The Caldera Symposium: A Scientific and Angling Exploration of the Henry's Fork

Transcription

1 Proceedings of The Caldera Symposium: A Scientific and Angling Exploration of the Henry's Fork July 12, 2012 Ponds Lodge Island Park, Idaho Photo by Susan E. Quinn

2 Funding for this symposium was provided by: Symposium organized by: James N. DeRito, Henry s Fork Foundation Lee Mabey, U.S. Forest Service Greg Schoby, Idaho Department of Fish and Game Acknowledgements Special thanks to: R.J. Cardwell and Carl Solden of Pond s Lodge, Brett Hicks of Idaho Liquid Sound, Matt Cahoon for video recording of the presentations, and Jack Ammon for editing and formatting of the presentations posted online.

3 Proceedings of The Caldera Symposium: A Scientific and Angling Exploration of the Henry s Fork Pond s Lodge Island Park, Idaho July 12, 2012 Edited by: James N. DeRito, Henry s Fork Foundation Lee Mabey, U.S. Forest Service Greg Schoby, Idaho Department of Fish and Game Jim S. Gregory, Lost River Fish Ecology, Inc. Proceedings available online: posted December 2012 Video-taped recordings of the presentations and panel discussion also available. Suggested citation formats for these proceedings: Entire Proceedings: DeRito, J. N., L. Mabey, G. Schoby, and J. S. Gregory, editors The Caldera Symposium: a scientific and angling exploration of the Henry s Fork. Symposium proceedings, available from the Henry s Fork Foundation, Ashton, Idaho. Abstract within the proceedings: Snyder, J. W Aquatic macrophyte abundance and distribution in Henry s Fork of the Snake River through Harriman State Park of Idaho, 1988 and Pp 10. in DeRito, J. N., L. Mabey, G. Schoby, J. S. Gregory, editors. The Caldera Symposium: a scientific and angling exploration of the Henry s Fork. Available from the Henry s Fork Foundation, Ashton, Idaho.

4 Table of Contents: Introduction... 1 Map of the Caldera Stretch of the Henry s Fork... 2 Presenter Biographies... 3 Session 1 - River context and aquatic plants. Moderator: Jim DeRito...6 Volcanoes, glaciers, water, and fish...6 Mel A. Kuntz... 6 Hydrology of the upper Henry s Fork: climate, geology, and water management...7 Rob Van Kirk... 7 Why do they come to the Ranch?...8 Nelson Ishiyama... 8 Geomorphic evaluation and flushing flow recommendation...9 Mark Tompkins, Anthony Falzone, and Paul Frank... 9 Session 2 - Plants continued and angler surveys. Moderator: Lee Mabey Aquatic macrophyte abundance and distribution in Henry s Fork the Snake River through Harriman State Park of Idaho, 1988 and Jeffrey W. Snyder Trends of Aquatic Macrophytes on the Henrys Fork in Harriman State Park Adonia Henry Why I Never Fish Anywhere but the Railroad Ranch John McDaniel Henrys Fork creel survey Greg Schoby Angler demographics, satisfaction and management opinions of the Henrys Fork in Harriman State Park Jim DeRito, Dan Garren, Rob Van Kirk Session 3 - Rainbow trout. Moderator: Greg Schoby Flows and fish - the relationship between rainbow trout abundance and flow releases from Island Park Dam Dan Garren Years of Guiding and Outfitting in the Caldera Mike Lawson... 16

5 Survival and movement of adult rainbow trout during winter and spring in the Henrys Fork of the Snake River Jim Gregory, Anne Marie Emery, Jim DeRito Changes in trout behavior René Harrop Winter use of Caldera tributaries by subyearling rainbow trout Anne Marie Emery, Jim DeRito, Lee Mabey, Greg Schoby Session 4 - Restoration, mapping, and panel discussion: Moderator: Jim Gregory Restoration opportunities on Caldera tributaries Lee Mabey Back to the future? Mick Mickelson Maps, Apps and Citizen Science Tom McMurray Panel Discussion Harriman State Park What do anglers want and where do we go from here? Caldera Symposium participant feedback survey... 26

6 Introduction The Henry s Fork between Island Park Dam and Mesa Falls (see Figure 1) contains some of the most renowned trout fisheries in the country. Some anglers have said, however, that fishing is not what it used to be with fewer fish, diminished aquatic insect hatches, and degraded habitat. To address these concerns, we brought together leading scientific and angling experts for the first Caldera Symposium. The objectives for the symposium included: 1) Exchange scientific findings and develop future integrated collaborations. 2) Gain an understanding of potential restoration projects. 3) Gather input from anglers and others about the river and what they d like to see. The full-day symposium was a culmination of the comprehensive Caldera Project, created by the Henry s Fork Foundation in 2008, to better understand and improve the upper river fisheries. HFF has coordinated a technical team of scientific experts who have made significant advancements in our understanding of the Henry s Fork. Most of the twelve scientific presenters in the symposium were members of this technical team. The symposium provided the opportunity to share these recent scientific findings and to determine the next steps for future work on the river. The scientific topics were generally organized from large area scope and breadth to smaller area studies for the four sessions of the symposium. We began the first session with presentations on geology and hydrology to set the stage for subsequent presentations and sessions that featured aquatic plants, trout ecology, angler surveys, and stream restoration, among other topics. The Symposium also included presentations about fly fishing in the Caldera from five renowned anglers, who have fished the Henry s Fork for several decades. These anglers have met the technical challenges of fishing the Henry s Fork with innovations in techniques that have been applied throughout the world of fly fishing. These presentations were interspersed throughout the sessions, providing a break from science, but more importantly integrating an anglers perspective throughout the day. We concluded the symposium with a panel discussion titled Harriman State Park what do anglers want and where do we go from here? We had all of our angler presenters as well as several scientists participate on this panel where everyone was able to ask questions of the presenters. It was fitting that we concluded the symposium with an emphasis on this revered stretch of river and what is being done to understand and improve it. We also include in these proceedings the results of a post-event survey of symposium participants. These results will be used to improve upon and plan for this event in the future in what s hoped will be a regularly scheduled occurrence. 1

7 Figure 1: Map of the Caldera Stretch of the Henry s Fork 2

8 Presenter Biographies Mel A. Kuntz, Ph.D. is a research geologist (emeritus) with the USGS. He has studied the basalt volcanism of the eastern Snake River Plain and Henry's Fork caldera periodically since His research has involved field mapping; studies of basalt eruption processes; and argon/argon, radiocarbon, and obsidian-hydration dating to give a temporal perspective to the complex volcanic history of the region. He is preparing a book, for the general public, having a title similar to the title of his talk. He is a graduate of Carleton College (B.A.), Northwestern (M.S.), and Stanford (Ph.D.). Rob Van Kirk, Ph.D. first fished the Henry s Fork in 1977, worked at Henry s Fork Anglers from 1981 to 1987, and was the Henry s Fork Foundation s research director from 1994 to He has published 21 peer-reviewed papers and book chapters, nine of them about the Henry s Fork. His current Henry s Fork research is supported by a $620,000 grant from the USDA. Rob is a recipient of HFF s Conservation Award and the Idaho Chapter American Fisheries Society s Native Fish Conservationist of the Year Award. He earned his Ph.D. from the University of Utah and is Professor of Statistics and Mathematics at Humboldt State University. Nelson Ishiyama has been the owner of Henry s Fork Lodge for 21 years and has fished the Henry s Fork for 48 years. His favorite fishing is spring creek dry fly fishing and his favorite place on the planet is the Railroad Ranch. His friends describe him as a lunatic fly fisherman, and he is an avid fly tier, old tackle collector and fly casting nut. His interest in the Henry s Fork and Island Park has also made him an active supporter of the Henry s Fork Foundation, Trout Unlimited, the Nature Conservancy, and Teton Regional Land Trust. Mark Tompkins, P.E., Ph.D. is a principal engineering geomorphologist at NewFields River Basin Services in Oakland, California, where he works on river and floodplain management and restoration and development of advanced technological tools for adaptive management of natural resources. Dr. Tompkins has taught graduate-level and professional courses in hydrology, hydraulics, and river restoration, and published and presented his work in peer-reviewed journals, books, and at conferences. Dr. Tompkins is a regular contributor of photo-illustrated articles on recreational angling, river conservation, and other watershed-related topics to a variety of popular magazines. Jeffrey W. Snyder, Ph.D. has been an Assistant Professor of Biology/Ecology at Western Oregon University since 2007 and an instructor in the Department of Fisheries and Wildlife at Oregon State University since His research interests are in applied ecological conservation, particularly those interests and questions involving the understanding and conservation of important terrestrial and aquatic ecological systems and species. He has degrees in Biology/Ecology (B.S. & M.S.) from Idaho State University and a Ph.D. from Oregon State University. 3

9 Adonia Henry is a wildlife biologist with over 10 years of experience in natural resource management, ecosystem restoration, monitoring, and applied research. Adonia has worked on more than 20 wetland restoration and management projects throughout the western United States and Hawaii. She provided technical assistance on wetland ecology principles including biology of endangered and migratory birds and aquatic vegetation. Adonia is an assistant instructor for wetland ecology and management workshops and has collaborated on various hydrogeomorphic assessments. John McDaniel, Ph.D. is a Professor Emeritus of Anthropology at Washington and Lee University, with M.A. and Ph.D. degrees from the University of Pennsylvania. During his 34-year career at W&L, John established and chaired the A. Paul Knight Program that has annually brought students to work with the Henry s Fork Foundation and The Nature Conservancy since John and his wife Nell Word Reeves have two daughters and four grandchildren. John is a life member and former board member of the Foundation, has invested full summers on the Ranch since 1983, and guided exclusively on the Ranch for TroutHunter since Greg Schoby has worked as a Regional Fisheries Biologist with the Idaho Department of Fish and Game in the Upper Snake Region for the past four years, working on the Henrys Fork and other waters throughout the region. Prior to that, he worked as a Fisheries Research Biologist for IDFG on Lake Pend Oreille from 2006 to 2008, and as a fisheries technician for IDFG in Salmon between 2000 and Greg received a B.S. in Biology from Central Washington University in 2000, and an M.S. in Biology from Idaho State University in Jim DeRito has been the Research and Restoration Director of the Henry s Fork Foundation since He coordinates aquatic research, restoration, and protection work throughout the Henry s Fork watershed. Jim directed the implementation of the Caldera Project in 2008 and has coordinated the Caldera Technical Team since He has degrees in Environmental Studies (B.A.) from Hobart College and Fisheries Management (M.S.) from Montana State University. Dan Garren has worked with the Idaho Department of Fish and Game for the past 11 years, eight of which were spent as the biologist working on the Henrys Fork. He received a master s degree in Fisheries and Wildlife Management from Virginia Tech before moving out west to work in Idaho. Dan is currently employed as the Regional Fisheries Manager for the Upper Snake Region, and enjoys spending his free time fishing and recreating outside with his kids. Mike Lawson is a native of Henry s Fork country. In 1976 he opened Henry s Fork Anglers with his wife Sheralee. Mike is a noted author, fly tier, and lecturer. His book, Spring Creeks, has already become a classic, and his newest book, Fly Fishing Guide to the Henry s Fork, is due out this month. Mike is also a dedicated conservationist a founding member of both the Henry s Fork Foundation and the Upper Snake River Fly Fishers. The great fly fishing he has experienced throughout the world only serves to reinforce his conviction that the best is right in his own backyard. 4

10 Jim Gregory received a bachelor s degree from University of Idaho and master s degree from Idaho State University. He started his own consulting business in In 1996, Jim moved to Mackay, Idaho to manage a recreational fishing ranch and run his one-man fisheries consulting company, which focuses on fisheries research, monitoring, and project management. He has worked on fisheries and habitat projects throughout southeast and central Idaho, western Wyoming, and northwest Colorado. He has completed numerous research, monitoring, habitat improvement, and fish passage projects. René Harrop has fished the Henry s Fork in the Caldera for nearly sixty years. During that time he has been a leader in the evolution of fly fishing on these waters. He has made his living as a renowned fly tier, author, and artist. René is a former guide and partner in TroutHunter. He spends s summers in Island Park and winters in St. Anthony. Anne Marie Emery works for the Henry s Fork Foundation as the Conservation Education Biologist. She has worked full time with the Foundation since 2006, playing a key role in the implementation of the Henry s Lake outlet restoration project, trout radio-telemetry studies, the Caldera Project, internship program development, and most recently, youth education and outreach programs. Anne Marie graduated from Albertson College with a degree in conservation biology and environmental studies, and is a certified member and board advisor of the Henry s Fork Chapter of the Idaho Master Naturalist program. She lives on the Henry s Fork with her son, Jack. Lee Mabey has worked as a fisheries biologist with the Forest Service for the past 21 years. The last 13 of those years have been primarily in the Ashton/Island Park and Teton Basin area for the Caribou Targhee National Forest. He has worked on a variety of projects: relicensing of hydropower projects, fish passage restoration, native cutthroat trout restoration, angler access, and stream restoration. He has also worked for the Uinta National Forest, Utah Division of Wildlife Resources, and the U. S. Fish and Wildlife Service while completing a Master s degree. Mick Mickelson, M.D. began fishing the Henry s Fork in the 1960s and then moved to Idaho in 1981 to become the team physician for Idaho State University s Sports Medicine Facility in Pocatello. Shortly after moving to Idaho, Mick helped found the Henry s Fork Foundation and served as president of the new organization from Mick currently co-chairs the Foundation s endowment campaign, guaranteeing the conservation, protection, and restoration of the Henry s Fork continues far into the future. Mick s contributions to conservation in Idaho also include serving on the board and as chairman for the Idaho Chapter of The Nature Conservancy. Tom McMurray, Ph.D. is President and CEO of Marine Ventures Foundation (MVF) and leads the BlueCloud conservation project. Since founding MVF in 2003, he has been involved in a wide range of conservation projects in the US, Argentina, Mexico, Cuba, Caribbean and Australia. He currently serves on the boards of The Ocean Foundation, Henrys Fork Foundation, Duke University School of the Environment, and Lighthawk. In his previous life, Tom was a partner at Sequoia Capital where much of the inspiration for leveraging cutting edge technology to attempt to modernize the conservation movement was born. He received his Ph.D. from Duke University. 5

11 Session 1 - River context and aquatic plants. Moderator: Jim DeRito Volcanoes, glaciers, water, and fish Mel A. Kuntz, U.S. Geological Survey volcanoguy@hotmail.com, or The Henry's Fork caldera formed during two climactic rhyolite eruptions at 2.1 and 1.3 million years ago. These eruptions formed the Huckleberry and Mesa Falls tuffs, respectively, and together produced the roughly 20-mile diameter, circular depression known increasingly in local parlance as "the caldera." The floor of the caldera has been the site of about a dozen eruptions of basalt beginning about 750 thousand years ago. The youngest basalt lava field is about 100 thousand years old, but basalt flows as young as about 12 thousand years old occur approximately 10 miles west of the caldera rim, indicating that the larger caldera area is a region of continuing volcanism. The course(s) of the Henry's Fork have been determined by the basalt lava fields, the river has been diverted across the floor of the caldera by each new basalt lava field. Field studies suggest that glaciers extended from Henrys Lake as far south as the Buffalo River. The Thurmon gravels, a suspected glacial kame terrace deposit, are nestled in the Northwest corner of the caldera. These gravel deposits have supplied much sediment to the Henry's Fork in The Ranch reach during periods of mostly glacial-dominated alluvial deposition. Surface groundwater mainly from springs located at the western margin of rhyolite lava flows of the Madison Plateau supply most of the flow of the Henry's Fork, but a significant volume of water is believed to be added to the river from underflow from beneath lava flows and buried alluvial deposits. Geological factors such as canyon cutting, alluvial deposition of sediments, and supply of cold water from underflow have significant effects on the unique character of certain locales of the Henry's Fork fisheries. 6

12 Hydrology of the upper Henry s Fork: climate, geology, and water management Rob Van Kirk, Department of Mathematics, Humboldt State University Robert.vankirk@humboldt.edu, The hydrologic regime of the upper Henry s Fork (upstream of Ashton) is determined by climate, geology, and water management. Topographic uplift associated with migration of the North American plate across the Yellowstone hotspot combined with subsidence in the hotspot wake creates a large elevation gradient between the Snake River Plain and the Yellowstone Plateau. This gradient produces an orographic effect that results in precipitation exceeding 50 inches per year on the Yellowstone Plateau, compared with only 12 inches per year in the lower elevations of the Henry s Fork watershed. Most growing-season precipitation is lost to evapotranspiration, leaving accumulated snowpack as the ultimate source of water to the river. Because the Yellowstone Plateau has little topographic relief, most snowmelt percolates into aquifers hosted in rhyolite flows that form the Plateau. Water then emerges from the base of these rhyolite flows where they contact older basalts and glacial deposits on the floor of the Island Park Caldera. These aquifers have low conductivity, are about 1000 feet thick, and tens of miles across, resulting in very high attenuation of the annual snowmelt peak and producing nearly constant discharge in springs that feed the upper Henry s Fork. The largest are Big Springs, the springs that feed the Buffalo River, and Warm River Springs. The morphology of the upper Henry s Fork and its major tributaries reflects the domination of the hydrologic regime by groundwater. Stream channels tend to have uniform, rectangular cross sections, and floodplains are narrow. Habitat for aquatic organisms in these streams is largely dependent on locally derived structure (i.e., rocks and terrestrial vegetation that fall into the river) and macrophytes, versus transport and deposition of alluvial material and woody riparian vegetation, as occurs in snowmelt-dominated streams such as the South Fork Snake River. Island Park Dam alters the natural hydrologic regime by storing water in the winter and releasing it during the mid-summer irrigation season. Operation of Island Park Dam is constrained by both its physical location (high in the system) and storage rights priority (junior to 75% of the rights) in the upper Snake River system. Because of its relatively high precipitation and groundwater-dominated hydrologic regimes, the upper Henry s Fork contributes a large and stable flow to the Snake River. Although it accounts for only 3% of the drainage area of the Snake River at King Hill, the upper Henry s Fork contributes 11% of the annual natural flow there. 7

13 Why do they come to the Ranch? Nelson Ishiyama, Henry s Fork Lodge nelsoni@ix.netcom.com, Anglers from all over the world are attracted to the Henry s Fork. It was twice named America s #1 trout stream by Trout Unlimited members over other great western rivers such as the Missouri, South Fork of the Snake, Silver Creek and Bighorn. The marquee attraction is the Railroad Ranch. Why? I think the principal reasons are: The legendary reputation of Ranch fishing chronicled in writings in the 1970 s and 1980 s glory days by prominent writers such as Doug Swisher & Carl Richards, Joe Brooks, Charles Brooks, Ernest Schwiebert and, more recently, John Gierach. The Henry s Fork on the Ranch is the ideal trout stream - clear flat water, a gorgeous alpine setting, easy public access, large rising fish, great hatches, easy and comfortable wading, and plenty of backcast room. Quality of fishing, not quantity of fish is what anglers appreciate most. Anglers surveyed in 2008 (collaboration among the Henry s Fork Foundation and the Idaho Department of Fish and Game) cited aesthetics, fish habitat, hatches and rising fish as most important. Least important was number of fish caught, followed closely by size of fish and numbers of other anglers. Wild trout management was highly supported among the vast majority of anglers surveyed in The Ranch section of the Henry s Fork is considered the ultimate challenge for anglers looking to test their skills. The Ranch is regarded as the Wimbledon, Augusta National or Yankee Stadium of trout fishing. Anglers come to Henry s Fork initially because of the almost-mythical reputation of the Ranch and return because of the beauty of the setting, the quality of the fishing and also the fishing in other parts of the river. 8

14 Geomorphic evaluation and flushing flow recommendation Mark Tompkins, Anthony Falzone, and Paul Frank, NewFields River Basin Services We conducted detailed hydrologic, hydraulic, geomorphic, and sediment transport evaluations in the Caldera Reach of the Henrys Fork to identify measures that could improve summer habitat for adult rainbow trout, habitat for aquatic invertebrates, and persistence of macrophytes through the winter to improve young-of-year rainbow trout survival. More specifically, the goals of our project included the following. Characterize channel morphology and sediment Develop 2-D hydraulic model and sediment transport tools Recommend flushing flow peak and hydrograph Evaluate channel form manipulations to optimize flushing flow results Improve conceptual model of sediment/macrophyte interaction We completed baseline field data collection (including channel geometry and longitudinal profile, channel bed sediment characteristics, and channel facies) in summer 2010 and conducted flood frequency, flow duration, and historical channel morphology evaluations in winter Next, using this baseline field and analysis data as input, we created and calibrated a two-dimensional hydraulic and sediment transport model of the Caldera Reach. We then used this model to evaluate the performance in a potential peak flow release from Island Park Reservoir to mobilize accumulated fine sediments. Our data collection, analysis, and modeling showed that fine sediment accumulations do still impair aquatic habitat in the Caldera Reach, especially in the vicinity of Big Bend and Millionaire s. In addition, we showed that a peak flow release of approximately 3,000 cubic feet per second (cfs - not significantly higher than natural peaks that have historically occurred in the system) from Island Park Dam, when combined with approximately 500 cfs from the Buffalo River, would have the capacity to mobilize and redistribute accumulated fine sediments. Further, we determined that constructing instream islands in key locations could significantly increase the extent of fine sediment mobilization in identified problem areas. Complications associated with maintenance work on Ashton Dam downstream of the Caldera prevented the peak flow release from occurring in the spring of 2011, but our work now provides the foundational information for conducting this release when hydrologic conditions are suitable in the future. 9

15 Session 2 - Plants continued and angler surveys. Moderator: Lee Mabey Aquatic macrophyte abundance and distribution in Henry s Fork the Snake River through Harriman State Park of Idaho, 1988 and 2011 Jeffrey W. Snyder, Oregon State University snyderj@wou.edu, Aquatic macrophyte cover was quantified in 1988 and 2011 along 68 random-placed sections from Last Chance to North Pinehaven on Henry s Fork of the Snake River through Harriman State Park of Idaho. In 1988, sampling was conducted from late August to early November; in 2011 sampling occurred in September. In 2011, significant increases in unvegetated, exposed river substrate were found throughout river sections of Henry s Fork through Harriman State Park. Between 1988 and 2011 the amount of bare, unvegetated river substrate near Last Chance increased 14.50%, and 58.53% at Big Bend. Moreover, percent cover of Watermilfoil (Myriophyllum spp.) declined 36.33% in the river near Last Chance. Overall, the greatest significant changes in the macrophyte community occurred in the upstream reaches (near Last Chance) compared to the downstream reaches (near Pinehaven). Aquatic macrophyte distribution and abundance through Henry s Fork of the Snake River is dependent upon available physical, chemical, and biological resources. As such, changes to these physical, chemical, and biological resources (and their interrelated effects) are causative factors affecting the composition of this unique community. Since 1988, increased sedimentation, low winter flows (that dewater the river channel, increase winter frazil and anchor ice formation that subsequently disrupt the physical substrate and remove macrophytes), loss of important nutrients, and waterfowl herbivory have been hypothesized as anthropogenic (human caused) and natural factors behind these significant changes. Continuous sampling, combined with experimental treatments, is needed to better understand long-term macrophyte community variation over time, that interactive factors that affect it, and its ability to withstand/respond to these anthropogenic and natural stressors. 10

16 Trends of Aquatic Macrophytes on the Henrys Fork in Harriman State Park Adonia Henry, Scaup & Willet LLC Aquatic macrophytes on the Henrys Fork of the Snake River provide important habitat for overwintering juvenile rainbow trout, adult and sub-adult trout, and macroinvertebrates. Loss of habitat is one of the factors attributed to the decline in the trout fishery on the Henrys Fork. Therefore trends in historical and current macrophyte data were examined. Aquatic macrophytes on the Henrys Fork were periodically sampled from 1958 to Different sampling methods make comparisons of historical results challenging; however several trends are apparent. Wet weight biomass of aquatic macrophytes during the growing season declined between 43 and 59% from the late 1970s to the mid 1980s. Percent cover of aquatic macrophytes did not significantly differ between 1988 and years following the 1992 sediment release from Island Park Reservoir. Average percent cover of aquatic macrophytes has ranged from 64 to 84% during for the years sampled from 1988 to During 2009, percent cover of aquatic macrophytes averaged 64% and was significantly lower than during 1993, 1994, and However, trends in percent cover appear to be cyclical with average percent cover greater than 75% observed during , , 1999, and Aquatic macrophytes also show seasonal trends in abundance with percent cover estimates in April ranging from less than 5% to 23%. The abundance of aquatic macrophytes in rivers is influenced by many factors, including nutrients, light, temperature, water depth, current velocities, physical properties of sediment, and foraging by waterfowl. Different species of aquatic macrophytes have different distributions throughout Harriman State Park related to sediment characteristics and water velocity. Nutrients, especially total phosphorus, have declined on the Henrys Fork since the 1970s. This may have contributed to the decline in macrophytes observed since the late 1970s. Sedimentation events may also negatively impact aquatic macrophytes. However, it appears that effects of sediment releases from Island Park Dam on aquatic macrophytes on the Henrys Fork are short-term. The population of trumpeter swans wintering on the Henrys Fork has also increased. In other studies, trumpeter swans can reduce the biomass of sago pondweed tubers up to 24% during the spring, but sago pondweed growth the following summer was not negatively impacted, suggesting sago pondweed has compensatory growth mechanisms to survive waterfowl foraging. Continued monitoring and quantitative assessments of the factors related to aquatic macrophytes are needed to determine the causes of variation in aquatic macrophytes on the Henrys Fork. 11

17 Why I Never Fish Anywhere but the Railroad Ranch John McDaniel, TroutHunter john.mcdaniel@starband.net, (406) The Ranch is the perfect place to cast a dry fly to large, selective trout. Our special rainbows grow quickly and rely on an insect diet after reaching a length of twenty inches and weight of four pounds. They will thrill you with their speed, strength and jumping ability. The abundance of insects, clear, slow moving water, and catch and release regulations make our mature fish as difficult to hook as any in the world of fly fishing. Experienced anglers agree the Ranch offers the finest dry fly fishing on the planet. The most compelling reason I never leave the Ranch is the gratification I derive from occasionally fooling one of our mature rainbows. To hook one, you must effectively present a highly realistic dry fly. The inherent difficulty, the challenge if you will, is addictive. There are other rivers that offer wonderful dry fly fishing; however, the following qualities separate the Ranch: 1. The size of the Ranch water. The width of the river allows our fish to demonstrate all their fighting qualities when hooked. Unlike on a small spring creek, our rainbows are not trapped in small pools. 2. It is impossible to find another fishery with as many types, and quantities, of aquatic and terrestrial insects. Even the great waters of New Zealand were a disappointment to me because of the paucity of insects. 3. The beauty of the Ranch is critical. I know many of us find comfort in that beauty and it is the reason I have no interest in fishing the Big Horn or the Missouri. 4. The Ranch has large populations of wild animals and birds. I derive great satisfaction, daily, from seeing and hearing them. 5. The special serenity and tranquility of the Ranch contributes to why I do not want to leave. The Ranch is psychologically comforting to me. 6. The Ranch is conducive to making friends. The fact you walk the banks of the river rather than floating in the bubble of a drift-boat makes it likely you will meet people. My Ranch friends are very important in keeping me from fishing elsewhere. My book available as of August 2012: Fishing the Harriman Ranch of the Henry s Fork of the Snake River Lessons Learned and Friends Made Sight Fishing to Selective Trout, The Whitefish Press. 12

18 Henrys Fork creel survey Greg Schoby, Idaho Department of Fish and Game greg.schoby@idfg.idaho.gov, In 2008, the Idaho Department of Fish and Game (IDFG) conducted a creel survey on the Henrys Fork of the Snake River from St. Anthony, ID upstream to Island Park Dam. We assessed angler use (hours of angling effort) and demographics, as well catch rates (both release and harvest rates) on five sections of the Henrys Fork (St. Anthony to Chester Dam [Chester], Chester Dam to Ashton Dam [Ashton], Ashton to Riverside campground [Warm River], Harriman Ranch, and Box Canyon). Non-residents comprised the majority (74%) of anglers in the upper reaches of the Henrys Fork (Box Canyon and Harriman Ranch), while the middle reach (Warm River) was nearly even, and residents comprised the majority of anglers in the lower river at Ashton (57%) and Chester (73%). Overall, non-residents comprised 56% of the anglers observed on the Henrys Fork. We estimated nearly 55,000 hours of angler effort on the Henrys Fork in 2008, with the majority of the effort in the Warm River reach (18,481 hours), followed by Box Canyon (12,112), Ashton (10,721), Harriman Ranch (7,401) and the Chester reach (5,690). Angler effort standardized by river mile (hours per mile) was highest in Box Canyon (2,329), followed by Ashton (1,649), Harriman Ranch (986), Chester (825), and Warm River (608). Catch rates (fish per hour) were highest in the Warm River reach (1.6), followed by Box Canyon and Chester (0.9 each), Ashton (0.8), and the Harriman Ranch (0.4). In the lower reaches of the Henrys Fork where harvest is allowed, we observed minimal harvest with rates of 0.01, 0.05, and 0.07 fish harvested per hour in the Chester, Ashton, and Warm River reaches, respectively. Overall, harvest of trout was insignificant when put in context with trout abundance. Although creel surveys were conducted sporadically in the Box Canyon and Harriman Ranch reaches from 1973 through 1996, differences in data collection methods (length and timing of surveys) and analysis make meaningful comparisons to the 2008 survey results difficult. Creel surveys scheduled for the Henrys Fork in 2014 will follow the methodologies used in 2008, and allow for comparisons of angler effort, catch and harvest rates. 13

19 Angler demographics, satisfaction and management opinions of the Henrys Fork in Harriman State Park Jim DeRito, Henry s Fork Foundation Dan Garren, Idaho Department of Fish and Game Rob Van Kirk, Humboldt State University jderito@tu.org, The Henrys Fork of the Snake River within Harriman State Park is one of the most well known angling locations in the world. Only fly fishing is allowed within the park boundaries. The waters within and adjacent to the park have been managed as a wild rainbow trout fishery since 1978 and catch-and-release regulations were implemented in In spite of these restrictive regulations, anglers during the early to mid-2000s expressed concern over a perceived decline in their angling experience - citing fewer fish, diminished insect hatches, and a lack of rising fish. Some anglers even suggested that trout stocking is the answer. These concerns warranted a survey of anglers, but standard creel measures are unlikely to fully describe this technical dry fly angling experience. Therefore, we developed an angler attitude survey to measure angler values and satisfaction, along with opinions on wild trout management versus hatchery trout management. A total of 614 anglers were surveyed at river access points for the park from June 15 (the season opener) through October, 2008 when angling use dropped off substantially. Anglers valued the quality of insect hatches, opportunities to fish to rising fish, and condition of fish habitat, but angler satisfaction with these factors was generally low. In 2008, anglers were about equally split between those who rated the quality of fishing in Harriman State Park today either as excellent (18%) or good (31%) versus those who rated it as fair (29%) or poor (22%). Similarly, these 2008 ratings fell in between those for a similar question from a low quality angling year of 1992 (7% excellent and 15% good) and that of a high quality angling year of 1993 (27% excellent and 38% good). Anglers rated 2008 as about average compared to all past years and since 2000, but lower than the 1990s or 1980s. Eighty-eight percent of anglers approved and 6% disapproved of managing the fishery for wild trout, whereas 16% approved and 76% disapproved of managing the fishery with stocked trout. The Henrys Fork within and adjacent to Harriman State Park will continue to be managed for wild trout. Future work will focus on habitat assessments and potential restoration options that may improve angler satisfaction with insect hatches, rising fish, and habitat. 14

20 Session 3 - Rainbow trout. Moderator: Greg Schoby Flows and fish - the relationship between rainbow trout abundance and flow releases from Island Park Dam Dan Garren, Idaho Department of Fish and Game dan.garren@idfg.idaho.gov, Flow releases from dams can have profound effects on fish populations residing downstream. Understanding the effects of flow releases can allow managers to shape flows to bring about positive changes in fish populations, which ultimately benefits anglers. Prior research in the Box Canyon reach of the Henrys Fork has shown winter flows play a role in shaping year class strength of rainbow trout. We determined age-2 trout to be the first fully-recruited age class to our electrofishing gear, and used linear regression to compare population estimates of age-2 trout to a suite of flow variables encountered by trout during their first year of life to determine what factors govern year class strength. We found no relationship between flow variables during the late spring, summer or fall, but did find significant relationships between winter flows and year class strength. Higher flows during the winter resulted in stronger year classes being produced. This is likely tied to a combination of thermal buffering provided by the higher volume of water coupled with increased habitat being available through increased wetted width or depth. We ve used this information in collaboration with water managers to shape winter flows from Island Park Dam. Flow management has emphasized higher releases beginning in December each year. The resulting stronger year classes should help improve trout populations throughout the upper river, and ultimately lead to increased angler satisfaction. 15

21 40 Years of Guiding and Outfitting in the Caldera Mike Lawson, Henry s Fork Anglers mike@henrysforkanglers.com, I began my career as a guide working for an outfitter in West Yellowstone in I became an outfitter in both Idaho and Montana when we opened Henry s Fork Anglers in Rules and regulations governing outfitting and guiding in Idaho have not changed since I first started the business. In Idaho the Outfitters and Guides Licensing Board sets policy and administers licenses. The board serves at the pleasure of the governor for the benefit of public interest. There are 7 legal outfitters on the Henry s Fork. In the early 1980s I served on a committee with other outfitters to draft the current boating restrictions on the Henry s Fork. These limits have protected the public from overuse by the outfitting and guiding industry. In the early years from the 1970s through the 1990s most of the guiding attention was focused on the Harriman Ranch and Box Canyon. The Ranch was loaded with cookie cutter type trout in the range. There were a few larger trout but there was never an evidence of healthy age classes of trout. The Box Canyon had some enormous trout and double digit weights were not uncommon. Later research revealed that many of these trout were being artificially stocked in the river as a result of being flushed through the Island Park Dam. That changed after the dam was retrofitted with a hydroelectric project. This substantially reduced the number of trout that were flushed through the dam. Today the trout population in the Ranch and Box Canyon is healthy and strong with distinct age classes. These trout continue to grow to trophy sized fish in the Ranch. Guiding and boating regulations limit the opportunity to grow the guiding businesses in the Caldera. The fishing on the lower Henry s Fork below Ashton has improved substantially since we first started our business. It has provided an opportunity to continue to grow our business because it provides additional fishing opportunities for our clients. In summary I think the fishery in the Caldera and outside of the Caldera on the Henry s Fork has actually improved since we began our business in

22 Survival and movement of adult rainbow trout during winter and spring in the Henrys Fork of the Snake River Jim Gregory, Lost River Fish Ecology Inc. Anne Marie Emery, Henrys Fork Foundation Jim DeRito, Henrys Fork Foundation Discharge downstream from Island Park Dam on the Henrys Fork of the Snake River in Idaho is reduced each winter to facilitate storage of irrigation water. The effect this has on survival and movement of adult rainbow trout (Oncorhynchus mykiss) in this area is unknown. Additionally, fish movement during the spring has not been evaluated but may affect population estimates conducted in the tailwater monitoring area downstream from Island Park Dam prior to opening of fishing season. Therefore, we used radio telemetry to evaluate winter survival and movement of 61 adult rainbow trout in the Henrys Fork downstream from Island Park Dam under low and extremely low early winter flow conditions. Spring movement was evaluated to assess whether the population estimates conducted in the monitoring area each spring represent fish from downstream adjacent reaches of the river, and how emigration between mark and recapture periods may affect the population estimate. Survival of radio-tagged trout was nearly 100 percent during early winter under both low and extremely low flow conditions and winter movement did not differ between the two years. Few radio-tagged rainbow trout from downriver were present in the monitoring reach during the time when the population estimate is normally conducted, indicating that large fluctuations in fish numbers in downstream reaches would likely be undetected based on population estimates conducted in the monitoring area. To remedy this, establishing a separate, regular population monitoring area in downstream reaches is recommended. We determined emigration from the monitoring reach between mark and recapture to have a minimal effect on the population estimate. However, we noted that all radio-tagged trout moving out of the monitoring reach during May moved into a short section of river between the monitoring reach and Island Park Dam, presumably to spawn. Therefore, emigration could be largely eliminated by extending the monitoring reach upstream to the dam. Editors note: the full study can be found in: Intermountain Journal of Sciences, December 2011, 17(1-4):

23 Changes in trout behavior René Harrop, House of Harrop Trout behavior has changed as fisheries management and angling techniques have evolved since when I first began fishing the slow water of the Henry s Fork in the Island Park Caldera in Trout were relatively easy to catch when fishing pressure was comparatively light. The river was managed with the stocking of hatchery fish, and harvest limits were liberal in the 1950s and 1960s. This resulted in relatively undisturbed trout that were not constantly alert to the dangers of an artificial fly. I relied on general patterns like the Adams, Light Cahill, and Quill Gordon. Trout became considerably more difficult to fool as direct stocking of the river ended. The number of anglers increased, and catch and release became common in the 1970s. Trout responded with a stronger resistance to a fly as they became educated to the perils of being hooked. As selective feeding behavior became more pronounced, so too did the rate of refusal by the most desirable trout. Motivated by rejection, my fly tying had to advance as I and others began an ongoing quest for better accuracy in the size, shape, and color of imitations. Emerger and cripple patterns were developed when it was recognized that trout were rejecting fly patterns duplicating fully developed insects and that they respond strongly to a condition of insect vulnerability during the hatching process. Presenting the artificial in a manner that would convince the fish that it was not a fraud required improved fly casting and presentation skills. The behavior of rainbow trout continues to change and has required refinements of technique. The completion of the Island Park Hydroelectric Project in the early 1990s further limited the significant influx of trout from the reservoir that could be easily caught on the river downstream. Wild trout may be further altering their behavior as angling pressure continues. Trout may be learning to avoid the danger of a steel hook by refraining from feeding on the surface where an artificial fly is most likely to be encountered. We may be witnessing an evolutionary change in the tactics that must be applied in order to be consistently successful. Sight nymphing and highly imitative nymphal patterns are now being used for success with large seasoned trout. I have a sense of gratitude to the trout, because they have made us better anglers as we continue to adjust to their changing behaviors. 18

24 Winter use of Caldera tributaries by subyearling rainbow trout Anne Marie Emery, Henry s Fork Foundation Jim DeRito, Henry s Fork Foundation Lee Mabey, Caribou-Targhee National Forest Greg Schoby, Idaho Department of Fish and Game annie@henrysfork.org, The number of rainbow trout in the Caldera Section of the Henrys Fork is primarily determined by how many age-0 rainbow trout survive their first winter. Heretofore, most age-0 rainbow trout research and restoration efforts have focused on the mainstem river. However, winter habitat availability for age-0 rainbow trout in the Henry s Fork mainstem can be limited with decreased discharge rates from the Island Park Dam. To understand and identify other sources of winter habitat for age-0 (<175 mm) rainbow trout, we evaluated four spring-flow tributaries using a combination of fish traps, seasonal electrofishing, and fish marking/tagging. At the Buffalo River Hydroelectric Project, a total of 15,470 age-0 rainbow trout (annual average of 2,578) have immigrated through the fish ladder (years ), with 85% of movement occurring from September thru December. Over 12,000 rainbow trout have been captured moving downstream ( ) at the hydroelectric project; 93% of these age-0. Most rainbow trout are moving downstream in the Buffalo River during the months of April and May during snowmelt runoff and higher water flows. In Blue Spring Creek, Thurmon Creek, and Fish Creek; mean densities of age-0 rainbow trout increased from autumn to spring (prior to snowmelt runoff) and then decreased during the summer. Mean age-0 rainbow trout densities (number of fish/100 m) in Blue Spring Creek were: 39 in autumn (2008); 170 in spring (2009); and 30 in summer (2009). Mean densities in Thurmon Creek were: 595 in autumn (2009); 876 in spring (2010); and 45 in summer (2010). Mean densities in Fish Creek were: 2 in the summer (2010), 72 in autumn (2010), and 151 in spring (2011). Lastly, we installed a picket weir at the mouth of Thurmon Creek to assess winter use by age-0 rainbow trout. Immigrating age-0 rainbow trout captured included 1,388 during winter and 1,908 during winter Capture of outmigrating rainbow trout from Thurmon Creek has been low, in part because of problems with the fish weir and research is ongoing to quantify outmigration. Our study results demonstrate that age-0 rainbow trout in the main stem river migrate into, and overwinter in the spring-flow tributaries of the Henry s Fork. Fish passage improvements and habitat restoration within these tributaries may increase age-0 rainbow trout overwintering use and survival, resulting in greater year-class strengths and increased angling opportunities in the Henrys Fork. 19

25 Session 4 - Restoration, mapping, and panel discussion: Moderator: Jim Gregory Restoration opportunities on Caldera tributaries Lee Mabey, Caribou-Targhee National Forest lmabey@fs.fed.us, There are three types of restoration work occurring within the caldera. First, is flow restoration. It has been determined that higher winter flows are needed to help age-0 fish survive through their first year. This has been accomplished by winter-flow management below Island Park Reservoir. Second, restoration of connectivity to allow life history expression such as the Buffalo Hydro fish ladder, which is passing 2,000-4,000 age-0 fish per year to overwinter in the Buffalo. Also spawning size fish are passed each spring and the following spring over 10,000 age-1 fish are recruited to the Henrys Fork from the Buffalo River. Lastly, physical restoration of favorable channel dimensions and vegetation to promote sediment transport and habitat, which is useful for salmonid: holding, spawning, rearing and overwintering. There are seven spring creek tributaries to the Henrys Fork in the caldera that have potential restoration opportunities. These spring creeks are ground water dominated, have substrates of sands and fine gravels, are very sensitive to disturbance and, due to low peak flows inherent to their spring creek nature, are very slow to self-heal. Many of these creeks and their channel dimensions have been altered by human activity such as grazing and are not supportive of good habitat due to over widening and fine sediments. There are techniques available using onsite native materials to restore these creeks to functionality. These techniques involve using sod mats to build new banks, with channel widths based upon reference reach dimensions where the stream is successfully moving fine sediments, exposing gravels, and undercutting banks. During 2012, a portion of Fish Creek will be restored using these techniques. This stream has not been grazed since the 1980s and small sections of the creek have begun to recover. However many parts of the channel, especially the meander bends, remain over widened, as evidenced by the primary flow pattern being on the inside of the meanders. Much of the system has a bankfull width of over 20 feet, while reference reach dimensions bankfull width is closer to 8-10 feet. Abandoned meander scrolls will also be reactivated and the cut-off channels plugged. We anticipate that improving these streams will result in better winter habitat for trout and ultimately more trout. Trout populations in restored steams will be monitored to assess success. 20