A Summer of Opportunity at CWS

By Larisa Thacher and Miranda Bell Tilcock

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Over the summer, the Center for Watershed Sciences (CWS) had the privilege of hosting three undergraduate research assistants in our “Opportunities in Watershed Sciences” program. Led by Junior Specialist, Larisa Thacher, this program was created to provide opportunities to undergraduate students who might not have had any experience working in a watershed but were nevertheless enthusiastic and interested. We wanted to give students a chance to get a taste of the different ways watershed science works, to try out the methods and perspectives of different labs, and have access to the range of knowledge offered at CWS – without having to commit to one before they knew what they liked.

The 8-week program was structured to give students exposure to the scientific method by formulating research questions, collecting data, and analyzing data. This included performing fish dissections and fish eye lens peeling with the Johnson–Jeffres Lab, zooplankton and macroinvertebrate identification with the Lusardi Lab, zooplankton sampling and trawling in the Delta with the Aquatic Research Collective, data analysis in R and ArcGIS with the Walter Lab, legal research with postdoctoral law and policy scholar Natalie Merline, sampling in the meadows with the Meadows Research Group, and writing with Miranda Bell-Tilcock! In this blog, they recount highlights of their summers at CWS.

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By Raina Zhong, Junior, Civil Engineering Major

The main reason I was interested in applying for this internship was the opportunity to learn from so many different professionals who have experience ranging from lab work to legal research. Rotating through different labs was the most valuable component of this internship for me; it gave me a chance to see how differing types of research and research methods all come together to help the Center better understand and tackle water challenges as a collective. Seeing all the different research each lab performs also made me excited about all the unique opportunities that exist in watershed sciences. Out of all the opportunities this internship provided me, I particularly enjoyed learning how to dissect a fish. It was interesting to not only learn dissection techniques, but also to learn about how each dissected part can be used towards research, from the eyeballs of the fish to its stomach. One of my favorite memories from this internship was getting to dissect a fish whose otolith contained a large portion of vaterite (see photo); it was really cool to see the jagged structure under the microscope.

I was also interested in this internship because of the chance to learn more about ecology and the way living organisms interact with the environment. As a Civil Engineering major hoping to work within water resources, I want to factor wildlife into the equation when considering how to maximize and improve water infrastructure for the public. A majority of my classes don’t heavily emphasize the ecological side of water resources, and through this internship, I’m really thankful I was able to learn more about wildlife and the role they play in watershed sciences. Some experiences I enjoyed that I would not have been able to experience through my coursework were learning how to identify bugs, fish eye lens peeling, and fieldwork opportunities – including trawling in a boat at Suisun City and fieldwork at Putah Creek and Child’s Meadow (see photo). I’m also grateful I got the chance to learn how to conduct data analysis using R, as well as learning about water policy. Both experiences have reinforced my interest in research, and I hope to get a Master’s degree in Water Resources Engineering someday. Overall, this internship gave me a variety of valuable insights that I will take with me and apply in future internships and career opportunities. Everyone I got to work with was really easy to talk to and they were always open to any questions I had, making the internship a lot more valuable and enjoyable. I hope to be able to work with the Center for Watershed Sciences again sometime!

A person holds a small catfish vertically over the deck of a boat. The fish has a pale yellowish-white belly, darker olive-brown sides, long whisker-like barbels around its mouth, and translucent brown fins. A second person wearing a yellow-and-gray jacket and dark pants is seated or kneeling on the right. The boat’s instrument panel, switches, gauges, fishing equipment, and metal supports are visible in the background. A fish-measuring board with inch markings lies at the lower right.

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A person holds a small catfish on a boat beside a fish-measuring board. — A person holding a catfish caught in Suisun City. Photo Credit: Raina Zhong

A circular microscope field occupies the lower portion of the image against a black background. Within it is a pale, translucent, irregularly shaped specimen with cloudy white, gray, and pink areas, scattered dark specks, faint branching or linear structures, and several rounded bright spots. A narrow graduated scale runs diagonally through the specimen, marked with evenly spaced tick marks and numeric labels from 0 to 100. The image is brightly illuminated in the center and darker toward the edges.

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Microscope view of a translucent, irregularly shaped specimen with a diagonal graduated scale marked from 0 to 100. — Two fish otoliths, with the one on the top containing vaterite. Photo Credit: Raina Zhong.

A narrow, calm stream winds through a grassy meadow in a forested mountain landscape. Tall golden-brown grasses and low green shrubs line both banks in the foreground, while dark evergreen trees rise densely on the left and continue across the distant hills. A young pine stands near the center of the scene. The background slopes are covered with trees, including areas of sparse or bare trunks. Above the landscape, a broad blue sky is filled with wispy, featherlike white clouds. The stream reflects the surrounding grasses and sky.

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A narrow stream flows through a golden grassy meadow surrounded by evergreen forest beneath a blue, cloud-streaked sky. — A picture taken at Child’s Meadow. Photo Credit: Raina Zhong.

Person wearing a yellow-and-gray life jacket takes a selfie in a small boat on rippling water. — Raina Zhong is a third-year civil engineering student interested in water resources. In her free time, she likes to draw and craft.

By Elizabeth Farias-Mendoza, Senior, Environmental Science and Management Major

This internship was my dream opportunity as a student studying the Watershed Science track at UC Davis. I got to learn about the amazing research coming from the Center of Watershed Sciences (CWS) in my classes, such as Rivers and Water Science & Management. The material transformed from lecture slides into projects where I could play a role. Experiencing the scientific method firsthand in various labs opened my eyes to the kind of work I could do in restoration and water resource management in the future.

A person stands in a shallow stream in a forested meadow under a clear blue sky. They wear chest waders, a dark long-sleeved shirt, a cap, sunglasses, and a utility vest, with both arms extended outward. The stream flows toward the foreground over a rocky bed and is bordered by tall grasses, green shrubs, and numerous short wooden stakes. A fallen tree lies along the far bank. Dense evergreen trees, including tall conifers and several dead trunks, fill the background, with patches of yellow-green foliage suggesting late-summer or autumn vegetation.

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Person standing in a shallow forest stream with arms outstretched, surrounded by grasses, shrubs, wooden stakes, and evergreen trees. — Near Lassen National Park, where I got to witness a Beaver Dam Analog for the first time! Photo Credit: Meadows Field Crew.

One of the most worthwhile parts of the experience was the people I met throughout the labs. Every single person was incredibly helpful in teaching me new skills, from pulling a giant net through the water to peeling back fish lenses. I also got to learn how to code in R and practice my GIS skills. The people at CWS represent the type of scientist I hope to be one day. Taking in all the new information from them made my summer enjoyable.

A unique aspect of the internship that I found truly beneficial was the interdisciplinary aspect of learning. I got a hand in participating across biological, physical, social, and engineering sciences during my time at CWS. It’s fascinating to witness the value of the various complex sides of searching for answers to water problems. Every discipline intersects with one another; I enjoyed getting to find out which aspects I favored working in the most.

A dimly lit close-up of a transparent plastic enclosure viewed through a scratched, reflective front panel. Inside, an elongated dark animal curves from the lower left toward the center and across the lower portion of the enclosure. Its body appears dark and textured along the edges, with a broad pale tan section illuminated by a bright warm light. The surrounding area is mostly dark, with indistinct objects visible in the background and strong glare obscuring some details.

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Dim close-up of an elongated dark animal inside a transparent enclosure, illuminated by a bright warm light. — One of the fish before I dissected it, which I thought looked particularly eerie under the microscope light. Photo Credit: Elizabeth Farias-Mendoza

My favorite thing I learned about is the 46-year-long study in the Suisun Marsh led by researchers at CWS. I got to be on a boat and hold a fish for the first time; it felt like I was living my Wild Kratt dreams. Learning how to identify the different fish I came across, as their fins poked me, will be stuck in my memory. As well as dropping my phone in a puddle on the boat.

A standout moment had to be in my favorite lab, the JJ lab, during my second day interning. I had a lens around 1mm under a microscope when PI Carson Jeffres and a visting Board of Directors walked into the lab for a tour. My first time meeting the boss resulted in me showing off my peeling skills for them with shaky hands; nevertheless, they were still impressed.

After such an amazing summer at CWS, I plan to join one of their labs during my last year here at UC Davis. I want to be here as much as possible to continue expanding my scientific skills. This experience gave me the chance to gain field skills, which I hope to employ in prospective jobs post-graduation. The California Conservation Corps Watershed Stewards Program is my goal after graduating with my B.S., before I go to graduate school. I plan to continue protecting water resources across California as my career continues to grow. I’m grateful to all the wonderful people at CWS who made this opportunity possible.

Person wearing a life vest and baseball cap sits in a boat on calm water, with marshland and mountains in the background. — With tired eyes but great enthusiasm, Elizabeth is out on the boat in the Suisun Marsh. | Elizabeth Farias-Mendoza is a first-generation student going into her fourth year at UC Davis. Her major is Environmental Science and Management, in the Watershed Science track. In Elizabeth’s free time, she likes to do karaoke and read. Photo Credit: ARC Field Crew

By Xitlalli Isordia, Junior, Comparative Literature Major

I applied to this internship because I was excited to explore my interest in fish while getting a more hands-on experience. Although I still wasn’t sure what to expect, I was quickly immersed once we started work. Getting to know different Junior Specialists, connecting with different labs, being out in the field, and even learning about bugs, this internship has provided me with new experiences that I loved.

One of my favorite experiences, overall, of the internship was seeing how welcoming our science community is. Everyone was always ready to offer support and geek out about what they know, so asking questions was more fun than intimidating. My favorite thing to find out, by accident, was that fish have three pairs of otoliths. This was an instant relief after I thought I ruined a specimen. Really, I just had to keep dissecting for the right one. (Thank you, Larisa, for being there!) A few other interesting things I learned were covered during my last week, like water law. I had taken an Environmental Law class just last quarter, so when I was scheduled to shadow a recent law graduate, it was really rewarding to connect new information with what I already knew. Although water law is a lot to tackle, I definitely appreciate the work lawyers do in that practice. Overall, it was exciting hearing different staff members share their knowledge and how they want to further support watershed sciences, either presently or in the future after grad school!

In many ways, the internship was self-paced. Because of this, it allowed several opportunities to ask questions, research while completing a task, and included many moments simply to take it all in. For example, some of my favorite memories were learning about aquatic macroinvertebrates. As someone who is working through their entomophobia, it was valuable to have worked with them. After looking under the microscope, I’d either research an answer or check in with my mentor for clarification. It was an unexpected experience, but I was truly in awe to learn about the lives our invertebrate friends live. What was initially the least interesting part of the internship for me turned out to be the biggest note-taking task, in the best way. This was particularly enriching for me because it bridged curiosity to admiration. For example, refer to photo A to see a Hydropsychidae, order Tricoptera. All the “hairs” you see on the abdomen are its gills; they make them look like a fluffy maltese. Hydropsychidae are really just free-roaming puppies. I do still think invertebrates can be a little grotesque, but I can appreciate what they do for the environment. All in all, this internship was more than just an addition to my resume; it was an opportunity to dissect what I want my future career to look like.

Left: Hydropsychidae under a microscope. Right: Plecoptera under a microscope. Photo Credit: Xitlalli Isordia

Xitlalli Isordia is a transfer and re-entry student majoring in Comparative Literature, with a minor in Environmental Policy. Bug identification and lab meetings have been two of her favorite internship memories!

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About the Authors

A smiling person stands outdoors under a cloudy gray sky, holding a speckled trout horizontally with both hands. The person wears a wide-brimmed dark hat and a gray-and-blue waterproof jacket. Behind them is a flat, grassy landscape with a body of water and distant low hills or shoreline. The fish has an elongated body, dark greenish-brown speckles, a pale underside, and an open mouth. — Larisa Thacher

Larisa Thacher began working in the Johnson-Jeffres group as a student in the summer of 2023 and continued as a Junior Specialist after graduating from UC Davis in 2024. She typically works on preparing and post-processing otoliths (Chinook salmon, O. mykiss, and Clear Lake hitch) for analysis, running the LA-ICPMS, and helping out with hatchery work and water sampling. She is particularly interested in reconstructing the life history of these fish using isotopes and trace elements found in the otoliths. She is looking forward to answering more ecological questions using these methods, as well as continuing to gain new skills in the lab. When she is not working, she is usually going on road trips, hiking, or hanging out with friends.

A close-up outdoor selfie of a smiling woman with long dark hair and black-framed glasses. She holds two small objects near the camera: a transparent graduated plastic syringe without a visible needle in one hand, and a small white elongated object with brown and black markings and a blue section near its base in the other. She wears a dark patterned top and several rings. A pale corrugated wall, utility fixtures, and gravel are visible in the background. — Miranda Bell-Tilcock

Miranda Bell-Tilcock is the Deputy Director of the Center for Watershed Sciences (CWS). Prior to this position change, her research at CWS focused mainly on fish eye lenses and isotopes, such as Chinook Salmon eyes, to reconstruct their life history. Her work on fish eyes and isotopes was featured on National Public Radio’s Science Friday. Miranda enjoys hanging out with her three children when she’s not working, as well as baking bread and other tasty treats.