Status and Monitoring of Natural and Supplemented Chinook Salmon in Johnson Creek, Idaho, 2006-2007 Annual Report.

Abstract

The Nez Perce Tribe Johnson Creek Artificial Propagation Enhancement Project (JCAPE) has conducted juvenile and adult monitoring and evaluation studies for its 10th consecutive year. Completion of adult and juvenile Chinook salmon studies were conducted for the purpose of evaluating a small-scale production initiative designed to increase the survival of a weak but recoverable spawning aggregate of summer Chinook salmon Oncorhynchus tshawytscha. The JCAPE program evaluates the life cycle of natural origin (NOR) and hatchery origin (HOR) supplementation fish to quantify the key performance measures: abundance, survival-productivity, distribution, genetics, life history, habitat, and in-hatchery metrics. Operation of a picket style weir and intensive multiple spawning ground surveys were completed to monitor adult Chinook salmon and a rotary screw trap was used to monitor migrating juvenile Chinook salmon in Johnson Creek. In 2007, spawning ground surveys were conducted on all available spawning habitat in Johnson Creek and one of its tributaries. A total of 63 redds were observed in the index reach and 11 redds for all other reaches for a combined count of 74 redds. Utilization of carcass recovery surveys and adult captures at an adult picket weir yielded a total estimated adult escapement to Johnson Creek of 438 Chinookmore » salmon. Upon deducting fish removed for broodstock (n=52), weir mortality/ known strays (n=12), and prespawning mortality (n=15), an estimated 359 summer Chinook salmon were available to spawn. Estimated total migration of brood year 2005 NOR juvenile Chinook salmon at the rotary screw trap was calculated for three seasons (summer, fall, and spring). The total estimated migration was 34,194 fish; 26,671 of the NOR migrants left in the summer (July 1 to August 31, 2005) as fry/parr, 5,852 left in the fall (September 1 to November 21, 2005) as presmolt, and only 1,671 NOR fish left in the spring (March 1 to June 30, 2006) as smolt. In addition, there were 120,415 HOR supplementation smolts released into Johnson Creek during the week of March 12, 2007. Life stage-specific juvenile survival from Johnson Creek to Lower Granite and McNary dams was calculated for brood year 2005 NOR and HOR supplementation juvenile Chinook salmon. Survival of NOR parr Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 28.2% and 16.2%. Survival of NOR presmolt Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 28.2% and 22.3%. Survival of NOR smolt Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 44.7% and 32.9%. Survival of HOR smolt Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 31.9% and 26.2%. Multi-year analysis on smolt to adult return rate's (SAR's) and progeny to parent ratio's (P:P's) were calculated for NOR and HOR supplementation Brood Year 2002 Chinook salmon. SAR's were calculated from Johnson Creek to Johnson Creek (JC to JC), Lower Granite Dam to Lower Granite (LGD to LGD), and Lower Granite Dam to Johnson Creek (LGD to JC); for NOR fish SAR's were 0.16%, 1.16% and 1.12%, while HOR supplementation SAR's from JC to JC, LGD to LGD and LGD to JC were 0.04%, 0.19% and 0.13%. P:P's for all returning NOR and HOR supplemented adults were under replacement levels at 0.13 and 0.65, respectively. Recruit per spawner estimates (R/S) for Brood Year 2005 adult Chinook salmon were also calculated for NOR and HOR supplemented Chinook salmon at JC and LGD. R/S estimates for NOR and HOR supplemented fish at JC were 231 and 1,745, while R/S estimates at LGD were 67 and 557. Management recommendations address (1) effectiveness of data collection methods, (2) sufficiency of data quality (statistical power) to enable management recommendations, (3) removal of uncertainty and subsequent cessation of M&E activities, and (4) sufficiency of findings for program modifications prior to five-year review.« less