PROJECT BACKGROUND

Non-native fish species are impacting native salmonid populations throughout the Pend Oreille Subbasin. Competition, hybridization, and predation by non-native fish have been identified as primary factors in the decline of native Bull Trout (BT) and Westslope Cutthroat Trout (WCT) populations. Over 99% of tributaries to the Pend Oreille River were historically occupied by native WCT; now less than 35% hold WCT. Although anthropogenic impacts contributed to significant declines over the past century, corrections to those impacts (i.e., habitat modifications), in the presence of non-native fish tend to benefit invasive species instead of the focal species, which are native to the system. Therefore, the goal of this project is to implement actions to suppress or eradicate non-native fish in areas where native populations are declining or have been extirpated and reintroduce native fish species where appropriate. These projects have been identified as critical to recovering native ESA-listed BT and declining populations of WCT. Actions developed through this project have either direct impacts on non-native fish species (e.g., reduced numbers through suppression/eradication activities),  lead to actions in which non-native fish species are directly impacted (e.g., collect fish distribution data to warrant action; develop management strategies for non-native fish species; collect data on impacted native salmonid populations) or monitor the response to recovered native fish populations  following actions taken against non-native fish species. As such this project will discuss actions categorized into two types:

1. Mechanical Suppression: Physical removal of non-native fish species of interest by way of electrofishing, netting (gill, fyke, seine, etc.), trapping (weir, light-minnow, minnow, etc.) or angling leading to a depressed or reduced population.
2. Eradication: Removal of non-native fish species of interest by way of chemical piscicide (pesticide) application or other mechanical removal technique leading to an eradicated population in the target project area.

MECHANICAL SUPPRESSION OF NON-NATIVE EASTERN BROOK TROUT IN TRIBUTARIES

GRAHAM CREEK (CALISPELL SUBBASIN): In an effort to conserve the remaining WCT in Graham Creek the KNRD installed a barrier structure in 2008 just up from the mouth to eliminate future upstream migration of Eastern Brook Trout (EBT). A pre and post installation electrofishing effort was completed to remove all observed EBT between the fish passage barrier and a natural cascade/waterfall barrier 700 m upstream. With EBT nearly eradicated, it is necessary to annually conduct additional removal treatments consisting of 1-2 passes using electrofishing gear to ensure complete removal of EBT. Environmental DNA (eDNA) samples will be collected to confirm presence/absence of EBT.

SAUCON CREEK (LECLERC SUBBASIN): Saucon Creek historically contained a pure WCT population. Saucon Creek is protected from invasion of EBT by a barrier low in the creek near the confluence with West Branch LeClerc Creek. Mechanical suppression of EBT using electrofishing techniques was implemented in beginning in 2014 in the 2.1 Km section where sympatric populations of WCT and EBT exist; upstream of this point is a barrier in which allopatric WCT occupy the remaining upstream habitat. In 2017, we will conduct an additional EBT removal treatment and investigate WCT densities upstream. To determine if EBT have also spread to a close proximity stream (unnamed tributary) to Saucon Creek, eDNA samples will be collected throughout fish-bearing habitat.

In 2017, thermographs will be installed in these tributaries to provide long term temperature monitoring data as the WCT population recovers and eventually stabilizes. This will aslo occur in West Branch LeClerc Creek Tributary 1 where mechanical suppression efforts led to the eventual extirpation of EBT.

ERADICATION OF NON-NATIVE EASTERN BROOK TROUT IN TRIBUTARIES

The Kalispel Natural Resources Department (KNRD) and Washington Department of Fish and Wildlife (WDFW) are operating a closely coordinated program to plan and implement actions focused on removing non-native fish species from select tributaries in the Pend Oreille Basin and subsequently restoring genetically pure, native WCT. These actions, focused primarily on the use of piscicide to remove  non-native fish species, are identified through Federal Energy Regulatory Commission (FERC) licenses issues recently to the Pend Oreille Public Utility District (PUD) for operations of Box Canyon Dam and Seattle City Light (SCL) for operations of Boundary Dam.

MONITORING WESTSLOPE CUTTHROAT TROUT POPULATION IN CEE CEE AH CREEK (CEE CEE AH SUBBASIN): A pilot piscicide treatment project conducted in Cee Cee Ah Creek provided the foundation for advancing this program to a planning and implementation phase. After a successful series of piscicide treatments (2008-2010), WCT were translocated in small numbers to the treatment area (2011-2012) and monitoring has indicated the population is successfully recruiting new age classes and expanding in the available habitat; population estimates indicate there are now >4,800 WCT in the Cee Cee Ah Creek project area.  We will continue to monitor the population in 2017 by conducting population estimates in each of the 8-1000 m reaches. Multiple pass depletion electrofishing surveys will be conducted in 100 m block-netted sections in each reach. Biological information will be recorded for all WCT captured (i.e., length, weight) and genetic samples will be taken and processed for a future comprehensive analysis of the population. We plan to conduct a snorkel or spot electrofishing survey in 2017 to examine the extent of distribution through the project area. We will also collect several eDNA samples on 2017 to ensure no EBT have been re-introduced to the treatment area. In 2017, thermographs will be installed in the project area to provide long term temperature monitoring data as the WCT population recovers and eventually stabilizes..

SMALLE CREEK PISCICIDE TREATMENT EFFECTIVENESS MONITORING (CALISPELL SUBBASIN): Having established the framework for the program in 2013-2015 (i.e., guiding documents) and funding for the first proposed project on Smalle Creek (Pend Oreille PUD), KNRD and WDFW, with assistance from Washington State University, implemented the education and outreach effort necessary to ensure piscicide project success. The upper reaches of Smalle Creek, above a natural barrier, were treated with piscicide in 2015 and 2016 to remove non-native EBT. This will occur again in 2017 with funding provided by the Pend Oreille PUD. Under this BPA contract, we will monitor the effectiveness of the 2015-16 treatments by collecting an eDNA sample every 250-300 m of the treatment area. This information will indicate if the project has successfully removed all EBT or if some individuals remain (and where) so we can target those areas in 2017. Once the project is deemed successful we will restore the WCT population and conduct monitoring protocols (2017-on)


MECHANICAL SUPPRESSION ACTIVITIES IN MAINSTEM RIVERS OR LAKES

PEND OREILLE RIVER NORTHERN PIKE SUPPRESSION: Northern Pike (NP), illegally introduced in the Clark Fork River, Montana has immigrated to the Washington’s Pend Oreille River, where they have caused drastic declines in native species and gamefish being managed by State and Tribal agencies. Northern Pike threaten to undermine current and future recovery efforts for BT and WCT, as well as other native salmonids, minnows, suckers and introduced gamefish in the watershed. Northern Pike also pose significant risks to the anadromous fisheries of the Columbia River and Endangered Species Act (ESA) recovery efforts if left unchecked to emigrate further downstream.

After engaging the public in 2011 and 2012, KNRD and WDFW developed a 3-pronged approach to suppressing the Pend Oreille’s Box Canyon Reservoir population to pre-2004 levels: increasing angler harvest through outreach and education, targeted (harvest-oriented) fishing contests, and mechanical suppression of the population with gillnets. The objective was initially to reduce the abundance of NP in Box Canyon Reservoir from the 2011 Spring Pike Index Netting (SPIN) survey catch-per-unit-effort (CPUE) value of 13.2 NP/net night in the southern half (core area from Pioneer Park to Riverbend including sloughs) to <1.73 NP/net night and from 1.9 NP/net night in the northern half (Riverbend to Box Canyon) to <0.5 NP/net night.
KNRD, with support from WDFW has implemented five years of mechanical suppression in BCR (2012-2016) with project support provided by BPA, US Bureau of Indian Affairs, WDFW, Kalispel Tribe, and Avista Corporation. Up to 35 specifically designed gillnets gill nets were deployed and retrieved daily, with target net saturation generally occurring from ice-off (March) through the spring freshet (June) or ended earlier if target reduction was met (2014) or later phases were unplanned (2015-on).

Thus far 17,159 NP were removed in 4,383 overnight gillnet sets in the Pend Oreille River. Based on 2016 SPIN results, the adult population in the core area (southern half of BCR and sloughs) was reduced by > 99% from the 2011 baseline of 13.2 NP/net to 0.073 NP/net night. Recreational angler harvest appeared negligible based on observations by field staff, derby results, and anecdotal reports and as anticipated, mechanical suppression removed the vast majority of NP. In 2015, a report on the effectiveness of mechanical suppression to remove 87% of the NP population was produced as a supplemental technical report to the 2015 Non-Native Fish Suppression (BPA Project No. 2007-149-00) annual report and submitted the Independent Scientific Review Panel of BPA’s Fish and Wildlife Program and is available to interested parties.

This project has largely been successful in recruiting and suppressing all available cohorts produced to date. Although the BCR population is largely depressed, a 2016 SPIN survey in the downstream Boundary Reservoir indicated the NP relative abundance was higher than anticipated and warrants additional mechanical suppression. Suppression in both reservoirs will occur in 2017 as part of the ongoing Pend Oreille River NP suppression Project. Staff from the Tribe and WDFW will meet annually and use all available data and information to make the appropriate decision on out year suppression.

LAKE TROUT SUPPRESSION IN UPPER PRIEST LAKE (IDAHO): The Idaho Department of Fish and Game (IDFG) has been suppressing lake trout in Upper Priest Lake (UPL) through extensive gill netting since 1997.  A larger effort has been annually implemented since 2007, with >28,000 Lake Trout (LKT) removed from 2007-2016. Bull Trout redds are annually monitored in the UPL watershed and have increased from 7 (2007) to 81 (2014), but have stabilized to 50-60 per year since.

The Hickey Brothers Research (LLC) will again be contracted to use gillnets to remove LKT from UPL using their 36 foot commercial gillnet boat. Gillnets will be fished over a 7 day period in late May/early June 2017. Nets will be oriented based on catch rates at a particular site and on the discretion of the netting crew; effort will be made to avoid incidental BT captures by avoiding known concentrations. Data from the 2017 effort will be summarized and compared to previous years’ efforts to monitor the effectiveness and success of the project. This BPA project provides cost-share funding to continue LKT suppression.  The US Fish and Wildlife Service also contribute funding. Continuing to reduce lake trout predation and competition with BT and WCT by removing LKT will assist in BT recovery and long term persistence of other native fish.


INVASIVE SPECIES COORDINATION AND PROJECT RESULTS SHARING

Given the scope of this project and the nearly two decades of invasive species management by KNRD, it is becoming more critical to be involved with the coordination of invasive species management and information sharing. In 2017 this BPA project will support attendance and presentation of invasive species management project data at local and regional conferences. This project will also support staff attendance at many local and regional coordination and technical staff meetings focused on addressing invasive species. The focal area is the Columbia River Watershed but other opportunities to address broader invasive species issues will be considered.