G350 Samick Project

Title
Troubled Trout

Author

Robert Samick
American River College, Geography 350: Data Acquisition in GIS; Fall 2008
samick@imail.losrios.edu

Abstract

This article describes the effects of stocking trout in the American River Silver Fork. This hydrological unit is representative of many watersheds currently stocked by the California Department of Fish and Game (CDFG). Topics include a description of the native trout and how their range has been altered, a brief history of how humans influence trout populations, efforts to restore trout populations, and the environmental impacts of reintroducing "catchable sized" trout into a permanently altered riverine ecosystem. Environmental impacts include climate changes, diseases and invasive species, legal guidelines established by the federal Endangered Species Act of 1973, California Environmental Quality Act and the California Endangered Species Act, and the water uses of this watershed.

Introduction

Purpose
The purpose of this report is to evaluate the effects of stocking trout along the American River Silver Fork and recommends that "catchable-sized" trout stocking continue on a limited number basis and “subcatchable trout” be released into this watershed.

Scope

This report analyzes criteria regarding the impacts of releasing "catchable sized" trout into just one of the many streams and rivers in the State of California. Also addressed are problems encountered by introducing/reintroducing catchable size trout into an ecosystem where the native species have been depleted through anthropogenic alterations. It then considers issues and actions implemented over time, up to and including present-day practices. These issues include the resources used to accomplish programs that are required by state law, analysis of revenue created by the fishing industry, advantages and disadvantages of the fish-stocking program at recreational and environmental levels. Recommendations for creating an environmentally efficient and more natural sustainable process for our stream ecosystems are included.

Procedure

Obtaining data for this project was gathered through interviews with California Department of Fish and Game (CDFG) personnel, manuals and textbooks, internet sources, and professional articles on the subject. Telephone interviews with fisheries management personnel provided current fisheries procedures, pathological concerns and preventions, and the status of procedure and practices manuals. Figures for fishing license statistics and fish release data were acquired from the CDFG web site. In addition, California historical population figures were obtained from Wikipedia.

Brief Problem Statement

Advancements in technological procedures allows for increased awareness of the status of our environment. Scientific studies and surveys have brought to light evidence of accelerated environmental deterioration. Before the period of European settlement in California, the natural hydrological process of spring runoff and reduced fall flows controlled populations and communities of the riverine ecosystems. These ecosystems were in their natural balance with (the limited number of) native inhabitants. Beginning in the late 19th century and especially during the Theodore Roosevelt administration (1901-1909), a declaration for water storage in the arid west was established, and the development of water reservoirs began. Without any consideration for what many thought an inexhaustible resource, mainly the environment, dams were placed in many watersheds in California. Because of the extensive nature of water storage in California, this project focuses on a 13.5-mile stretch of river, the American River Silver Fork. The creation of water storage reservoirs along the entire American River watershed, the controlling of water flows, combined with easily accessable roadside fishing locations and the popularity of trout fishing, trout populations soon became depleted. Fish stocking programs were implemented to restore only one aspect of the altered ecosystem, replacing the (revenue-generating) trout.

Background

Trout

Trout is a common name given to a number of species of freshwater fish belonging to the Salmonidae family (Wikipedia). Scientific classification of the Pacific trout is the genus Oncorhynchus, belonging to the salmonidae family of the salmoniformes order. The Rainbow Trout, O. mykiss, and its closest relatives (Cutthroat, Golden, Mexican Golden, Arizona Native or Apache, and Gila Trout) are known as the black-spotted trouts because they are covered with numerous prominent black spots. The spots may cover the entire body or may be more abundant near the tail. There are many subspecies of the rainbow trout as they commonly hybridized with other salmonids. All trout hybridize whenever they inhabit the same water, producing fertile offspring with all manners of confusing color combinations and intermediate characteristics. However, genetic analysis shows no significant genetic differences so they are considered to be of one species.
The average length of a rainbow trout is 12 - 18 inches with some fish growing to 36 inches. The largest rainbow trout on record weighed 43.6 pounds. Trout coloration varies greatly with size, habitat, and spawning periods. Colors and patterns evolved as forms of camouflage based on the trout’s surroundings. Stream dwellers and spawners usually show the darkest and most vivid colors and markings. Coloration and patterns can vary dramatically in trout that live in different environments. While noted for the red or pink stripe along the middle of its sides, this stripe may not be present on all forms.

The Steelhead, O.mykiss irideus, is the ocean-going form of the rainbow trout (anadromous rainbow trout). Steelhead, like the salmon, must return to freshwater to spawn. Unlike the salmon, the steelhead is iteroparous (reproducing more than once in a lifetime). After spawning steelhead return to the ocean to start the migration process once again. Before dams, steelhead would return to the rivers and tributaries of the Pacific Ocean, traveling hundreds of miles inland and up to 1,830 m (6,000 feet) in elevation into the Sierra Nevada Mountains to spawn their next generation. Young steelhead may remain in rivers for up to a year before migrating to the open ocean. Steelheads reach lengths of 20 - 48 inches and on average weigh from 5.5 to 22 pounds, with the record weight being 55 pounds.

Rainbow trout are opportunistic feeders. Their diet is highly variable, with some fish seemingly taking nearly any living thing that drifts or swims by. The bulk of their diet is comprised of insects, small mollusks, and baitfish (i.e. any smaller size fish). The larger a trout grows the more their diet changes from small insects to larger prey such as other trout. When catchable sized trout are planted, they need to maintain a higher nutrient-efficient diet, which puts smaller wild fish at a higher risk of predation. Studies have proven that not only are the wild trout impacted by this direct predation, but they are also impacted through competition for food and habitat, the spread of disease and invasive organisms, and interbreeding which has been found to weaken their genetic quality. A weakened genetic fitness affects a fish's ability to respond to environmental changes such as water flows and decreased breeding success.

Historical Trout Range

Rainbow trout are native to the west coast of North America, from southern Alaska to Durango, Mexico and inland as far as central Alberta in Canada, south to Idaho and Nevada in the United States. Outside of the trout's natural range, it has been transplanted to the lower Canadian provinces, and much of the United States. Worldwide, trout have been introduced in New Zealand, Australia, South America, Africa, Japan, Southern Asia, Europe, and Hawaii.

Range of Planted Trout

Historically, hatchery raised trout have been released throughout the state of California where environmental conditions support growth and survival. (See map for California planted trout range). One part of the analysis for this paper is how far stocked fish range once they have been released. Studies suggest that most fish harvested are caught within 1/4 mile of the planting site. This is because of heavy angling pressure immediately following the release. Some fish were taken up to 1 mile upstream of the planting site and others were washed from 3 to 7 miles downstream. (Butler 46-47).

When Trouble Began…

"There's gold in them there hills". Not the precious metal, but another natural resource that has filled the California State coffers with hundreds of millions, if not billions, of dollars annually. This resource swims in our streams and rivers and is one of the most highly prized game fish, the trout. Not only are trout important as economical and recreational resources they are also known as an "indicator species". Trout indicate the health of a stream by their presence, numbers, and health…or lack of. Trout prefer cold, clean, and often free-flowing water. As an indicator species, when our stream and river habitats change, the trout are the first indicator of an environmental problem. Trout are also known as a “keystone” species, when trout are removed from the community a critical gap is left in the ecosystem, this gap can result in overpopulation in the species the trout prey upon in the food web and a reduction in the populations of the species that prey on the trout.
From the days of the discovery of gold at the Marshall gold discovery site in Coloma, California, the state's population began growing at an exponential rate.

California Historical Populations
Census	Pop.	%+/-
1850	92,957	-----
1860	379,994	310.4%
1870	560,247	47.4%
1880	864,694	54.3%
1890	1,213,398	40.3%
1900	1,485,053	22.4%
1910	2,377,549	60.1%
1920	3,426,861	44.1%
1930	5,677,251	65.7%
1940	6,907,387	21.7%
1950	10,586,223	53.3%
1960	15,717,204	48.5%
1970	19,953,134	27%
1980	23,667,902	18.6%
1990	29,760,021	25.7%
2000	33,871,648	13.8%
Est.2007	36,553,215	7.9%

Throughout this process of growth, the state's natural resources, especially the fragile ecosystems of the trout, were being altered and depleted. Over the past 200 years, humans have inadvertently degraded and destroyed considerable amounts of fish habitat (Chiras 311).
With California's growing population and the need for a release from urban tension, the impact of the human predator on fish populations continues to intensify (Chiras 307). Following the law of diminishing returns, the harvest of fish easily overcame the natural reproductive numbers resulting in depleted fisheries.
In an effort to fill the niche left by the harvesting of trout, and to increase/improve recreational fishing opportunities, restocking programs began in the late 1800s. Originally, the stocking was accomplished by frontiersman and later, systematically, by the newly formed California Sierra Club (1892). Not only were waters that once held trout restocked but many mountain lakes and streams that were devoid of fish became stocked. Research studies in the early 1990s found “entire ecosystems were being altered by introduced non-indigenous trout species into trout free waters”. The California Department of Fish and Game (CDFG) began rearing and stocking fish in the inland waters of California when the state of California enacted legislation to restore and preserve fish in state waters in the late 1800s. Officially, the DFG assumed responsibilities for the state stocking operations in the 1920s. The California State Fish Hatchery System was renovated and expanded in the late 1940s and early 1950s to "meet the pent-up demand for trout". (Calhoun 1965). To answer questions about the validity of the program, namely the costs, the CDFG initiated the "Catchable Trout Study". This study was designed to measure angler success and the effectiveness of the program. The study showed that roughly half of the states anglers pursue trout. Of these anglers, it was found that heavy angling pressure depleted trout in easily accessible roadside waters. The "catchable sized" trout program was created to replenish these easily harvestable fish.
CDFG Hatchery Locationss

The CDFG operates 21 fish hatcheries throughout the state that participate in the spawning and rearing of many different subspecies of the salmonidae family. 13 hatcheries are for rearing inland trout species, namely the rainbow trout.
Today, environmental studies and survey information is available which leads to the controversial subject of the CDFG trout stocking programs. In a letter to the CDFG, the Pacific Rivers Council (PRC), relating to the restocking of native fish species and the introduction of non-native fish species, has compiled numerous studies, dating back to 1981. Armed with the findings of these studies, the PRC notified the CDFG; “to express our concerns about the state’s fish hatchery and stocking system and to recommend needed changes that will ensure that the system does not negatively impact California’s native biological diversity”. (PRC July 2006). Additionally, the PRC filed a lawsuit in October 2006 (with the Center for Biological Diversity) over the DFG’s failure to consider the impacts of fish stocking on sensitive aquatic species throughout the state. Because of this lawsuit, Patrick Marlette of the Sacramento Superior Court ruled that California’s fish stocking program must comply with the California Environment Quality Act (CEQA). The program is currently under review to determine compliance.

The American River Silver Fork

The American River Silver Fork flows down the ancient tertiary drainage from an elevation of 2,210 m (7,252 feet) at the Silver Lake dam. The drainage follows a northwesterly direction for approximately 13.5 miles, to its confluence at an elevation of 1,201 m (3,937 feet). The Silver Fork empties into the American River South Fork near the small town of Silver Fork, located on US Highway 50.

Approximately 7 miles of the river is easily accessible by road. This stretch of river has endured all the signs of environmental degradation from human use. Well-worn trails run the length of the roadside waters. Trash and "toilet flowers" can be seen, especially near heavily used, primitive, streamside campsites. Recently, vehicles have been restricted from access to the streamside of the road to help reduce soil compaction, stream bank erosion, disturbance of the natural flora and discouraging easily accessible primitive streamside camping.
Only catchable sized trout are released into the roadside section of the Silver Fork, the locations of the stockings are left up to the discretion of the stocking truck driver (Starr). Exact locations are usually not disclosed to discourage "truck following" anglers. Unethical people will even go as far as stretching nets across the river and scoop out the trout after the truck has left.
Trout released into the Silver Fork for the past eight years have been catchable sized rainbow trout. The numbers of fish released have been approximately 36,000. There have been a limited number of releases of subcatchable trout as part of "Trout in the Classroom" programs and other environmental studies. Brown Trout, Salmo trutta, have also been introduced as part of a University of California Davis study.

Revenue

The fishing industry in California is a multibillion-dollar year-round industry that draws anglers to the mountains in favorable weather and to the lower elevation waters during the winter months. The list of expenses endured by anglers can be limitless, just stop by any sporting goods store, and visit the fishing equipment section. Monies spent by anglers span more than just the fishing equipment they buy for themselves and their families. Other industries include consumable items, (groceries, snacks, beverages etc.), fuel, lodging, travel, camping gear and fees, restaurants, and, of course fishing licenses. Along with the basic resident fishing license, many created "special category stamps" (additional fees), like the Second Rod stamp, Bay -Delta Enhancement stamp, Steelhead Report card, etc. are available or required for certain fishing activities. (See the DFG fishing license handbook for a complete list). Only approximately one third of the money generated is mandated to be returned to the fishing programs of the state. The graphs below indicate revenue generated from 2000 to 2008, compared to the increase or decrease in the number of resident fishing licenses sold. Note how the annual fee increase recovers "lost revenue from a decrease in sales" from the previous year. Why the decrease in fishing license sales? No fish! No fisherpersons! No license sales! Solution: fish stocking programs.


Fishing Licenses Sold	Revenue Generated

Environmental Impacts

Stocking trout impacts more than just the native and wild populations of trout. Trout stocking also affects other native fish, amphibians, and flora. Scientific studies have shown that stocking trout has brought about a decline in numerous native species. The Pacific Rivers Council (press release 2008) states three main problems that fish stocking creates, the listed problems are:

Fish stocking can spread disease and invasive species or unwanted fish.
Stocked fish prey on and compete for food and habitat with native species.
Stocked fish disrupt the food web and alter natural ecosystem processes to the detriment of native species.

The PRC also finds that "many of the native fish and amphibian species listed under the Endangered Species Act, a substantial number of them are threatened by fish stocking". Impacts of stocking trout are not easily reversed. Trying to remove non-native fish causes further ecological harm from the removal process such as the collateral damage caused by the use of picicides killing more than just fish.

Threatened and Endangered Species and the Endangered Species Act of 1973

The purposes of the Endangered Species Act of 1973 are “to provide the means whereby the ecosystems upon which endangered species and threatened species depend may be conserved, to provide a program for the conservation of such endangered species and threatened species, and to take such steps as may be appropriate to achieve the purposes of the treaties and conventions set forth in subsection (a) of this section.” (ESA of 1973). Also, “... and the species of fish, wildlife, and plants are the aesthetic, ecological, educational, historical, recreational, and scientific value to the nation and its people” (Sec. 2. Findings. (3) ESA of 1973). The Mountain Yellow-Legged Frog, (Rana sierrae), and the Foothill Yellow-Legged Frog, (Rana boylii), are listed by the Department of Fish and Game as a "Species of Special Concern" (SSC) and therefore need to be protected. The American River and its tributaries fall within the range of these two species. The stocking of trout in the American River, including the American River Silver Fork, is currently under review to have stocking suspended until further studies are completed.

Climate Changes

Global warming is predicted to increase the likelihood of drought conditions and cause a reduction in the natural water supply to rivers and streams (watersheds). With a warmer atmosphere, more precipitation falls as rain and not snow. Instead of water being stored in snow and enlarging glaciers, a faster runoff of rainwater occurs and does not allow for natural infiltration/seepage through the soil. In a study conducted at the geology department at Portland State University, Hassan Basagic discovered that Sierra Nevada glaciers have lost an average of 55% of their surface area from the early 1900s until 2004. This trend is expected to continue. With higher annual air temperatures and runoff from rain, water temperatures rise; this creates a drop in dissolved oxygen levels, which can suffocate fish. Another aspect of warmer water temperatures involves the spawning cycle of trout. Cool water triggers spawning activity and incubates trout eggs (Kinsella 12). Without the properly cooled water, spawning cycles may be interrupted. In addition, non-seasonal high water flow releases scour streambeds, disrupt natural insect cycles, destroy fish "redds" (fish nests) and "flush" the small frye and fish from the system.

Disease and Invasive Species

"Viruses, bacteria, and parasites are what we look for in trout", replied Mark Adkinson, Ph.D. Fish Health Lab Lead Pathologist, CDFG Nimbus Fish Hatchery, when asked about the pathological concerns of hatchery raised trout. Mark stated that while diseases are still of major concern and monitoring of farmed and wild trout, a new, possibly greater threat to the riverine ecosystems has been the invasive species of Quaqqa muscles, Zebra muscles, and New Zealand mud snails, which can quickly reproduce by the millions. These invasive species can alter the riverine ecosystems at the benthic level, effectively eliminating the food web and leaving a river barren. The spreading of these invasive species occurs by stocking fish and inadvertently being transported by anglers. Anglers spread the invasive species when the invasive species attach themselves to anglers gear or through improper cleaning of fish. When the invasive species spread to fish hatcheries, hatchery raised fish may consume them or the invasives may be transported in the stocking truck water from the hatcheries. Subsequently, when the fish are released they effectively spread the harmful invaders.

Spreading of New Zealand Mud Snails

One disease of major concern because of its introduction and spreading, mainly in central California, is Myxobolus cerebralis (Mc), more commonly referred to as "Whirling Disease". Whirling disease is actually a parasitic infection that infiltrates the head and spinal cartilage of fingerling trout Myxobolus cerebralis causes skeletal deformation and neurological damage to salmonids.

Hydrologic Troubles for Trout

The construction of six water storage reservoirs, both, above, and below the American River Silver Fork, has forever altered its natural ecosystem. Two reservoirs above the Silver Fork, (Silver Lake and Caple's Lake), control water flow levels while four reservoirs below the Silver Fork, (Nimbus Dam, Folsom Lake, Chili Bar and Slab Creek Reservoir have extirpated the natural migration and spawning of steelhead (the natural method of stocking trout).

Hydrologic flows from Silver Lake and Caples Lake, recorded by the United States Geological Survey since 1922, have shown yearly declines in the rate of discharge from these lakes into the Silver Fork drainage. The charts below show historical discharge rates (1923-2007) compared to discharge rates for 2007, in cubic feet per second.


Caples Lake Discharge	Silver Lake Discharge

The records of the rate of water discharge does not take into account the controlling agencies reasons for discharge rates, such as recreational kayaking purposes, water needs, drawdown for emergency dam repairs, or heavy runoff years.

Methods

Many issues confront the actions taken in the use of the American River Silver Fork. Pressing and present issues, currently under review, are being evaluated for compliance with the Environmental Protection Act of 1973 (EPA of 1973), The California Endangered Species Act (CESA), and California Environmental Quality Act (CEQA). Former practices of planting "catchable size" trout have been temporarily suspended until the completion of an Environmental Impact Report/Environmental Impact Statement (EIR/EIS), currently being conducted by the California Department of Fish and Game. Areas in need of research involve a wide range of environmental impacts from the hydrologic use of the watershed to recreational activities, including procedures mandated by federal and state laws. Results of acquired research were presented earlier in this paper.

To evaluate the question: "How do stocked trout affect the American River Silver Fork?” is not an easily answered question through the application of the Geographic Information System. The use of a GIS in analyzing this question gives the reader a general idea of the geographical area of the American River Silver Fork.

To display geographical information, spatial data using a raster data set was downloaded from the US Geological Survey (USGS) site http://gisdata.usgs.net/ned/. Hydrological and road layers added to enhance the map were obtained from CaSil: CA Base Map: Project Filelist at http://casil.ucdavis.edu/frs/?group_id=119. The coordinate system used for the raster dataset and vector layers is GCS_North_American_1983. The datum applied is D_North_American_1983.

Sensitive frog species range data was downloaded through CaliforniaHerps.com. Georeferencing the frog range with the American River Silver Fork hydrological unit using county and state boundaries displayed the range of the Mountain Yellow-Legged frog encompassed the entire AR Silver Fork. The Sierra Madre Yellow-Legged frog, also known as the Southern Mountain Yellow-Legged Frog does not inhabit the American River Silver Fork watershed. Biologist determination of stocked trout ranged from the point of release; 1 mile upstream to 3 - 7 miles downstream effectively covers the full 13.5-mile stretch of river with no need for buffering or clipping of map data for analysis purposes.

Results

The results of data collection began with researching the different effects hatchery raised fish could have on an established fishery of natural succession when introduced as larger predators. The acts of larger fish feeding upon smaller fish, either wild or stocked, have been documented in studies and through personal observations. Personal observations include the process of eviscerating and examining stomach contents from harvested trout. In addition, immediately after harvesting, many times the tails of smaller fish could be seen protruding from the predator fish’s throat/stomach. A high number of catchable sized hatchery fish, released into a stream-sized stretch of water would be detrimental to the naturally established populations. Not only do the larger released trout prey upon the smaller fish they also feed on other sources of available foods such as crustaceans and insects, reducing available food sources for the entire community. Releasing hatchery-raised fish also has the potential of spreading viruses, bacteria, parasites, and invasive species into an ecosystem where there may be no natural defense mechanisms to eliminate these parasites. Decreasing water volumes has also had a detrimental effect on both the wild and introduced fish. Water release data obtained from the USGS for Silver Lake and Caples Lake shows a considerable reduction in available water as spring runoff and glacial melting. The effects of higher annual temperatures have shown less snowpack storage and higher rainfall runoff. This relates to less water, less fish habitat, less food, and ultimately less fish.

Another effect of releasing catchable sized trout into streams are the attention they raise to attract anglers. As the population of California continues to grow, the number of anglers grows also. The DFG’s responsibility to create recreational opportunities has led to an increase of providing fish for anglers to catch. As angler "catch rates" become more successful through advanced fishing technologies and skills, the number of times they go fishing also increases. Humans not only degrade the environment but more specifically, they pollute waters, spread invasive species, erode stream banks (eroding streambanks reduce water clarity), and disrupt streambeds. The disruption of stream beds dislodges redds and other benthic dwellers from their natural habitat.

Gathering data on threatened and endangered species resulted in no conclusive evidence that any riparian inhabitants have been affected along the American River Silver Fork from stocking trout. Although the Mountain Yellow-Legged Frog’s range encompasses the entire AR Silver Fork, I could find no studies conducted on this species along this watershed. The only data gathered concerning the Mountain Yellow-Legged Frog was its listing as a species of special concern by the State of California and it is currently being "considered" as a candidate for listing on the Federal EPA of 1973. Analyzing the actual listing as a"Species of Special Concern", the Mountain and Sierra Madre (Southern Mountain) Yellow Legged Frogs, neither has any legal standing as endangered or threatened (only considered). Therefore, until research concludes the need for listing these species on the endangered species list, the stocking of trout has not shown any adverse effects on local populations of the frog.

Analysis

The transformation of the American River Silver Fork from a natural flowing ecosystem into a diverse drainage of water storage (top priority) and recreational use has had detrimental effects on this ecosystem. The anthropogenic changes bestowed upon this river are irreversible from a human needs point of view, namely water storage. This river encompasses close to a 50/50 diversity with the stretch of river from Silver Lake to the Fitz-Rantz Bridge having no road access and the lower reach having approximately 7 miles of road accessibility with a few deep canyons along the roadside and an almost inaccessible deep canyon mile at the mouth. The American River Silver Fork offers a diverse fishing opportunity for anglers seeking a "quality fish" fishing experience in solitude or fish of lesser quality, easy accessibility, and a higher catch rate.

Successful data acquisition for this project proved to offer in-depth statistics for some issues while other datasets were more general, covering geographically similar watersheds.

Difficulties in assessing the actual impact of stocking trout are left up to interpretation of research data, when and how in-depth the studies were designed, the general or specific locationsof the studies, and the decision-makers. With the California Trout Stocking program currently under review, new research studies may be able to determine to a greater degree of precision, per watershed, the impacts in question. Striking a sustainable use balance should be the goal of this and other watersheds that have already encountered irreversible ecological damage. Here, the author discusses the results and gives details on what was successful, what was difficult, and how difficulties were overcome or how alternatives were selected.

Conclusions

Research into the question determining the affects of stocked trout along American River Silver Fork has led to the following conclusions.

The rainbow trout is a native inhabitant of the west coast of North America, including coastal rivers and their tributaries inland, up to approximately 6000 feet.
The creation of water storage reservoirs has severely limited the range of the rainbow trout.
Fish hatcheries were built to help replenish fish where their natural range was limited by the creation of water storage facilities.
The overstocking of "catchable-sized" trout has proven to have a negative impact on wild fish, especially when planted in numbers greater than what the natural reproduction would produce to meet a natural carrying capacity of the river
Angler success rates have severely affected the natural reproductive rate of the trout, especially as fishing gear continually improves and fishing skills are honed.
Angling success exploits the river to heavier fishing pressures as word spreads, especially with the availability of modern communications (posting planting schedules in papers and through Internet resources.)
Current stocking programs are undergoing scrutiny to enforce practices mandated by State and Federal laws.
Environmental degradation from heavy human use has had a negative aesthetic and biological effect on easily accessible reaches of the Silver Fork.
The controlling of water storage and releases to accommodate climate changes, recreational use (kayaking), and emergency dam repairs have shown a negative impact on the river.
. High water flows during "out of season" releases scour the streambed and flush the river, disrupting the entire river ecosystem.
The reduction of snowpack storage of water has lead to decreased natural water flows with less seepage through the soil into the river.
To some extent, there is a need to release fish into the American River Silver Fork, because of the reasons stated above. The size and number of fish being released should be evaluated to determine what extent and limitations the California Department of Fish and Game needs to maintain to create a sustainable use balance for all uses of the American River Silver Fork.

References

Adkinson, Mark. Telephone Interview. 13 Nov. 2008

Advocating for Fish Stocking Reform. Pacific Rivers Council. 3 Nov. 2008. http://www.pacrivers.org/fish%20stocking.cfm

Butler, Robert, David Borgeson. ‘California “Catchable” Trout Fisheries.’ Fish Bulletin 127. 1965.The Resources Agency of California, Department of Fish and Game. 9 Oct 2008. http://content.cdlib.org/xtf/view

Chiras, Daniel, John P. Reganold. Natural Resource Conservation. 9th ed. NJ. Pearson Prentice Hall. 2005.

Court Orders Review of California’s Harmful Fish Stocking Practices. Earth Share-Oregon. 9 Oct.2008.http://www.earthshare-oregon.org/our-groups/profiles

Kinsella, Stephen. Trout in Trouble. July 2008. Natural resources Defense Council. http://www.nrdc.org/globalWarming/trout/contents.asp

Starr, James. Telephone Interview. 10 Nov. 2008

The Need for Fish Stocking Reform in California. Oct. 2006. Pacific Rivers Council. 3 Nov. 2008. http://www.pacrivers.org

Water Data Reports. Unites States Geological Survey. 10 Nov. 2008 http://wdr.water.usgs.gov/wy2007/pdfs.pdf