The effects of summer flow augmentation on the migratory behavior and survival of juvenile
Snake River fall Chinook salmon
Statement of Work and Budget FY2005

BPA Project Number:  1991-029-00
BPA Project Title: Effects of summer flow augmentation on Snake River fall Chinook salmon
Contract Number:  NEW
Contract Title:  The effects of summer flow augmentation on the migratory behavior and survival of
Juvenile Snake River fall Chinook salmon
Performance/Budget Period: June 1, 2005 - May 31, 2006

BACKGROUND
Dams reduce the survival of Chinook salmon smolts during early seaward migration.  Summer flow augmentation is implemented annually to mitigate for Snake River fall Chinook smolt mortality caused by the four dams in the lower Snake River by increasing downstream migration rate and survival.  There are two philosophies regarding summer flow augmentation within the resource management community of the Columbia River basin.  One philosophy embraces summer flow augmentation based on studies that show flow augmentation increases the migration rate and survival of fall Chinook salmon smolts.  The other questions the existing migration rate and survival studies, and advocates the use of limited reservoir water for other fishery and economic purposes.  For the present and near future, summer flow augmentation will be implemented annually as one measure to recover Snake River fall Chinook salmon listed for protection under the Endangered Species Act.  Fishery managers will require pre-augmentation data to develop annual water management plans, and post-augmentation data for evaluation.  Fishery managers also need new and more detailed information on how summer flow augmentation affects water temperature, water velocity, juvenile fall Chinook salmon migratory behavior, and survival in Lower Granite Reservoir.

COORDINATION
Coordination with the agencies and tribes is necessary to avoid duplicating work and to make efficient use of existing resources and personnel.  Since 1991, personnel of this project have effectively coordinated its juvenile fall Chinook salmon research with the Bonneville Power Administration, Environmental Protection Agency, Fish Passage Center, Idaho Fish and Game, Idaho Power Company, National Marine Fisheries Service, Nez Perce Tribe, Oregon Department of Fish and Wildlife, Pacific States Marine Fisheries Commission, U. S. Army Corps of Engineers, U. S. Fish and Wildlife Service, U. S. Geological Survey, University of Idaho, and Washington Department of Fish and Wildlife.   Our personnel will continue to seek coordination into the year 2006.

GOAL
Our research goal is to provide fishery managers with an understanding of the migratory behavior and survival of juvenile fall Chinook salmon in the Snake River, so that maximum recovery benefits of summer flow augmentation can be realized.

OBJECTIVES AND RATIONALE
Objective 1: Provide information to fishery managers to maximize the effectiveness of summer flow augmentation.

Rationale: To be effective, summer flow augmentation must be implemented when juvenile fall Chinook salmon are rearing or migrating downstream in Lower Granite Reservoir. The Fish Passage Advisory Committee and the Technical Management Team provide forums for planning and implementing summer flow augmentation.  Much of the data used by fishery managers in these forums are supplied by our project in the form of records compiled on wild fall Chinook salmon juveniles we tag with Passive Integrated Transponder (PIT) tags (Prentice et al. 1990).  The PIT-tag data are provided weekly each year via the PIT-tag Information System, where in turn, it is downloaded, analyzed, and posted in real time on Internet services (e.g., DART; Program RealTime, Burgess and Skalski 2001).  We analyze the PIT-tag data to evaluate the effectiveness of summer flow augmentation after it is implemented.  Objective 1 of our research will help to maximize the effectiveness of summer flow augmentation by providing real-time data for planning, and post-season analyses for evaluation.

Objective 2: Understand how summer flow augmentation affects water temperature, water velocity, juvenile fall Chinook salmon migratory behavior, and juvenile fall Chinook survival salmon in Lower Granite Reservoir.

Rationale:  The efficacy of summer flow augmentation has been disputed (e.g., Dreher et al. 2000).  Summer flow augmentation will continue to be implemented in 2002 based on results of past studies and reviews of the current state of knowledge (e.g., ISAB 2001).  The ongoing dispute, however, raises some important questions.  Fishery managers need more information on (1) the effect of summer flow augmentation on water velocity and temperature in Lower Granite Reservoir, (2) the roles water velocity and temperature play on migratory behavior of juvenile fall Chinook salmon in Lower Granite Reservoir, and (3) where and when juvenile fall Chinook salmon die during freshwater rearing and early seaward migration.  This objective will provide information on how fish respond to augmented flows so that the benefits of augmentation can be more precisely defined when its efficacy is reevaluated by the ISAB and fishery managers in the future.

LITERATURE CITED
Burgess, C., and J. R. Skalski.  2001.  Evaluation of the 2000 predictions of the run-timing of wild migrant yearling and subyearling chinook salmon and steelhead trout, and hatchery sockeye salmon in the Snake River basin using Program RealTime.  Volume VI in the BPA Technical Report Series.  The monitoring and evaluation of smolt migration in the Columbia Basin.  Bonneville Power Administration, Portland, Oregon.

Connor, W. P., R. K. Steinhorst, and H. L. Burge.  2000.  Forecasting survival and passage for migratory juvenile salmonids.  North American Journal of Fisheries Management 20:650-659.

Connor, W. P.   2001.  Juvenile life history, downstream migration rate, and survival of wild Snake River fall chinook salmon.  Ph.D. dissertation.  University of Idaho, Moscow.

Dreher, K. J., C. R. Petrich, K. W. Neely, E. C. Bowles, and A. Byrne.  2000.  Review of
survival, flow, temperature, and migration data for hatchery-raised subyearling fall chinook salmon above Lower Granite Dam, 1995-1998.   An unpublished report prepared by employees of the state of Idaho, Boise.

Cormack, R. M.1964.  Estimates of survival from the sightings of marked animals.  Biometrika 51:429-438.

ISAB (Independent Scientific Advisory Board).  2001.  Review of lower Snake River flow augmentation studies.  ISAB 2001-4.  

Prentice, E. F., T. A. Flagg, and C. S. McCutcheon.  1990b.  Feasibility of using implantable passive integrated transponders (PIT) tags in salmonids.  Pages 317-322 in N. C.  Parker, A. E. Giorgi, R. C. Heidinger, D. B. Jester, E. D.  Prince, and G. A. Winans, editors.  Fish-marking techniques.  American Fisheries Society, Symposium 7, Bethesda, Maryland.

Skalski, J. R., S. G. Smith, R. N. Iwamoto, J. G. Williams, and A. Hoffman.  1998.  Use of passive integrated transponder tags to estimate survival of migrant juvenile salmonids in the Snake and Columbia rivers.  Canadian Journal of Fisheries and Aquatic Sciences 55:1484-1493.

Tiffan, K.F., T.J. Kock, and D.W. Rondorf.  2005.  Migratory behavior of subyearling fall Chinook salmon in relation to summer flow augmentation in the Snake River, 2003.  Pages 34-65 in K.F. Tiffan and W.P. Connor, editors.  The effects of summer flow augmentation on the migratory behavior and survival of juvenile Snake River fall Chinook salmon.  2003 Annual Report to the Bonneville Power Administration, Portland, Oregon.