Grad Student Profiles

Get to Know Our Current Graduate Students

 Sam holding an octopus at the tidepools

Sam Ahlman

Hello! My name is Sam Ahlman and I'm a first year grad student in the joint BA/MS program having graduated from USD in May 2020 majoring in marine ecology. I am studying the byssal thread production and burrowing ability of an invasive mussel (Arcuatula senhousia - or Musculista senhousia if you ask Jeff Crooks or Drew Talley) in different sediment grain sizes to see how it might affect predation rates and ultimately the distribution of mussels in the bay. I hail from the great (though admittedly oceanless) state of Illinois but am now a resident of central Texas. My love for the ocean was definitely born somewhere within the Shedd Aquarium, probably in front of the shark exhibit. I am also a proud member of the USD Women’s rowing team and over my four years as an undergraduate here, rowing has slowly become my only personality trait so forgive me when I inevitably relate every conversation point to rowing somehow. I love my EOSC and rowing families here at USD and I’m excited to keep this train rollin’!

Caitlynn and Michael Scott her advisor.

Abby Bierzychudek 

I am a third-year graduate student studying the distribution of mobile fauna along the salinity gradient of Los Peñasquitos Lagoon. I am also interested in how increased amounts of anthropogenic freshwater runoff will affect the mobile fauna communities. I graduated with my B.S. in zoology from Colorado State University. I came to San Diego because of my love for marine biology, and I chose to continue my education at USD because of my advisors and the close knit community. 


Caitlynn and Michael Scott her advisor.

Grace Cawley

Hi! I’m a second-year graduate student a part of the BA/MS program here. I graduated in May 2019 from USD with a degree in marine ecology. I am from Salem, Massachusetts, and as a result say “wicked” a lot. My research looks at phytoplankton in marine snow aggregates, and the different characteristics of phytoplankton that influence copepod ingestion. In short, phytoplankton form aggregates, and I want to know what about these aggregates potentially make them tasty! When I am not in the lab (which is not often), I enjoy getting outside and soaking up some Vitamin D, I enjoy anything regarding water, going to farmers markets, exploring San Diego, baking baked goods, and figuring out the perfect vanilla ice cream to root beer ratio! I am also a graduate assistant in the EOSC department. I choose USD because of the supportive and welcoming community; all the professors want to see you succeed and it’s a cool place to live and learn. #PlanktonRock

 Annabel holding a tape measure to a soupfin shark off a small boat

Annabel Gong

I am a first-year graduate student in the joint BA/MS program, graduating from USD as an undergrad in May 2020. I research the adorable, charismatic leopard sharks off the shores of La Jolla, just south of Scripps Pier. I track their movement through video footage taken from aerial drone footage and attempt to make sense of how they interact with their environment and each other. Aside from constantly talking about sharks, I constantly talk about myself and other scientists as a co-host of the LGBTQ+ STEM Cast, a podcast where we interview LGBTQ+ scientists from around the world. I also work in tech theater and do lighting design at a theater back at home in the Bay Area. I keep in touch with my creative side through guitar, photography, and on occasion, muppetry. I've loved this department since I first found my way here and am incredibly thankful for the supportive faculty and amazing opportunities I've had thus far!

Riley stands on the ship.

Riley Henning

I am in my second year of graduate work in the new BA/MS combined degree program. I am originally from Atlanta, Ga, and I finished my undergraduate degree at USD in May of 2019. I am excited to develop my undergraduate research experience into a master’s thesis. My research is centered on marine snow formation. Specifically, I use stereoscopic imaging to track phytoplankton aggregates in 3D. I hope to be able to track collisions and formation of these aggregates to get a better understanding of how marine snow forms, since it is an important part of the carbon cycle and the biological pump, bringing lots of carbon down to the deep ocean. I also work as an instructor at a local art school, and in my free time I like to golf, backpack, and surf. My favorite part about the Environmental and Ocean Sciences department is how close-knit both the faculty and students are. Everyone is always willing to lend a hand and provide guidance, so it is a community that works together very well.

 Riley stands on the ship.

Ravleen Kaur Khalsa-Basra

I am a third-year graduate student, studying hydraulic variables and geographic influences on the Los Peñasquitos Creek. My study is a quantitative analysis on the baseline measurements for grain size, potential trace metal contamination, organic matter content, and fluvial geomorphology.  The field work included surveying and sampling methods and the laboratory protocols incorporate particle size analysis (sieving and LPSA), X-Ray Fluorescence (for metals), Loss on Ignition (organic matter), GIS (mapping and analysis) and possible future hydraulic modeling. These baseline measurements can provide information for watershed management and for future research for impact on freshwater/wetland communities or even sources of contamination.

I graduated from Towson University (MD) with a BS in Chemistry, worked in Chemistry, Quality and Regulatory Sciences on Personalized Medicines/Therapeutics for 3 years in Maryland and San Diego. I moved to San Diego to pursue Environmental Sciences. I worked as a tech in a laboratory at the Scripps Institute of Oceanography and decided I preferred to work with freshwater systems.  The primary reasons I chose USD was because of the small department size, opportunities, the overall community, the cleanliness of the lab spaces and the beauty of the campus!

Angela is on a boat with snow. 

Angela Klemmedson

I am a fifth-year graduate student researching the population dynamics of Antarctic mesopelagic fishes in response to environmental variability. I’m using otoliths (fish ear stones) to collect age and growth rate information for the myctophid species Gymnoscopelus nicholsi over the past 20 years. Understanding the population dynamics of this ecosystem component is important for understanding the stability of the Antarctic ecosystem, which is one of the fastest warming regions on the planet. In 2013, after earning my BA in Biology and Environmental Studies from Gonzaga University (Spokane, WA), I moved to San Diego and worked for California Cooperative Oceanic Fisheries Investigations (CalCOFI) for three years before deciding to continue my education. I chose USD because of its proximity to marine science resources, including collaborators such as NOAA and Scripps Institution of Oceanography. In addition to my research, I also work for the EOSC department as a Physical Science Graduate Assistant, responsible for prepping geology labs and desert field trips. I am happy to be a part of the USD community and the small size of our EOSC program provides increased interaction and support from faculty and other students.

Sam has a hat on and stands in front of some trees.

Samantha Leander

I am a third-year graduate student, studying size and sex composition of Delphinus spp. schools in Southern California with Lisa Ballance and John Durban at NOAA SWFSC. My research aims to better understand school structure in common dolphins, which can then aid in answering questions regarding susceptibility to anthropogenic disturbance and habitat preference of the species. I received a Bachelor's degree from UC Santa Barbara, where I majored in Biology through the College of Creative Studies. During my undergraduate studies, I was a part of the McCauley lab and completed an internship with elephant seals at Point Reyes National Seashore. Since graduating, I have worked as an ecology tech at Cabrillo National Monument and SPAWAR and a marine science instructor at SeaCamp San Diego. I chose USD because the EOSC faculty have a wide array of backgrounds and work with many different institutions, which has been instrumental in shaping me into a well-rounded scientist.

Stephanie stands by the ocean holding a sea hare.

Stephanie Nemeth

I am a third-year graduate student studying rockfish at the NOAA Southwest Fisheries Science Center with Dr. Nick Wegner. In particular, I am examining rockfish tolerance to low oxygen, or hypoxia, and how this tolerance is affected by barotrauma. Rockfish are a commercially important, deep dwelling species that experience barotrauma when they are fished from depth.  The quick reduction in pressure causes the gasses in the swim bladder to expand, injuring the fish.  Understanding the relationship between hypoxia and barotrauma can therefore improve catch and release success, assisting in management of this over harvested species.  
I graduated from Miami University of Ohio in 2016 with a BA in zoology and environmental science with a minor in neuroscience.  I then worked for two and a half years at SeaWorld San Diego where I was an associate trainer at Shamu Stadium as well as an animal trainer at the Pets Rule show.  Having pursued my childhood dream of training animals for a few years, I then decided to make a return to the science world by pursuing my masters degree at USD.  It is wonderful to be back in the academic world, and the EOSC department is the perfect place for me to earn my degree.

Michelle is standing on rocks in front of the ocean

Michelle Robidas

I am a second-year graduate student from Massachusetts. I love hiking, biking, skiing, crossfit, and of course...the ocean! My research focuses on what oceanographic variables significantly impact anchovy larvae survival and hence recruitment success. In years past, scientists believed that the Northern anchovy (Engraulis mordax) thrived under colder sea surface temperatures while the Pacific sardine (Sardinops sagax) thrived under warmer SSTs. In 2014 however, a marine heatwave disturbed this multi-decade hypothesis. To determine which oceanographic conditions improve the anchovy's recruitment success (to help fishery management), I will be comparing larval growth rates from "good," "poor," and "average" larval survival years. My project is supported by NOAA's Southwest Fisheries Science Center using their larvae collection from California Cooperative Oceanic Fisheries Investigations (CalCOFI). USD (and San Diego!) is a great place to learn more about our oceans and gain valuable skills, from scientific communication to grant proposal writing.  

Rachel on a research vessel with muddy hands

Rachel Sarner

This is my first year as a graduate student in the joint BA/MS program at USD and I am continuing my undergraduate research studying microplastics in the benthic sediments of the shelves and basins offshore of San Diego. My research involves studying the trends of microplastic concentrations with ocean depth and distance from urbanization along with gaining a better understanding of the transportation processes of plastics to the seafloor and any potential patterns found with certain sediment characteristics. My love for nature as a whole is what truly inspired me to study our environment and how we can preserve it. With that, any free time I can find usually means camping in the desert or sunset surfing. I am beyond grateful to be continuing my research with the EOSC family at USD as every student and faculty member shows nothing but genuine support for one another. 

Nancy is standing on a research vessel.

Nancy Torres

I am a second-year graduate student studying the ecotoxicology and hydrology of the Tijuana River Estuary. My project involves sampling for contaminants in the estuary's water, sediment and target biota tissue. This will be coupled with the synthesis and analyses of historical data to provide insight into how the ecosystem's health has changed over time. This binational region has undergone dramatic physical and ecological changes and I'm excited to help inform its future management.
I graduated from UC Santa Barbara with a BS in Environmental Studies with a concentration in Earth Science. Through the McNair Scholars Program, I worked in the Valentine lab studying marine microbial consumption rates. Through a Research Experience for Undergraduate (REU) program for the Oregon Institute of Marine Biology, I was able to conduct research on phytoplankton abundances along the Coos Bay Estuary with the Shanks lab. I love all things water and adventuring outside! I also love being at USD with such a great, supportive community at an amazing location.