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The Amazing World of Trout Stream Bugs, with Anna Le

Description: This week, my guest is educator and aquatic entomologist Anna Le [18:57], who introduces us to the amazing world of trout-stream invertebrates. She tells us how to gauge the health of a river by looking at the bugs, and also how we can all be citizen scientists and alert the authorities when we see a decline of important indicator species.
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Podcast Transcript:

Tom: [00:00:10.988] Hi, and welcome to the "Orvis Fly Fishing" podcast. This is your host, Tom Rosenbauer. And my guest this week is Anna Le. Anna is an entomologist and scientist and educator. And we're gonna talk all things bugs. We're gonna talk about how the trout stream insects that we all know and love are valuable indicators of the environmental health of a river, how you can be a citizen scientist and observe these things. And I think it'll also help your fishing a little bit.
[00:00:45.263] But it's an interesting talk, and I know that a lot of you like to hear podcasts about bugs because you're confused about the entomology. So, hopefully, this will clear up a few things and get you a little bit more interested in and observant when you're on the water.
[00:01:06.353] Couple announcements. One is you gotta try one of those new Helios rods. Go to your Orvis dealer or Orvis retail store and try one. They are amazing. And I just can't think of a more fun thing to do on a Saturday afternoon or a Sunday afternoon than go to your local fly shop and try one of these things out. I think you're gonna be blown away.
[00:01:32.223] And then another announcement, I do have a hosted trip. If you wanna go fishing with me, I have a hosted trip just announced, September 28th to October 5th, 2024, at Three Rivers Ranch in Idaho, one of my very favorite places in the world for the fishing and the people and the food and the accommodations. I just love going there and I'd love to share it with you. And there's actually an opportunity for two extra days of fishing, October 6th and 7th, if you are interested for an additional charge, obviously. But I'd love to fish with you and love to meet you. So, if you're interested, contact...the trip is listed on the Orvis website and contact the people at Orvis Adventures, and they can help you out.
[00:02:21.697] And another announcement. The podcast is a little thin this week. And not the podcast itself, it's a great podcast, but the fly box is a little thin this week because I'm gonna be gone for a few weeks. And I wanted to make sure that you had some new podcasts in the podcast feed. So, as you're hearing this, I'm off somewhere out of the country on a couple of hosted trips. And so, yeah, it's a little bit shorter than it usually is, but I just didn't have enough, new questions in the mailbox. So, we've got some, but not as many as we usually do.
[00:02:59.697] And if you have a question for the fly box, you can send it to me at This email address is being protected from spambots. You need JavaScript enabled to view it.. You can either type your question in your email or you can attach a voice file. Please don't record your voice file in moving traffic or in the car unless it's stopped and it's quiet because I can't use those audio files. It's just hard to hear what you're saying.
[00:03:28.652] So, without further ado, let's do the fly box. So, first one's from Richard. "As a 70-year-old fly fisherman who primarily wades while fishing, your conversation with Lindsay Kocka about safe wading was of great interest. I agree with everything being said, but it seemed to me that you both missed an important safety measure, 'Don't fish while you are moving.' Focus on the wading first. And not until you are stable, begin your casting. I learned this lesson the hard way by falling down in the upper Connecticut River while fishing a few years ago. I not only lost my good Smith prescription sunglasses, but I had a very uncomfortable, very wet 2-mile walk back to the car. And furthermore, I did not catch the fish. Hung onto my Orvis bamboo rod, however, thank God. Anyway, don't move and fish is now pretty much burned into my fishing brain. As always, thanks for all you do for our community."
[00:04:31.225] And that, Richard, is a great tip, and I'm guilty of that sometimes myself. And we should have mentioned that. Absolutely. We should have mentioned it. So, it's another good wading safety tip. Thank you for sharing that with us.
[00:04:47.993] Next, email's from Alex from Ontario. "Thanks for the great podcast. I was recently gifted an old, 7-weight Pflueger Medalist reel and haven't been able to find a good, 7-weight rod within my price range. Would it be fine to rig it up with an 8-weight line and mount it to an 8-weight rod? I've scoured the internet for a good answer to this, but can't seem to find a good answer."
[00:05:08.402] Well, Alex, you can absolutely do that. The thing you might find with an 8-weight line is you may not be able to get as much backing on that. But I assume that you are using this for either trout streamers or bass for which you almost never need any backing at all. So, you may have to remove some of the backing from the reel, but it's perfectly fine to put that Pflueger Medalist on an 8-weight rod. It should fit fine and it should hold an 8-weight line. If it holds a 7-weight line, it should hold an 8-weight line just with a little less backing.
[00:05:43.966] But as we all know, we don't really need it for most of the fishing we do. I wouldn't use it in salt water because you might not have enough backing there, and there are much better reels to use in salt water than a Pflueger Medalist. I don't believe that those were anodized, and you could experience some corrosion. And the drag really isn't up to today's standards, but perfectly fine for freshwater fishing.
[00:06:10.730] Here's one from Dan. "A while ago, you had folks chime in on strange ways to break a fly rod. Well, I had one at the time, but I procrastinated. Something happened just today that prompted me to write. Last August, two buddies and I were in the Owens Valley, California fishing Hot Creek. Caught a few, not great. Leaving the stream, we put our rods into the back of my 2003 Tundra with camper shell. The backsliding windows were open, so we slid the rod tips into the cab. Great idea, huh? Well, about a quarter mile up the dirt road, we hear a snap. My fly rod's tip section exploded into about 10 pieces. The mystery was that the leader was gone, and so was the section of fly line. For the rest of the trip, we hypothesized as to what had happened. Finally came to the possibility that the leader had gotten sucked down between the track bed and the cab, and had gotten caught under a tire that caused a snap. Whatever happened, we now know not to leave a loose leader when transporting rods like that. Almost the end of the story. Today, I was under the truck in the process of installing a backup camera, and here's a photo of what I saw. Mystery solved. The line had gotten wound around the drive line. It had stayed there for the past six months. The leader, yes, Orvis as well, is still in good shape, and I'll use it on my first cast this spring."
[00:07:37.017] Well, I hope you're joking, Dan, because that leader being wrapped around the drive shaft probably experienced quite a bit of heat and abrasion and all kinds of environmental insults. So, I don't think that leader's any good. But thank you for the tip. And, you know, if you're gonna put your rods still together in your car, make sure that that leader is not loose. And thanks for the tip.
[00:08:11.912] Here's an email from Old Eyes from Ohio. "As I get older, my eyesight and my finger dexterity is not what it used to be. I'm having trouble tying my favorite knots, like the non-slip mono loop. I even started to have trouble last fall tying simple knots with light tippets. Do you have any knot recommendations for older adults?"
[00:08:33.133] So, Old Eyes, unfortunately, you know, you need relatively complicated knots for nylon and fluorocarbon leader material. Because of the slippery nature of those, you can't just tie a very simple knot. And, you know, the clinch knot is about the simplest, which is the one I use to tie on a fly. And, you know, that does require a little bit of finger dexterity.
[00:09:01.487] There's a knot called the Double Davy Knot that you can look up online that is maybe a little bit simpler than the clinch knot. And it's a very popular knot, so you might try that one. The only other option would be... And I'm assuming that you have good light and you have good closeup glasses, so it's not your vision that's a problem, it's your finger dexterity. There are devices called quick clips, or No Knot Fas-Snaps that are a little clip that goes on the end of your leader. And probably wouldn't use 'em with small dry flies, but people use 'em with streamers and nymphs and things. And, you know, you got a hook eye, and you got a hook bend and a point sticking out of the back of your hook. So, a little bit of extra metal in front of your fly is probably not gonna hurt things very much.
[00:10:00.996] And you can tie these at home when, you know, got good light and you got time to do it. And then when you get to the river, you can just clip your fly onto these quick clips or No Knot Fas-Snaps. So, look those up. Orvis doesn't sell 'em, but you can find 'em online and give those a try. That's about the only thing there and try that. Double Davy Knot are about the only things that are gonna help you with the finger dexterity.
[00:10:31.368] Here's one from Ewen from Wisconsin. "I often fish small streams nearby. Besides trout, the most common fish there are creek chubs as well as river chubs. These fish love to take the dry, the fly. And I was wondering what your thoughts were on this fish. If so, would you recommend dries or nymphs for them, and why most consider these a trash fish? I'm interested to hear your thoughts. Thanks."
[00:10:53.280] Well, Ewen, I'm not a big fan of chubs and I'm kind of disappointed when I catch 'em. But I have a couple friends who actually go out after chubs and fallfish and they think they're great sporting fish. So, definitely, a worthwhile target for a fly rod. And probably, you know, they will take a dry, they will rise. They feed on the same things as trout do.
[00:11:21.383] A smaller nymph is probably, maybe a little bit better bet, but a dry-dropper rig with a small dry and a small nymph should work quite well. They don't seem to be as difficult to catch as trout, and they're not quite as spooky as trout. You can get a little closer to 'em. So, you know, just any small dry and small nymph should work well for those fish. They don't fight as hard as trout either, but sometimes a big chub or a big fallfish will give you a pretty good tussle. So, just keep chasing them.
[00:11:56.092] Here's one from James. "Hi, Tom. I live in Kentucky, and in the spring, summer, my primary fish to catch either by wading or floating is smallmouth. Would it be worth putting a few cicada patterns in my box for this summer? And if so, which ones? Top water, or do I need some that sits just below the surface? But I'm also concerned if there's a plethora of them, will they shy away from them? Thanks."
[00:12:19.324] So, James, yeah, fish go crazy. And I have never hit a big cicada fall. It's not a hatch, really. They fall into the river. But they're big and they're clumsy, and fish love them and fish will move a long way for 'em. And even things like catfish and carp will come up and rise for them when they're abundant because they're such an easy, highly caloric meal. So, I would definitely have some patterns. I think that often, just a popper will work about the size of the cicadas, cicadas. We've never figured out exactly how to pronounce that. But just a popper will often work. And there are specific cicada patterns that are available.
[00:13:09.813] Personally, I would probably start with a tan or a olive-colored, chubby Chernobyl. That's a good, kind of all-round, big dry fly that you can slap down on the water. And fish are probably not gonna be terribly selective. They're just gonna be looking for big pieces of meat hitting the water during this. So, they could get tough. But what I would use is any big foam dry fly, I guess. And I don't think that if there's a lot of 'em, the fish are gonna shy away from... If there's a lot of them, you may find them even more aggressive to eating them. They'll eat 'em until they just can't eat anymore and they're stuffed. So, I would look forward to it, and hopefully, you do well with them.
[00:13:59.179] Here's an email from Don. "As a PhD toxicologist, fly tier, and fly fisher, I wanna provide a slightly different perspective on the California Proposition, 65-warning label that are on some fly tier materials. Rather than completely ignore the warnings, as you suggested, I recommend some simple practical steps to ensure safety. This is especially important if the tiers are children learning the craft, pregnant, tying closed quarters for long periods of time, etc. I do not know all the chemicals used in the industry, but clearly, dyes are used, and some dyes are suspected human carcinogens with associated birth defects in laboratory animals. Hence, I would advise tiers to take some simple precautions. Here's my list. One, use a sponge or a cup of water to wet your fingers when needed, not your mouth. Two, wash your hands after tying and before eating. Three, tie in a large room or have a fan to circulate the air. I hope this short list is easy for everyone to use and will reduce exposure to chemicals in fly-tying materials. Thank you for your time and all that you do for Orvis and for our sport.
[00:15:10.009] Well, thank you, Don. And that's a good warning, and appreciate your comment. I guess I was a little too flippant in my recommendation that you ignore those warnings.
Joe: [00:15:24.923] Hey, Tom. Thanks for the excellent podcast. I have a few fly-tying questions today. The first one being about tying on tails like pheasant tails on nymphs under the size of 18. I don't have very large hands, but even with medium-sized hands, it's hard to get the right size of tail to pinch it on there. And usually, it ends up being too long or too short. I just can't quite get it right. Do you have any tips for tying on tails on small hooks, especially on curved shank hooks where the jaws kind of limit your accessibility to the back end there? Secondly, I've got sister's getting married in June this year in Kansas City, Missouri, and it just so happens that there's a big cicada year coming up that year. I just want to know if you have any favorite cicada flies. And yeah, thanks again and have a great day. Bye.
Tom: [00:16:37.532] Well, Joe, see above for the cicada recommendations. I don't have any favorite patterns because I've never fished a heavy cicada hatch. I've fished on the Green River where they were not terribly abundant, but occasionally around, but not in any concentration like you may see this year.
[00:17:00.305] Regarding the tails on your flies, I do have a suggestion there. So, what I would do is start your thread, take it back to the bend of the hook, and tie in your tails long. Just tie 'em in with about three, relatively loose turns of thread. Don't trim the tails, keep 'em long. Then take your fingers away, or take one of your fingers away. Keep one finger on the far side of the hook, and gently tug those tails forward until they're as short as you want 'em. Then you can go ahead and secure the tails with some tighter turns.
[00:17:48.038] Doing it this way will, you know...if you try to tie 'em in and you trim 'em so that they're even with where you want to tie 'em off yeah, you're right, you can have problems with 'em. So, I would just tie 'em in long. And then just be careful as you tweak 'em forward to make sure that you keep your finger on the far side of the hook so they don't roll over on the far side because you haven't put really tight turns of thread on there.
[00:18:14.986] The other option is to start at the other end and put your tails down on the hook, on top of the hook, arrange 'em how you want 'em, and then tie back toward the bend. Either way will work. But just keeping 'em long, don't try to tie 'em in real short, keeping 'em long and then trimming 'em afterwards, I think, will help you out. So, I hope that tip helps you.
[00:18:44.674] All right. That's the, admittedly, short fly box for this week. But we've got a good, full podcast for you with Anna Le. Let's go talk about bugs.
[00:18:57.731] My guest today is Anna Le. And Anna is a fish biologist, an educator, and she's also the founder of Grayling Education. And we're gonna talk about aquatic macroinvertebrates and how they're indicators of water quality, and what anglers can do to become citizen scientists, and, you know, add a little bit of, I think, enjoyment to your fishing by studying these things. But before we get into that, Anna, tell us a little bit about Grayling Education.
Anna: [00:19:33.090] Yeah, thank you, Tom. Grayling Education is a small, consulting business that really focuses on making environmental education a lot accessible and fun for people in conservation and science. And so, that's what we really strive to do at Grayling Education, is just bridging the barrier between, you know, science, conservation, and just make it, you know, attainable for people to care a little bit more about the world that we live in.
Tom: [00:19:59.305] And, like, do you have retreats or meetings or organization? How do you do that?
Anna: [00:20:06.464] So, right now, we really work with a lot of agencies to kind of, you know, consult them on what they can do better with their environmental programming, the languages that they use, kind of the infographics that they have in public and general audiences to see if it's actually being used by people. Also, lots of guest presentations as well as, hopefully in the future, workshops as well for people to come and just, you know, learn more about water quality or about wildlife photography, more of just like, place-based education by just participating in the activity itself.
Tom: [00:20:42.157] Great. And how would people find out more about Grayling Education?
Anna: [00:20:46.971] So, you can find out more about Grayling Education by going on the website. So, it's Or even checking out our Instagram page, which is just Grayling Education. And what I mean about Grayling is just gonna be about the same Thymallus fish that people know about hopefully.
Tom: [00:21:03.430] Great. Okay. Now, let's talk about bugs.
Anna: [00:21:07.971] Perfect.
Tom: [00:21:09.847] So, I'm gonna let you take it away.
Anna: [00:21:12.423] Okay. So, bugs, that's what really got me started to becoming a fisheries biologist. And so, back when I was an undergrad in college, the first few seasonal tech jobs I ever had was actually just studying bugs underneath a microscope for about maybe 5 to 10 hours each day, just in a microscope using forceps or tweezers and really sorting these freshwater macroinvertebrates, which are also known as the flies that people typically see when they're fishing.
[00:21:44.311] Macroinvertebrates just physically break down into two words, meaning macro is smaller than, you know, tiny, but just, like, big enough where your naked eye can just see it without needing a microscope. And then invertebrate just means critters that just don't have spine. And so, putting those two words together, macroinvertebrates are pretty awesome, you know, bugs and insects that you typically can see in a marine or freshwater ecosystem. And so, yeah, I just kind of think it's a great gateway for people to learn more about their water bodies around them.
Tom: [00:22:20.656] And what are they gonna tell us? Like, give us an example of know, you're poking around in a river bed and you're turning over rocks, or you maybe got a little sane in the water and you're kicking around. What are they gonna tell us?
Anna: [00:22:35.571] Yeah, that's a great question. So, people actually don't realize that with macroinvertebrates or these aquatic insects, they're what we call bioindicators. And so, what that really means is that they tell a story about the health of, you know, an ecosystem primarily when it comes to fresh water.
[00:22:52.530] And so, as you actually see like caddis fly or a Stonefly or even a mayfly, those three primary insects will actually tell you that the water quality is great. They're also known as, you know, pollution-sensitive, meaning that if there's any indication of pollution, whether it's from an upstream or nearby, you know, cause of that, then those insects will be the first ones to tell you, and let us know that there is something wrong with the water and their presence may be an indicator of that or lack of presence.
Tom: [00:23:23.252] Okay. And what types of macroinvertebrates would you find in a more distressed, polluted water?
Anna: [00:23:35.045] So, with a more distress or polluted water... So if there's something that you go onto a river ecosystem or even a lake and you just see stagnant water that's highly warm from, like, a mid-July day, really filthy, sandy bottom, high turbidity, just somewhere that typically, you wouldn't really go fishing in just because you're a little weary about it. So, some of the insects that you could find in that would be, you know, your snails unfortunately, and some of, like, the worms and, like, what we call scuds. And so, those are typically indicators that, you know, they're higher tolerant for pollution, and so you can find them in areas that may be representative of a distressful stream.
Tom: [00:24:18.773] Oh, so scuds and sowbugs are not as sensitive as the mayflies and stoneflies and caddis flies?
Anna: [00:24:28.102] Correct.
Tom: [00:24:28.758] Okay. Interesting. And how about crayfish? Are they sensitive to...? Because, you know, you see them a lot when you're turning over rocks. Are they sensitive to pollution?
Anna: [00:24:40.432] I believe they're not as sensitive as some of the caddis flies and mayflies and stoneflies. So, I think they're a little bit more tolerant than most other macroinvertebrate species, but they aren't gonna be... They, like, lie right in the middle.
[00:24:53.302] So, yeah, what's interesting with macroinvertebrates is that although they can tell us a lot about the water quality, that shouldn't just be the only, you know, variable that you test for when you're looking at a stream. So, they do kind of start this conversation of, hopefully, anglers when they're out there, one year and they're coming back the next year and realizing that, "Last year I had more blue-winged olives, right, and this year there's a lower number."
[00:25:20.998] Kind of having that question in your mind and also asking local fish and wildlife departments to see if there's anything impacting the stream. So, whether it's climate change or even weather patterns or even, like, upstream pollution that's maybe affecting downstream that people might not know about. But I think these macroinvertebrates are really just good storytellers and also conversation starters. So, although they aren't the one-all, be-all, you know, conclusion to, if a stream is healthy or not, I think they do bring a really good story to the forefront for people to care about.
Tom: [00:25:57.402] Okay. It's really difficult as an angler, you know, as an amateur like myself to quantify because hatches are so unreliable anyway. I mean, you go back the next year and there's no hatch. And it can be just due to a lot of factors and not necessarily water quality. So, is there any way that an amateur scientist like myself can quantify these things?
Anna: [00:26:28.570] Yeah. So, maybe quantification isn't a way to go about it, right, just because you said, you know, some years might be a little bit weirder than other years. And so, maybe finding those patterns as you continue with your angling journey.
[00:26:43.477] So, what I typically like to do is actually bring a Rite in the Rain notebook that fits in my fly pack with me. And so, when I'm out there, I kind of make, you know, notes of what I'm observing out there, what kind of insects I'm looking at, what kind of birds I'm experiencing, any wildlife spotting that I see that day or even the fish counts that I've hooked up onto.
[00:27:06.825] And then also just, like, having that in mind, I think, as you look throughout the years of your experience as an angler while comparing that data to, you know, USGS stream flows and CFS for the year, right? And also really paying attention to local politics and what may be happening. And so, what I mean by politics I mean just, like, going beyond angling. It's also like showing up for public hearings and seeing what's actually happening within the watershed. And so, I think that really starts with, you know, although you're looking at patterns looking that may be unquantifiable, but just really taking notice on how these changes may occur throughout the year could really spark more questions for yourself.
Tom: [00:27:48.807] Okay. Couple of questions about variable weather and climate change. You know, streams have been experiencing periods of floods, of course, they always have, and periods of drought. And they always have, but they seem to be more common and more prevalent now. How does a flood affect the macroinvertebrates, and how do droughts affect the macroinvertebrates?
Anna: [00:28:23.991] That is a great question. And so, you are correct when you mentioned that because of climate change, all of these variables are actually shifting at a faster rate or a slower rate just due to climate change. And so, this baseline data that we're, you know, used to looking at is shifting, right?
[00:28:43.156] And so, regarding to droughts or even a flood season, those really just affect stream flow. So, like, the level of water that you see in a stream, so the CFS, you have the feet per second, and also the temperature changes as well. So, if you ever go out to Central Oregon and fish doesn't shoot, each year you can actually see the river being affected by the rises of water and actually cools down a system. So, with the cooling of a water body, that actually affects the rate in which the macroinvertebrate will hatch.
[00:29:17.460] And so, what people typically mean by hatch, it just means that they're emerging from their, like, nymph and emerging stage and then going into their, like, terrestrial stage where they actually get on land, you can find them in the brushes, and then they're flying around poorly because they're horrible flyers. And then, they will lay their eggs and then die within one day to a week.
[00:29:41.413] And so, those changes actually shift when it comes to temperatures of the water. Whereas, you know, with a stonefly, it would take them about a year to four years to lie in their nymph stage. And just depending on the temperature and the condition, it may take them a little bit faster or longer to be in those other stages in their lives.
Tom: [00:30:02.242] Okay. And how deleterious are floods to these macroinvertebrates?
Anna: [00:30:10.989] They are pretty significant according to impact just because these macroinvertebrates, they do lie in the same areas of the stream. Even though they're mobile, they don't really move around as much as trout, right? So, when it does come to, you know, flood or drought impacts and water levels, it does really affect on their habitat and also just other variables that they may need for being able to live in these conditions just like trout. And so, also with level of oxygen, turbidity also plays a role in it, and also the level of sediment or silt that's present in the water as well.
Tom: [00:30:52.674] So, when a mayfly or stonefly is on the bottom under a rock and it floods, unless the gravel actually starts moving or big rocks start moving, they're not affected that much by a flood, are they? Because they're in an area of almost zero velocity underneath a rock.
Anna: [00:31:15.813] Yes, correct. So, yeah, they don't get washed downstream. It's more of just those other variables that may affect whether they thrive or not in that spot that they live in.
Tom: [00:31:28.142] Okay. So, it's silt and water temperature and things like that, not necessarily the force of the current.
Anna: [00:31:34.168] Yes.
Tom: [00:31:34.810] Okay. And when you have a drought, they are mobile, do they...? I can imagine that, you know, a lot of them live in the margins of the stream. Can't they just scuttle out toward the center of the river where there's more current and more water?
Anna: [00:31:54.010] Yes and no. Although they can do that, I feel like these minute changes that look minute to us may not be minute to these macroinvertebrates, right? So, if you're talking about a shady part of a riparian system next to the banks, yes, you might be able to see that change occurring. But I feel like, for these macroinvertebrates, a lot of the times, these, you know, very insignificant changes that are not so insignificant may still really impact their capability to live in these ecosystems.
Tom: [00:32:29.539] Okay. Okay. So, they like stable flows and they like, obviously, cool water, oxygenated water, and anything that is gonna affect that is gonna affect them.
Anna: [00:32:41.783] Yes.
Tom: [00:32:43.832] And how about land use practices? So, something that keeps me up at night is the presence of neonics. I live in an agricultural valley. I don't know what's being put on the fields by farmers upstream of me. And I don't think that they're required to, although they have to... I mean they have to have permits, right, to use pesticides and herbicides. But they're not required to tell anybody, a citizen what they're putting on their fields, right?
Anna: [00:33:28.484] They're not. But I believe if they do apply for those permits, they do have to inform, say, like the Department of Environmental Quality on what, you know, fertilizer and how much they intend to use. And that is being reported. So, with agencies like the Department of Environmental Quality, their duties are to keep track of what they're permitting, how many they're permitting, and also to ensure that whatever, you know, ranchers and farmers are using aren't gonna have a major impact in the freshwater ecosystem around them.
Tom: [00:34:01.754] Can that information be obtained by the public, or is it just kept by the Department of Agriculture and Environmental Quality?
Anna: [00:34:10.901] It should be attainable by the public because it is a public agency. In terms of, you know, the personal ranch and farm names, I don't think that is public information. But I do know on an annual basis they do have to report it somewhere. And you can probably go online and actually look up those reports and see, you know, like what is the quota this year, what's allocated, how many permits were given, what were the areas, what were the watersheds as well.
Tom: [00:34:38.754] Okay. We know that pesticides, particularly neonics, are damaging our insect populations. I don't think there's any question about that. How about herbicides? Do they have any effect on the aquatic insect life?
Anna: [00:35:02.307] So, with herbicides, I believe they do contribute to more, like, harmful algal blooms, especially with, like, the influx and levels of nitrogen. So, it really just depends on how much is really getting into our water systems due to runoff and usage as well on land, and then, how that's controlled. But again, going back into, you know, maybe it's not a direct factor to these macroinvertebrates and maybe it's coming from more harmful algal blooms that causes higher temperatures in the water ecosystem and lower oxygen levels that really affect fish and macroinvertebrates. And so, there are some connections there for sure, but yeah, it definitely depends on how much you're using and kind of the approach to it as well.
Tom: [00:35:49.063] So, the herbicides can actually stimulate an algal bloom?
Anna: [00:35:54.272] Yes. They can.
Tom: [00:35:56.159] Really? Herbicides are meant to kill plants, right, and algae or plants.
Anna: [00:36:03.400] Yes. And someone out there could probably email me and double-check me on this, but I know, because it's not my specialty. But I feel like with herbicides and any of these, like, fertilizers or chemicals that are used to, you know, kill one life to maintain another, there are some implications of chemical usage in there. And depending on the compound and the makeup of it, it does, you know, form another consequence out there that could be directly impacting other wildlife and other quality of the ecosystem.
Tom: [00:36:41.114] Okay. Okay. I know I'm giving you the hard questions here, but I'm curious.
Anna: [00:36:47.998] It's a great conversation.
Tom: [00:36:52.607] So, as citizen scientists, what can we do? Let's say, one year we find a lot of stoneflies, which I think are the most sensitive. Aren't they more sensitive than even mayflies and caddis flies?
Anna: [00:37:10.188] Correct.
Tom: [00:37:10.834] So, we find a lot of stoneflies one year, and over a course of a couple of years, there are fewer and fewer stoneflies just by eyeballing, you know, turning over rocks and eyeballing, "Oh, God, I'm not seeing many stoneflies and I'm seeing fewer mayflies in the creek, in the river." What can an individual do about that?
Anna: [00:37:37.306] I would definitely advocate for asking more questions. And I feel like a lot of people don't do enough of that, right? And I don't feel like a lot of people have these conversations, because when I'm on a river with you someday and I notice that, you know, there's a of stoneflies or mayflies from previous years, it's like having these conversations with your fishing buddies and also asking these questions too like, "Hey, what do you think could be happening this year that is affecting the population levels of last year's?"
[00:38:10.301] And so, really looking into it and going back home and actually doing a simple Google research can go really far as well where, you know, there might be a legislation or, you know, any political turmoil in the news that says like, "Oh, yeah, there is a mine that's being sued right now because they are using and dumping in the rivers beyond their quota. And that may be affecting the downstream part of it."
[00:38:38.145] Also, just, like, going in and asking Fish and Wildlife as well if they can share any of their stream surveying data that they've taken that year and see if anything changes throughout the last 5 or 10 years, right? And also just, like, raising questions as well where you can ask these professionals within these agencies more about what you're seeing and kind of your concerns about it.
[00:39:03.215] And I think when you're raising these concerns, there are room for discussions and dialogue where maybe people don't really think to notify the public of what's going on, right, or maybe there needs to be more education around what's going on. And so, yeah, I think just asking these questions and going back and doing your research, and also just exploring and continuing approaching the stream with, like, a childlike curiosity where you just have to go in knowing that you don't know what you don't know, and going home and making a mental note and just, you know, bring up these conversations can be a really good start for people, especially anglers to be stewards in their watersheds.
Tom: [00:39:48.713] So, asking questions, making calls, doing their research, and finding out what could be going on. And maybe nobody knows about it, right? Maybe you're gonna be the first one to ring the alarm.
Anna: [00:40:04.046] Yeah, absolutely. And also going home and picking up an aquatic insect book, right, and also learning more about their lifecycle and what makes them unique, and the biodiversity around them. So, maybe in the past, like 30 years ago, there might be a species of macroinvertebrates that was prevalent in your local watershed and now it's no longer there, right? And then asking these questions like, "Why may that be?" And also, "What happens to the biodiversity?"
[00:40:30.377] So, really learning about the animal itself too, and how it's all cyclical and seasonal. Understanding the lifecycle of these macroinvertebrates not only makes you a better steward but also, you know, goes back into being an amazing angler by understanding, you know, trout food, also, like, the levels of water and how that may be affecting it. So, everything is really truly connected.
Tom: [00:40:52.488] Okay. Do you have any books you would recommend or websites for people who want to learn more about their aquatic insects? I get this question all the time. And I have piles of books on aquatic insects, but I wanted to see what your recommendation might be.
Anna: [00:41:11.800] Yeah. So, one of my favorite books that I've ever picked up was from, like, a local indie bookstore that was used and battered, and it's called "Hatch Guide for Western Stream." It's by Jim Schollmeyer. I believe most folks are maybe familiar with him, maybe not. But he does a really good job of putting identification guide of the actual macroinvertebrates itself and then put them side by side with the actual flies.
[00:41:39.147] And because I started off as a scientist learning more about, like, the Latin terminology and the genus that these insects really fit into, I'm still a newbie when it comes to learning about my flies and the different names for them. So, that's, like, one of my favorite books where if people are starting from the opposite realm where they started off as an angler and learning more about the flies, that's one of my favorite books that I would recommend for people.
[00:42:03.212] Because I'm located in Oregon, I picked up "Western Stream." So, obviously, there are gonna be guys out there that might be for, you know, Midwest and also the East Coast, or even the South as well. So, finding something local to you would be really helpful.
[00:42:18.248] And then there's a website called, which is open access, public education use where you can actually go in there and zoom in to the deepest part of this macroinvertebrate and seeing the thorax and also the legs and the ligaments and the body parts. And it actually is really cool resource to see what these macroinvertebrates look like close up and also learn how to better identify them and learn more about their life history as well.
Tom: [00:42:50.097] So, it's called
Anna: [00:42:55.145] .org.
Tom: [00:42:55.969] .org. Okay. Yeah, that sounds like a great one. I wasn't familiar with that one. And does it have keys in there where you can actually try to key it out to genus or even species?
Anna: [00:43:08.126] Yes, absolutely. They have dichotomous keys where you can you said, you know, if this one has antennas, no antennas, which way do I go for these insects? And then they do a really good job of already storing them out into the genus groups already. So, you know, mayflies, stoneflies, caddis flies, but then just the different biodiversity that you see and different species as well.
Tom: [00:43:31.072] I'm gonna use that myself. Interesting. Yeah. It's always good to have an online resource. And I wasn't aware of that one. So, that's a great one.
Anna: [00:43:42.811] Yeah. Let me know if you do end up using it and what your thoughts are on it because I'd be curious, from an angler perspective.
Tom: [00:43:48.975] Yeah. It's interesting most of us know our flies, but we don't know the bugs, and you know the bugs and you don't know the flies as well. So, it's an interesting take on the situation.
Anna: [00:44:02.111] Yeah. And, I guess, the question I have for you is that, from a person who know their bugs and not their flies, and maybe there are others like that who are probably getting to fly fishing for the first time, do you have any tricks, or, you know, knowledge on how I could better learn my flies?
Tom: [00:44:21.110] I'm supposed to be asking the questions here.
Anna: [00:44:24.056] I'm sorry.
Tom: [00:44:24.163] You don't get to ask any... No. You know, really the best way to get you to know your flies is to begin tying your own flies. I think that you're never gonna really know flies and you're never gonna really be able to tell, you know, a hassar from a flashback hassar or a pheasant tail until you start tying them because then you start looking at the various parts of the fly. Instead of just seeing a fly, you see, "Oh, the tails are this and the body's this, and the thorax is this, and the wing case is this." So, I think that learning flies better, tying flies is the best way.
[00:45:18.608] Another way is, when you buy flies, label 'em. You know, label 'em on your box or somehow take a picture of them, take a picture of a fly with your phone and with the name of it on there, and then you can refer to it later. I mean, there are a lot of online retailers of flies, and there's printed catalogs of flies that you can use for reference to. You know, books like Jim Schollmeyer's book that you've recommended, that's a good one. But I really think that you need to learn to tie flies, Anna.
Anna: [00:46:06.066] Okay. Perfect. Well, maybe we can jump on another call in the future and tie flies together.
Tom: [00:46:11.756] Okay. And, you know, certainly, people should understand you don't need to imitate an insect to this specific genus or species or even order. You know, fish see these things going by pretty quickly in the drift. And as long as it looks like food, they're probably going to eat it. As long as it looks like something they're used to eating, they're probably going to eat it as long as it's moving naturally with the current.
[00:46:47.244] So, you know, people shouldn't agonize over exact imitations of insects because I don't think you need to. I always tell people, I think you need to learn your macroinvertebrates to the order level. So, you need to be able to tell a mayfly from a caddis fly, from a midge, from a stonefly, and then, you know, some of your crustaceans like sowbugs and scuds and crayfish. But I don't think you need to know the exact species of aquatic worm or midge larva in your stream. I don't think that's gonna do you that much good unless you're just interested in it like you are.
Anna: [00:47:30.239] Yeah. And I think that's a really good point because sometimes I'm watching trout or salmon in a river and a leaf falls, and then everyone's trying to go at it and feeding on it. And so, yeah, sometimes you can put anything else there and the fish will eat it, right? So, yeah, you don't have to be so in tune and specific with the type of flies that you're using when it comes to the species.
Tom: [00:47:51.823] No. If they didn't make mistakes, we'd never catch 'em, right?
Anna: [00:47:55.245] Yeah. Yeah.
Tom: [00:47:56.107] Because everything we fish has a tip sticking at one end and a hook sticking out the other end, and they ignore that. So, if they ignore that, you don't need to be that close with your imitation.
Anna: [00:48:11.280] Yes.
Tom: [00:48:14.939] All right. So, what else were we gonna talk about? Oh, you know, the one thing you didn't...talking about pollution-tolerant insects or macroinvertebrates, it's interesting that you didn't mention midges, because I've always been under the impression that midges are able to tolerate low-oxygen, polluted waters better than other aquatic insects. Is that true?
Anna: [00:48:46.749] That is true. And thank you for bringing up midges, because yes, we're graced by midges, and I know a lot of people actually fish with midges or a fly that looks like a midge out there. And they do actually fare well a lot better in pollution, more polluted or, you know, degraded streams than other macroinvertebrates such as the mayfly or the salmonfly or the caddis.
Tom: [00:49:13.192] Okay. Okay, good. And I think that, you know, you see that in tailwaters a lot where you see it especially very close to the dam because the water that's, you know, often coming out of these tailwaters is colder, but it's often lower oxygen because it's coming out of the bottom of a reservoir. And, you know, the closer you get to the dam, the more midges you see as opposed to mayflies and stoneflies and caddis flies. Do you see that in your research?
Anna: [00:49:49.459] I actually haven't taken notice into that. So, that's definitely something for myself as a biologist and educator to notice next time I go out.
Tom: [00:49:58.421] Yeah. I've just noticed that over the years, you know, the water coming out, you know, from deep reservoirs generally more nitrogen, less oxygen, and midges seem to be able to handle that better.
Anna: [00:50:14.663] Yeah. I'll have to look into that for the next time I go out into a stream.
Tom: [00:50:19.282] Yeah. We're gonna have to have you report back on that.
Anna: [00:50:22.363] I do. I guess, like, once... Oh, go ahead.
Tom: [00:50:28.059] You know, another question I wanted to ask you, something that I've always been curious about. So, we know that riffles add dissolved oxygen to the water. So, in times of low oxygen, whether it's pollution or warm water that holds less oxygen, fish are going to tend to be, and probably the bugs are gonna tend to be closer to the riffles, right, closer to the whitewater to where the air to water interchange is more vigorous. Do you know how quickly oxygen comes out of solution? So, in other words, I got a riffle and it's, I don't know, 8 parts per million oxygen. How fast does that oxygen come out of solution? Do you know?
Anna: [00:51:24.578] With a specific number, I don't know. But I do know it is pretty quick.
Tom: [00:51:28.694] It's pretty quick. Okay. Okay. That's good to know. I've always wanted to test that myself, but I looked into buying a dissolved oxygen meter and it was more than I wanted to spend. So, I haven't done the research.
Anna: [00:51:48.612] It is. Yeah, they are pretty much of an investment for sure. And I was gonna joke that Orvis should probably carry the old meter kits just for anglers, but that would be, like, a really pricey scientific project that people can do at home. But I do know that you can probably get that data somewhere at your local, like, agency or nonprofit who have been doing these community science projects and collected that data themselves too, and even classrooms.
[00:52:15.421] There are so many freshwater macroinvertebrate classroom projects now. So, like in Colorado, there's, like, a statewide one where they actually go and collect water quality data. And that goes back into, like, a statewide database, right? And so, I think that's a really cool way for students and also teachers to tie back into their local watersheds while learning more about these scientific variables within the freshwater rivers and lakes.
Tom: [00:52:41.629] Yeah, that's great. I know a lot of the local schools here in Vermont have been doing that, have been doing water testing. And I think Trout Unlimited also has some programs where people can collect water samples and send them in. All right. So, I guess we've covered everything that we wanted to cover. Any final words for, you know, my listeners who are anglers first and entomologists, maybe not at all, or definitely a second or third priority, what they can do, how they can learn, what they should do?
Anna: [00:53:29.058] That is a great question. Yeah. If you start off as an angler first and see a stream as an angler before you see it as a scientist or as a biologist, I highly recommend trying to push yourself, hopefully in the next few years or even this year too, to start asking these questions and also look at a stream in a different perspective, because I think that would actually help you become a better angler and also just become a better steward when it comes to these local watersheds as well.
Tom: [00:54:01.898] Yeah. Okay. All right. Well, we're all gonna promise that we're gonna be more cognizant of these things in the coming season.
Anna: [00:54:12.750] Yeah. I hope so.
Tom: [00:54:16.048] Okay. All right, Anna. Well, thank you very much for joining me today and sharing your knowledge. This has been great. And I know a lot of my listeners are curious about the aquatic insects. So, I think you've really added to all of our education about this very important topic.
Anna: [00:54:35.533] Yeah. Thank you for having me on. And if folks out there have any questions, feel free to reach out over, you know, social media or even my email as well, and I'd love to have a discussion with you.
Tom: [00:54:45.904] Okay. I wouldn't give people your email, but they can probably reach out to you through your Instagram account, right? Are you the one that monitors that?
Anna: [00:54:57.932] Yep. Instagram account or even the contact form on my website.
Tom: [00:55:01.506] Okay. So, Gralying Education.
Anna: [00:55:04.183] Yes.
Tom: [00:55:04.847] All right. Well, thank you, Anna. This has been nice talking to you.
Anna: [00:55:09.932] Yeah, it was good talking to you, Tom. Thank you.
Tom: [00:55:11.963] Okay. Bye-bye.
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