Why Read When You Can Watch?
This past week I traveled to Lexington, Virginia to attend the annual meeting of the Virginia Chapter of the American Fisheries Society. Why would I go to a Virginia conference? Mostly because I wanted to. From my first conference in 2008, mentor lunches that helped guide my way, meeting my would-be Master’s advisor, and several leadership positions that led to awards and fellowships, I owe lot of my interest and success in fisheries to members of VCAFS. It had been a couple years since I was able to get back to a VCAFS meeting, but now with some data to present and a little break in field work, it was a great opportunity to return home. I received a great homecoming from many of my former professors and state biologists, and I even managed to win Best Paper for my talk on trout movement in Loyalsock Creek.
But, now, winter conference season is officially over. Ahhhhh…
Conferences are great. Lots of reunions with old friends and colleagues, handshakes with people you’ve only “met” through email and literature, and it’s also the start of many future collaborations. But, it’s also a lot of poor eating, lots of science that melts your brain, and really long nights. It’s an exhausting type of fun, and for now I’m glad to be unpacking the suitcase for a little bit.
Because I’m mostly melting into the couch today, I’m taking an opportunity to share with you a video Danielle Massie made from some photos we’ve amassed during the field season last year. It’s a great tool for describing why I’m doing the research I do, and I’ll be posting it throughout the website so that visitors can quickly learn more about the work the Penn State trout team is doing (it the link below doesn't work, it can be found by clicking here)
Next week, it’s back to field preparations. Can’t believe the winter has already flown by.
Genetics Make Terrible Guests
Last week I presented some preliminary genetics results using the image to the right, and used it as evidence that brook trout moving into Loyalsock Creek likely spawn outside of their home stream in later years. To put it another way, the fact that we see a mixing of genes at most locations (except for Mill Run), means that these populations were at least historically connected (and the telemetry data suggest at least some of them probably still are now).
Genetics data are such terrible guests for a blog. They come in unannounced, make a mess of the place, and don’t know when to leave. In this case, the mess they created was a lot of questions about what we expected this data to look like. While I’m excited that people want to know more, the answer just isn’t that easy.
For starters, my expectations of this dataset were zero. As you may recall, I hate genetics. My feelings towards the field are starting to evolve into a past-tense form of repulsion, but every day remains a struggle.
Those with a basic understanding of population genetics may have looked at that figure with doom and gloom and wondered why in the world those populations are so isolated. Separated by only a stone’s throw, we would expect all of those populations to be genetically very similar. This is particularly true when we think of land dwellers, which are generally more mobile than aquatic species. In fact, for many terrestrial species and larger-bodied fishes, we’d probably have to separate populations by many miles before we start seeing genetic isolation similar to the above diagram.
But, those that study headwater fishes may have found the results to be of no surprise. Most headwater fishes have very limited dispersal, owning to the fact that downstream habitats become increasingly wider and hotter with faster flows, making them less suitable environments for species that have evolved to live in tiny streams. There are also more predators downstream, so small bodies that are perfect for small streams quickly get eaten by larger fish like bass, pike, etc.
All this to say, interpreting genetics data is a not entirely straight forward. We can get numbers that tell us things about genetic diversity, population isolation, and anything else you might be interested in knowing. But, that’s not the full story, and those numbers are actually meaningless, and potentially dangerous, if used out of context. Our expectations for what the results should be really depend on the species, study location, historic stream use, stocking, etc., etc. It’s a bit of a detective game. So, for those interested in specific numbers describing diversity, FST, AR, NE, rxy, you’re out of luck. They’ll appear in a publication eventually, but only sparingly in this blog.
What I will do is compare, in broad terms, how our data stack up against other studies of brook trout. For starters, our genetics data cover far more than just the sites in that figure. We sampled 28 streams across the Loyalsock Creek watershed, making our study one of the largest scale studies of brook trout population genetics.
Usually changing the scale of a dataset means that you can use your results to answer new questions, questions that may be more appropriate for how we manage species. For example, genetics data are usually collected at the scale of a single stream or maybe a few streams in a small area. However, we don’t generally manage fish at this small of a scale. We generally make management decisions for entire watersheds. So, given that we now have genetics data for an entire watershed, it makes sense that we can now shed new light into the population genetics and management of brook trout at a watershed-level.
Wrong. But, don’t feel bad. I led you on.
The reason our dataset isn’t all that revolutionary, at least at the surface, is because brook trout populations are known to quickly isolate, even at fairly small spatial scales. Even side-by-side tributaries can be isolated from one another. So, if we see isolation at small scales, it’s not that surprising to see isolation at large scales. And, it’s no secret that that is what we’ve found in much of our dataset. Sites that are separated by 3+ miles are isolated from one another, and that’s pretty typical for brook trout.
That said, brook trout genetics are very diverse, particularly at sites separated by less than a mile. Sometimes they are genetically different, and other times they aren’t. To me, this is where things get interesting. If two sites are separated by the same distance and similar habitat, why do we sometimes see isolation and other times connectivity?
I don’t have an answer, but we’re hoping to explore this question with our dataset. And, we have some preliminary ideas. For example, we see that sites near a mainstem river system seem to have more connectivity than sites that are connected by a mid-reach run. What is it about mainstem rivers that makes them better for connecting fish populations? Or, to really wig your brain, what is it about fish living near a mainstem that makes them different (i.e., more mobile) than fish living higher in the headwaters?
That last question may seem a bit far-fetched, but brook trout are known for having a diverse range of life histories. Many of you may be familiar with “coasters,” brook trout living in Lake Superior that make long-distance migrations into the lake’s tributaries to spawn. There are also “salters” which spend a significant portion of their life in saltwater before returning to smaller freshwater tributaries to spawn.
Are fish moving between headwaters and mainstems (like we see in Loyalsock) a true life history variant? If so, how cool would that be? We’re a really long way from being able to say anything about behavioral variation in populations, but I will say that we aren’t the first study to document such dramatic differences in individual behavior. So, there’s support out there for the idea.
But, going back to the main question, how do our data compare to other brook trout population genetics studies? That’s an easy, albeit unsatisfactory, answer. Previous studies showed a lot of variation, and our study shows a lot of variation. So, Loyalsock Creek, as a whole, is not more or less isolated than we would expect given other studies. When we zoom in we see patterns were certain sites do seem oddly disconnected, and others more connected than we would have thought. And, seeing if we can explain that variation is going to be what makes our study so interesting.
A First Look at Telemetry Results
Okay, I admit it. I slacked this week on blog post duties. February has already proved chaotic with personal and work-related travel, and the rest of the month will be much of the same. Seems lately I’m treading water just to stay behind. But, that’s the way it goes sometimes.
Thankfully, thought last week’s travel started quite stressful, it ended up being fun. The entire Wagner lab rarely gets together aside from occasional sampling trips to Loyalsock Creek. But, last week we all traveled to California, PA for a joint meeting between the West Virginia and Pennsylvania Chapters of the American Fisheries Society. We represented the lab well with Megan Schall receiving the award for Best Student Presentation and myself receiving the Cooper Award for exemplary fisheries work by a student member. It was also the first conference that Tyler Thompson and Danielle Massie attended, and they did a great job fielding questions about their posters. So, not only did the four of us get a chance to hang out outside of the office, but we did some great science as well.
The stressful part of the week came before we left. I’ve known for over a month that I was going to present results of our telemetry study at this meeting. Yet, even 24 hours before we left town, I still had no real data. I’ve said before that the telemetry dataset is fairly messy and complex, and it wasn’t really clear to me what numbers I wanted to present. All along I assumed I would just describe general trends in the data, but, the more I put together the presentation, the more it become obvious that some visuals were needed.
So, I started measuring fish movement. By hand. And kept measuring fish movement right up until the point we got in the car to leave. Sure, there are programs that will automate this process, and I intend to use them very soon. But, it takes a long time to get those programs to run and I was quite confident I wouldn’t get results within a day. At least by hand I knew I would have presentable data. As an added bonus, as I was measuring the movements I was reminded how cool the dataset is. Sometimes when you’re in the thralls of data collection you forget that your results are actually interesting.
What did I find in my whirlwind analysis? For starters, it confirmed that movement varied drastically across the three populations, and individuals vary considerably in their propensity to move.
Movement data for each of the three major telemetry sties, Pole Bridge (green) Double (black), and Shanerburg (red) runs. You can see that fish rarely moved from their starting location, particularly in Pole Bridge, during summer. However, after spawning, fish in Double and Shanerburg runs made long-distance movements downstream and into the mainstem Loyalsock Creek.
Second, in looking at the genetics, I found that movement is likely effective, meaning that at least some individuals that move into Loyalsock Creek eventually migrate to, and spawn in, tributaries outside of their home stream. This point is important because it indicates that movement into the mainstem is not random. Instead, fish that make long-distance dispersals into the mainstem are maintaining population and genetic connectivity, which we know are critical for long-term population survival.
Results of genetic assignment tests where each pie chart represents the frequency of certain genes in each populations. For example, in Double Run, the majority of fish have genes consistent with Double Run being their home stream, but other fish have genes consistent with an origin in Shanerburg (red). Pole Bridge (green), and areas outside the study (grey). Similarly, Shanerburg Run is comprised of fish from Double, Pole Bridge, Bear, Coal, and sites outside of the study area. Taken together, this indicates that a lot of fish move between these populations.
Pretty cool for a day of analysis, right?
Next week I’m giving the same presentation at the Virginia Chapter of the American Fisheries Society. I attended Virginia AFS for seven years before moving to Pennsylvania, so my motives for going are mostly personal. But, though this crowd is unlikely to care about the current conservation status of Loyalsock Creek, they likely will find the data of considerable interest to the conservation of their own trout populations. I’m just glad I don’t have to analyze the data again for that talk.
My Two Cents
It’s no doubt that the current political climate has many natural resource professionals on edge. Jobs are being cut, budgets are dwindling, and some of us are even questioning whether we will be able to release the results of research we have dedicated our lives to- research that is vital to heal the wounds that remain after centuries of environmental neglect.
Believe it or not, that is not a political statement. It is almost un-American how little I keep up with current events, especially in politics. And, I try to not let my opinions be swayed by my friends, family, social media, or fly-by-night news sources. To do politics “right” requires a lot of fact checking and research, and so I don’t have all the information necessary to form an opinion about many hot topic issues. But, when politics enter your wheelhouse, you feel a little more compelled to speak out.
Recently, the House of Representatives and the Senate (of which Republicans own the majority vote) both repealed a ruling from the Obama administration that prevented coal companies from dumping mining debris into streams. The regulation also required pre-mining assessment reports of the ecosystem and assurance that mining activities would cause no hydrological disturbance. The original law was meant, in large part, to regulate mountaintop removal mining where (as the name suggests) entire mountain tops are blown up to access coal seams that lie underneath. As you can imagine, this creates a lot of debris, and most commonly that debris was dumped into surrounding valleys. And, you know what else are in valleys? Streams. An estimated 2,000 miles of headwater streams have been buried by coal debris since the 1990s.
Debris is rarely dumped into rivers and larger streams, but rather the target is small, sometime intermittent headwaters. The streams, though tiny, hold some of the highest diversity of fish (including brook trout), macroinvertebrates, and amphibians in the United States. Many of these species are threatened or endangered, and are highly endemic; occupying only a few streams in the entire world. Yet, with a couple dumps of the backhoe, coal debris fills in valleys and completely removes entire streams (and the organisms in them) from the map.
But, the effects are felt even downstream where water quality is degraded with high concentrations of heavy metals, high conductivity (a measure of the concentration of ions in the water), and levels of some chemicals (such as selenium) that are toxic to fish and even lethal to laboratory-tested animals. And, it’s not only aquatic life that is harmed as terrestrial species (like birds) that eat fish and macroinvertebrates are poisoned by toxins in their prey. Unfortunately, once mining debris is dumped into a valley, ecosystem recovery is very difficult to achieve. Even decades later, areas downstream of a dumping site have significantly fewer fish and macroinvertebrates than reference control reaches.
Why Congress repealed this “dumping regulation” is debatable. Some believe it was an easy target, as it was passed in mid-December making it repealable under the Congressional Review Act (which, by the way, could soon cause many other newly inked regulations to be overturned). Others believe that the bill was unfair to coal companies and it made it significantly more expensive, and even impossible, to mine many sites adjacent to streams. If nothing else, most agreed that the wording of the regulation was hopelessly complex, leaving many to feel like it was nothing more than bureaucratic red tape.
News that the dumping regulation was being repealed had many rejoicing at the thought of a resurgence of big coal, particularly in Virginia, West Virginia, and Kentucky where coal mining was once much more prevalent than today. I’m one of the first to recognize that human-environment interactions are give and take. Sometimes situations arise were we can’t prevent negative impacts on the environment if we are to complete a project that, ultimately, is for human good.
But, reckless coal mining, the type of coal mining that will be permissible if the dumping regulation is repealed, is not one. In my former life I was a Master’s student at Virginia Tech studying an undescribed species of minnow found almost exclusively in watersheds with mining activity. Brought to the area to study fish, I found myself equally interested in the social dynamics of mining. These boom-and-bust towns are shells of their former selves, and hidden beneath the overgrown shrubs and collapsing buildings are signs of a once vibrant community. Remaining families depend almost entirely on coal to put food on their tables, and in recent years lucrative positions in mining have become increasingly rare. These families are proud of their heritage of hard work and dedication. At the same time, they are praying for assistance, and I can only image that repeal of the dumping regulation (and several other regulations pertaining to natural resource extraction) has many excited about the potential for revitalization and new, better career opportunities. A “way out” of hard times that have fallen.
I cannot pretend to know what is best for these coal communities. Coal is a culture, one with which I cannot relate. Nor can I predict with any certainty the economic ramifications that repeal of the dumping regulation could have. But, I do know that the idea of coal saving these communities has been oversold. Though many believe declines in coal production are the result of more stringent regulations (like the dumping regulation) the truth is that it has been outpriced by natural gas and phased out by a trend towards using more sustainable energy sources. Further, while repeal of mining regulations could increase production, it will also likely result in increased prevalence of illnesses and cancers that are common in coal communities when drinking water becomes contaminated. So the more likely reality, the reality that seems hidden from many discussions recently, is that increased, less regulated coal mining will result in short-term increases in coal production, and much longer-term decreases to human and ecosystem health.
As of today, the repeal of the dumping regulation awaits President Trump’s signature. If he signs, as he is expected to do, decades of restoration and reclamation and improvements to rural living conditions, will be threatened.
If you want to read more about the effects of debris dumping, click here