Brood Year 2007 Hatchery Steelhead Report

Author : Charles D. Warren
Publisher :
ISBN 13 :
Total Pages : 62 pages
Book Rating : 4.:/5 (126 download)

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Download or read book Lower Snake River Compensation Plan Steelhead Fish Hatchery Evaluations, Idaho written by Charles D. Warren and published by . This book was released on 2019 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes production, survival, and adult return information for brood year 2009 (BY09) summer steelhead Oncorhynchus mykiss for the Lower Snake River Compensation Plan (LSRCP) and Idaho Power Company (IPC) hatchery mitigation programs operated within the state of Idaho. Clearwater, Hagerman National, Magic Valley, and Niagara Springs fish hatcheries received eyed eggs from broodstock collection facilities and reared them for one year prior to release. Eyed egg-to-smolt survival across all hatcheries and stocks was high with an average of 88% (range = 72%-96%). Average smolt size at release ranged from 5.2 fish per pound (fpp) to 3.7 fpp. Combined, these facilities released 5,656,363 smolts at multiple sites in the Clearwater and Salmon river basins as well as the Snake River downstream of Hells Canyon Dam. Representative groups of hatchery steelhead in each rearing facility were tagged with passive integrated transponder (PIT) tags to evaluate migration timing and survival from release to Lower Granite Dam (LGD). Survival estimates from release to LGD averaged 82.6% (range 67.6%- 99.1%). Recovery of coded wire tags (CWT) and analysis of parentage based tagging (PBT) from the fisheries and hatchery traps was used to reconstruct the BY09 return of adult steelhead. The total estimated return to the mouth of the Columbia River from BY09 releases was 109,057 adult steelhead during the 2011-12, 2012-13, and 2013-14 runs including 62,133 from LSRCP funded facilities (Clearwater, Hagerman National, and Magic Valley fish hatcheries) and 46,924 from IPC funded Niagara Springs Fish Hatchery. The estimated return of adults back to the project area upstream of LGD was 91,175 including 53,879 from the three LSRCP facilities and 37,296 from Niagara Springs Fish Hatchery. Exploitation by recreational anglers upstream of LGD accounted for 55,315 of the returns and steelhead recovered at hatchery traps accounted for 18,852 of the returns to LGD. The remaining fish (17,008) were classified as unharvested escapement and composed of fish that were returning to offsite release locations with no trapping facility to remove them. The smolt to adult survival rate (SAS), defined as the percent of smolts released that returned as adults to the Columbia River mouth was 1.9% for all hatcheries and release groups combined. Smolt to adult return rate (SAR), defined as the percent of smolts released that returned as adults to the project area upstream of LGD, was 1.6% for all rearing hatcheries and release groups combined. Progeny to parent ratios (PPR), which is the ratio of the total number of adults produced to the number of males and females spawned to create the progeny in question, ranged from 52.6 for DWOR stock releases from Clearwater Fish Hatchery to 8.9 for the EFNAT stock released into the East Fork Salmon River from brood year 2009 spawners. In addition to estimating adult returns through run reconstruction methodologies, brood year 2009 steelhead releases from all three LSRCP rearing facilities and Niagara Springs Fish Hatchery were PIT tagged at a sufficiently high rate to estimate returns to Bonneville and Lower Granite dams. The return estimate based on the sum of PIT expansion values exceeded the run reconstruction estimates by 10% at Bonneville Dam. The PIT tag return estimate at LGD was 9% less than the run reconstruction estimate.