Kelt Reconditioning and Reproductive Success Evaluation Research: 2015 Annual Technical Report
The Kelt Reconditioning and Reproductive Success Evaluation Project is a research, monitoring, and evaluation (RM&E) uncertainties category project funded through the Columbia Basin Fish Accords. The objectives are to evaluate methodologies to produce viable artificially reconditioned repeat steelhead spawners and to determine the productivity of repeat spawners. Work occurs in the Yakima and Snake river basins. We focused on collecting steelhead kelts at juvenile bypass facilities in Prosser and Lower Granite dams, and additionally some fish were collected at Dworshak National Fish Hatchery, and the Fish Creek weir. These kelts were reconditioned (given prophylactic treatments and fed a specially formulated diet) at Prosser and Dworshak National fish hatcheries. Survival of long-term reconditioned kelts has been 40% (16 years) for Yakima River at Prosser Hatchery and at Dworskak Hatchery 28% (4 years) for hatchery origin fish, 32% (4 years) for mixed stock collections at Lower Granite Dam, 27% (2 years) for South Fork Clearwater collections, and 34% (2 years) for Fish Creek collections. Using estradiol assays, we have established that steelhead rematuration rates vary annually and spatially and range from 10.4% to 80.0%. We determined that kelts can remature as consecutive or skip spawners, typically returning to spawn in 5 or 6 months after kelting or 17 to 18 months later. We characterized the outmigrating Snake River kelt run as primarily composed of Salmon, Grand Ronde, and the Imnaha populations based on GSI analysis at Lower Granite Dam. A total of 24 reconditioned B-run steelhead were released below Bonneville Dam in 2015 to address Reasonable and Prudent Alternative 33 of the FCRSP Biological Opinion. We air-spawned a group of maiden Dworshak Hatchery steelhead in 2015. These fish were then reconditioned and rematuring fish air-spawned as consecutive repeat spawners in 2015 to compare performance between maiden and repeat spawnings. Repeat spawners relative to maiden spawners had higher fecundity, larger eggs and similar fertilization rates. Reproductive success of reconditioned steelhead was confirmed in the Yakima River once again with assignments of 42 juvenile fish to 11 unique parents. Lifetime reproductive success for reconditioned kelt steelhead was estimated as 2.06 relative to single time spawning steelhead. Mature reconditioned steelhead kelts were stocked in the Cle Elum Hatchery Spawning Channel in 2015, to evaluate the feasibility of using the facility to evaluate reproductive success in a more controlled setting. A population model was further developed to provide a means to the management implications of a kelt reconditioning program. The model mimics iteroparity in ways explicit to body condition, reconditioning, and release method. We have shown that repeat spawners could contribute up to 10% of spawning if sufficient kelts are captured and reconditioned, consistent with existing data on survival and maturation rates and estimates of repeat spawner fecundity. This modeling tool provides the means to examine several questions regarding potential avenues for recovery, and management options for doing so. We conducted feed trials with cooperation of the USDA Aquaculture research group from Bozeman, MT and found that the feed produced shows promising results with kelts increasing in lipid levels. Our team has published 9 manuscripts, 1 manuscript is in press, and 3 papers are currently in review. Additionally, the team gave 11 professional presentations in 2015.
Hatch, D., R. Branstetter, J. Stephenson, A. Pierce, A. Matala, R. Lessard, W. Bosch, S. Everett, J. Newell, N. Graham, L. Medeiros, L. Jenkins, T. Tall Bull, M. Elliott, K. Huggler, T. Cavileer, J. Nagler, M. Fiander, C. Frederickson, J. Blodgett, D. Fast, J. Whiteaker, and R. Johnson. 2016. Kelt Reconditioning and Reproductive Success Evaluation Research: 2015 Annual Technical Report. Bonneville Power Administration Annual Report, 2007-401-00, 156 p.