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Flathead Basin What are the challenges facing native fish in the Flathead? |
Bull
Trout Discover information and issues particular to this native species. |
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Lake
Trout The high cost of stocking predators where they don't belong. |
Cutthroat Trout What is being done to help our native fishes? |
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Other
Watersheds Problems faced by natives across the West. |
General
Fisheries Documents Papers and agreements affecting our native fish. |
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Websites Online native fish information. |
Interested
Organizations Private and government groups interested in native fish policy and conservation. |
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News Articles Flathead native fish in the news. |
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Beattie, W., P. Clancy, and T. Vogel. 1986. Effect of Operation of Kerr and Hungry Horse Dams on the Reproductive Success of Kokanee in the Flathead System. We conducted creel surveys during 1985, and estimated that anglers caught 192,000 kokanee. Anglers harvested 49,200 fish during the ice fishery in Skidoo Bay, 129,000 fish during the summer fishery on the lake, and 13,800 during the fall river fishery. Estimated fishing pressure for the year exceeded 188,000 angler hours. BPA Report DOE/BP-39461-4, Annual Report 1986.
Beauchamp, D.A., M.W. Kershner, N.C. Overman, J. Rhydderch, J. Linn and L. Hauser. 2006. Trophic Interactions of Nonnative Lake Trout and Lake Whitefish in the Flathead Lake Food Web. Bioenergetics model simulations of the altered food web of Flathead Lake following the introduction of Mysis relicta and the crash of the kokanee population. Predation on Mysis by lake trout and whitefish is estimated. Seasonal and size-related predation on native and nonnative fish species is discussed.Report to the Confederated Salish-Kootenai Tribes
Darling, J.E., P.Pajak, M.P. Wunderlich, J.M. DosSantos and P.D. Cross. 1984. Flathead Basin Annual Report. Annual report for 1984 produced by CSKT. Annual study to assess the effects of Kerr Dam operations on the fisheries of the Lower Flathead System. Population numbers and structure in the lower river and how they are affected by power operations of Kerr Dam. Dominant habitat types were mapped, and physical habitat and biological monitoring methods were evaluated and selected. Permanent habitat transects, water quality stations, fish sampling, gillnetting, seining, and trapping sites were established. Bull trout tagging and recapture study was done in the south bay of Flathead Lake. Research Report for Bonneville Power Adminstration, Agreement No. DE-AI79-83BP39830.
Deleray, M. L. Knotek, S. Rumsey, and T. Weaver. 1999. Flathead Lake and River System Fisheries Status Report. Recent reports (1999) and long-term monitoring field surveys to establish the health and status of the fisheries of the Flathead Lake and Flathead River system. “This report emphasizes how important the inter-connected lake, river, and tributary system is to fisheries of the Flathead drainage, especially to native fish species.” This report attempts to describe characteristics, changes and trends in Flathead fish populations since the introduction of Mysis. Includes extensive data and discussion of bull trout spawning and redd counts. Good bibliography.DJ Report No. F-78-R-1 through 5, SBAS Project No. 3131, Montana Fish, Wildlife and Parks, Kalispell, Montana
Deleray, M., W. Fredenberg and B. Hansen. 1995. Kokanee Stocking and Monitoring: Flathead Lake – 1993 and 1994. Early results from the program designed to recover kokanee populations by heavy stocking in Flathead Lake. Annual stocking of 1 million hatchery-raised kokanee was attempted to see if kokanee could be reestablished. Monitoring concluded that “excessive lake trout predation precluded significant survival of kokanee stocked in 1993.” 1994 sampling demonstrated that lake trout predation was the primary factor affecting survival of planted kokanee. “We estimated that lake trout consumed a minimum of 232,000 kokanee in Big Arm Bay during the first eight weeks following stocking. This represents 29 percent of kokanee planted. U.S. DOE, BPA, Project No. 91-19, 91-19-01, 91-19-04, 91-19-03.
Dux, A.M. 2005. Distribution and Population Characteristics of Lake Trout in Lake McDonald, Glacier National Park: Implications for Suppression. Study by a graduate student on lake trout in Lake McDonald, GNP. 2005. Study of the spatial and temporal distribution as well as population characteristics, growth rate and diet. Study included model simulations to determine the amount of exploitation or removal of it would take to reduce the lake trout population. How to focus suppression to achieve maximum efficiency. Includes table of stomach contents showing the percent by weight of lake trout prey species in Lake McDonald.Masters Thesis, Montana State University, Bozeman, Montana.
Ellis, B.K. Stanford, J.A. Goodman, D. Stafford, C.P. Gustafson, D.L. Beauchamp, D.A. Chess, D.W. Craft, J.A., Deleray, M.A, and Hansen B.S.. 2010. Long-term effects of a trophic cascade in a large lake ecosystem. Study of how introduced or nonnative species can affect major changes on the trophic structure of an ecosystem using Flathead Lake as a model. http://www.pnas.org/cgi/doi/10.1073/pnas.1013006108
Evarts, L., B. Hansen and J. DosSantos. 1994. Flathead Lake Angler Survey: Final Report FY 1992 – 1993. BPA funded angler survey prepared by CSKT. Roving creel survey conducted on Flathead Lake 1992-1993 representing 4,410 anglers, Representing A total of 47,883 angler days of pressure and a harvest of 42,979 fish. 79% of the angler effort was directed at lake trout during the survey. Some comparisons were made to previous creel surveys. The study noted a “dramatic decline” in fishing pressure from 1985-1992. Report for BPA Contract No. DE-B179-92BP60479.
Fraley, J.J. and B.B. Shepard. 1989. Life History, Ecology and Population Status of Migratory Bull Trout (Salvelinus confluentus) in the Flathead Lake and River System, Montana. Study by Montana FWP to obtain information to aid in managing bull trout in the face of various threats. This study was done prior to the large population decline attributed to Opossum Shrimp. Good descriptions of the life history of bull trout in the Flathead basin. Tributary redd counts and trapping data are examined. “Bull trout in the Flathead River system are dependent on habitat quality and management of the interconnected river, lake, and tributaries.”Northwest Science, Vol. 63, No. 4, pp. 133 – 143.
Fredenberg, W. 2002. Further Evidence That Lake Trout Displace Bull Trout in Mountain Lakes. Survey of five lakes in Glacier National Park by gill net in 2000. Results were compared to similar surveys in 1969 and 1977. Data indicated a “broad decline” in bull trout numbers and corresponding increases in lake trout. “Four of the five bull trout populations I studied in Glacier National Park lakes are currently at high risk of extirpation, due primarily to incompatibility with introduced lake trout populations.”Intermountain Journal of Sciences, Vol. 8, No. 3, pp. 143 – 152.
Fredenberg, W., D. Carty, M. Deleray, L. Knotek and B. Hansen. 1999. Mitigation: Kokanee Stocking and Monitoring in Flathead Lake: Final Report 1999 to Bonneville Power Administration. Final report on the five-year effort to reestablish a kokanee population in Flathead Lake by stocking hatchery-raised fish. Approximately 5.8 million kokanee were planted in the lake and river system. “Returns of adult kokanee did not achieve, nor even approach, numeric target levels.” “All direct and indirect evidence indicates that lake trout predation was the overwhelming limiting factor to yearling kokanee survival.”BPA Report DOE/BP-60559-5.
Hanzel, D. 1994. Flathead River Creel Report 1992-1993; Final Report. "This document summarizes the creel survey on the river system. The purpose of these creel surveys was to quantify fishery status prior to mitigation efforts and provide replicative survey methodology to measure success of future mitigation activities.. USDOE/BPA Project 91-19-02.
International Joint Commission, Biological Resources Committee. 1987. Flathead River International Study, Technical Report Summary. "Migratory fish populations, important to the entire Flathead Lake/River system, would experience significant long-term population declines because of severe damage to spawning and rearing habitat in the vicinity of the mine. Summary of report to the IJC.
Kalinowski, S.T., C.C. Muhlfeld, C.S. Guy and B. Cox. 2010. Founding population size of an aquatic invasive species. This paper estimates the number of fish that originally colonized Swan Lake in Montana. “Examination of genetic diversity and allele frequencies within the Swan Lake populations showed that most of the genes in the lake trout population are descended from two founders. This emphasizes the importance of preventing even a few lake trout from colonizing new territory.”Conservation Genetics, DOI 10.1007/s10592-009-0041-8
Marotz, Brian. 2004. Tough Love; Why it makes sense to kill some fish to save others. Magazine article on why some lakes in the South Fork Flathead were targeted for nonnative fish removal. Montana Outdoors March/April 2004.
McIntyre, J.D. Facilitator. 1998. An Assessment of Bull Trout and Lake Trout Interactions in Flathead Lake, Montana. Report by the scientific advisory panel to the Montana Bull Trout Restoration Team. The panel met in Nov. 1997 to assess the most likely reasons for the decline of bull trout in Flathead Lake and to examine options for restoring the species to the drainage. The expanding lake trout population was judged by most panelists to be the primary reason for the decline of kokanee and native populations. “Under present management, most panelists judged that lake trout, lake whitefish, and opossum shrimp populations will remain at today’s levels for at least the next 20 to 30 years, but other fish populations will decline even further.” The 1997 current population of lake trout 14 inches and longer in Flathead Lake was estimated at “over 200,000” fish.Panel Report to the Montana Bull Trout Restoration Team; Montana Fish, Wildlife and Parks and Confederated Salish and Kootenai Tribes.
Montana Fish, Wildlife and Parks and Confederated Salish and Kootenai Tribes. 2000. Flathead Lake and River Fisheries Co-Management Plan, 2001 – 2010. MTFWP and CSKT fisheries management plan for Flathead Lake 2001 – 2010. “Within the 10-year period of this management plan, we will accomplish the following goals: • Increase and protect native trout populations (bull trout and westslope cutthroat trout). • Balance tradeoffs between native species conservation and nonnative species reduction to maintain a viable recreational/subsistence fishery. • Protect the high quality water and habitat characteristics of Flathead Lake and its watershed.”
Montana Fish, Wildlife and Parks. 2009. Environmental Assessment and Decision Notice for and Experimental Removal of Lake Trout in Swan Lake, Montana. “The goal of this project is to determine the feasibility of using gill nets as a management tool for reducing the population of lake trout in Swan Lake.”James Satterfield, Regional Supervisor
Muhlfeld, C.C. and B. Marotz. 2005. Seasonal Movement and Habitat Use by Subadult Bull Trout in the Upper Flathead River System, Montana. Using radio telemetry to track the movement and habitat use of sub-adult bull trout. “Our results elucidate the importance of maintaining natural connections and a diversity of complex habitats over a large spatial scale to conserve the full expression of life history traits and processes influencing the natural dispersal of bull trout populations.”North American Journal of Fisheries Management, Vol. 25, pp. 797 – 810.
Muhlfeld, C.C., D.H. Bennett, R.K. Steinhorst, B. Marotz, and M. Boyer. 2008. Using Bioenergetics Modeling to Estimate Consumption of Native Juvenile Salmonids by Nonnative Northern Pike in the Upper Flathead River System, Montana. This is the report that estimated the abundance and predation habits of northern pike in the lower river above Flathead Lake. The study found a population of 1200-1300 pike that consumed conservatively 8 metric tons of fish annually. They estimated 13,000 cutthroat trout and 3,500 bull trout consumed each year.North American Journal of Fisheries Management. Vol. 28, pp. 636 – 648.
Muhlfeld, C.C., M.L. Taper, D.F. Staples and B.B. Shepard. 2006. Observer Error Structure in Bull Trout Redd Counts in Montana Streams: Implications for Inference on True Redd Numbers. Variability in estimates of bull trout redd counts and ways to make redd counts more precise. Transactions of the American Fisheries Society, Vol. 135, pp. 643 – 654.
Muhlfeld, C.C., S.E. Glutting, R. Hunt, D. Daniels and B. Martoz. 2006. Winter Diel Habitat Use and Movement by Subadult Bull Trout in the Upper Flathead River, Montana. Monitoring the daily movement of bull trout between different habitats. “Resource managers who wish to protect the overwintering habitat features preferred by subadult bull trout in the upper Flathead River should use natural flow management strategies that maximize and stabilize channel margin habitats at night.”North American Journal of Fisheries Management, Vol. 23, pp. 163 – 171.
Muhlfeld, C.C., L. Jones, D. Kotter, W.J. Miller, D. Geise, J. Tohtz and B. Marotz. 2011. Assessing the Impacts of River Regulation on Native Bull Trout (Salvelinus confluentus)and Westslope Cutthroat Trout (Oncorhynchus Clarkii Lewisii)Habitats in the Upper Flathead River, Montana, USA. "Our results suggest that past flow management policies that created sporadic streamflow fluctuations were likely detrimental to resident salmonids and that natural flow management strategies will likely improve the chances of protecting key ecosystem processes and help to maintain and restore threatened bull trout and westslope cutthroat trout populations in the upper Columbia River Basin." River Research and Applications 2011.
Zubik, R.J., Fraley, J., 1986. Determination of Fishery Losses in the Flathead System Resulting from the Construction of Hungry Horse Dam. Losses to the Flathead fisheries due to construction of Hungry Horse Dam. Loss of 69 km of stream habitat was inundated that would support about 21,000 juvenile cutthroat trout. About 2/3 of those fish would have moved to Flathead Lake. About 65,000 adfluvial cutthroats were lost to Flathead Lake annually. Habitat for about 2,100 bull trout was lost to Flathead Lake annually.Research Report for Bonneville Power Administration. Project No. 1985-23. BPA Report DOE/BP-23638-1
National Park Service. 2009. Large-Scale Removal of Lake Trout in Quartz Lake: Environmental Assessment. EA for netting proposal for Quartz Lake. Discusses the impacts of reducing or eliminating lake trout in Quartz Lake to prevent the loss of native fish in the lake.
Spencer, C.N., D.S. Potter, R.T. Bukantis and J.A. Stanford. 1999. Impact of predation by Mysis relicta on zooplankton in Flathead Lake, Montana, USA. Paper documents changes in the zooplankton community of Flathead Lake following the introduction of Mysis relicta. The three common cladocerans have been drastically reduced and in some cases were probably eliminated. The two species which declined the most were those that had the most habitat overlap with mysis. Journal of Plankton Research, Vol. 21, No. 1, pp-51-64 1999
Steed, A., D. Belcer, R. Hunt, S. Glutting and M. Boyer. 2009 Investigations of the Hungry Horse Mitigation Program, 2007-2008 Annual Report. 2007-2008 annual report. Includes: Investigations of hybridization between native westslope cutthroats and rainbow trout. Spawning movement of cutthroats, rainbows and hybrids. Population trends for rainbows and hybrids in the Flathead River. Movement and survival of westslope cutthroat, bull trout and mountain whitefish in the mainstem. Juvenile emigration and adult return of bull trout in Trail Creek. And results of habitat restoration projects.BPA Project number 199101903
Weaver, T., M. Deleray, and S. Rumsey. 2006. Flathead Lake and River System Fisheries Status Report. Status update as of 2006 on the various indices selected for ongoing monitoring of the fishery in Flathead Lake and the interconnected river system and how those trends should affect management decisions. Pre-mysis and post-mysis gill net surveys showed a ten fold increase in lake trout catch and a large decrease in bull trout catch. Westslope cutthroat catch also declined.DJ Report No. F-113-R1-R-4, SBAS Project No. 3130, Montana Fish, Wildlife and Parks, Kalispell, Montana
American Fisheries Society. 2002. Response to FWP & CSKT Security Levels for the Flathead System. Montana Chapter of the American Fisheries Society responds to the document setting security levels for bull trout in the Flathead. AFS Correspondence.
Andrus Center for Public Policy. 1995 Searching For Solutions: Solving the Bull Trout Puzzle. Proceedings of a policy conference at Boise State Univ. following the near listing of bull trout as endangered. “The bottom line of all this is simple: the bull trout is a native Montana fish, and Montanans have not only a legal but a moral obligation to maintain viable populations of native species. We owe it to future generations of Montanans to be good stewards of resources that are as much theirs as ours.” MT Gov. Marc RacicotScience and Policy Conference, Transcript.
Dunham, J., C. Baxter, K. Fausch, W. Fredenberg, S. Kitano, I. Koizumi, T. Nakamura, B. Rieman, K. Savvaitova, J. Stanford, E. Taylor and S. Yamamoto. 2008. Evolution, Ecology, and Conservation of Dolly Varden, White-spotted Char and Bull Trout. Review of the ecology and conservation of three lesser known chars (genus Salvelinus): Dolly Varden, white-spotted char, and bull trout across their range. “Since bull trout are naturally sympatric with either rainbow trout or cutthroat trout across most of their range, interactions with these species or with kokanee seem less likely to be negative and may even be beneficial in providing high quality food resources for bull trout.”Fisheries, Vol. 33, No. 11, Nov. 2008, pp. 537 – 550.
Fraley, J. and Shepard, B. 1989. Life History, Ecology and Population Status of Migratory Bull Trout (salvelinus confluentus) in the Flathead Lake and River System, Montana. The population may be limited by quantity and quality of rearing and spawnrng habitat, and spawning escapement. Specific requirements for spawning and rearing habitat, and general sensitivity of each life stage, make the bull trout an excellent indicator of environmental disturbance. Northwest Science, Vol. 63, No. 4.
Hunter, C. 1997. Bull Trout Restoration Planning – Montana Style. History of bull trout management in Montana. “I hope that with a determined and committed effort with a multitude of partners we will show that we can change the status quo and thereby ensure that future generations have the same opportunity to fish for bull trout that we have had.”Friends of the Bull Trout Conference Proceedings 1997, pp. 115-118.
Knowles, C.J. and R.G. Gumtow. 1996. Saving the Bull Trout. Life history, habitat and challenges faced by bull trout. “One chip laid down in this biological roulette is the bull trout. Having survived millennia of glacial retreat, this habitat-selective fish is facing an onslaught of problems its genetic makeup is ill equipped to deal with.”Report for the Thoreau Institute, April 1996.
Montana Bull Trout Scientific Group. 1996. The Role of Stocking in Bull Trout Recovery. Recommendations to the Restoration Team on the use of hatchery stocking in restoring bull trout in the Flathead Watershed. Paper from the Bull Trout Restoration Team.
Montana Fish, Wildlife & Parks, Confederated Salish & Kootenai Tribes. 2002. Native Trout Security Levels for the Flathead System. Establishment of minimum levels for bull trout survival in the Flathead. Objective for the Flathead Lake and River Co-Management Plan 2001-2010.
Porter, M. and M. Nelitz. 2009. A Future Outlook on the Effects of Climate Change on Bull Trout (Salvelinus confluentus) Habitats in the Cariboo-Chilcotin. A review of expected challenges that will be faced by bull trout due to climate change. “Given our general understanding of the adverse effects of climate change and role of human actions in both positive and negative ways, it is critical we develop strategies to help fish species cope.”Prepared by ESSA Technologies Ltd. For Fraser Salmon and Watersheds Program, B.C. Ministry of Environment and Pacific Fisheries Resource Conservation Council.
Racicot, M. 1995. Walking the Walk for Bull Trout. A loose reprint of the comments made by Governor Racicot at the Boise State policy conference. “The bottom line of all this is simple: The bull trout is a native Montana fish and Montanans have not only a legal but a moral obligation to maintain viable populations of native species. We owe it to future generations of Montanans to be good stewards of resources that are as much theirs as ours.”Montana Outdoors, September – October 1995. pp. 28-31.
Rieman, B.E. and D.L. Myers. 1996. Use of Redd Counts to Detect Trends in Bull Trout (Salvelinus confluentus) Populations. Cautionary note on using redd counts alone to predict bull trout population trendsConservation Biology, Vol. 11, No. 4, August 1997, pp. 1015-1018.
Reiman, B.E. and J.D. McIntyre. 1996. Spatial and Temporal Variability in Bull Trout Redd Counts. Reasons for year-to-year changes in the number of redds within and between streams. "Common declining trends among all streams within a single lake basin show that even well-dispersed regional populations face important risks."North American Journal of Fisheries Management, Vol. 16, 1996, pp. 132-141.
Rieman, B.E. and F.W. Allendorf. 2001. Effective Population Size and Genetic Conservation Criteria for Bull Trout. Effective population sizes to assure a viable bull trout population. “We conclude that cautious long-term management goals for bull trout populations should include an average of at least 1,000 adults spawning each year.”North American Journal of Fisheries Management, Vol. 21 2001, pp. 756 – 764.
Rieman, B.E. and G.L. Chandler. 1999. Empirical Evaluation of Temperature Effects on Bull Trout Distribution in the Northwest. Bull trout require cold, clean water. This paper investigates the importance of water temperature on survival and reproduction. “Because many bull trout populations are already believed to be at risk, temperature may be a critical element in the persistence of many populations.”Final Report for USEPA, Contract No. 12957242-01-0
Rieman, B.E. D. Isaak, S. Adams, D. Horan, D. Nagel, C. Luce and D. Myers. 2007. Anticipated Climate Warming Effects on Bull Trout Habitats and Populations Across the Interior Columbia River Basin. “We concluded that climate does strongly influence regional and local bull trout distributions, and we estimated bull trout habitat response to a range of predicted climate warming effects. Warming over the range predicted could result in losses of 18–92% of thermally suitable natal habitat area and 27–99% of large (.10,000-ha) habitat patches, which suggests that population impacts may be disproportionate to the simple loss of habitat area.”Transactions of the American Fisheries Society, Vol. 136, pp. 1552 – 1565.
Smith, T. 2010. A History of Bull Trout and the Salish and Pend d'Oreille People. An excellent history of the relationship between native people of the Flathead and native fish, with detailed notes and bibliography. Natural Resource Department Confederated Salish and Kootenai Tribes.
Tennant, L.B. 2010. Spawning and early life charistics of bull trout in a headwater-lake ecosystem. Masters thesis to characterize the spatial and temporal dynamics of bull trout spawning migrations and associate areas of high redd accumulation to abiotic factors. Masters Thesis, Montana State University, Bozeman, MT.
Thomas, G for Montana FWP. 1992. Status Report: Bull Trout in Montana. Status report contracted by FWP that outlines extinction risk for separate bull trout populations in Montana following large declines in some populations. Report to Montana Fish, Wildlife and Parks Aug. 1996.
USFWS. 1998. Bull Trout Facts. Short compilation of facts about bull trout, why they are in trouble and what can be done to help.From USFWS bull trout website
USFWS. 2005. Status Report: Bull Trout (Salvelinus confluentus): Draft Recovery Plan. Status review of the current (2005) situation of bull trout including population viability, genetic concerns and habitat loss concerns.USFWS 2002; Final Critical Habitat Rule – 2005.
Johnson, B.M. and P.J. Martinez. 2000 Trophic Economics of Lake Trout Management in Reservoirs of Differing Productivity. The high cost of stocking fish in lakes containing large populations of lake trout. “Though highly sensitive to the size at which hatchery fish are consumed, the per capita costs to sustain lake trout growth at observed levels would total about US$200 per lake trout in the more productive reservoirs and $300–600 per lake trout in the less productive reservoirs.”North American Journal of Fisheries Management. Vol. 20, pp. 127 – 143.
Martinez, P.J., P.E. Bigelow, M.A. Deleray, W.A. Fredenberg, B.S. Hansen, N.J. Horner, S.K. Lehr, R.W. Schneidervin, S.A. Tolentino and A.E. Viola. 2009. Western Lake Trout Woes. Extensive article by top scientists for the American Fisheries Society on the experience of seven western states to implement strategies to control lake trout. Fisheries, Vol. 34, No. 9. Sept. 2009, pp. 424 – 442.
Varley, J.D. and P. Schullery (editors). 1995. The Yellowstone Crisis: Confronting a Lake Trout Invasion. Prescient 1995 report to the National Park Service on the impact of lake trout in Yellowstone Lake on the largest surviving cutthroat trout fishery in North America. “Though a lake trout fishery will evolve in the lake consonant with the cutthroat decline, it will be a highly specialized fishery of interest only to a comparatively few anglers and will not occur at all on the rivers and streams. The replacement fishery will in no respect (ecologically, economically, or socially) replace the fisheries it destroys.”Report to the Director of the National Park Service.
Muhlfeld, C.C., B. Marotz, S.R. Thorrold and J.L. FitzGerald. 2005. Geochemical Signatures in Scales Record Stream of Origin in Westslope Cutthroat Trout. Technical paper on using the chemical composition of bull trout scales in the Flathead watershed to determine stream origin of westslope cutthroatTransactions of the American Fisheries Society, Vol. 134, pp. 945 – 949.
Muhlfeld, C.C., S.T. Kalinowski, T.E. McMahon, M.L. Taper, S. Painter, R.F. Leary and F.W. Allendorf. 2009. Hybridization Rapidly Reduces Fitness of a Native Trout in the Wild. “Human-mediated hybridization is a leading cause of biodiversity loss worldwide. How hybridization affects fitness and what level of hybridization is permissible pose difficult conservation questions with little empirical information to guide policy and management decisions.”Biology Letters: The Royal Society, published online.
Muhlfeld, C.C., T.E. McMahon, D. Belcer, and J.L. Kershner. 2009. Spatial and Temporal Spawning Dynamics of Native Westslope Cutthroat Trout, Onchorhynchus clarkia lewisi, Introduced Rainbow Trout, Onchorhynchus mykiss, and Their Hybrids. “This study provides evidence that hybridization increases the likelihood of reproductive overlap in time and space, promoting extinction by introgression, and that the spread of hybridization is likely to continue if hybrid source populations are not reduced or eliminated.”Canadian Journal of Fisheries and Aquatic Sciences, Vol. 66. pp. 1153 – 1168.
Muhlfeld, C.C., T.E. McMahon, M.C. Boyer and R.E. Gresswell. 2009. Local Habitat, Watershed, and Biotic Factors Influencing the Spread of Hybridization Between Native Westslope Cutthroat Trout and Introduced Rainbow Trout. “Our results suggest that hybridization is more likely to occur and spread in streams with warm water temperatures, increased land use disturbance, and proximity to the main source of hybridization.” Transactions of the American Fisheries Society, Vol. 138, pp. 1036 – 1051.
Fredricks, J. and A. Dux. 2009. Lake Pend Oreille Fishery Recovery Update, November 2009. Overview of the gill netting program on Lake Pend Oreille, ID. 90,000 lake trout were removed since 2006. Survival of age 1-2 kokanee has increased from just 10% to over 70% and the number of bull trout redds has increased.
Gresswell, R.E., 2009 Scientific Review Panel Evaluation of the National Park Service Lake Trout Suppression Program in Yellowstone Lake. Annual report for 2008 on lake trout suppression efforts in Yellowstone lake. “Although population metrics suggest that lake trout abundance in Yellowstone Lake has continued to expand, it appears that suppression has reduced the rate of population increase.”Final Report of Scientific Review Panel, August 25-29, 2008.
Hansen, M., Liter, L., Cameron, S., and Horner, N. 2006. Mark-Recapture Study of Lake Trout Using Large Trap Nets in Lake Pend Oreille 07/01/06 – 11/30/2006. Progress report for 2006 on the success of mark-recapture methods for targeting lake trout netting. The study suggested that “the adult lake trout population in Lake Pend Oreille would double every 1.6 years and reach 131,000 adult fish by 2010, if the population did not reach carrying capacity sooner.”Interim Progress Report. IDFG Report 07-19.
Koel, T.M., P.E. Bigelow, P.D. Doepke and B.D. Ertel. 2005. Nonnative lake trout result in Yellowstone cutthroat trout decline and impacts to bears and anglers. Early study on the decline in cutthroat populations in Yellowstone Lake due to predation by lake trout, its effect on bears that use the spawning streams and on angler success. “As several important consumer species, including the threatened grizzly bear (Ursus arctos horribilis), use this population as an energy source, preservation of remaining cutthroat trout could be essential to maintain the integrity of the Greater Yellowstone Ecosystem.”Fisheries, Vol. 30, No. 11. pp. 10-19.
National Park Service, Edited by J. Varley and P. Schullery. 1995. The Yellowstone Lake Crisis; Confronting a Lake Trout Invasion. While the potential ecological losses are staggering, the potential economic losses can be summarized as equally immense.. Report to the Director of the National Park Service.
Bohl, R.J., T.B. Henry, and R.J. Strange. 2010. Electroshock-induced mortality in freshwater fish embryos increases with embryo diameter: a model based on results from 10 species. The purpose of this study was to develop a model to predict electroshock-induced mortality in embryos of freshwater fishes. Journal of Fish Biology, Vol. 76, pp. 975-986.
Duffield, J, J. Loomis, and R. Brooks. 1987. The Net Economic Value of Fishing in Montana. "The state average net economic value for lake fishing is $89 per trip. For streams, the value is $113 per trip. This means an angler would be willing to pay $89 and $113 more per trip to have the opportunity to fish lakes or streams, respectively." Montana Department of Fish, Wildlife and Parks publication.
Wenger, S.J., D.J. Isaak, C.H. Luce, H.M. Neville, K.D. Fausch, J.B. Dnnham, D.C. Dauwalter, M.K. Young, M.M.Elsner, B.E. Rieman, A.F. Hamlet, and J.E. Williams. 2011. Flow regime, temperature, and biotic interactions drive differential declines of trout species under climate change. "Our models forecast significant declines in trout habitat across the interior western United States in the 21st century, a result we expect will apply to much of the rest of the temperate world because three of our study species (rainbow, brown, and brook trout) are common on multiple continents." www.pnas.org/cgi/doi/10.1073/pnas.1103097108.
Flathead Lake Facts. - From the Flathead Lake Biological Station at Yellow Bay. Includes lake statistics and a bathymetric map
U.S. Fish & Wildlife Service Bull Trout Website. Includes information on Critical Habitat
U.S. Fish & Wildlife Service - Final Bull Trout Critical Habitat Designation - 2010
Westslope Cutthroat Trout in Montana. American Fisheries Society
Bull Trout Research Papers from the USFS Boise Aquatic Sciences Lab - Website
Lake Trout in Montana. American Fisheries Society
Mack Days. The official website for Flathead Lake fishing contests. Courtesy of CSKT.
Articles|
1989 - Montana Outdoors,
"Travelin' Fish" by John Fraley 1990 - Montana Outdoors "Old Fish, New Fish, Big Fish; The Changing Face of Flathead Lake" by Jim Vashro 1994 - Montana Outdoors "Further Adventures of a Travelin' Fish" by John Fraley 1998 - Missoulian "Bringing Back The Bulls" |
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| 2009 - Missoulian "Calls increasing for aggressive approach to take out non-native trout in Flathead Lake" | ||
| 2009 - Daily Inter Lake - Opinion: "Money being spent to both save, wipe out lake trout" | ||
| 2009 - Missoulian Opinion: "Now is the time to save native fish" - FVTU Editorial | ||
| 2010 - Missoulian: GREG TOLLEFSON: We have chance to save native trout in Flathead | ||
| 2010 - Flathead Beacon: Is Gill Netting the Answer? Myers Reece | ||
| 2010 - Missoulian: Obama administration reverses Bush policy on bull trout habitat | ||
| 2010 - Missoulian: Glacier Park's nonnative fish on path to wipe out bull trout | ||