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 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 ESA-listed bull trout (BT) and declining westslope cutthroat trout (WCT).

From 2003 to 2013, 2,232 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 lower densities of BKT and potential harm to WCT in multiple treatments, in 2013 we modified the protocol to complete the removals in one treatment using multiple pass depletion techniques using continuous block-netted 100m sections. BKT will be removed from the stream and WCT will be returned to the stream not more than 100m from the capture point. This protocol will continue in 2014 and with the level of success in removing BKT to date and the very few remaining in Trib 1, we feel that complete eradication could be achievable.

In 2013 a restoration project was developed and submitted to Washington's Salmon Recovery Funding Board (SRFB) in which multiple fish passage barrier culverts were to be removed and/or replaced in the upper West Branch LeClerc Creek watershed. Investigating fish presence surrounding the impacted project area, it was determined that brook trout (BKT) had been stocked, unknown to resource managers, in Saucon Creek, located in the headwaters of the West Branch of LeClerc Creek. Based on genetics and snorkels surveys conducted in the 1990’s-2000’s, Saucon Creek held a pure, moderately high density WCT population. Saucon Creek is protected from invasion of BKT by a barrier low in the creek near its confluence with West Branch LeClerc Creek. Although the extent of BKT distribution is unknown, Saucon Creek is a good candidate for mechanical removals of BKT given 1) the presence of a natural barrier limiting natural invasion of BKT, 2) an established and high-density population of WCT, and 3) relatively low numbers of invasive BKT.  In 2014 we will conduct one BKT removal treatment consisting of multiple pass depletion techniques in continuous 100 m block-netted sections from the barrier at near the confluence with WB LeClerc to the extent of observed BKT distribution (up to 3.2 Km total). BKT will be removed from the stream and WCT will be returned to the stream not more than 100m from the capture point. Following the initial removal project, an estimate of BKT:WCT densities will be known and a future management strategy will be determined (e.g., continue mechanical removals, use piscicide to remove BKT).

In an effort to conserve the remaining WCT in Graham Creek, a tributary within the Calispell subbasin (Winchester Creek), 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. In 2013, again in a single pass, we collected 182 WCT (not including YOY fish) and only 1 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. BKT will be removed from the stream and WCT will be returned to the stream not more than 100m from the capture point. We are document increasing numbers of WCT with decreasing (almost non-existent) BKT and feel that complete eradication of BKT could be achievable at this project.

In 2013, KNRD and WDFW began planning a collaborative approach in planning, coordinating, and implementing piscicide (rotenone/Antimycin) 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.  Planning supported by and outside of this project, continues to take place in an effort to develop and prioritize tributary piscicide projects, develop strategic plans to salvage or restore existing WCT and understand their respective genetics, as well as developing the steps necessary to reintroduce WCT into treated reaches. Under the FY 2013-14 Non-Native Fish Suppression Project (BPA Project No. 2007-149-00) we are supporting the development these planning efforts which will be complete in mid-April 2014. Once we have all the necessary components completed (e.g., Tributary Piscicide Identification and Prioritization Plan, Tributary Piscicide Education & Outreach Plan, WCT Salvage and Reintroduction Plan), we will approach the public and expect to accomplish the goal of public acceptance prior to implementing the first treatment in 2014.

As in 2007, with the outreach effort that took place prior to implementing the non-native fish removal project in Cee Cee Ah Creek, WSU Extension collaborated with KNRD and WDFW to conduct initial public outreach and input both on process of decision making and scoping any potential concerns. This laid the groundwork for future efforts, yet we expect a significant effort will again be necessary to ensure that we carry forward momentum and maintain support in implementing multiple projects using piscicide as a management tool for native fish recovery.

As part of the current project, KNRD and WDFW, in partnership with Washington State University (WSU) Extension will utilize a collaborative decision-making approach to work with the local community towards addressing issues associated with non-native fish suppression and eradication using fish toxicants (piscicide).  This effort will include a sub-contract with WSU to prepare for and facilitate 3-4 public meetings to disseminate all relevant information on planned tributary piscicide treatments over the next 10 years. Although the meetings are distinct from one another, the content will generally include information on past successes in similar treatments, long and short term treatment plans, specifics on upcoming individual treatments, information on piscicide use in tributaries and perceived issues, WCT salvage and reintroduction plans, public comments/input, and planned communication strategies with the public. An additional component will be to adapt the education and outreach plan for future use with the modification and/or creation of additional public information materials summarizing scientific data on use of piscicide for fish species management as well as anything else responding to stakeholder information interests.

The Idaho Department of Fish and Game has been working at suppressing lake trout in Upper Priest Lake (UPL) through extensive gill netting.  A larger effort has been annually implemented since 2007, with 22,288 lake trout (LKT) removed from 2007-2013. Bull trout redds are annually monitored in the UPL watershed and have increased from 7 (2007) to 53 (2013). Although large numbers of lake trout are removed annually, the population continues to rebound, through in-lake recruitment and immigration of mature, ripe LKT from Priest Lake in the fall. Permanent suppression of LKT in Upper Priest Lake will require successful continued suppression in UPL and either elimination of LKT migratory access from or suppression in Priest Lake (lower).

In 2014, Hickey Brothers Research (LLC) will be again contracted to use gillnets to remove LKT from UPL in using their 36 foot commercial gillnet boat. Funding for this contract will be provided by the USFWS and through this project. Gill nets used in Upper Priest Lake are 91 m long and range in height from 1.5 to 2.2 m. Multiple panels of graded mesh sizes ranging from 44 mm to 89 mm are randomly arranged in each net. Individual gill nets were tied together end to end to create a continuous net spanning up to 3,017 m. Gill nets will be fished over a 7 day period from May 7 – June 2, 2014. Nets will be set throughout the lake and were moved based on catch rates at a particular site and on the discretion of the netting crew. Gill nets will be set perpendicular to shore when fishing shoreline areas and at various angles when fishing deeper offshore areas. Nets were fished from around 5 A.M. to 7 P.M. Nets set on the bottom will vary at depths ranging from 10 to 31 m. A concerted effort will be made to avoid incidental bull trout captures by avoiding areas known to hold concentrations of bull trout. Data from the 2014 effort will be summarized and compared to previous years’ efforts to monitor the effectiveness and success of the project.

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 are implementing a suite of measures, including mechanical suppression of the population, that began 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 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 threatens 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.

In the first year of suppression (2012) a total of 5,808 northern pike were removed in 1,031 overnight gillnet sets. In addition, a total of 6,452 northern pike were removed in 1,217 overnight net sets during the second year (2013) suppression effort. The 2013 phase I effort, which targeted 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 March and declined gradually to 2-4 NP/net night in May-June.

Effectiveness of the suppression effort was evaluated with the Spring Pike Index Netting (SPIN) survey. Mean CPUE in the 2013 SPIN survey was 1.21 NP/net night in southern ½ of the reservoir and 1.44 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). SPIN survey data indicated the adult population (>350 mm) was reduced 83% from 2011 levels (in the core area south of Riverbend) during Phase I suppression in 2012. Based on 2013 SPIN results, the adult population south of Riverbend, the core population area, was reduced by 91% when compared to the 2011 relative abundance data.

Phase II (2013) of suppression focused on locations, particularly in the north ½ of the reservoir, where limited pressure was applied in Phase I or SPIN data indicated an exceedance of target CPUE. Many of the known spawning aggregation sites in the southern ½ of the reservoir were also briefly targeted as well. During Phase II, 499 northern pike were removed in 190 overnight gillnet sets. As compared to the 2012 suppression effort where Phase II data indicated that 31% of the female northern pike had already spawned, only 8% of females captured in 2013 were spawned out. Although there was no notable shift in the overall proportion of females in the first two years catch (~48-50% in 2012 and 2013), there was a significant decline in the catch of mature females in 2013 (18%) as compared to 2012 (50%). This suggests the suppression project is successfully reducing the population of mature females available to spawn.

Based on an assessment of pre-suppression length frequency distribution (LFD), a shift toward immature individuals indicated that strong year classes were produced in 2010 and 2011.  The LFD of northern pike collected in 2012 and 2013 confirmed that those year classes are and will continue to recruit to the gillnets.  Moreover, the dominant group in the 600-800 mm range was all but absent in the 2013 catch  indicating the 2012 effort removed a significant proportion of those mature adults. A large number of northern pike removed in 2013 were produced in either 2010, 2011 or 2012 based on length-at-age analysis (n= 2,594 ; 40.2%) and therefore not modeled as part of the 2010 adult population estimate used to establish population targets. Since the 2010 population model did not account for any northern pike under 350 mm, the 2009 year class could also be added to the analysis, bringing the total to 4,458 (69.1%) 2009-2012 progeny removed during the 2013 suppression effort. Although the 2012 and 2013 results were encouraging, suppression efforts must continue through 2014 to account for full recruitment of 2011/2012 juveniles to our gear.

We will again conduct the SPIN survey in 2014 and plan to monitor the fish community with a standardized warmwater fish survey in 2014 to detect trends in abundance and population characteristics as a response to removal efforts. Unfortunately, quantifying a response in bull trout and westslope cutthroat trout survival and abundance in the near-term is problematic. Low densities and isolated distributions of those species make sampling for relative abundance difficult.

In year three of the project (2014), a report on the effectiveness of mechanical suppression, angler education, and fishing contests to remove 87% of the NP population will be produced. This report will be prepared for the Independent Scientific Review Panel of BPA’s Fish and Wildlife Program and be available to interested parties.

As part of the 2014 Non-Native Fish Suppression Project (BPA Project No. 2007-149-00), a long term NP monitoring and management plan for the POR will be developed to guide post-initial suppression efforts. Given the success of NP suppression to date and implications associated with discontinuing suppression efforts (financial investments, ESA recovery, recreational fishery management, downstream entrainment of NP, movement into neighboring waters) stakeholders and managers will assemble to determine the appropriate management direction for BCR NP. The steps involved in developing the plan will be 1) initiate the discussion with a meeting of key stakeholders and fisheries managers and create the framework for a draft plan, 2) draft a management plan, 3) meet with stakeholders to review and comment on the plan, and 4) finalize and publish the management plan. The eventual outcome of the stakeholder/manager meetings will be to produce a long-term management strategy (plan) for NP in BCR (and potentially downstream waters) that incorporates ISRP comments and suggestions, knowledge to date on the NP population in BCR, population management thresholds and methods (with alternatives), monitoring strategies, management agencies' responsibilities, and financial needs for long-term implementation. As an addition to the proposed plan, we will also discuss investigating NP in Boundary Reservoir downstream of Box Canyon Reservoir in the Pend Oreille River. At a minimum, the Joint Stock Assessment Project (BPA Project No. 1997-004-00) and WDFW will continue to monitor the effectiveness of mechanical removal (and other measures) and the NP population status using an annual SPIN survey and periodically monitoring the fish community with standardized warmwater fish surveys to detect trends in abundance and population characteristics. Future suppression efforts if warranted, and their frequency, will be determined during the development of the management plan in 2014.



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