Non-native salmonids 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 some native bull trout and cutthroat trout populations. 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 then reintroduce native fish species. These projects have been identified as critical to recovering native bull trout (BT) and westslope cutthroat trout (WCT).

Westslope cutthroat trout have recently been extirpated in upper Cee Cee Ah Creek due to displacement by brook trout. Prior to implementing non-native fish removal and WCT translocation in upper Cee Cee Ah Creek, an extensive public outreach program was initiated.  In 2007, much of the effort for this project was made towards public education and involvement in using piscicides for native fish recovery.  To date, public acceptance of using piscicides as a management tool has been accomplished.  In 2008, 2009, and 2010, Cee Cee Ah Creek was treated with rotenone and non-native brook trout were successfully eradicated. Re-invasion of the treatment area is impossible due to the Cee Cee Ah Falls.  In 2011, efforts to reintroduce WCT commenced: 100 mature WCT were collected from East Fork Smalle Creek, a neighboring tributary, and translocated directly into reclaimed reaches of Cee Cee Ah Creek.  Those translocated fish should have spawned in the spring of 2012 and will be monitored beginning in 2013 .  

From 2003 to 2012, 2,219 brook trout were removed from West Branch LeClerc Creek Tributary 1 (Trib 1) using standard electrofishing gear. This work element was originally implemented through the Kalispel Resident Fish Project (1995-001-00).  Initially, brook trout outnumbered WCT by a ratio of 3 to 1.  In 2011, first pass electrofishing numbers for WCT and brook trout were 449 and 53, respectively.  The second pass in 2011 yielded 686 WCT and 4 brook trout.  In 2012, we conducted a series of two treatments with the intention of conducting two passes per treatment. In the first pass of the first treatment we collected 253 WCT and 42 BKT. Considering the low number of brook trout captured in the lower section of Trib 1 (3), we decided to limit the second pass of the first treatment to the upper section to minimize injury to WCT; the second pass yielded 33 WCT and 48 BKT. We only completed one pass on the second treatment as well, to limit injury to WCT; this pass yielded 131 WCT and 3 BKT.  Given the level of success in removing brook trout, we feel that complete eradication is could be achievable and we will continue with two additional treatments in 2013.

In an effort to conserve the remaining WCT in Graham Creek, a tributary within the Calispell subbasin, KNRD installed a concrete barrier just up from the mouth to eliminate future upstream migration of BKT. Both prior to and following the barrier construction, we electrofished Graham Creek to remove all observed BKT between the fish passage barrier and a natural barrier (cascade/waterfall) located ~700 m upstream. In 2012 we conducted a single pass electrofishing survey to determine if any BKT remained in the treatment area; we collected 136 WCT (not including YOY fish) and 15 BKT. With the continued presence of BKT in Graham Creek, it is necessary to conduct an additional removal treatment consisting of two passes using standard electrofishing gear in 2013.  


In 2013, KNRD and WDFW will began planning a collaborative approach in coordinating and implementing piscicide (rotenone) treatments in tributaries to the Pend Oreille River in Washington as well as tributaries to the Priest River in Washington/Idaho. The intent of this program is to use coordinated funding approaches (e.g. FERC projects, BPA) to eliminate BKT from specific stream reaches in an effort to protect, restore or enhance native WCT populations.  As in 2007, with the outreach effort that took place prior to implementing the non-native fish removal project in Cee Cee Ah Creek, a significant effort will again be necessary to ensure that we have support in carrying out multiple projects using piscicide as a management tool for native fish recovery. We will partner with and sub-contract WDFW to develop an education and outreach program that explains the validity of piscicide as a management tool and how this program will be implemented over the next ten years. Additional planning outside of this Non-Native project will take place in developing strategic plans to salvage existing WCT and understand their respective genetics, as well as developing the steps necessary to reintroduce WCT into treated reaches. This one year outreach effort should accomplish the goal of public acceptance prior to implementing treatment in 2014.

The Idaho Department of Fish and Game has been working at suppressing lake trout in Upper Priest Lake through extensive gill netting.  Since 1997, over 10,000 lake trout have been removed from the lake; however, the population continues to rebound, through in-lake recruitment and immigration of mature, ripe lake trout from Priest Lake in the fall. Permanent suppression of lake trout in Upper Priest Lake will also require successful suppression in Priest Lake.  The intent of lake trout suppression in Upper Priest Lake and the thorofare is to prevent a population explosion in the upper lake prior to initiating suppression efforts in Priest Lake.

In 2009, IDFG contracted Harbor Fisheries (with funding from USFWS) to install and operate trap nets and gillnets in the Thorofare in the fall on an experimental basis.  The intent of the project was to identify whether or not nets could be used to effectively curb immigration through the Thorofare in the fall.  Initially, the trap nets proved to be ineffective.  Lake trout were able to avoid the trap nets, despite using leads that completely spanned the Thorofare channel.  One challenge faced by any project aimed at controlling lake trout immigration is the need to maintain boat passage.  In 2009, the crew submerged a portion of the trap net leads and a portion of each gillnet and used markers to guide boats.  
Several modifications were made to the trap nets, and toward the end of the project, the nets were effective in capturing a portion of the upstream migrants.  The contractors were confident that additional modifications, including larger throats, heavier lead lines on the leads, and staggering leads to create a boat channel would further improve trap efficiency.  In 2010 the modifications were made and the trap nets captured 182 lake trout while gill nets set upstream of the trapnets to monitor effectiveness captured 59 lake trout.  In 2011, the Thorofare trap nets were fished an additional two weeks and, combined with increased net efficiency, 355 lake trout were captured.

In 2012, this project provided cost-share funding for the IDFG project and enable them to continue with lake trout removals in the Thorofare by installing and operating the modified trap nets and gillnets from mid September through mid November in an effort to refine the immigration control efforts.
Northern pike (NP), illegally introduced in the Clark Fork River, Montana have immigrated to the Box Canyon Reservoir (BCR) where they are causing drastic declines in native species and gamefish being managed by the Kalispel Tribe Natural Resources Department (KNRD) , Washington Department of Fish and Wildlife (WDFW) and Idaho Department of Fish and Game (IDFG). The NP population grew exponentially from <400 in 2006 to >5,500 in 2010 between Newport (Pioneer Park) and Riverbend. Reservoir-wide, we estimate the population to be over 10,000 individuals today. Northern pike threaten to undermine current and future recovery efforts for bull trout and westslope cutthroat trout, as well as other native salmonids, minnows, suckers and introduced gamefish in the watershed. Northern pike pose significant risks to the anadromous fisheries of the Columbia River and Endangered Species Act (ESA) recovery efforts if left to emigrate further downstream.  The KNRD and WDFW plan to implement a suite of measures, including mechanical suppression of the population, beginning in 2012.

The BCR population is currently expanding exponentially and has expanded their range in the reservoir, as well as been documented in small numbers in Boundary Reservoir, upper Columbia River in Canada, and Lake Roosevelt. Although angler effort has increased 20-fold in the last decades, angler exploitation alone cannot likely control or reduce the abundance of NP at the level of effort and harvest observed in 2010. Anglers presently release a large portion (>50%) of the NP they catch and harvest exploitation is less than 25% (Connor et al. in prep.). Modeling with the Fisheries Analysis and Simulation Tool (FAST) indicated that under current conditions greater than 55% of the population would have to be removed annually to begin reducing their abundance (WDFW unpublished).

Northern pike pose immediate threats to the survival of bull trout and westslope cutthroat trout entrained at Albeni Falls Dam (AFD). KNRD, U.S. Army Corps of Engineers (USACE), Bonneville Power Administration (BPA), Eastern Washington University (EWU), and Pacific Northwest National Laboratory (PNNL) have been studying the feasibility of fish passage at AFD and have been temporarily providing passage for bull trout with the use of electrofishing and angling. Movement, habitat use, behavior, and survival of bull trout and westslope cutthroat trout has been monitored in the watershed with biotelemetry since 2007. Bull trout and westslope cutthroat trout collected near the tailrace of AFD are all thought to originate from upstream source populations, based on size, color, behavior, and genetics. For example 100% of the bull trout collected at the tailrace area of AFD have been genetically assigned to upstream tributaries. Of those that were transported upstream and entered tributaries, 100% entered either their primary or secondary genetic assignment. Thirty-six percent of those originated from severely depressed Lake Pend Oreille tributaries including Morris Creek, Lightening Creek, East Fork Lightening Creek, and Rattle Creek. We are only just beginning to understand the magnitude of entrainment at AFD and plan to genetically catalog westslope cutthroat trout collected below AFD beginning 2013 to identify source populations. Entrainment of westslope cutthroat trout tagged at the mouth of Priest River exceeded 30% in 2011 (Connor and Olson in prep).

Northern pike threatens bull trout and westslope cutthroat trout survival due to high degree of habitat overlap, especially during summer when reservoir temperatures surpass 18 °C and native salmonids seek thermal refuge. Documented cold water refuge include a spring-fed culvert near AFD, Charr Springs, Indian Creek, Kent Creek, and tributary mouths farther downstream (e.g. Cedar Creek). A bull trout has been observed holding at Charr Springs in an area less than 1 m2 after navigating >100 m through dense macrophytes (Paluch et al 2011). Adult NP in BCR are capable of consuming all but the largest adult bull trout that we have encountered (Bean et al. 2011), and have been collected in close proximity spatially and temporally (i.e. same electrofishing pass). Efforts to increase the relative abundance of native salmonids in the lower Pend Oreille through mainstem fish passage projects, tributary restoration, and conservation aquaculture may be seriously compromised by the establishment and expansion of NP in the watershed. Furthermore, NP also threaten Lake Pend Oreille native salmonid populations as well.

Mechanical suppression of northern is a well established management tool and efforts are currently or have recently been implemented in the Missouri River drainage, MT (MFWP 2011), Susitna River drainage, AK (Ivey et al. 2011), Colorado River drainage, UT, WY, CO (Monroe  and Hedrick 2008; Finney and Haynes 2008), and AZ reservoirs (Kuzmenko et al. 2010).  A variety of methods have been employed for suppression including electrofishing, fyke netting, and gill nets. Gill netting methods that focus effort on sloughs and backwaters during spring when pike are congregated for spawning have been developed and implemented in Alaska’s Alexander Creek, a tributary to the Susitna River that once supported popular chinook and coho salmon fisheries decimated by illegally stocked NP. Ivey et al. (2011) demonstrated that large numbers of mature NP could be efficiently removed with this strategy.

To assess the feasibility of such a strategy in BCR, KNRD and WDFW initiated a pilot removal project in 2011 under the range of environmental conditions, water elevation and surface area, and access limitations commonly experienced. We assessed CPUE, spawn timing and duration, maturity, sex ratio, fecundity, diet, age and growth from two representative slough locations from ice-off through June when flood level flow (120Kcfs) reduced access and CPUE dropped sharply. With minimal effort (4 nets/week; 48 total nets), we removed 647 NP (1.16 tons). Spawning began in late March and peaked the 4th week of April. Over 90% of mature females collected after May 1 were post-spawn. CPUE was consistent between locations and peaked in April and May at reservoir elevations of 2035-2040 ft (Figure 6).  Shallow depth sets (<2 m) produced nearly 3 times the catch of deep sets (>4 m). The size distribution has not changed appreciably, with 90% of the catch less than 700 mm. Males averaging 611 mm accounted for 60% of the catch. Bycatch included 11 fish species, 394 individuals, with brown bullhead, tench, yellow perch and peamouth accounting for 84% of bycatch. Four brown trout were the only salmonids collected (Connor et al. in prep). We concluded that intensively netting NP in sloughs and backwaters from ice off through the spring freshet could drastically reduce the abundance of NP in BCR.

In 2012, KNRD and WDFW began implementing a suite of measures designed to drastically reduce NP abundance in BCR including: classification as a prohibited species and removal from the list of gamefish, allowing for two-pole permits to increase angler exploitation, public education and outreach, promotion of harvest-oriented fishing contests (e.g. PikePalooza), and mechanical suppression. KNRD has implemented year 1 of a 3-year mechanical suppression project in BCR with support provided by BPA, US Bureau of Indian Affairs, WDFW, Kalispel Tribe, and Avista Corporation.

A total of 5,808 northern pike were removed in 1,031 overnight net sets during the 2012 suppression effort, representing an 88% reduction in the adult population based on 2010 Peterson mark-recapture population estimate. Phase I effort targeting known spawning locations with continuous netting removed the majority of mature individuals as they staged for spawning. Weekly mean catch-per-unit-effort (CPUE) peaked in mid April and declined rapidly to 2-3 NP/net night in May-June. Effectiveness of the suppression effort was evaluated with the Spring Pike Index Netting (SPIN) survey. SPIN survey data indicated the population was reduced 83% from 2011 levels during Phase I suppression. Mean CPUE was 2.3 NP/net night in southern ½ of the reservoir and 0.8 NP/net night north of Riverbend, nearly meeting the target abundances necessary to cease suppression netting for the year (<1.7 NP/net night in south ½ of the reservoir and <0.5 NP/net in north ½). Not meeting our target reduction, we continued netting through June until rising river levels and decreased catch forced us to discontinue for 2012. Although these results were encouraging, it is necessary to continue suppression efforts in 2013/2014 to account for full recruitment of juveniles produced in 2010-2012.

Following the 3-year suppression effort, the Joint Stock Assessment Project (BPA Project No. 1997-004-00) and WDFW will monitor the effectiveness of mechanical removal and other measures by annually monitoring the NP population with SPIN survey and periodically monitoring the fish community with standardized warmwater fish surveys (Bonar et al. 2000) to detect trends in abundance and population characteristics as a response to removal efforts.