A Guide to Native Trout Restoration: Science to Protect and Restore Coldwater Fishes and their Habitats

Trout Unlimited, Arlington, Virginia April 2006

Our goal in producing this guidebook is to help the angler, landowner and interested conservationist restore native coldwater fishes and their habitats. Healthy streams and associated streamside riparian areas are important national assets that provide not only highquality fish habitat but also recreational opportunities and dependable sources of clean water. Streams also serve as a source of natural beauty for eyes that are too often adjusted for the clutter of our unnatural urban environments. We have condensed many years of stream ecology research as well as trial-and-error lessons into a series of scientific principles to guide successful trout and char restoration projects. Our principles are designed to increase the long-term viability of fish populations and to restore the health, integrity and productivity of streams. Our emphasis is on basic conservation biology and restoration ecology principles, which equates to long-term and large-scale approaches to restoration. We promote working with nature rather than depending on highly engineered or artificial approaches that address short term issues. Restoration of native trout and char is, of course, about more than simply applying the latest scientific guidance. It is an opportunity to bring people together--the angler and landowner, agency official and public citizen. It also enables us to engage school children in a better understanding of the natural world. Barry Lopez described these broader ambitions of restoration as “accepting abandoned responsibilities…as the joyful mending of biological ties.” We hope this guidebook can assist in this effort.

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Prepared by Jack E. Williams, Warren Colyer, Nathaniel Gillespie, Amy Harig, Dana DeGraaf and Joe McGurrin.

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This guidebook is divided into the following topics: 1. 2. 3. 4. 5.

A discussion on native trout and char and their values Causes of declining populations and the need for restoration Using the Conservation Success Index to assess status and trends Protecting and restoring watersheds Protecting and restoring populations

At the end of this guidebook, we provide a short list of additional resources from printed materials and the internet that will provide further guidance for restoring degraded habitats and reduced populations.

Native trout and char of the United States No other family of fishes generates as much interest as the Salmonidae, which includes at least 66 species of trouts, chars, whitefish, grayling, steelhead and salmon in the Northern Hemisphere. Scientists estimate that most species have been around for millions of years and their distribution has been shaped by the ebb and flow of continental glaciers, uplift of mountains, downcut of canyons, and changes in climate. Over this evolutionary history, today’s salmonids successfully moved across vast distances and occupied new and expanding habitats. The complex evolutionary history of the Salmonidae has sometimes confounded taxonomists as they have attempted to categorize and name the various species and subspecies. Excluding salmon and whitefishes, there are about 30 species and subspecies of trout, grayling and char that are native to the United States. Two of these, the yellowfin cutthroat trout in Colorado and the Alvord cutthroat trout of Nevada and Oregon, are extinct. Some of the remaining species are listed as endangered or threatened species according to federal and state governments, while others are considered as “sensitive” or “rare” species. All have substantially declined from their historic distribution. In the western United States, native trout and char include bull trout, coastal cutthroat, golden trout, redband trout, Apache trout, Gila trout, westslope cutthroat, Yellowstone cutthroat, Bonneville cutthroat, Rio Grande cutthroat, Paiute cutthroat, Lahontan cutthroat, greenback cutthroat, and Colorado River cutthroat. In the eastern and midwestern United States, brook trout is the primary native salmonid. In addition, there are a number of genetically distinct but undescribed subspecies or other population groupings that are worthy of specific identification and management.

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Values of native salmonids Native trout and salmon are vital resources to all Americans. They are adapted to a wide variety of habitats and water conditions, and their natural diversity means they are more likely to survive future environmental change. For example, native redband trout thrive in small, seemingly inhospitable high desert streams. Redband in desert streams of southwest Idaho have been documented in streams with temperatures of 80oF. Some native cutthroat trout prefer turbulent mountain streams, while others thrive in low-elevation desert lakes. In short, the native trout have adapted to local environments for many thousands of years and are therefore more likely to survive periods of drought, flood, wildfire or other natural catastrophes than are non-native or hatchery-reared fish.

Figure 1. Map on left showing native ranges of many western salmonids. Map on right showing native range of brook trout in the United States.

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Figure 2. (upper left) Small desert stream and redband trout; (lower left) valley bottom river and westslope cutthroat trout; (below) Pyramid Lake and Lahontan cutthroat trout.

Credit: Nat Gillespie, TU; (inset) Mike Dean, CDFG

Credit: Dan Doerner; (inset) Peter Rissler, Pyramid Lake Fisheries

Credit: Nat Gillespie, TU; (inset) Rob Roberts, TU

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Many trout species are important indicators of the health of our nation’s lakes and rivers. Species such as Yellowstone cutthroat trout and bull trout are highly sensitive to chemical pollutants and sedimentation, making them our “canaries in the coal mines” for lakes and streams. As compared to hatchery-produced trout or other non-native species, native cutthroat trout and bull trout have quite narrow tolerances for changes in the chemical or physical conditions in their streams. Salmon, steelhead and trout are important to our nation’s economy and are highly valued as recreational resources. Each year, many millions of dollars flow into local economies from commercial and recreational fishers. In the U.S., trout anglers spend $6.4 billion annually on fishing. As noted by the American Sportfishing Association, these expenditures are a powerful engine in the broader economy of recreational angling, which generates $74.8 billion in economic outputs, $4.8 billion in tax revenues, and nearly 684,000 jobs. In California alone, recreational angling accounts for nearly $3 billion in annual revenue and more than 92,000 jobs. A recent study by IBM Business Consulting determined that the value of wild steelhead in British Columbia’s Skeena River is nearly $110 million annually, including recreational angling ($15 million), commercial fishing ($13.8 million), fish processing ($32.8 million), tourism ($7.6 million), Native interests ($4.2 million) and other values. Many anglers prefer wild fish for their fighting prowess compared to more domesticated hatchery-produced fish. Native trout and salmon are among the most beautiful creatures and are a priceless connection to wild lands and wild rivers. Many anglers pursue native trout and steelhead, not for food, but rather for the chance to experience some of our finest wildlands and to escape from the stresses and hectic pace of urban life. Roadless and wilderness areas often are among the last strongholds for native trout, salmon and steelhead. The importance of protecting native species is reflected in national laws and policies. When the Endangered Species Act was passed, virtually unanimously by members of the House and Senate, there was a clear priority that native species were of significant scientific, ecologic and economic value to our country and deserved protection. Similarly, laws from the Clean Water Act to the National Wildlife Refuge System Improvement Act legislate the need to restore the natural integrity of our lands and waters.

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Causes of decline and need for restoration According to estimates from the American Fisheries Society and The Nature Conservancy, nearly 37% of freshwater fishes in North America are greatly reduced in range or qualify for threatened or endangered status. Many native trout and West Coast salmon are listed as endangered or threatened species. What has caused these declines?

Figure 3. Percentage of animal groups at risk within the United States. Note that aquatic groups have a much higher proportion of their species at risk of extinction compared to terrestrial groups. Historically, overfishing and habitat degradation were the principal causes of decline for many trout and salmon species. For most species, overfishing is no longer a problem, but loss of habitat and degradation of remaining habitat remains the primary cause of decline. Introductions of non-native species have grown to be nearly as large a threat as habitat decline. Non-native trout may hybridize with native trout, compete with them for limited resources, prey on their young, or serve as vectors for new diseases and parasites. However, non-native fishes are not the only concerns. Exotic invertebrates, such as the New Zealand mud snail, can cause significant disruption among macroinvertebrate communities. Habitat decline, often caused by a complex suite of problems, remains our most widespread concern but one that can be addressed through restoration efforts. In many trout streams, some combination of livestock grazing, road construction or timber harvest has accelerated erosion rates and deposited fine sediments into spawning gravels. Riparian vegetation – the critical streamside plant community – has been removed or seriously degraded in many areas. As we lose trees along streams, shade decreases, water temperature rises, and the source of

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woody material for improving stream habitat disappears. Over time, deep pools fill in and channels that were naturally narrow and deep become wide and shallow.

Credit: Nat Gillespie, TU

Figure 4. Common stressors for streams are shown clockwise below: channelization, double box culvert impeding fish passage, road along stream bank causing sedimentation, and livestock removing riparian vegetation and adding nutrients and sediment. Perhaps the most disturbed stream systems are in urban areas and low-elevation agricultural areas. If provided with suitable habitat including riparian vegetation, streams meandering through urban areas can be cool and wet attractions for people on a hot summer day. Unfortunately, most streams in and around our cities suffer a myriad of problems stemming from plain neglect to use as wastewater drains. Urban streams often are channelized or buried in culverts. Hydrocarbons from stormwater runoff as well as fertilizers and insecticides from lawns contaminate streams and poison fish populations.

The Conservation Success Index: assessing status and trend The status of our native trout and char provides a good indicator of the condition of the streams and rivers they inhabit as well as broader watershed health. For this reason, trout and char are often the focus of large-scale landscape assessments, such as those conducted in recent years by federal land management agencies including the Forest Service and Bureau of Land Management. Native trout and char are good indicators of environmental conditions for the following reasons. First, they typically are sensitive to degradation of habitats, reduced stream flows 7

and poor water quality. Therefore, their presence is usually a good sign of the quality of the habitats they occupy as well as those upstream areas that contribute to downstream habitat quality. Second, native trout and char occur widely in a number of different river basins and lake systems and they provide vast coverage across the country. Third, scientists know more about trout and char than they do about other species. We have better information on their historical ranges, their present habitats, and causes for changes in abundance and distribution. Therefore, even when stream conditions and water quality cannot be measured directly over large areas, the distribution of native trout and char provides information about broader habitat conditions. In 2004, Trout Unlimited launched a new effort aimed at developing a better understanding of the conservation status of native coldwater fishes across the United States and the waters they inhabit. This effort is called the Conservation Success Index (CSI). Simply put, the CSI provides a framework to compare and report on the various conditions of our native trout and char and to better understand the scope and complexity of threats they face. The CSI builds upon a number of high-quality assessments of native trout in the West that have been completed in recent years by state and federal agencies. In the East, the CSI utilizes a rangewide assessment of brook trout completed by the Eastern Brook Trout Joint Venture in 2006. Part of the CSI includes a new generation of map products, focusing on the subwatershed scale, that facilitate strategic approaches to restoration projects and priorities. The CSI uses a variety of metrics under the four broad categories of historical versus current geographic distribution, population integrity, habitat integrity, and future vulnerability as the basis for evaluating the conservation status of native trout and char.

Table 1. Twenty metrics analyzed in CSI process. Characteristic

Discussion

Comparisons between historical and current distribution Percent of historical Best remaining trout populations occupy 50% or stream habitat occupied more of their historical habitat Percent of historical This may be an important indicator for subbasins occupied remaining genetic and life history diversity Percent of historical This will indicate how well remaining habitat is subwatersheds distributed as compared to historical conditions occupied Percent of habitat Ideally, there should be mixture of headwater occupied by stream habitat and larger stream habitat orders Percent of historical If lake habitats were important to fish lake habitat occupied historically, restoration efforts should include these habitats Population integrity

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Population density

Best adult trout populations are more than 400 fish/mile Larger populations are less vulnerable to loss from drought, flood or wildfire Generally, genetic purity is critical; populations less than 90% pure are compromised

Population extent Genetic purity

Disease vulnerability

Non-native fish often are sources of new diseases or parasites Most trouts have resident stream, lake and migratory habitat types – migratory and lake forms are highly vulnerable to disturbance

Life history diversity

Land stewardship Watershed connectivity

Habitat integrity Amount of habitat in protected areas such as parks, refuges and wilderness areas Instream barriers, dams, and water diversions fragment habitat and disconnect watersheds

Watershed condition

Condition indicators include road density, riparian habitat quality, stream habitat diversity

Water quality

Quality indicators include number of water quality limited streams, number of mines and number of road crossings Includes daily and seasonal fluctuations

Flow regime

Land conversion

Introduced species

Resource extraction

Flow modification Climate change

Vulnerability: future threats Private lands and higher road densities may indicate a higher likelihood of land conversion Likelihood of additional introduced species occurs with increasing access (e.g., roads along streams) and loss of fish barriers Mineral resources, mining claims and oil and gas leases indicate higher likelihood for future activity Pending water rights applications and dam applications indicate future modifications Larger, well-connected populations in high quality habitat will be more resistant to future climate change

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Many fish assessments provide information at various scales, including the stream reach, subwatersheds, watersheds, or larger river basins. We recommend focusing on multiple scales with special emphasis on the stream reach and subwatershed. Subwatersheds (defined as 6th level hydrologic units across the country by the U.S. Geological Survey) range in size from about 10,000 to 40,000 acres. This is an appropriate scale for many restoration efforts because it is small enough to reflect local projects and stream conditions but also clearly links to larger hydrologic units.

Figure 5. A hypothetical fish assessment showing subwatershed conditions and how local population data facilitates status calls. With the CSI process, local population data and a specific protocol designed for consistency of analysis facilitates classifying the population status of individual subwatersheds. Green subwatersheds are strongholds of larger fish populations, yellow subwatersheds contain reduced fish populations, red subwatersheds contain greatly reduced fish populations, and 10

gray subwatersheds indicate historical range from which the fish has been extirpated. Subwatersheds with little or no quantitative data on population status are coded as well. Maps are then produced that paint a color-coded picture of current population status across the historical range of that fish.

PROTECTING AND RESTORING WATERSHEDS The evaluation of native trout populations using the CSI demonstrates the inherent link between the status of native salmonid species and the health of the watersheds that they inhabit. The CSI can be very useful in identifying those watersheds that are a priority for species conservation, but it is up to agency managers, scientists and local conservationists to protect and restore those areas. Knowing your stream: the watershed context H.B.N. Hynes, a well-known stream ecologist, often said that we must not divorce the stream from its valley. For the restorationist and land manager, Hynes was implying that understanding the connections between streams and their surrounding lands is critical for successful restoration. Water provides many of these connections as it flows from headwaters to downstream reaches, and as rain or snow falls on slopes and percolates downhill. Streams also connect to the landscape when floodwaters spill onto floodplains. In many watersheds, human activities such as road construction, dams, water diversions and channelization have severed these connections. The first step in any successful native trout restoration effort is developing a solid understanding of existing watershed conditions: what are the fundamental causes of any problems, how the stream has changed over time, how the stream compares to undisturbed streams of similar hydrology (reference conditions), how natural disturbances such as flood or wildfire shape the stream, and how human-caused disturbances affect natural processes. Many streams will have water quality plans, watershed analysis, or other assessments already in existence that will provide a good start in understanding stream conditions. Stream classifications systems also can assist the manager in understanding the inherent capabilities of their stream. Perhaps the most widely used stream classification system was devised by David Rosgen (see Recommended Reading and Information Sources section at end of guidebook). By classifying a stream it is possible to predict a stream’s behavior and understand hydraulic and sediment relationships for various stream channel types.

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We encourage a holistic approach to stream restoration with the following recommended steps: 1. assess watershed condition and determine the primary factors affecting stream habitats; 2. develop ecologically-sound project goals and quantifiable objectives; 3. design and implement a plan, in concert with partners and appropriate agencies, that addresses the fundamental causes of stress; and 4. monitor and evaluate results and modify actions as needed. Post-project monitoring and evaluation are just as important to success as is any other element of the project--although they often are overlooked. There is no substitute for monitoring a stream through the change of seasons and over multiple years to learn what will work best to correct problems and limitations and how to design more effective management in the future. This is the heart of adaptive management.

Characteristics of healthy trout streams More often than not, trout and char habitat has been incrementally degraded over time by multiple factors. Often degradation has proceeded to the point that it is difficult to determine natural conditions and the inherent capabilities of the stream. Although different streams will vary in their potential, the following table provides general characteristics of healthy trout and char streams. Conservation actions usually seek to protect or restore one or more of these desired characteristics. Characteristic Habitat diversity

Description Roughly equal numbers of pools, riffles and runs should be present. Complex braided channels are preferred over simple, straight streams.

Large wood

Downed trees and other large woody debris functions to create pools, store sediments, and act as a source of needed organic matter.

Water quality

Cool, pollutant-free water is critical to spawning, juvenile rearing and adult resting habitat for many fish o

species. Generally,