Kelt Reconditioning and Reproductive Success Evaluation Research: 2014 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 to fall of long-term reconditioned steelhead was 61% at Prosser and 30% at Dworskak hatcheries in 2014. Using estradiol assays, we have established that steelhead rematuration rates vary annually and spatially and range from 10.4% to 80.0%. We have also determined from our study streams 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 34 reconditioned B-run steelhead were released below Bonneville Dam in 2014 to address Reasonable and Prudent Alternative 33 of the FCRSP Biological Opinion. We air-spawned a group of maiden Dworshak Hatchery steelhead in 2013. These fish were then reconditioned and rematuring fish were air-spawned as repeat spawners in 2014 to compare performance between maiden and repeat spawnings. Comparisons of fecundity, fertilization rate, and egg size variables revealed that repeat spawners had larger eggs and a greater abundance of eggs and no differences in fertilization rates were detected. Reproductive success of reconditioned steelhead was confirmed in the Yakima River with assignments of 23 juvenile fish to 11 unique parents. A work plan was developed and approved to use the Cle Elum Hatchery spawning channel to improve reproductive success estimates for reconditioned kelt steelhead. Fish will be stocked in the channel in 2015. We used radio telemetry in 2014 to track 19 reconditioned kelts to spawning streams to refine our estimates of production in the Yakima River and its tributaries. We developed a model to examine population recovery from the perspective 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. Our team published 5 manuscripts and gave 14 professional presentations in 2014.
Hatch, D., Branstetter R., Stephenson J., Pierce A., Matala A., Lessard R., Bosch W., Everett S., Newell J., Graham N., Jenkins L., Elliott, M., Caldwell, L., Cavileer T., Nagler, J., Fiander M., Frederickson C., Blodgett J., Fast D., Whiteaker J., Johnson R. Kelt Reconditioning and Reproductive Success Evaluation Research. 1/1/2014 – 12/31/2014 Annual Report 15-04, 2007-401-00. 165p.