Jason Hwan

In critical spawning and overwintering habitat for salmonids Hwan studies the effects of temporal stream fragmentation across three organizational levels of ecology: population, community, and ecosystem levels.

Transcript

Speaker 1:        Spectrum's next 

Speaker 2:        [inaudible].

Speaker 1:        [00:01:00] Welcome to spectrum the science and technology show on k a l x Berkeley, a biweekly 30 minute program bringing you interviews featuring bay area scientists and technologists as well as a calendar of local events and news. 

Speaker 3:        Hi, my name is Brad Swift. I'm the host of today's show. Our interview is with Jason won a third year phd student in the Carlson lab, which is [00:01:30] part of the environmental science policy and Management Department of the College of natural resources. Professor Stephanie Carlson directs the lab and she is a fish ecologist. Jason is researching the effects of summertimes stream drying on fish ecology in the John West fork, a creek in Marin county. The John West fork is the spawning grounds for two varieties of salmon the summer of 2011 Woolmark the third year of his research on this stream. [00:02:00] His research will continue for two and possibly three more years. This interview is prerecorded and edited. 

Speaker 4:        Jason, welcome to spectrum. Thanks for coming in. Thank you. Wanted to ask if you could, uh, give us a brief overview of your research and add in there how it's being funded. My research is looking at the effects of low summer flow on juvenile steelhead, on the insect communities out in the stream and [00:02:30] on certain ecosystem processes such as Algal production and leaf decomposition. And it's currently being funded by, mostly by my, by my guiding professor, Stephanie Carlson. And I also have some funding from our department and the division within our department. All right. We get out a sperm wildlife grant, which helps fund the research. And also I'm currently on an NSF graduate research fellowship. Described the, the general [00:03:00] area of the site that you chose. Sort of put it in context of where it is. So my study say, uh, the John West work is in point Reyes national seashore, which is about an hour north of Berkeley in a national park in and surrounded by some state parks. 

Speaker 4:        Also. Can you explain the watershed and the area that you're working, how it all interrelates to the watershed? So I'm, I'm working in the Lagunitas watershed. I'm working [00:03:30] in a creek that is a tributary of a tributary of a creek to the lock Anitas to log in neatest creek and log Anitas creek flows into Tomas Bay in point rays. The creek that I'm working in is a little different in that there are only two species of fish up there. Both our salt Monets, there are still head and coho salmon. This is because it's not that the creek went dry, completely dry one year and there's, there [00:04:00] was a culvert that was put in place and other fish species weren't able to recolonize the creek, but someone had adults can jump over the barrier. And so they were able to recolonize the creek and they're actually jumping through the culvert. 

Speaker 4:        Yeah. And through this culvert and swimming up swimming into the two John West work. And what's the drop on the culvert like from, from the the bottom lip to the dead of the bid. Lower part [00:04:30] of the creek. It's about four feet. Four feet drop-off. Yeah. So that's quite a leap for the salmon. Yeah. And so with this study, what is it that you're trying to learn? That is not already known. So I'm basically trying to look at the effects of low flow and my study is really looking at what the affects are at a really fine scale. So I'm tracking, uh, juvenile steel head growth, movement and survival and I'm tracking them on a weekly basis. So [00:05:00] it's pretty fine scale monitoring, which is something that hasn't really been been carried out before. And the low-flow period is when, uh, the low, the low flow start after the last records. 

Speaker 4:        And as the, as a temperature gets warmer, the stream starts to dry and it pretty much lasts throughout the summer until the first rains of the following year. Are you collaborating with other people on your project? Not directly with my lab mates on [00:05:30] my project. Sometimes they might come out and help me, but for the most part I've been working alone with the help of some undergraduates. There are certain side projects that we collaborate on. Um, there's also a person who is working with me from, uh, from a different department. He's not really working on my project, but, uh, something that's related to my project out on my field site. It mean it helps both of you? Yeah, definitely. And is that going to have some bearing is his, his [00:06:00] work or her work and I have some impact on your results. It definitely is connected. It is connected to, I'm more at the temperature and looking at how stratification and pull temperature stratification in pools might affect fish behavior. 

Speaker 4:        So where, where they kind of hang out in the pool. So that's something that could definitely help us fold into your report. Yeah, exactly. So in doing your research [00:06:30] and working in the field as opposed to, uh, if you're working in the field and the lab, how much time do you spend in the field and in the lab? Um, when I'm out during the summer, uh, during my field season, it's a pretty big chunk of it. About 80 to 85% is probably spent in the field and the remainder is spent in the lab. Um, but once the summer is over and on, the field season is over. Most of the time is spent in the lab, um, [00:07:00] crunching data, processing samples and stuff like that. 

Speaker 5:        [inaudible]

Speaker 2:        you're listening to spectrum on KALX Berkeley. Today we're talking with Jason Juan about his research into summertime streaming drying its effect on Fish Collagen

Speaker 5:        [00:07:30] [inaudible]. 

Speaker 4:        And so was there fish breeding going on in this part of the Stream? I would assume that that's the reason they're up there. Yeah. So one of the adults jump up into the stream. They breed typically during the winter when the rains, they come back with the rains [00:08:00] and they breed and the eggs hatch and spring. And then I kind of track the juveniles once they get to a large enough size to be able to monitor to them. So as you start to go up in the early spring, you're seeing lots of of small fish. Yeah. And it's so the fish that have spawned, have they left then or are do some stay? Yeah, but most of them have left. They're too large to stay in some of these pools. So most of them leave and with the Coho that or [00:08:30] they die right after they breed because they just breed once and they die. 

Speaker 4:        But with the, with the steelhead, they're able to breed multiple times. And Are you tracking it all that mortality of the coho that are coming up and breeding? No, but the park service is definitely keeping track of adults, adult spawners they go up every winter and quantify the amount of a salmon reds, which are the nests that someone is build. And they also try to [00:09:00] keep track of how many fish, adult fish that they see. Talk about the insects in the fish in the same context of the frequency. So with, with the insects, um, it's, it's a pretty disturbing method to go and collect them. So we try not to collect them too frequently. We recollect them once at the beginning of the summer and again at the end of the summer. So we don't want to disturb the habitat too much that we have to kind of dig in [00:09:30] to the stream and it just disrupts, disrupts things a lot. 

Speaker 4:        So we try to keep the frequency down and with the fish, um, we go out again, it's similar to to the insects that's we have to go and shock them and which as you can imagine, um, is quite stressful to the fish. So we shock them once in the beginning, beginning of the summer and we place pit tags into them, um, which allows us to monitor them across [00:10:00] the summer without having to actually handle them. Also, while we, um, capture them during the first event, we weigh them and measure them. And then during the late season capture event, we weigh them and measure them again and we're able to identify which the fish that were tagged, we were able to determine their growth rates and their survival. In addition, we can monitor them using the pet tags. We have a, a [00:10:30] handheld antenna that we take out and we just place it over the stream and we're able to find out where they're located or, and also if they're other still alive. 

Speaker 4:        So that happens pretty much once a week. So the pet tag is like a radio. Gotcha. Yeah, it's an audio id, tariff id similar to what is found in a for pets, the microchips that they use for pets. And then you can also measure the mortality with that as well I guess if, yeah, so we go [00:11:00] out and we try to track their movement and also if we find a pit tag, we just kind of disturb the area around, uh, around the tag lightly. And if, if the tag isn't moving, then we kind of can surmise that there has been a mortality event that that occurred. Do you remove the fish or the die or now it's pretty hard to find them because we don't track them every day. So, so things happen [00:11:30] within the week and sometimes we kind of look around for the tag but it's pretty hard to find the tag. 

Speaker 4:        But if we do come across any fish we do, we do take you back to the lab. Any dead Fisher and they are often tagged or have they not? Some of them are just untagged. We try to tag as many fish that we can capture at that are a certain size. They to be a certain size and size for them. So we do try to capture and tag every fish that is of [00:12:00] a certain size, but whether we do within that period of time that you can do the, that you're doing the tagging because you try to limit that. Yeah. How long is that period? What do you do? I've tried to do it all in a week. Three to four days. The tagging, the taking takes about three to four days. The caption and taking. And what's that like in terms of a process? Is it, is it you and a bunch of people doing it together? 

Speaker 4:        Yeah. Take a little group out. Yeah, we actually took a group out, um, and we actually stayed out there for the three, three or four days. We wanted to get an early start [00:12:30] in the day and it takes about an hour to get, get out there each day. So we just decided to stay out there and it's actually quite fun. Um, most, most people really everybody volunteers to do to do like fish capturing. They're like, oh yeah, I want to do that. It's something that the interns really enjoyed. So is that time that you're in the creek, are you actually standing in the creek? So I, yeah, I actually get into the creek and I have a, an electrical Fisher and I move through the creek, [00:13:00] shocking the fish and there are a couple of them matters beside me on the scoop up any fish that had been shocked and we placed them into a bucket and then from there we kind of weigh them and measure them after, after all the fish have been captured for a certain pool. So you do this pool by Paul? Yeah, exactly. 

Speaker 5:        You [00:13:30] are listening to spectrum on KLX Berkeley. We're talking with Jason y about his researching the summertime scream drying and its effect. 

Speaker 4:        So Jason, how did you get interested in science when you were in high school, say or college? [00:14:00] I've always kind of really been interested in science as a kid. I really enjoyed reading science textbooks and it was as one of my favorite subjects and I just decided to stick with it. And I, I majored as a, as a biology student. And what about it appealed to you when you were young? It was like, it was the investigative process, [00:14:30] I guess that that appealed to me. It was just something that you can go out and observe and I really like that, that you can, you can actually just go out and see how nature works. And I was really fascinated by that. So biology was sort of the entree and then as you went through high school, College, yeah, I majored in biology and I really enjoyed my ecology class, just getting up out [00:15:00] there and I wasn't too keen on the molecular side of biology, but the ecological part aspect of it was really fun to get out there and observe things. And, and so it was it field work then that led you to streams? Yeah, I actually worked as a, as an undergraduate. I worked with a professor of mine and he would take me out into streams in southern California and it was quite a great experience for me. And what sort of work and studies research [00:15:30] was he doing? He was, he was doing, uh, population, uh, studies of endangered and threatened fish in southern California. 

Speaker 4:        So when you're in the lab, what sort of data are you gathering? So for instance, with the leaf litter bags and the Algo production, um, when we come back from the field we have to process those samples. So we deploy tiles and we have to scrape off the LG from the tiles. And then we [00:16:00] have to run an analysis to quantify chlorophyll production. With the leaflet or bags that we set out, we bring them back and we, we way leaves in them and quantify how much leaf litter mass has been lost across time. What is it about the algae that you want to know in the river? With both the algae and the leaf litter, we want to see how the stream drying effects say Algal PR productivity or leaf litter decomposition. So we want [00:16:30] to see how much, how much Algo productivity there is in the early part of the summer when or when the stream is still pretty connected. 

Speaker 4:        And then again, we want to track that change over time to see how productivity changes as the string gets dry and dry and with the leaf decomposition, same thing, seeing it over the, over the time, yeah. We want to see how decomposition rates change as the stream gets dryer and with that we're finding that decomposition rates slowed down quite a bit. [00:17:00] As the stream dries, there's less microbial activity, less insect funner to shut up the leaves. Are there other key data points that you're collecting out of the stream? Yes. I'm trying to measure the volume of water in the creek. Mostly the volume of water in between the pools of the fast flowing portions called riffles. I tried to measure how much water is in these portions and I go out pretty much every week and measure the dimensions [00:17:30] of the riffles and I'm able to get volume on every week and I'm able to quantify how this volume gets smaller and smaller every week. Eventually these, these pools are isolated and there's no more flow exactly. Between pools. Yeah. The, the riffles just most of them completely dry up by the end of summer. 

Speaker 3:        And so the fish are then isolated in these, yeah, they're isolated. 

Speaker 4:        The there aren't able to move among the different pools 

Speaker 3:        at this point. Is it too soon in your study to, to [00:18:00] reflect on what you might conclude? Well, I'm, 

Speaker 4:        I'm already seeing some pretty drastic inter-annual variation and precipitation in the area. So as I mentioned earlier, 2009 was a very dry and that was your first year? Yeah, 2009 was a very dry year, so I noticed that there was quite a bit of a mortality for the fishes. Uh, this past year, 2010 and during that summer was a lot wetter. There was a lot more habitat for the fish. A survival was a lot higher. So [00:18:30] Marty seen, uh, some significant results in terms of inter annual variation and how more extreme temperatures and extreme dry might influence the fish population. 

Speaker 3:        Is there any part of water quality that you're measuring? 

Speaker 4:        Temperature and a dissolved oxygen levels? Not In terms of pollution really, but a temperature and dissolved oxygen are are really key for [00:19:00] some almond species in particular, they require cool temperatures that are pretty well oxygenated. 

Speaker 3:        The information that you're getting from your study will have an impact on other streams and creek management potentially. Yeah, that's, that's my hope 

Speaker 4:        is that especially in certain areas where water withdrawals occur and there needs to be a certain amount of a water, hopefully our findings can maybe influence these areas where water withdrawals occur in the [00:19:30] stream comes even more dry than they typically should naturally. 

Speaker 3:        Jason, thanks very much for coming in and talking about your research. Yes. 

Speaker 6:        Oh, 

Speaker 7:        [inaudible].

Speaker 3:        A regular feature of spectrum is dimension. [00:20:00] A few of the science and technology events happening locally over the next few weeks. Joining me this week to bring you the calendar is Rick Karnofsky. 

Speaker 8:        In 1848 gold was discovered in the Sierra Nevada mountains luring people by the thousands to California. Join Ranger Tammy on Saturday, August 13th from 11 to noon to find out how this event changed the San Francisco Bay forever at the Bay model visitors center in Sausalito. This is a free event on Saturday August 13th at 4:30 PM Christopher de Carlo [00:20:30] will present how to be a really good pain in the ass. A critical thinkers guide to asking the right questions at Kelly's Irish pub, five 30 Jackson Street, San Francisco visit. Reason for reason.org for more info. That's r. E a s o n, the number four R e a. S. O. N. Dot. O. R. G. 

Speaker 3:        The science at Kow lecture series for August will be presented by Dr Willie Michaelson and is entitled nanotechnology, Enabling Environmental Monitoring. [00:21:00] Dr Michelson is the executive director of the center of Integrated Nano Mechanical Systems known as coin's, a nanoscale science and Engineering Center headquartered at UC Berkeley dedicated to enabling and realizing novel environmental monitoring applications using nanotechnology. The date of the lecture is Saturday, August 20th at 11:00 AM in the genetics and plant biology building room. 100 

Speaker 8:        August 17th center night takes [00:21:30] place at the rickshaw. Stop. One 55 [inaudible] street at Van Ness in San Francisco from seven 30 to 10:00 PM at this $8 old age of show you'll hear talks about winery building, a virtual reality chocolate factory and neutrophils, one of the first immune cells to reach infection sites. Be there and be square. Visit SF dot [inaudible] Dot Com that's SF dot n e r, d an ite.com 

Speaker 8:        nightlife takes place Thursday nights from 6:00 PM to 10:00 PM at the California [00:22:00] Academy of Sciences in San Francisco's Golden Gate Park. It is 21 and over and pictures music, cocktails and exhibits centered around a theme. In addition, the regular exhibits such as the rainforest and planetarium will be open. August 25th nightlife is on dinosaurs. Paleo lab will present a fossil shone till featuring trilobytes Coprolites, Aka fossilized dyno poop and other amazing fines that are 65 to 500 million years old. Check out additional specimens from the academy's research collections and at dyno burlesque. Show [00:22:30] the planetarium will feature cosmic collisions, a fulldome show depicting the hypersonic impacts that drive the evolution of the universe, including a recreation of the meteorite impact that hastened the end of the age of dinosaurs 65 million years ago. Clearing the way for mammals like us to thrive admission is $12 for more info and for tickets, visit www.cal academy.org that's www dot c a l a c a d e m y dot o r g 

Speaker 3:        [00:23:00] and now several news stories. This item from the inside science news service scientists battle the dramatic declines of honeybee colonies with targeted breeding. There are a handful of pests and diseases that individually and in combination are causing unprecedented mortality in [00:23:30] honeybee colonies in Europe and North America. Serious efforts are being made to find solutions that can eradicate the pests and diseases. While the search for a solution continues. Researchers in Canada and the United States are attempting to bees that are resistant to Mites and viruses that attack bee colonies. The breeding process exposes the Queens to high levels of what is termed disease pressure. According to Rob Curie, professor of entomology [00:24:00] at the University of Manitoba. The survivors are then bred next season and so on. Seven generations have been bred so far. We are looking for bees that are resistant to mites and with a greater tolerance to viruses because they appear to be the two main factors behind colony loss. 

Speaker 3:        QRI said and added breeding attribute pursued by the Canadian breeders is the ability to withstand the brutal North American winters. Curious said [00:24:30] that normally only 46% of the species known as European honeybees survive the Canadian winter, but the newest generations have a 75% survival rate. The total losses from managed honeybee colonies in the United States were 30% from all causes for the 2010 2011 winter according to the annual survey conducted by the US Department of Agriculture and the apiary inspectors of America. [00:25:00] This is roughly similar to the losses reported in similar surveys done in the four previous years. This story from Metta page today, lab grown trickier implanted in patient June 9th, 2011 at the Karolinska University Hospital in hunting, Stockholm, Sweden. Dr Paolo Macchiarini implanted the first ever bio artificial trachea grown on a synthetic [00:25:30] substrate using the patient's own stem cells. The patient was a 36 year old cancer patient for this procedure. Dr Macchiarini and his colleagues collected stem cells from the patient who had late stage tracheal cancer since no suitable donor windpipe was available. The researchers used a nano composite tracheal scaffold designed and built by Alexander Se Follian Phd of the University College London. [00:26:00] They seated the polymer model with auto Lucas stem cells. These are blood forming stem cells and grew them for two days in a bioreactor. Dr Mk Jadine says there's no room for rejection because of the cells are the patient's own. Thus, there is no need for him to be on immuno suppressive drugs. 

Speaker 2:        [inaudible] [00:26:30] occurred during the show is pointless on a David Kearns album, folk and acoustic made available for creative Commons license 3.0 attribution [inaudible] mm editing assistance provided by Judith White Marceline production assistance provided by [00:27:00] Karnofsky [inaudible]. Thank you for listening to spectrum. We are happy to hear if you have comments or questions, please send them to us via email address. Is Spectrum. K A l s yahoo.com 

Speaker 5:        [00:27:30] genius at this same time. [inaudible] 

Speaker 2:        [inaudible]

Speaker 5:        [inaudible] [inaudible] [inaudible] [00:28:00] [inaudible].