by Jim Erickson. 1999. Jim has been active in the cormorant hazing programs cited in Bayer's two reports for Tillamook County. Although Jim has indicated that their cormorant hazing programs greatly reduces predation, he does not mention this in these web pages that were available on 2 August 2000. OSU researchers found that 55% of 20 radiotagged hatchery coho smolts were taken by predators in spite of cormorant hazing (see section K-7 in Bayer 2000).
- Attraction of Birds to Hatchery Releases of Juvenile Salmonids at Yaquina Bay and Coos Bay, Oregon by R. D. Bayer. 2000.
- Predators of Juvenile Salmonids at Alsea Bay in Attraction of Birds to Hatchery Releases of Juvenile Salmonids at Yaquina Bay and Coos Bay, Oregon by R. D. Bayer. 2000.
*********************************************************************
Northern pikeminnows are the fish predator of most concern. This species was known as northern squawfish prior to 1998.
- White Paper: Predation on Salmonids Relative to the Federal Columbia River Power System by National Marine Fisheries Service. 2000. (PDF file, 157K.)
- Predation Issues: Introduced Fishes. Draft Review. By R. Temple, K. Daily, T. Shrader, and B. Hooton. June 1998. Oregon Dept. of Fish and Wildlife.
- Management Implications of Co-occurring Native and Introduced Fishes. Proceedings of the Workshop, October 27-28, 1998. Sponsored by Oregon Department of Fish & Wildlife and the National Marine Fisheries Service. Portland, Oregon. There are several articles of importance about introduced fishes in relation to salmonids; two of which are listed below:
- Recreational Fishery Management Issues in Oregon by Kin Daily, Warmwater Fish Biologist, Oregon Department of Fish and Wildlife (PDF file, 30K) ("ODFW is considering removing limits on non-native fishes in waters where they co-occur with native species that are listed or being considered for listing under state or federal endangered species acts. This action is strongly opposed by most warmwater angling groups who feel that they are being singled out or made "scapegoats" to bear the brunt of native fish restoration when more important issues, such as dams and other habitat degradation, aren't being addressed because of political considerations. The evidence of harm to native fish populations by exotic fishes is mixed and the prospects for relief from predation and competition through increased exploitation of non-native fishes are also mixed. In most cases it is predicted that there would not be measurable increases in the sustainability of native fish populations. Anglers have said that if the state is serious about reducing populations of non-native predatory fishes in the Columbia River, it should advocate restoring a riverine environment to make the habitat less suitable for the exotic predators and more suitable for native anadromous salmonids. In the face of these arguments and the opposition that deregulation of non-native fish species will generate, the state should consider whether the potential benefits outweigh the negatives.")
- Bass Anglers Perspective on the Recreation and Economics of Oregon Black Bass
Fishing: An Argument Against De-Regulation by Bruce Shupp, National Conservation Director, B.A.S.S., Inc., 5845 Carmichael Road, Montgomery, Alabama 36117. (PDF file, 19K).
- Introduced Fishes Management Strategies: Public Review Draft 4-14-1999 by K. Daily, T. Shrader, R. Temple, and B. Hooton of Oregon Dept. of Fish and Wildlife. (PDF file, 270K).
- Yakima River Species Interactions Studies: Annual Report 1999 by
T. N. Pearsons, A. L. Fritts, K. D. Ham, G. A. McMichael, E. L. Bartrand, G. M. Temple, and C. W. Hopley. 2001. Washington Department of Fish and Wildlife, Report to Bonneville Power Administration, Contract No. 1995BI64878, Project No. 199506402, (BPA Report DOE/BP-64878-7)(PDF file, 654K)(Includes diet of smallmouth bass, channel catfish, and northern pikeminnow.)
Also see other annual reports with the same title at the BPA web site at http://www.efw.bpa.gov/cgi-bin/ws.exe/websql.dir/FW/PUBLICATIONS/QueryCustom.pl?Category=P&SortOrder=DOEBPNum
by searching for "species interactions."
- Effectiveness of Predator Removal for Protecting Juvenile Fall Chinook Salmon Released from Bonneville Hatchery, 1991 by R. D. Ledgerwood, E. M. Dawley, P. J. Bentley, L. G. Gilbreath, T. P. Poe, & H. L. Hansen. 1993. U.S. Dep. Commer., NOAA Technical Memorandum NMFS-NWFSC-9. (Pikeminnow predation.)
- Search for "native predators" in Chap. 7 of Return to the River by Independent Scientific Advisory Board (ISAB). 2000. ISAB Report 2000-12 to the Northwest Power Planning Council. (PDF file, 280K.)
- Links to information about the Northern Pikeminnow Management Program (NPMP), which is in the Columbia River downstream of Priest Rapids Dam and the in the Snake River downstream of Hells's Canyon Dam.
- Northern Pikeminnow Sport Reward Fishery: How to Save a Salmon and Make Money Doing It by the Northern Pikeminnow Management Program. (This program is for mainstem reservoirs of federal dams and downstream of Bonneville Dam. This page and links has much information about the sport fishery component of the Northern Pikeminnow Management Program.)
- Draft Predator Control Program (Mainstem/Systemwide Province): Program
Summary by D. L. Ward, K. Collis, J. H. Petersen, D. D. Roby, and S. P. Barnes. October 24, 2002 draft prepared for the Northwest Power Planning Council. (PDF file, 509K.) (Predation by fish, birds, and marine mammals is partially reviewed for the Columbia Basin, but control programs of birds at dams and of northern pikeminnows at mainstem dams owned by the Chelan County Public Utility District are not mentioned, so this is not comprehensive of all mainstem dams.)
- Bonneville Power Administration Fish and Wildlife Publications. (Search for
predator and predation and there are many reports about fish predators in the Columbia Basin. Most of these reports may be too large to view without a broadband Internet connection. The Bonneville Power Administration finances much of the research about salmon recovery in the Columbia Basin.)
- Predation Studies on Juvenile Salmonids in the Mainstem Columbia and Snake Rivers by Jim Petersen of Columbia River Research Laboratory of the Biological
Resources Division of U.S. Geological Survey. (This is about predatory fish, especially Northern Pikeminnows.)
- The Northern Pikeminnow Management Program: an Independent Review of Program Justification, Performance, and Cost-effectiveness by D. G. Hankin and J. Richards. 2000. Northwest Power Planning Council Document No. 2000-16. (PDF file, 120K)
- Evaluation of the Northern Pikeminnow Management Program by Columbia River Investigations of the Oregon Dept. of Fish and Wildlife.
- Pikeminnow by Jim Muck. (Gives top bounty winners for the Northern Pikeminnow Management Program sport fishery each year and the amount that they earned.)
- Predation Links by Red Fish Blue Fish. (Has about 5 newspaper articles about northern pikeminnow management.)
- Links to information about northern pikeminnow control at Chelan County Public Utility District's Rocky Reach and Rock Island Dams. The Northern Pikeminnow Management Program (NPMP) is at some federal dams; there are also control programs in reservoirs for dams owned by other entitities.
- Northern Squawfish (Ptychocheilus oregonensis) Population Reduction Program Rocky Reach Dam and Rock Island Dam 1997 by T. R. West. 1997. Public Utility District No. 1 of Chelan County, Wenatchee, Washington. (PDF file, 2,273K)
- Northern Pikeminnow (Ptychocheilus oregonensis) Movement Upstream and Downstream of Rocky Reach Dam 1998 by T. R. West. 1999. Public Utility District No. 1 of Chelan County, Wenatchee, Washington. (PDF file, 1,567K)
- Northern Pikeminnow (Ptychocheilus oregonensis) Population Reduction Program
Rocky Reach Dam and Rock Island Dam 2001 by T. R. West. 2002. Public Utility District No. 1 of Chelan County, Wenatchee, Washington. (PDF file, 59K)
- Fish Community Structure and the Effects of Resident Predators on Anadromous Fish in the Rocky Reach Project Area by BioAnalysts, Inc. 2000. For Public Utility District 1 of Chelan County, Wenatchee, Washington. (Also includes information about other fish predators.)(PDF file, 135K)
- Also see the Fish Studies web page by Chelan County Public Utility District for additional reports.
*********************************************************************
*********************************************************************
Return to Table of Contents for Predation of Juvenile Salmon
Also see A Sampling of Salmon Recovery Viewpoints for the Columbia Basin & Oregon Coast
Email comments to
Range D. Bayer, rbayer@orednet.org, Home Page, P. O. Box 1467, Newport, Oregon 97365 USA.
(Range [Richard] Bayer is an independent biologist; he is not a consultant nor is he employed by or a volunteer to do biology work or research for a governmental agency, educational institution, or nongovernmental group)
