Potlatch River Steelhead M&E, M8

This project was originally proposed as an RME project, but has been reclassified as an Intensively Monitored Watershed so the final reporting metrics are different than those proposed. Monitoring and data collection covered 56.2 miles of stream in the East Fork Potlatch River and 63 miles in Big Bear Creek. This contract completed the 10th year of monitoring in Big Bear Creek and the 7th in the East for Potlatch River.

This contract funded the third year of the before-after-control-impact (BACI) study in the Potlatch River watershed to examine density and growth rate differences between control and treatment streams. Two control/treatment pairs are in the study; the upper control/treatment streams are the West Fork Potlatch River and East Fork Potlatch River respectively and the lower control/treatment streams are Pine Creek and Big Bear Creek respectively. There were 86 electrofishing surveys conducted for this BACI study phase. There were 76 snorkel surveys conducted to monitor inter-annual trends in juvenile steelhead abundance and 563 juvenile steelhead were PIT-tagged during the roving tagging surveys within the control/treatment streams. The final activity implemented to establish levels of steelhead production and productivity were juvenile recapture surveys to estimate summer to fall growth.

The East Fork Potlatch River floating weir and the Big Bear Creek PIT-tag array were operated in 2015 to assess steelhead escapement into the Potlatch River drainage. The East Fork Potlatch River floating weir was operated from February 26th through June 3rd 2015. There were 76 adult steelhead marked and released as upstream spawners and 30 were captured as downstream migrating kelts, with 21 being recaptures. Total mark-recapture escapement estimate for the EFK was 105 fish (95% CI 64-165). The Big Bear Creek PIT-tag array to estimate adult escapement was operational at a full span of antennas across the channel for 96 days. The array was partially operational with limited interrogation ability for 36 days and non-operational with no interrogation ability for 16 days during the 2015 adult migration from January 29th – June 25th. Array efficiency was calculated using the USER software program (Lady et al. 2003) with the number of unique upstream, unique downstream, and shared upstream and downstream detections as the input. The array efficiency estimate at BBC was 53.6%. Fifteen adult steelhead were detected at the BBC array site during the 2015 spring migration, 6 of which were previously tagged as adults at Lower Granite Dam (LGR) for the ISEMP project. Based on the tagging rate at LGR and the estimated array efficiency, the total escapement estimate for the BBC drainage was 294 fish (95%CI 166-694).

Juvenile fish rotary screw traps were operated on both Big Bear Creek and the East Fork Potlatch River to assess juvenile steelhead emigration from the Potlatch River watershed in 2015; traps were operated from February 1st – June 3rd and February 24th - June 3rd in the each respective stream. Average daily trap efficiency for the BBC trap was 15% with a range of 0-63%, whereas; trap efficiency for the East Fork Potlatch River trap was 9% with a range of 0-67%. Mark-recapture juvenile steelhead trapping at screw traps on BBC and EFK during the 2015 field season resulted in outmigration estimates of 8,536 (95%CI, 7,786 - 9,463) and 27,519 fish (95%CI, 16,644 – 53,264) at the two sites respectively.

A statistically robust set of habitat monitoring sites in the control/treatment streams were selected for the Low-Water-Habitat-Availability Protocol surveys to estimate instream rearing conditions for juvenile steelhead and were conducted July 6th – August 6, 2015 in the upper Clearwater control/treatment streams and in the lower Clearwater control/treatment streams July 25-31, 2015. There were 21 thermographs deployed throughout the project area.

Wild steelhead are tagged in this project

The monitoring and evaluation effort within the Potlatch River drainage is focused on Snake River Basin ESU Steelhead. Work funded by previous PCSRF and NOAA IMW funds has successfully established a baseline recruit/spawner productivity curve for the Big Bear Creek Drainage. The recruits/spawner productivity relationship is key to understanding the benefit of habitat restoration and its impact on freshwater productivity. This project will continue similar work within the East Fork Potlatch River where the baseline recruits/spawner productivity curve has yet to be completed. The proposal will also help fund the BACI study design within the drainage. This work will document juvenile density in treatment and control reaches, life history characteristics and juvenile steelhead growth within the two index tributary areas. This data will also be used to track habitat restoration success as it relates to density dependent factors within these drainages.