Challenges to Trout Conservation
Sorry, folks. I'm copping out this week. I'm on the heels of another conference, and the there's a tornado of activity as I try to wrap up loose ends at the office before embarking on an eight-state, 12-day tour of the mid-west. Badlands, Rushmore, Bozeman...quick conference in Yellowstone....Jackson Hole, Salt Lake. I live the silver spoon grad school life.
In all seriousness, my advisor is more than generous with his allocation of resources and supports me making these trips. Not all advisors give their students the freedom to attend expensive conferences. But, I also help my cause and do some of my own fundraising. A few days ago I was honored to be named a recipient of the 2017 Marty Seldon Scholarship to offset some travel costs to the Wild Trout Symposium in Yellowstone. The application was fairly straightforward- an essay describing my research, involvement in professional fisheries organizations, and what I feel are the most pressing issues in trout conservation.
Below is my submission. For many of you seasoned readers, you already know the spiel. For some of you newer readers- sit back, learn a little about me, my research, and what I'm fighting for.
Conservation of wild trout populations is met with a myriad of challenges with none more pervasive than climate change. Look no further than the northern-receding margins of the eastern brook trout’s range, collapse of cutthroat trout populations in the Rockies, and declines of European brown trout to find evidence that climate change is threatening salmonids worldwide.
Managing coldwater fisheries under climate change is a complex problem of scale. Large-scale changes to stream temperature, flow regimes, and habitat availability transcend watershed and political boundaries, often making management logistically and financially unfeasible. Yet, there are also small-scale changes to species interactions, population vital rates, and individual fish physiologies that are not only difficult to manage, but also remain poorly understood. Together, the effect that climate change has on trout populations within and across scales produces unanticipated, nonlinear patterns and dynamics that reduce our ability to predict future outcomes of habitat loss and effectively manage trout populations.
The efficacy of present-day management objectives, which largely focus on increasing population sizes and habitat availability, will only continue to decline as climate change outpaces restoration efforts. Accordingly, management must become more forward thinking and include conservation of the fine-scale properties that naturally increase population resistance and resilience to habitat loss. To accomplish this goal, a better understanding of individual variation is needed to answer questions such as: why are some populations and individuals more fit than others, are there specific genes that lead to higher thermal tolerance, why do fish behave differently from one another, and is individual variation important for population survival?
These are just some of the questions I am addressing in my dissertation research at Pennsylvania State University in the lab of Dr. Tyler Wagner. Specifically, I am merging the fields of genetics, behavior, and population ecology in a series of field and laboratory studies to investigate the adaptive significance of intraspecific variation in native brook trout populations in Pennsylvania.
At a molecular level, I am studying population genetic structure to identify spatial patterns in genetic diversity. While previous studies suggest that brook trout populations readily isolate at small spatial scales, my research suggests that genetic connectivity and diversity remain high near mainstem river corridors as compared to headwater populations. This suggests that the processes that maintain metapopulation dynamics differ across the species’ range. Further, because genetic diversity is correlated to adaptive capacity and resiliency, the location of a population within a stream network could predict evolutionary potential and extinction risk.
I am also completing one of the first studies of gene expression in wild trout populations to quantify expression patterns of heat shock protein 47 (HSP47), a common indicator of thermal stress in fishes. In total, I evaluated gene expression for nearly 700 fish using non-lethal gill and blood samples collected every 1-3 months for over a year. Preliminary results suggest that HSP47 expression is highest in early spring, and nearly absent in summer when stream temperature is warmest. This suggests that brook trout begin expressing heat shock proteins in response to mild increases in stream temperature, and that there is a limit to how much HSP47 can be produced before gene expression stops. Ultimately, these results could indicate a limited scope for adaptation and plasticity in stress protein production.
To determine how intraspecific genetic and behavioral variation influence population structure and survival, I completed a multi-season telemetry study on 180 wild brook trout distributed across four tributaries to Loyalsock Creek, Pennsylvania. From this work, I documented significant individual variation in behavior, including some fish that completed large-scale, post-spawn movements to overwinter in mainstem Loyalsock Creek; a system largely considered unsuitable for brook trout prior to my study. Taken together, the observed zero-centered leptokurtic distribution in movement and patterns in population genetics describe above suggest there may be multiple life history strategies in some brook trout populations, including some highly migratory individuals that disproportionately increase genetic connectivity among populations. In the future, I will complete a genome-wide association study to identify specific genes that correlate to different movement patterns.
In the lab, I am completing several studies to determine whether inter-individual differences in behavior can be explained by fish personality. While it is understood that personality can modulate growth, reproduction, and mortality, the ecological and evolutionary significance of personality has not been rigorously explored in any taxa. I determined that boldness, the most studied personality trait in fish, reduces spatial learning ability. This finding suggests that phenotype influences learning and memory processes, and could explain differences in habitat use and movement among individual trout. I am currently conducting another lab study to determine how boldness influences the ability of fish to compete for resources at different stream temperatures. I hypothesize that the higher metabolic demand of bold fish will decrease their success at defending resources at higher temperatures.
Though I hope to increase the efficacy of trout management with novel research objectives, I am equally passionate about improving conservation through communication. I am the first author of seven peer-reviewed manuscripts ranging in topics from long-term stream habitat management to social learning in trout. I have also given over 20 presentations at state and national conferences, many of which receiving best paper awards.
In addition to professional communication, I continually seek opportunities to interact with the public through outreach and education. I am particularly passionate about introducing prospective biologists to stream ecology within the framework of professional service. For example, my election to President (Virginia Tech Chapter), Membership Chair (Virginia Chapter), and Social Media Coordinator (National Chapter) of AFS has afforded me the opportunity to lead educational programs and workshops for students and professionals and increase AFS participation at all levels. I also served as the Southern Division AFS Newsletter Editor that represents 15 states and am currently a member of the Virginia AFS Outreach Committee. My leadership in AFS has been recognized with several state and national awards.
Having realized my passion for science communication, I extended my outreach efforts beyond AFS programs and founded www.thetroutlook.com, a website specifically devoted to improving public access and understanding to information related to coldwater stream and trout ecology. Through weekly updates, I provide information about my research and introduce the readership to topical issues in fisheries conservation. This website has been viewed over 70,000 (side note- this number is getting closer to 100,000 now) times by an international audience, is regularly used as a teaching tool in K-12 schools, and has attracted attention from community groups and universities. Because of this media presence, within the last year I was invited to give nearly 20 seminars to several universities and to the Pennsylvania Council and local chapters of Trout Unlimited.
My passions for research, outreach, and education underlie my desire to pursue a career in academia. I believe that the persistence of natural resources will depend on inspired, well-trained scientists who can think creatively and critically to solve some of the world’s most pressing problems. I want to enable the next generation of problem solvers by fostering in them a life-long curiosity for ecological research. This is a goal I have already started realizing as the lead advisor for seven undergraduate students at Penn State and Susquehanna universities completing independent research projects or internships.
Think Outside the Stream
I may be too stubborn to stop wearing shorts, but there’s no question that summer has ended in Pennsylvania. Tomorrow I’ll be headed to Loyalsock for my first day of fall sampling, and the third-to-last sampling event of my PhD (crazy). It’s been one wild ride, and the last day I drive out of Loyalsock is going to be a bittersweet exit. But, I have a few months before I need to think about that.
What’s on my mind today is the feedback that I’ve gotten from my post last week on stocking. Great discussions, great questions, and hopefully a few people that thought twice about their positions on trout stocking. Generally speaking, the vibe I get from most people is that they do support stocking programs, just not in Class-A wild trout streams. Some even go as far as to advocate for the end of stocking in all streams that support wild trout, regardless of abundance.
There’s nothing wrong with these views. In fact, my own opinions are casted with shades of this logic. They present a compromise- potentially a stocking protocol that could allow for increased recreational opportunities while still protecting wild trout.
Notice I say “potentially”? In ecology, everything is connected. And, when we do one thing to one stream, we can’t be certain that it will or won’t impact the streams around it. That’s what makes natural resource management a game of knowledge and know-how, but sometimes also a lot of luck. Mother Nature can be finicky. We can do math, study the science, and prescribe a certain management protocol and get the same result 99 times. And then the 100th time it fails. Hopefully it’s a contained failure with minimal loss, but other times the damage cascades throughout the ecosystem causing damage at levels. Not often, but sometimes.
So, we can limit stocking. We can even put a moratorium on stocking Class-A streams, or any other stream that holds a special designation. But, how much damage control does that really do? Seriously, I’m asking- I don’t know the answer.
The uncertainty comes from the fact that fish move. A lot. Particularly large, stocked fish that are spooked by their new surroundings when they are plopped down into a stream for the first time. In our dataset, we found evidence of hatchery introgression and fish straight off the hatchery truck at sites that are several miles from the closest stocking location. And, we routinely find a pulse of very large fish moving into smaller tributaries in June- the same time when water temperatures in larger waters get too warm. I can’t say that these are definitely hatchery fish, but I would bet money on it (and on a grad student salary, that says a lot).
So, my post today is just a cautionary tale. To protect and conserve waters, we can’t keep thinking of streams as individual units. Effective restoration of one stream often requires action to be taken on surrounding streams and on the landscape. Likewise, the effects of stocking will extend beyond the streams that fish are put in. Not stocking Class-A streams would be a great success for native trout conservation. But, if there is a stocking location in the next adjacent tributary, then the successes could still be minimal.
As long as we are stocking trout somewhere, there will still be some chance for negative effects to native populations. That isn’t meant to be a rally call for the end to hatcheries. It’s meant to be a warning that the solution isn’t quite as easy as “stock here, not there.” How far hatchery fish can spread is not certain, and it is going to vary depending on a lot of factors. When determining stocking locations, we need to think beyond the immediate radius of the release location. We need to consider what streams are within a few hundreds yards, to maybe even as far as a few miles. Could those stream be influenced by hatchery trout?
This brings up a bigger point, and that is nature is too variable for a “one size fits all” approach to management. It’s probably not advisable to advocate for a single management strategy to be deployed across an state. We need more emphasis on adaptive management- on adjusting management protocols in response to changing demands from humans, shifts in climate, and loss or gain of habitat. We need to use all the data available to us and make decisions. If we suspect that a certain management action is threatening trout populations, then it needs to be looked at a little closer and sooner rather than later.
It’s a daunting task, and certainly easier said than done. But, aren’t our natural resources worth it?
I’m back! And, boy was my absence untimely. While I enjoyed soaking up the rays attending the annual meeting of the American Fisheries Society in Florida, I unfortunately missed the Pennsylvania Wild Trout Summit. The PA Fish and Boat Commission was quick to post presentations online, so I’ve been able to catch a few talks (including the one below by my advisor, Ty). But, I’ve also been reading some feedback from a few attendees and my takeaway is that the best talk wasn’t by a platform presenter- it was among members in the audience. One of the reasons I love studying trout is the passionate anglers and citizen scientists that are invested and devoted to wild trout conservation and restoration. There is no other angler base that is as informative and fun to interact with as you all, and I was sad to miss the opportunity.
My other observation is that there was some disappointment in what wasn’t discussed. Most notably, it seems a lot of people in attendance wanted to discuss the state’s trout stocking plans. I’m not surprised. Stocking is controversial and there will probably never be a stocking plan that makes everyone happy. But, I’m also encouraged. The public is trying to voice their opinions on this really complex problem, and, from what I’ve seen, seem to largely understand the delicate balance between the science of native fish conservation and the social dynamics of recreational fishing. It’s not an easy line to walk.
I’m also encouraged because it means there is interest in our current research beyond the scientific community. Our manuscript on native and hatchery fish interbreeding is nearing completion, and the results are getting closer to being released. Until then, I’ve been spending most of my days pouring over manuscripts published over the last 20+ years from other studies of hatchery-wild interbreeding and trying to summarize their findings. From this, I’ve already summarized the pros and cons to hatchery stocking, but I’ve left you in limbo the last two weeks. Overall, do hatcheries have more of a positive or negative effect on wild trout populations?
Before I answer that question, there are two caveats. First, I’m only discussing recreational stocking- or stocking done to temporarily increase population sizes to allow for increased angling opportunities. The potential pros and cons to conservation stocking are a bit different. Second, I am only focusing on the hard science. I’m not going to attempt to compare the social benefits of stocking with the impacts to native fish diversity. But, you should. Everyone should weigh the pros and cons and make their own informed decisions about stocking. It’s not my place to make the decision for you, but it is my job to present the science so that you can be informed. We know that stocking increases recreational opportunities and can be an economically profitable business, both of which valuable. Taking that into consideration, I have drawn a line in my mind where I think stocking is worthwhile and where it’s not. You need to find that line without someone telling you where they think you should put it.
So, after 20+ years of study, what do we know about the effect of hatchery stocking on wild trout populations?
So, where does that leave us? With a lot of uncertainty. Hatcheries can have negative effects on wild populations. But, not always. And, hatchery interbreeding can be high in stocked populations. But, not always. And, we know that there are long-term negative consequences of interbreeding. But, yet again, not always. We just don’t know.
Perhaps a more important question- where does that leave you in your thoughts on stocking?