2024 Field Science Fellows

2024 Field Science Fellows
2024 Field Science Fellow Madeleine Stewart will study the growth and development of sexual dimorphism in young northern elephant seals at the NRS’s Año Nuevo Island Reserve. Image credit: Courtesay Madeleine Stewart

By Kathleen Wong, UC Natural Reserve System

Among many animals, the sexes are nearly indistinguishable—think turtles and rabbits, dogs and goldfish. But there’s no mistaking a mature male northern elephant seal for his female counterpart. At up to 5,100 pounds, bulls are the size of a small car, and sport a schnozz like their species namesake. Adult females can be more than two tons smaller, with the pointed nose of most other seal species.

That drastic difference in size and shape is a phenomenon called sexual dimorphism. Scientists believe sexual dimorphism has a profound effect on nearly every aspect of an elephant seal’s life, from what it eats, to how it feeds, to where it searches for food, to its chances of survival.

Yet how and when male and female Mirounga angustirostris diverge in their growth and anatomy remains poorly known. It’s impossible to tell the sex of a pup at a glance.

Madeleine Stewart of UC Santa Cruz is working to fill in those knowledge gaps by working at the NRS’s Año Nuevo Island Reserve. “I’m measuring the head, teeth, and flipper sizes of a range of juvenile seals and trying to understand at which age they become sexually size dimorphic,” says the undergraduate marine biology major.

Stewart will be able to work full time on her field-based research project thanks to the NRS’s Field Science Fellowship. She and her faculty mentor, UC Santa Cruz Assistant Professor Roxane Beltran, are one of three UC undergraduate-faculty teams to receive the fellowship this year. The fellowship is designed to enable undergraduates, especially those from underrepresented backgrounds in the field sciences, to spend a summer working full time on research based at NRS reserves, while also encouraging the mentoring relationships critical to future success. Each team will receive $5,000 for the undergraduate and $1,000 for project costs.

2024 Field Science Fellows
Madeleine Stewart measures a pair of seal flippers at the NRS’s Año Nuevo Island Reserve with lab colleagues from UC Santa Cruz. Photo taken under NMFS research permit #23108 during a routine seal sedation procedure.

As a Black woman, Stewart says, “There aren’t many marine biologists who look like me.” That’s one reason Stewart sought to work in Beltran’s lab. “When I first found out about her lab, I thought, this is amazing—a young woman running this huge program and doing this great science. We met and clicked and it’s been one of the most amazing experiences of my life.”

Stewart anticipates the fellowship will enable her to learn even more with Beltran as the research progresses. Stewart says Beltran’s level of guidance is just right. “I work through problems in my own way, develop methods on my own, and then we talk through my thought process together. I appreciate she’s not just telling me what to do or giving me a completed project.”

Stewart has developed her project in conjunction with her graduate student mentor, Salma Abdel-Raheem. Stewart’s fellowship project will be part of Abdel-Raheem’s PhD dissertation research.

Steward has been fully immersed in the scientific process during this research: from project brainstorming, to hypothesis testing, to method development. She is learning not only how to measure seal anatomy, but also to manage and execute a collaborative research project with multiple mentors and partners.

The fellowship funding not only enables Stewart to devote her summer to research, but has enabled her to purchase equipment for the project. The dedicated camera and digital calipers she bought helps standardize the data, because the photos and measurements will always be taken with the same equipment.

“This fellowship has definitely made being a field scientist more accessible to me. I feel less anxious about the project, because I know I have the resources to make it the best it can be,” Stewart says.

With plans to go to graduate school and continue in marine mammal science, Stewart feels the fellowship research opportunities will advance both her academic and career goals. She also hopes that being a fellow encourages others to pursue their field research dreams.

Says Stewart, “If younger, aspiring high school students see my face associated with the NRS, then they’ll realize there’s someone who looks like me doing this successfully.”

2024 Field Science Fellows
Renee Rincon of UC Riverside will study whether long-term fire retardants discourage plants from establishing symbiotic partnerships with beneficial root fungi at Motte Rimrock Reserve for her 2024 Field Science Fellowship. Image credit: Renee Rincon

Fire retardant could disrupt underground partnerships

For Renee Rincon, getting to UC Riverside has been a longer journey than for most undergraduates. She’s a single mother of a 12-year-old, and the first in her Mexican-American family to go to college.

“I was pregnant at 17. I did go straight to college after high school, but it was hard. After I had my daughter, I had to stabilize my life before I was really able to go back to school,” Rincon says.

While working, Rincon began attending community college. She put off her science requirement for years due to previous difficulties passing math. Then she walked into her first biology lab. “I just fell in love. It was this amazing feeling when I was looking at things under the microscope,” she says.

Buoyed by a newfound enthusiasm for science, Rincon transferred to UC Riverside. Her busy life, made more hectic by an hour-and-a-half commute each way to school and a lack of stable babysitters, calmed once she secured on-campus housing.

“I learned that once you get the resources to support you, that you can thrive,” Rincon says.

2024 Field Science Fellows
Rincon working with samples of plant roots in the laboratory to identify the presence of microscopic symbiotic fungi. Image credit: Courtesy Renee Rincon

With more time on her hands, Rincon began volunteering in Assistant Professor Sydney Glassman’s lab last fall. Glassman is an expert in ectomycorrhizal fungi—fungi that form symbiotic relationships with the roots of plants. Her lab is where Rincon learned that these microscopic plant partners might be affected by modern firefighting.

Instead of always fighting blazes with water, firefighters now proactively coat forest and fields with long-term fire retardants that render vegetation unable to burn. Many retardants, such as the popular brand Phos-Chek, are largely made up of phosphate. Plants often depend upon their root fungi to deliver the phosphates they require. This raises the question of whether plants will forgo their ancient relationships with helper fungi.

“We have a feeling there is a negative impact of Phos-Chek on the colonization. We don’t know what it’s doing,” Rincon says.

For her Field Science Fellowship, Rincon will be investigating whether California sagebrush, a widespread native plant, is less likely to associate with ectomycorrhizal fungi. At the NRS’s Motte Rimrock Reserve, she will compare unsprayed plants against those she has sprayed at the start of the summer, as well as those treated with Phos-Chek a decade ago. She’ll then sample the roots and examine them under the microscope to see which plants have relationships to the friendly fungi.

She hopes the fellowship might help her attain her eventual goal: getting into medical school. “This is great for people like me, who aren’t the typical students presented with opportunities like this,” Rincon says. She thinks experience will also further a more personal objective, too. “This helps me set a good example for my daughter. She’s 12, and excited her mom got a grant to work in science,” Rincon says.

2024 Field Science Fellows
Carmen Ott of UC Irvine is comparing the functional traits of algae found in the intertidal zone of Scripps Coastal Reserve and Bodega Marine Reserve for her 2024 Field Science Fellowship. Her measurements include using a PAM fluorometer such as this one to identify the light wavelengths different algae use to conduct photosynthesis. Image credit: Carmen Ott

The services of the seaweed canopy

A blanket of algae clothes many of California’s rocky shorelines. When the tide is out, these stretches of shoreline look more like piles of tangled rags than a community of living things. In fact, there are clear organizing principles behind this shoreline jungle. Just as the tallest trees in a forest shelter an understory of smaller plants to grow beneath their branches, larger species of marine algae protect a complex community of smaller seaweeds from the hot and drying rays of the sun.

Silvetia is this one seaweed that seems very predominant, and when you pull back the canopy there’s a bunch of other seaweeds under it. I want to investigate further how Silvetia is interacting with the seaweeds beneath,” says UC Irvine Field Science Fellow Carmen Ott.

Ott has been working in the field with her faculty mentor, Professor Matthew Bracken, on intertidal algae since she transferred to UC Irvine from community college last fall. As a Field Science Fellow, she plans to compare the traits of Silvetia and other members of the intertidal algal community. She will conduct her research at the NRS’s Bodega Marine Reserve west of Wine Country against those of Scripps Coastal Reserve in San Diego.

2024 Field Science Fellows
Pulling back the long strands of Silvetia often reveals smaller species of marine algae growing underneath. Image credit: Carmen Ott

“Down here in southern California, we have a lot less nutrients in our waters. It’s much hotter. It’s much more stressful. In northern California there’s more intense upwelling, and a lot more rain,” Ott says. “It’s going to be very important seeing what species could be more susceptible to climate chanage, and how Silvetia could potentially facilitate their growth in other regions that could be harsher,” Ott says.

At each site, Ott will study what types of seaweeds are found at different elevations across the shore, from the high intertidal zone, where they spend the most time dry and exposed, through the middle intertidal zone, where Silvetia is most commonly found, to the low intertidal zones, which remains inundated for longest. She will also note how species are layered in each zone.

Back at the lab, she will note the functional traits of each species, such as the thickness, size, and surface area of their blades, their ability to retain water and uptake nutrients, and the light wavelengths at which they best photsynthesize, to determine whether these characters predict their roles in the seaweed canopy.

Growing up with few financial resources and an immigrant parent, Ott is particularly appreciative of the opportunities afforded her by the fellowship. “It’s basically a dream come true” both personally and professionally, she says. That’s because she nearly attended UC Davis for the chance to work at Bodega Marine Reserve and Laboratory, and now aspires to become a field researcher and possibly a professor. “It’s really important for me to be able to get that experience early. The people I can meet and the chance to grow my understanding of research techniques will be an amazing experience,” she says.

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