Fewer than 1% of Pennsylvania’s historically native brook trout subwatersheds are intact. Brook trout are listed by U.S. Fish and Wildlife as a species of greatest conservation need in Pennsylvania. However, the Pennsylvania Fish & Boat Commission has no special regulations or management areas to protect this native fish. (Henry Ramsay photo)
March 03, 2023
By James Suleski
This article was originally titled "Pennsylvania Natives" in the "The Migration" column of the April-May 2023 issue .
Pennsylvania isn’t doing enough to save its remaining native brook trout. A 2006 Eastern Brook Trout Joint Venture (EBTJV) report stated that Pennsylvania had fewer than 1% of historically wild native brook trout sub watersheds “intact” (>90% occupied). If you guessed that poor land use practices and warming water were to blame, you would be only partly right. According to the EBTJV, those are the top two issues. However, they rate nonnative trout introductions as the third biggest issue—ahead of urbanization and sedimentation. Per EBTJV, “Regional experts cited competition and predation from brown trout as the third highest ranked impact [to native brook trout] across the state.”
It’s time we face the threat that nonnative trout pose to wild native brook trout in Pennsylvania. Brown and rainbow trout are listed by the International Union for Conservation of Nature on their top 100 world’s worst invasive species list due to harming many native species around the world.
Wild native brook trout, on the other hand, are listed as a species of greatest conservation need in the 2015-2025 Pennsylvania Wildlife Action Plan. “Conservation” aims to maintain biodiversity because ecosystems that have more different species are less susceptible to instability. Invasive species decrease biodiversity and destabilize ecosystems. This is why there is no such thing as conservation of an invasive species.
While the impact of invasive trout species may surprise some, fisheries scientists are well aware of the threat they pose. They use a model called the five-component framework to look at factors governing stream-dwelling trout populations. The five components are: hydrology, connectivity, water quality, habitat, and interactions with other species. Fisheries scientists view harmful interactions with nonnative trout species as an impairment, just like sediment, animal waste, or warm water.
It is well known that if one of the five components in this model is fixed, for example habitat, and another dominant limiting component like interactions with invasive species is ignored, the restoration will likely fail.
Are some streams too warm or degraded to support brook trout? Absolutely. However, the seven-day upper lethal temperature difference between brown and brook trout in one study was less than 1 degree Celsius.
Many cold, forested streams in Pennsylvania are home to nonnative trout, while streams polluted with acid mine drainage, which have proved too acidic for nonnative trout, do support wild native brook trout. The reality that nonnative trout occupy cleaner, healthier streams than native brook trout in some cases forces us all to acknowledge that tunnel vision on clean, cold water and habitat ultimately fails for wild native brook trout if invasive trout are ignored.
Research has shown that brown trout prevent native brook trout from using small, critically important areas of cold water called “thermal refuges” needed for surviving warm water. A study done by Dr. Huntsman et al. in West Virginia showed “habitat restoration could only be beneficial for native brook trout when nonnative trout were absent from the restored sampling area.”
This is because nonnative trout have been shown to exclude brook trout from those thermal refuges and other prime habitats, as demonstrated in multiple studies. Further, these nonnative trout can reduce or eradicate native brook trout by excluding them from any new prime habitat created by stream enhancement projects. Instead, nonnative trout use improved stream habitat to expand their own populations.
(Trey Piper photo) An example of this would be the Kiap-TU-Wish chapter’s 2.11-mile habitat enhancement project on Pine Creek, Wisconsin, which resulted in a shift from originally 94% wild native brook trout and 6% wild nonnative brown trout, to a 70% decrease in the brook trout and more than a 3,000% increase in the browns. Despite the habitat improvement, this shows a trajectory of a complete loss of the brook trout population in the future.
There is even research that shows nonnative trout can function as a barrier to movement for wild native brook trout—much like a poorly designed culvert. A study that removed nonnative brown trout from Coolridge Creek in Minnesota demonstrated that after their removal, brook trout moved downstream, increased in number, and displayed increased growth rates.
SIDEBAR: Trout Classifications Native: Indigenous; originating or occurring naturally in a particular place.Nonnative: Not indigenous or not historically present.Invasive: Nonnative + causing ecological or economic harm.Wild: Born in the wild of naturally deposited eggs.Stocked: Fish or eggs from a hatchery planted in a stream.Habitat Alone I eventually came to the realization that focusing only on clean, cold water and improved habitat while ignoring invasive species often favors proliferation of wild nonnative trout that can harm the native fish and other aquatic organisms we’re trying to protect or restore. This is what led me to join the Pennsylvania chapter of the Native Fish Coalition (NFC). While water quality and habitat are important for native brook trout, the NFC has taken on the underserved task of public awareness of this issue. Our chapter does conservation work with multiple species of native fish. However, a current focus is public education and advocacy in efforts to bridge the gap between established fisheries science on the harmful effects of nonnative trout species and how native brook trout are currently managed in Pennsylvania.
In Pennsylvania, native brook trout enjoy the same protections as wild brown trout where they exist in Class A trout streams. In streams where the trout biomass does not meet Class A status, the state can and does stock hatchery trout on top of native brook trout. (James Suleski photo) Despite the EBTJV ranking invasive brown trout as the third largest threat to native brook trout in Pennsylvania, the state still stocks brown and rainbow trout, directly on or near wild native brook trout in many watersheds statewide.
Further, there are currently no specific regulations or management areas for native brook trout in the state. The Pennsylvania Fish & Boat Commission only has “wild trout” management stream sections where the goal is to have both native brook trout and the nonnative brown trout that are actively displacing them.
In the upper section of Big Spring Creek—a potential native brook trout management zone for Pennsylvania—nonnative rainbows are still protected with catch-and-release regulations.
And just downstream, hatchery brook trout capable of causing harmful genetic pollution are still stocked by the state. Given the vast amount of research showing nonnative trout can harm wild native brook trout, managing for “wild trout” means in many cases managing for displacement of native brook trout.
These “wild trout” stream sections are designated by electroshocking them in the heat of summer. When these surveys find a enough wild trout to meet the state’s Class A status, it generally gets protections against stocking. Stream sections with significant numbers of wild native brook trout, but with not enough to meet Class A status, do not have any protection from stocking.
Even when Class A stream sections are protected from direct stockings, harmful hatchery trout are regularly stocked immediately downstream of these sections, and run up into them in large numbers. A study of 78 streams in northwestern Pennsylvania showed streams were 12 times more likely to have brook trout than brown trout when a barrier was present between a given sample site and the nearest downstream brown trout stocking location. This in-state example shows we cannot coherently manage a stream section for conservation of wild native brook trout when they are connected to stocked invasive trout fisheries. Stocked trout move.
Gene Flow Wild native brook trout move as well, and research in Pennsylvania has shown that reflecting it in how we manage them is critical to their success.
Dr. Shannon White et al. discovered that wild native brook trout in the Loyalsock Creek watershed require the use of large downstream waterways to leave their tributary and travel to other tributaries containing wild native brook trout so they can share their genes with them through spawning. This “gene flow,” makes populations more genetically diverse and helps prevent harmful inbreeding.
Each different gene is potentially a tool to be used to endure threats to survival like climate change. This gene flow creates genetic diversity that gives wild native brook trout a better tool box to adapt to threats. It is maximizing this adaptive capacity that should be the goal of those managing native brook trout.
These fish have the intrinsic ability to solve many of their own problems over time by genetic adaptation, but to maximize it, the entire watershed—made up of different brook trout streams connected by a larger waterway—must be managed for their use and movement. Obviously, stocking nonnative trout in these larger streams is detrimental.
Another important function of these large downstream waterways is providing food abundance for native brook trout, which allows larger potential growth than in headwater streams. However, if stocking nonnative trout displaces brook trout from this larger food-rich habitat, it relegates them to infertile headwater streams.
Regional Examples Unfortunately, the state of Pennsylvania still stocks many of these important connective waterways with extremely dense populations of hatchery-raised nonnative trout. Other states have acted on scientific research and taken appropriate action to manage entire watersheds for native brook trout.
West Virginia, for example, has selected multiple watersheds to manage entirely for wild native brook trout with catch-and-release regulations and no stocking. Here is a quote from West Virginia fisheries manager and biologist David Thorne in a 2017 article from the WV MetroNews about a watershed-scale management program that provides almost 200 miles of stream dedicated to wild native brook trout.
“This is a watershed idea based on a lot of the research I and other people have conducted. Connectivity between the tributaries and main stems is how we see increased growth in fish. They have larger habitat, more food available, and can move to different habitats during different parts of their life cycle.”
Brook trout need more than isolated headwater streams to survive. They need the connectivity of larger watersheds to promote “gene flow” and to take advantage of these food-rich areas to grow larger. (Dennis Pastucha photo) Maryland has also integrated this science showing the importance of managing entire watersheds into its fisheries management by creating the Upper Savage River Special Brook Trout Management Area. This 100-mile+ Upper Savage River watershed has catch-and-release regulations for wild native brook trout based on research showing this would decrease mortality and still allow for a year-round fishery. Also, there is almost no stocking except for a small number of nonnative rainbow trout. The results of watershed-level management here have been incredible. Wild, native brook trout are living to seven years old and commonly reaching sizes the mid teens in inches—truly, a trophy native brook trout fishery.
While fisheries management of wild native brook trout in other states is far from perfect, it has been frustrating to see other states hit home runs with special brook trout management zones, while in Pennsylvania there are no specific regulations or management areas for native brook trout.
A wild native brook trout management zone encompassing an entire watershed would be a great place to start for Pennsylvania. It should have multiple distinct native brook trout populations, catch-and-release regulations, and no stocking. Research and successful projects from out of state tell us these protections at watershed scale are a recipe for success.
Currently no authorization is required for the private stocking of trout in Pennsylvania waterways, leaving the Pennsylvania Fish & Boat Commission to guess where private hatchery trout are harming wild native brook trout populations. The commission originally proposed a stocking authorization to monitor private stocking and control the spread of invasive species and diseases—something most other Northeastern states have done. However, after proposing the authorization, the commission encountered opposition from private hatcheries and still does not have the power to approve or deny private stockings. Instead, they now require only a notification of private stocking to track where it occurs. They reported needing “years” potentially before implementing a required stocking authorization.
The Native Fish Coalition , Trout Unlimited, and many other groups and individuals are calling for significant and badly needed stocking reform in Pennsylvania. A big reason it has not succeeded to date is that the general public is largely ignorant to issues concerning fish in general, let alone native ones.
Lenny Lichvar, the current Pennsylvania Trout Unlimited president says, “The challenge is to use resource science to create and justify a generational culture shift away from long accepted tradition, and the political science that empowers it, toward a more native-resource-friendly approach. The current test of meeting a portion of that challenge is to gain more public support to achieve acceptance of a much-needed stocking authorization and the total elimination of hatchery-raised brook trout. So far, the failure to garner enough pubic effort to fully achieve both of those goals at the agency level points to the need to find more innovative methods to translate new science, that is currently understood by a few, into a format that can be more easily comprehended and then actively supported by the many that may lead to a new and better tradition of native resource management.”
Ultimately the abovementioned research demonstrates that Pennsylvania needs large-scale reform to its public and private stocking policies. But until there is more widespread education, meaningful stocking reform initiatives, and a change in messaging surrounding native fish coming from the Pennsylvania Fish & Boat Commission, the majority of the general public will continue to be okay with stocking hatchery trout and management of wild invasive species where we could and should be conserving wild native brook trout.
Dr. James Suleski is a board-certified internist and lives in Hershey, Pennsylvania. He is a board member of the Doc Fritchey Trout Unlimited chapter in Pennsylvania, and he’s also a board member of the Pennsylvania chapter of the Native Fish Coalition.
Addendum The following addendum was created to connect readers with a wealth of reliable and trusted sources of fisheries science information about native brook trout relevant to their management. You can quickly scroll through each topic reading take home points from publications (in quotes) and context I have provided (not in quotes). Or click the link to each individual study/publication to read it in its entirety and take a deeper dive into a topic of interest to you.
Many of the below resources are links from the Eastern Brook Trout Joint Venture website. There is an enormous wealth of wild native brook trout fisheries science, restoration projects, mapping(many interactive GIS maps), and more featured on this site. I highly encourage you to browse the website and familiarize yourself with all it has to offer you for everything wild native brook trout conservation. Also there are links to follow on facebook and twitter on the site for even more great content from them.
https://easternbrooktrout.org/
Native Brook Trout Status and Threats Native Fish Coalition FAQ/Terminology (wild, native, stocked) Five Components of Streams Model Stream Habitat Needs for Brook Trout and Brown Trout in the Driftless Area Authors: Douglas J. Dieterman, and Matthew G. Mitrob “Hydrology, water quality, connectivity, biotic interactions and physical habitat/ geomorphology regulate fish population abundance in streams. Management of only one component will be ineffective if another component limits the population” “An important implication of the five-component approach is that management emphasis on only one component, such as restoring physical habitat/geomorphology, may still fail to protect and enhance fish populations if other components, such as water quality or biotic interactions, are also limiting to a population.” Harmful interactions with invasive trout species are biotic interactions Evaluating Trout Stream Restoration Benefits: A Case Study at Pine Creek, Wisconsin Author: Kent Johnson This case study I have shared is an unfortunate example of what can happen when one of the 5 components of streams model components, such as biotic interactions (invasive trout species), is not factored into a stream restoration project originally intended to help native brook trout by improving some of the other 5 components. In this example a stream project intended to help native brook trout actually helped brown trout reduce their numbers and may ultimately result in elimination of native brook trout from the stream. “On average, pre-restoration trout abundance in Pine Creek was 3,991 trout/mile, with brook and brown trout present in a 96%:4% proportion.” “Within eight years post-restoration, numbers of brook trout per mile decreased by 70% (3,800 to 1,200), while numbers of brown trout per mile increased by 3,150% (175 to 5,600). A continuation of this trend may lead to the loss of the brook trout fishery.” Brook trout listed as a species of greatest conservation need in this plan developed in large by PA fish and boat. “Action: Remove brown trout in areas managed for brook trout. Objective: Reduce competition.” Despite above recommended actions, PA does not have any invasive trout removal projects to date listed on a recent EBTJV summary chart detailing invasive trout removals and native brook trout reintroductions by state. A large compilation of research shared with the general public online via EBTJV website that touches on many different topics related to conservation of native brook trout. A science communication website built by brook trout ecologist and PhD Dr. Shannon White. It takes fisheries science concepts important to native brook trout conservation and translates them into language understood by the general public. “The purpose of The Troutlook is to take research an extra step and make it more accessible to the general public. We believe that conservation, while often guided by science, can only be enacted by the public. However, scientists do a poor job of fostering this partnership by hiding important information behind privacy walls and complicated jargon. We can do better. In fact, we must do better. Brook trout, and countless other native species, are depending on us to get this right.” The Negative Effects of Stocking Invasive Trout Downstream of Brook Trout in Pennsylvania Why Managing Entire Watersheds for Native Brook Trout, Not Just Stream Sections, is Critical to their Success A novel quantitative framework for riverscape genetics Authors: Shannon L. White, Ephraim M. Hanks, and Tyler Wagner “Accordingly, brook trout management efforts are rarely put into a metapopulation context, and the significance of conservation actions or disturbance events are generally considered to be restricted to a single stream. However, results of the BGR model question the validity of these assumptions for brook trout in Loyalsock Creek with results suggesting that mainstem Loyalsock Creek serves as a seasonal movement corridor that increases population connectivity across relatively large spatial scales. Consequently, changes in habitat suitability at one site can have significant, unintended consequences to large-scale metapopulation genetic structure and demography (Letcher et al. 2007). In addition, maintaining the ecological integrity of habitats that are only seasonally suitable for brook trout occupancy appears to be critical for maintaining gene flow and population connectivity in this system.” Brook Trout Restoration Authors: J. Todd & Eric P. Merriam “Historically, most studies of brook trout population ecology have focused on isolated populations within relatively small headwater streams. There is emerging evidence, however, that brook trout population dynamics may be influenced by factors and processes operating at the drainage network scale (Petty et al. 2005, 2012). We have found that the factors limiting brook trout populations vary depending on the location of the focal population within the drainage network. For example, headwater stream populations may be strongly limited by acidification and reduced reproductive success. However, populations in medium sized streams are dependent on immigration from smaller streams, and consequently, may be limited by the productivity of nearby streams and by dispersal barriers. Finally, brook trout populations in larger rivers are fully dependent on highly mobile individuals that move between headwater spawning habitats and larger river foraging habitat (Figure 6). These populations can be strongly limited by poor habitat, high water temperatures, angler harvest, and dispersal barriers. If brook trout populations are influenced by watershed scale processes rather than localized stream segment scale processes, then it is likely that: 1 — factors limiting populations in one area will affect populations in another area; 2 — the overall metapopulation will be limited by multiple rather than single factors; and 3 — connectivity among subpopulations will be more important to population viability than local habitat conditions.“ DNR looks to enhance native brook trout waters Author: Chris Lawrence, Metro News Quote from biologist David Thorne of West Virginia DNR in regard to their watershed level brook trout management zones that are catch and release for native brook trout with no stocking allowed. “They need to be a large, contiguous and well connected native brook trout watershed,” said Thorne. “This is a watershed idea based on a lot of the research I and other people have conducted. Connectivity between the tributaries and main stems is how we see increased growth in fish. They have larger habitat, more food available, and can move to different habitats during different parts of their life cycle.” The Upper Savage River Brook Trout Special Management Area – A Decade of Learning! Authors: Maryland DNR Details the success story of the Upper Savage River Brook Trout Special Management Area in Maryland. Here watershed level management with catch and release regulations and very little stocking has allowed the Upper Savage River Watershed native brook trout population to survive to 7 years old and grow into the mid-teens in inches. Invasive brown trout exclude native brook trout from important resting habitat Competition Between Brook Trout (Salvelinus fontinalis) and Brown Trout (Salmo trutta) for Positions in a Michigan Stream Authors: Kurt D. Fausch and Ray J. White “After brown trout removal, brook trout larger than 15 cm chose resting positions with more favorable water velocity characteristics and more often in shade. The position shift was greatest for the largest brook trout, those of 20-38 cm. Feeding positions of brook trout changed little upon brown trout removal according to our criteria. The shift in resting positions of brook trout after release from competition with brown trout indicates that brown trout excluded brook trout from preferred resting positions, a critical and scarce resource. The combined effects of such interspecific competition, differential susceptibility to angling. differential response to environmental factors, and predation of brown trout on juvenile brook trout may account for declines of brook trout populations while brown trout populations expand in many streams of the northeastern United States where the two species are sympatric. “ Research Demonstrating Invasive Trout Impair Brook Trout’s Ability to Use Critical Focal Cold Areas in the Stream During Warmer General Stream Temperatures A new USGS study shows non-native Brown Trout can place a burden on native Brook Trout under the increased water temperatures climate change can cause. “Our research indicates that reducing Brown Trout numbers can benefit native Brook Trout where the species co-occur,” Hitt said. “Moreover, Brown Trout management could help Brook Trout be more resilient to anticipated effects of climate change.” Brook trout use of thermal refugia and foraging habitat influenced by brown trout Authors: Nathaniel P. Hitt , Erin L. Snook, and Danielle L. Massie “Our results indicate that removal of introduced brown trout may facilitate native brook trout expansion and population viability in downstream reaches depending in part on the spatial configuration of groundwater upwelling zones.” Non-native trout limit native brook trout access to space and thermal refugia in a restored large-river system Authors: Cory T. Trego, Eric R. Merriam, J. Todd Petty “Non-native trout consistently occupied more thermally suitable microhabitats closer to cover as compared to brook trout, including the use of thermal refugia (i.e. ambient–focal temperature >2°C). These results suggest that non-native trout influence brook trout use of restored habitats by: (1) displacing smaller brook trout from restored pools, and (2) displacing small and large brook trout from optimal microhabitats (cooler, deeper, and lower velocity). Consequently, benefits of habitat restoration in large rivers may only be fully realized by brook trout in the absence of non-native species.” Research Highlighting a Relatively Small (Less than 1 degree Celsius) Difference in 7 Day Upper Lethal Temperature Limits for Brown and Brook Trout Brook Trout Response to Invasive Brown Trout Removal Demographic Responses of Brook Trout to Removal of Brown Trout from a Driftless Area Stream in Minnesota Authors: John H. Hoxmeier and Douglas J. Dieterman ”Brook trout abundance increased in lower Coolridge after brown trout suppression (2-way ANOVA interaction term, logtransformed; Age-0, P = 0.04; Adult, P = 0.01). The magnitude of response was greater in the lower reach compared to the upper reach of Coolridge Creek where few brown trout were present before removal efforts. Adult brook trout increased from a pre-treatment mean of 51/mile to 164/mile in lower Coolridge. Recruitment of age-0 brook trout was higher in lower Coolridge after brown trout removal, increasing from a mean of 67/mile to 326/mile. Abundance of both adult and age-0 brook trout steadily increased after the initial brown trout removal, and reached their highest levels at the end of the study” Acid Mine Pollution Remediation Project in PA Stream Allows Brown Trout to Invade Brook Trout Stream Post Project and Eat a Large Amount of the Population (Video) Habitat Restoration Projects-Invasive Trout Species Prevent Native Brook Trout from Benefiting from Them and Can Even Use These Projects to Reduce or Eliminate Native BrookTrout in the Stream Non-native species limit stream restoration benefits for brook trout Authors: Brock M. Huntsman, Eric R. Merriam, Christopher T. Rota,J. Todd Petty "We used a joint species occupancy model within a BACI sampling design to show that brook trout occupancy of main stem habitat was highest post-restoration within restored sampling reaches, but this benefit to native brook trout was conditional on brown trout (Salmo trutta) not being present within the main stem habitat. Collectively these results indicate that habitat restoration was only beneficial for native brook trout when non-native trout were absent from the restored sampling area. Proactive approaches to restoration will be integral for supporting resilient ecosystems in response to future anthropogenic threats (e.g. climate change), and we have shown that such actions will only be successful if non-native competitors do not also benefit from the restoration actions.” Non-native trout limit native brook trout access to space and thermal refugia in a restored large-river system Authors: Cory T. Trego, Eric R. Merriam, J. Todd Petty “Non-native trout consistently occupied more thermally suitable microhabitats closer to cover as compared to brook trout, including the use of thermal refugia (i.e. ambient–focal temperature >2°C). These results suggest that non-native trout influence brook trout use of restored habitats by: (1) displacing smaller brook trout from restored pools, and (2) displacing small and large brook trout from optimal microhabitats (cooler, deeper, and lower velocity). Consequently, benefits of habitat restoration in large rivers may only be fully realized by brook trout in the absence of non-native species.” Evaluating Trout Stream Restoration Benefits: A Case Study at Pine Creek, Wisconsin Author: Kent Johnson This case study I have shared is an unfortunate example of what can happen when one of the 5 components of streams model components, such as biotic interactions (invasive trout species), is not factored into a stream restoration project originally intended to help native brook trout by improving some of the other 5 components. In this example a stream project intended to help native brook trout helped brown trout reduce their numbers and may ultimately result in their elimination from the stream. “On average, pre-restoration trout abundance in Pine Creek was 3,991 trout/mile, with brook and brown trout present in a 96%:4% proportion. ” “Within eight years post-restoration, numbers of brook trout per mile decreased by 70% (3,800 to 1,200), while numbers of brown trout per mile increased by 3,150% (175 to 5,600). A continuation of this trend may lead to the loss of the brook trout fishery.” Invasive Trout Species can Act as Barrier to Movement of Native Brook Trout Much Like a Poorly Passable Culvert Hatcheries Themselves can Harm the Ecosystems that Native Brook Trout Live in. PA Fish and Boat Experiences an Outbreak of Invasive New Zealand Mud Snails that Could be Swallowed by Hatchery Fish and Transferred to New Waterways to Spread Where Stocked Mudsnails found in two state hatcheries in central Pa., but trout stockings continue Author: Brian Whipkey, York Daily Record “The big concern? “They don’t need a partner to reproduce, so they reproduce asexually, each individual can produce a couple hundred offspring a year. It just takes one snail and it can really explode if the conditions are right,” Brian Niewinski, chief of the division of fish production services, said.” Big Spring Creek in Cumberland County, Pennsylvania, gets a makeover for wild brook trout fishery Author: Marcus Schneck, Pennlive.com “According to Bill Ferris, who helped to launch the Big Spring Watershed Association in 2001 and was fighting for the restoration of the stream years before that, most of the amazing brook trout fishery passed out of its prime when the Pennsylvania Fish and Boat Commission built a fish hatchery at the headwaters of the stream in 1973. “When the hatchery came in, we lost the brook trout,” he said. “They crashed because of the high levels of phosphorus” discharged into the stream from the hatchery and the accompanying loss of oxygen from the water in the stream. After years of often bitter debate and increasingly tougher discharge restrictions issued by the heavily pressured state Department of Environmental Protection, the commission closed the hatchery in 2001.The stream quickly began to heal itself and by 2008 the headwaters section again had a brook trout population of more than 350 pounds per acre of water, which rates it as one of the most productive brook trout streams in the country.” How many brook trout populations in the state of PA would similarly greatly benefit from hatchery closures? This is a topic we do not hear alot about in a state with a surprisingly high number of private and state run hatcheries. A list of invasive trout removals and brook trout reintroductions by state Eastern Brook Trout restoration summary table Chart displayed on Eastern Brook Trout Joint Venture (EBTJV) website This chart on the EBTJV website illustrates PA is well behind many other states in terms of numbers of projects for native brook trout. PA has only one listed project for it’s state fish in the below link, a reintroduction of brook trout into Big Spring Creek where a PA Fish and Boat trout hatchery largely wiped out the original population necessitating this reintroduction. Big spring is still stocked with harmful hatchery brook trout to this day capable of causing harmful genetic pollution to wild native brook trout. Also wild invasive rainbow trout are still protected with regulations to this day in the upper big spring. The state of Pennsylvania has performed no known removal projects of invasive trout species to date and still stocks them in many brook trout streams and watersheds statewide. PA Fish and Boat’s AIS web page does not list brown and rainbow trout, currently stocked statewide, as an invasive species with a control plan. They are not mentioned at all despite their ranking in the International Union of Conservation of Nature’s top 100 world’s worst invasive species list, numerous publications documenting their invasion of native trout streams, current removal efforts in other eastern states because of invasion, and meeting the listed definition for invasive species featured on the commission’s AIS web page. Conservation Genetics, an extremely critical part of native brook trout management and conservation but largely unheard of by the angling public. Scicomm webinar: development of a genetic baseline for brook trout in North Carolina Webinar by NCWRC Biologist Jake Rash Watch this video to understand the importance of conservation genetics and genetic diversity. (Skip in Webinar to 15 min 35 sec) Brook Trout Genetics Eastern Brook Trout Joint Venture A sizable collection of research, videos and presentations about the importance of conservation genetics and how it can be used for reintroductions, genetic rescues, determining the health of populations and much more. STAC Brook Trout Workshop: Understanding Genetics for Successful Conservation and Restoration of Resilient Chesapeake Bay Brook Trout Populations A link to highly informative presentations given by experts in native brook trout conservation genetics at this workshop to fisheries managers from different states. Good information included on the forces shaping native brook trout genetics in both positive and negative ways. Each gene a brook trout population has is potentially a different tool that can be used by brook trout to better survive their environment and the threats they face. If a brook trout population is genetically diverse, has more different genes, they have more tools to adapt to better survive a warming environment and other threats. Then if that population can move and share those genes with brook trout in another stream, a process called “gene flow”, it can potentially make other populations more genetically diverse as well by sharing all those survival tools. Large waterways are critical highways where this gene flow takes place. As mentioned in one of the presentations from this conference, invasive trout can decrease gene flow as pointed out by Casey Thomas Weather’s dissertation. PA Fish and Boat currently stocks many large waterways connecting multiple brook trout streams across our state. Are Hatcheries Bad for Brook Trout? Author: Shannon White, Troutlook The “Are Hatcheries Bad for Brook Trout?” section explains the dangers of stocked hatchery fish in terms of the negative effects of hatchery brook trout genes that are ill-suited for survival on wild native brook trout. Brown and Rainbow Trout as an Invasive species: Research International Union of Conservation of Nature’s Global Invasive Species Database 100 of the World's Worst Invasive Alien Species (Brown Trout & Rainbow Trout are number 82 & 63 respectively in the top 100 world’s worst invasive species) Trout as Native and Nonnative Species: A Management Paradox Authors: Michael J. Hansen, Christopher S. Guy, Phaedra Budy, and Thomas E. McMahon “We describe examples of three trout species, Lake Trout Salvelinus namaycush, Brown Trout Salmo trutta, and Brook Trout Salvelinus fontinalis, that are managed for the opposing goals of restoration versus suppression, in relation to their opposing roles as both native and nonnative species in aquatic communities. We also attempt to develop insights into how this information might be used to accomplish both seemingly incompatible ends.” Effects of introduced species on native brook trout: a guide to the scientific literature (a compilation of 38 studies/publications) Compiled by: Nathaniel P. Hitt, Karmann Kessler, and Hannah Macmillan of United States Geological Survey Leetown Science Center Brown Trout as an Invader: A Synthesis of Problems and Perspectives in North America Authors: Phaedra Budy and Jereme W. Gaeta Texas Invasive species institute: Brown Trout National Park Service puts bounty on invasive brown trout in Lee’s Ferry stretch of Grand Canyon to help endangered native fish species Author: Debra Utacia Krol Impacts of Exotic Rainbow Trout on Habitat Use by Native Juvenile Salmonid Species at an Early Invasive Stage Authors: Isabel Thibault & Julian Dodson Dr. David Kayzak's video the harmful genetic impacts of invasive trout species, why we need watershed level management, and what we can do to help brook trout adapt
