Below is the list of student poster presentations that will occur in the afternoon during the TIDES conference. Each entry lists the presenting author, title of presentation, co-authors (if available), and the full abstract for the project.
SESSION A (2:15PM – 3:00PM)
Danika Asgeirsson, University of Washington, Environmental Science and Terrestrial Resource Management
Analyzing day and night activity of Longfin Smelt in Bellingham Bay
Our eDNA evidence supports the hypothesis that Longfin Smelt (Spirinchus Thaleichthys) move between deep waters in the day and near surface waters at night. We found that eDNA is an effective tool to study diel migration in water columns. These diel movements cannot be attributed to variations in pH (figure 3), temperature (figure 4), phytoplankton biomass (figure 5), or phytoplankton community composition (figure 6). Little change was found in these variables within a 24-hour period, leaving them to be unable to account for shifts in Longfin Smelt movements. Instead, we need to look for other explanations for these movements. We found our zooplankton surface tows to be dominated by small jellyfish, with virtually no zooplankton that Longfin Smelt feed on being found in our tows. It's possible that Longfin Smelt move between deep and shallow water to avoid competition with jellyfish. Unfortunately, we lost our zooplankton net to the bay and were unable to obtain night samples. Alternatively, it's plausible that Longfin Smelt were avoiding predation during the day, as we observed hundreds of cormorants on the bay during the day. A third possibility is light sensitivity, as it is known that during the spawning run, Longfin Smelt spawn at night, and prefer turbid water. This behavior could be paralleled during their time at sea, where they undergo diel migration due to their light sensitivity. In the future, we plan to collect additional eDNA samples to study diel movements of Longfin Smelt.
Mollie Ball, University of Washington, Aquatic and Fishery Sciences
Gut Check for Ocean Health: A Meta-Analysis Marine Mammal Gut Microbiota
Marine mammals contribute billions of dollars to the blue economy through tourism, ecosystem services (e.g., carbon sequestration and nutrient cycling), and cultural identity. Yet threats such as environmental change and shifting prey availability have left roughly a quarter of marine mammal species threatened. Further, most health assessments remain costly, invasive, and logistically challenging, all of which limit our ability to anticipate individual-, population-, and ecosystem-level impacts. Gut microbes play essential roles in digestion, immunity, and stress response, making them a powerful indicator of marine mammal condition and ecosystem health. Thus, the microbiome, explored using genetic metabarcoding of fecal samples is emerging as a powerful non-invasive tool for health screening. Here, we conduct a meta-analysis of gut microbiome sequence data from fecal samples collected from live, stranded, and harvested animals, obtained from the NCBI Sequence Read Archive. These data are used to characterize microbial community structure in marine mammals. DADA2 is used to clean raw sequence data and to obtain taxonomic assignments for gut microbes. We use Phyloseq in R and NMDS to explore within- and between-species variation in gut microbiota to evaluate how host taxonomy influences the gut microbiome. By synthesizing existing work, we identify core microbial communities, contributing to a baseline for microbiome-based indicators of marine mammal health. As the science for using the microbiome as a health index matures, we look towards integrating this information into monitoring to improve management to support the persistence of marine mammals as vital drivers of ocean and economic health.
Lucy Brock, University of Washington, Oceanography
Characterizing underwater ambient sound using Distributed Acoustic Sensing
Co-authors: Chih-Chieh Chien, Shima Abadi
Distributed Acoustic Sensing (DAS) is an emerging technique for measuring strain using fiber-optic cables, enabling dense and continuous measurements of acoustic signals. By transmitting laser pulses through the cable and interpreting strain-induced phase variations in the backscattered light, DAS effectively forms a large array of acoustic sensors. This study includes two datasets from underwater DAS experiments conducted in Puget Sound, Washington, and along the Ocean Observatories Initiative (OOI) Regional Cabled Array off the coast of Oregon. The analysis focuses on ambient noise in the DAS recordings, including microseisms, wind-driven processes, and ocean surface gravity waves. Primary results from the Puget Sound dataset indicate frequency-dependent relationships between high-frequency signals and low-frequency wave-induced noise, with pronounced effects in shallow-water regions and along steep bathymetric slopes. The OOI dataset shows that ocean surface gravity waves and swell can generate high-frequency noise, while microseisms are concentrated near steep slopes. These findings demonstrate the capability of DAS to capture key components of the ambient ocean soundscape and its potential to significantly enhance long-term monitoring of ocean acoustic environments.
Samantha Chee, University of Washington, Environmental Science and Terrestrial Resource Management
Structure of Fish Communities Associated to Acroporid Patches Impacted by a Recent Coral Bleaching Event in Bocas del Toro
Panama's Bocas del Toro archipelago is home to a plethora of fish species that rely on healthy coral reefs for habitat and food. The reef fish communities support the local economy as a significant tourism attraction and food supply. Changing environmental and anthropogenic conditions have affected fish communities associated with Acroporid corals. El Niño events compound environmental changes to create harsh environments and more extreme temperatures for the Acroporid corals, which are key reef-building species due to their branched growth form. Fish abundance and diversity data has been collected for before and after the Summer 2023 Caribbean Coral Bleaching event that killed most Acroporid corals. In both univariate and multivariate analyses, the two main findings were higher biodiversity outside Almirante Bay than inside Almirante bay and higher biodiversity before the 2023 bleaching event than after. Through Fall 2023, diversity exhibited an upwards trend, sharply declining after the bleaching event in 2023. Coral type and Seasonality did not cause significant differences in biodiversity. This research suggests that dead coral still provides habitat for fish communities but for a limited time while undergoing disintegration. These findings reinforce the need for urgent climate policies to mitigate the global ecological effects of ocean warming.
Victoria deJong, University of Washington, Oceanography
Under Pressure: Development of a Modular Pressure Testing System for Prototype Salinity Sensor Characterization
Co-authors: Erin Firth, Jaehyun Chung, Scott Soelberg, Zachary Taylor, Anuscheh Nawaz
Seawater salinity measurements provide important information about biological, chemical, geologic and physical processes in the ocean and atmosphere on local to global scales. Modern oceanographic sensors derive salinity from highly accurate and precise conductivity measurements. However, these conductivity sensors are quite costly, limiting the spatial resolution achievable with a given budget. This restricts robust scientific inquiry and ocean monitoring, potentially prohibiting access to the technology altogether—particularly for resource-limited coastal communities and industries. To address the growing need for high spatial resolution salinity data and accessible ocean sensors, the Nawaz Lab is developing a novel salinity sensor, Salino, projected to cost $50 with 0.1ppt accuracy and 150m depth rating. Here we present the hardware and testing framework developed to characterize function and signal dependency in response to pressure in the ongoing development of Salino. Our hardware consists of a custom pressure chamber and sensor housing capable of manual pressurization up to 500psi, simultaneously controlled pressure and salinity environments via a specialized pressure actuator and live data monitoring. The sensor housing is usable in a flow-through mode during benchtop experiments for before/after pressure characterizations of key sensor response metrics. Our testing framework monitors for continued sensor function and characterizes pressure-dependent signal response by comparing baseline sensor drift and effective Nernst sensitivity across a range of deployment-relevant salinities. Testing with this hardware and framework has been successfully leveraged in the continued development of Salino sensors, with sensor failure able to be identified during gradual, step-wise pressurization via live monitoring and post-pressurization benchtop comparison against baseline Nernst sensitivities. After at-depth function is consistently achieved, this hardware and framework will continue to be used for characterization and quality assurance. The modular nature of our hardware can be further adjusted for future prototype development, enabling Salino to reach increasing deployment depths.
Sophia Eckhart, University of Washington, Marine Biology
Drivers of Zostera marina Seed Germination: The Roles of Seed Morphometrics, Sediment Microbiome, and Planting Time
Co-authors: Emma Sturgill, Conor Fitzgerald, David Jiang, Catherine Xu, Sandy Wyllie-Echeverria
Eelgrass (Zostera marina) meadows protect coastlines, store carbon, and provide essential habitat for invertebrates, small fish, and waterfowl, yet fewer than one in five seeds successfully germinate in the wild, limiting restoration efforts. As ocean temperatures rise and political support for marine conservation becomes increasingly uncertain, eelgrass restoration faces growing challenges. We are trying to determine what factors determine germination success. Answering this question is critical for improving the effectiveness of restoration in an era of ecological and institutional uncertainty. Previous research suggests that seed characteristics and sediment microbial communities may influence germination, but these factors have not been experimentally tested in the Pacific Northwest. We investigate three potential drivers of germination success: (1) seed size and color, (2) the presence of the parent sediment microbiome, and (3) planting timing. A total of 583 seeds collected from Picnic Cove, Shaw Island, WA were measured for length, width, weight, and color. Seeds were grouped by weight and distributed evenly between outdoor flow-through tanks containing either parent sediment or sterilized sediment, with plantings conducted in November 2025 and January 2026. Temperature, salinity, and germination are being monitored. Preliminary results indicate that seeds from this season are larger on average than those from previous years at Picnic Cove and include a slightly higher proportion of darker-colored seeds, which are commonly associated with greater maturity. We expect darker seeds, natural sediments, and later plantings to yield higher germination success. Findings from this study will directly inform eelgrass restoration strategies in the San Juan Islands and support collaborative conservation efforts among regional research and Tribal partners.
Rachel Ha, University of Washington, Oceanography
Investigating Sea Ice and Ocean Influences on Phytoplankton Blooms on the Antarctic Continental Shelf
Co-authors: Ethan Campbell, Jodi Young
The Southern Ocean (SO) around Antarctica is a region that supports high biological productivity and plays a significant role in global carbon cycling, largely driven by phytoplankton activity. Phytoplankton blooms in the SO are modulated by light availability and nutrient input, particularly iron, both of which are closely related to the seasonal changes in sea ice coverage and its associated impacts on the upper ocean. The abrupt decline in Antarctic sea ice coverage in 2016 raises concerns over potential impacts on spring phytoplankton blooms in the SO. This study investigates how recent sea ice changes have affected phytoplankton on the continental shelf, where blooms are strongest, by analysing satellite-derived sea ice concentration data from the National Snow and Ice Data Center (NSIDC)‚ Climate Data Record (CDR) and ocean colour data from the European Space Agency (ESA)‚ Ocean Colour Climate Change Initiative (OC-CCI). Pre- and post-2016 trends in average chlorophyll concentrations show significant interannual variability in chlorophyll and an apparent increase across the sea ice zone after 2016, though no change on the continental shelf. However, we find a significant positive interannual correlation between ice-free days and chlorophyll on the shelf, potentially due to increased light penetration. Using ocean reanalysis mixed layer depth, atmospheric reanalysis sea surface temperature and wind speed, and ice shelf basal melt data, we further analyse and determine the significance of these physical factors in influencing nutrient input that fuels productivity on the shelf. Improving our understanding of blooms in the Southern Ocean could inform fisheries management and the placement of Marine Protected Areas, ultimately affecting the marine economy.
Lydia Kelley, University of Washington, Oceanography
Expanding the Search for Possible Tectonic Tremor-like Signals Offshore Cascadia
Co-authors: Zoe Krauss, Marine Denolle
Detailed constraints on the locking state of the shallow Cascadia subduction zone (CSZ) are essential for defining the frictional characteristics of the megathrust, and in turn, hazards associated with great earthquakes and tsunamis. However, the shallow portion of the CSZ lies offshore, where limited instrumentation makes it difficult to observe small tectonic signals. New findings of possible tectonic tremor-like signals from a cabled ocean bottom seismometer (OBSs) on the Ocean Observatories Initiative Regional Cabled Array (OOI-RCA) offshore Oregon suggest small, localized slow slip events may occur near the deformation front at ~44.5 N. Knowing whether these tectonic tremor-like signals are widespread or spatially concentrated in shallow Cascadia, either along-strike or along-dip, will help to inform whether they are consistent with a tectonic origin, and if so, whether they occur on the plate interface, faults on the incoming plate, or faults in the outer wedge. We therefore expand the search for tectonic tremor beyond Oregon using autonomous Cascadia Initiative (CI) OBS stations from 40 N to 48 N, spanning the incoming Juan de Fuca plate to the outer Cascadia wedge. We utilize 40 CI stations with data from September 2012 to October 2015. We also analyze data from the northern CSZ using 5 OBSs on the outer wedge from the Ocean Networks Canada NEPTUNE cabled observatory, which provides > 10 years of continuous data. For all OBSs, we use a single-station approach specifically designed for OBSs to identify and isolate tectonic tremor-like signals from environmental noise using waveform and spectral characteristics. Altogether, this study represents an additional step towards a more complete understanding of the extent and type of tectonic signals present offshore Cascadia, with the end goal of detailing locking state variations along the shallow CSZ.
Aurora Leeson, University of Washington, Civil & Environmental Engineering
Modeling Ocean Alkalinity Enhancement (OAE) in the Salish Sea
Co-authors: Kate Hewett, Alex Horner-Devine, Parker MacCready, Alex Gagnon, and Rick Berg
To limit warming to a safe threshold by the end of the century, carbon emission reductions must be supplemented with carbon dioxide removal (CDR) strategies. The ocean has high potential for CDR because it is naturally a large reservoir for carbon and there is persistent exchange between the ocean and atmosphere. Marine CDR (mCDR) technologies include direct ocean removal (DOR), where CO2 is chemically removed from intake seawater then discharged back into the ocean, and ocean alkalinity enhancement (OAE), where alkalinity additions change local carbonate chemistry. Both technologies aim to alter surface water chemistry and increase its capacity to absorb CO2 from the atmosphere. However, the amount of time these modified water masses remain at the surface is an important factor. Observations alone cannot quantify the efficacy and extent of mCDR strategies because the physical scale of mCDR perturbations can spread across a large volume, necessitating the use of numerical models. Furthermore, models are needed to compare perturbed and baseline carbonate chemistry conditions near a deployment location. In this study, we use LiveOcean, a regional numerical model of the Salish Sea and surrounding coastal waters, to assess the CO2 uptake efficiency of multiple different OAE deployments across the model domain. We select locations that span current testbed or industrial facilities, such as wastewater treatment plants, and locations that span regions predicted to have high and low surface residence times based on a dye release experiment. The goal of this study is to quantify OAE efficiency across the different sites and to describe the physical processes that make some sites better candidates for mCDR than others.
Lorenzo McCleese, University of Washington, Environmental Science & Informatics
Red Abalone Refugia Across Variable Thermal Regimes
Co-authors: Jessica Bolin, Mikaela Provost
Red abalone (Haliotis rufescens), a culturally and ecologically vital species along California's coast, declined dramatically after the 2014-2015 marine heatwave known as “The Blob” devastated bull kelp forests, its primary food source. Identifying climate refugia, areas buffered from environmental extremes, may support population recovery by reducing exposure to extreme ocean conditions or promoting local adaptation. This study evaluates whether two thermal refugia definitions predict H. rufescens density: (1) areas where red abalone experience lower short-term variability (STV) in temperature over a 5-10 day moving window, and (2) areas with fewer degree heating days (DHD), defined as fewer total days where water temperatures exceed physiological thresholds (20 C). Long-term SCUBA survey data from Northern and Central California (1999 - 2021) were integrated with ocean reanalysis bottom temperature fields, and generalized linear, additive, and mixed-effects models were used to compare patterns before and after the marine heatwave. In Northern California, STV refugia were positively associated with abalone density prior to The Blob, but this relationship weakened afterward. In contrast, DHD refugia showed no effect prior to the heatwave but became negatively associated with abalone density post-event. In Central California, neither refugia definition showed significant relationships with abalone density. These results suggest that thermal stability, rather than heat avoidance, might better support red abalone persistence in Northern California and highlight how extreme events like The Blob may reshape refugia efficacy. Post-Blob DHD patterns indicate shifting stress dynamics that call for further research. By testing theoretical refugia definitions against field observations, this study advances the identification of climate-resilient habitats and provides insights to inform efforts to prioritize them for monitoring, restoration, and potential fishery recovery.
William Menapace, University of Washington, Oceanography
Investigating Seasonal Fluctuations in Tidally-Forced Stratification Patterns in the Main Basin of Puget Sound using Seagliders
Co-authors: Katie Kohlman, Ayden van den Berg, Sasha Seroy
Puget Sound is an estuarine system with a mixed semidiurnal tidal cycle that experiences strong seasonal fluctuations affecting stratification and water column dynamics. Tidal cycles that vary in magnitude also influence mixing in Puget Sound. In-situ observations are currently limited to sparse moorings and ship tracks, with a clear need for consistent and sustainable sampling. The Student Seaglider Center (SSC) is a student-led, ocean tech lab at the University of Washington focused on conducting novel research using autonomous underwater vehicles called Seagliders. Puget Sound serves as an optimal space for the SSC to conduct consistent research and produce data. UW OTTERS is an ongoing mission in the main basin of Puget Sound that occurs twice a year during the summer and winter months for two weeks at a time, with Seagliders completing full-depth dives along east/west-oriented transects. This project investigates how stratification of the water column is influenced by seasonal changes in tidal phases, according to shifts in temperature, salinity, dissolved oxygen, and chlorophyll content. Preliminary findings suggest that the summer months show greater stratification of the water column and it is expected that this is exacerbated during a neap tide. We propose that the least stratified water column will occur in the winter months during a spring tide when the greatest level of mixing occurs. This dataset will provide context for future environmental changes within Puget Sound, including how stratification may change with global warming and varying seasonal dynamics. This consistent environmental monitoring is important for gauging productivity and nutrient content within this estuarine ecosystem. The OTTERS mission provides SSC students with consistent training and education in glider maintenance, piloting, data analysis, and conducting novel research. Additionally, this data will prove useful in validating current regional models that historically have minimal data for comparison.
Tejas Naladala, University of Washington, Electrical and Computer Engineering
Design of a continuous plasma activated water (PAW) disinfection system for fresh produce industry
The fresh produce industry relies predominantly on chlorine-based washing systems for postharvest sanitation. While effective, these methods generate toxic disinfection byproducts, leave chemical residues, and face increasing regulatory scrutiny. Plasma Activated Water (PAW) has demonstrated antimicrobial efficacy in laboratory settings, yet scaling this technology for industrial application has remained a significant challenge. This study introduces an innovative, industrial-scale continuous PAW system specifically designed for the fresh produce industry and optimized for micro to small enterprises. The system leverages a novel non-uniform electrode design within a dielectric barrier discharge reactor to enhance average field strength to approximately 55 kV/cm, driving the efficient generation of reactive oxygen and nitrogen species (RONS) for steady-state PAW production. Key components include a self-aspirating venturi bubble generator for optimized gas-liquid interaction, eliminating the need for external gas supplies or compressed air systems. The plasma reactor is integrated into a continuous spray and conveyor setup featuring variable residence time control, enabling consistent PAW production and application across different produce types. Our preliminary lab trials on tomatoes and spinach indicate approximately 1.5 log‚ÇÅ‚ÇÄ CFU/g decrease in total aerobic mesophilic bacteria immediately after treatment, which further decreased to 2.5 log‚ÇÅ‚ÇÄ CFU/g towards the end of storage life for tomatoes stored at optimal conditions, with 20 kV applied to the reactors and a total residence time of 20 minutes. The extended antimicrobial effect during storage suggests continued activity of long-lived reactive species. An evaluation of maximum energy consumption indicated a process cost contribution of less than $0.5 per ton of treated produce, making the technology economically competitive with conventional methods. The promising initial results, modular and scalable design, cost-effectiveness, and elimination of chemical inputs make this technology suitable for improving food safety while supporting sustainable production practices in the fresh produce supply chain.
Emily Pinneo, University of Washington, Oceanography
Distribution of Benthic Fauna at the Methane Seep Pythia's Oasis
Co-authors: Katie Bigham
Methane seeps are critical sources of productivity and habitat in the deep sea, potentially supporting major fisheries, but many remain unmapped and ecologically unexamined due to expense or time constraints. Pythia's Oasis is a seep that has unusually high rates of venting fluid, possibly sourced from overpressure in the Cascadia Subduction Zone near the plate boundary and funneled to the site along a fault. This study constitutes the first survey of benthic megafauna at Pythia's Oasis, and investigates the relationship between taxa distribution and substrate type. Working from a dataset of georeferenced ROV images taken in 2019, this study used the YOLOv12 object detection algorithm to increase the efficiency of fauna annotation. Over twenty taxa were present, listed here in order of abundance, including anemones, sponges, sea cucumbers, snails, corallimorphs, rockfish, and soft corals. Stalked anemones and black corals found at the site may represent undescribed species. Substrate was also annotated and interpolated across the site, and we tested whether taxa were associated with different substrate types. Finally, we compared our data to the nearby methane seep Southern Hydrate Ridge. Preliminary analysis shows that Pythia's Oasis had a higher abundance of sea cucumbers. This study demonstrates how technologies like machine learning make image processing scalable, allowing us to establish an ecological baseline in methane seep habitats. As anthropogenic impacts on the deep sea escalate, this data is increasingly important, because it can be used to improve ecosystem modeling, provide the groundwork for conservation, and support sustainable fisheries management.
Abirami Subramanian, University of Washington, Informatics
Development of nanOS: A Profiling Float Software System for Precise Underwater Data Transmission
Co-authors: Krishna Maanasa Ramadugu
Profiling floats are commonly used autonomous tools and are critical for collecting data that help us study oceanographic processes. However, they can be costly and are mainly used for studying deep open ocean environments. To combat this, the Science subteam at the Underwater Remotely Operated Vehicles Team (UWROV) at the University of Washington designed NanoFloat 1.2. NanoFloat is a profiling float system designed to achieve controlled vertical profiling and accurate pressure data transmission for shallower ocean environments at a lower cost. The system employs custom software, called nanOS, that incorporates autonomous depth-based control, using the BlueRobotics MS5837 pressure sensor as the primary feedback mechanism. The design exemplifies closed-loop depth control without relying on encoder-based positioning, with continuous pressure measurements sampled at one-second intervals providing depth readings with an accuracy of ±0.2m. Wireless telemetry is facilitated by an RFM69 900 MHz radio transceiver operating at 20 dBm, enabling real-time broadcasting of sensor data, including depth, temperature, and pressure. An MCP23017 I2C GPIO expander is utilized to minimize microcontroller GPIO requirements. The modular design of the NanoFloat allows for autonomous execution of vertical profiles with configurable target depths and hold durations. It includes critical safety features such as depth limits, motor timeouts, and EEPROM-based state persistence for mission recovery. At TIDES, the UWROV Science subteam will present the NanoFloat’s capabilities through a live demonstration of data transmission using nanOS. In addition to the demonstration, we will highlight our development process, particularly our challenges with code implementation and integration, including platform migrations, I2C configuration issues, and library compatibility problems. We will provide insight into how these challenges were successfully resolved, bringing us closer to a system capable of competing at the MATE ROV robotics competition and aiding in the exploration of our open oceans.
Mark Yamane, University of Washington, Aquatic and Fishery Sciences
Adding to the picture: building optic and active acoustic data products for autonomous near-real-time ecosystem monitoring
Co-authors: John Horne, Hank Statscewich, Rob Cermak, Seth Danielson
Autonomous sampling platforms, including underwater gliders, continue to host an increasing number and diversity of remote sensing instruments and data streams. We have integrated active acoustics (WBT Mini; 200 kHz) and an optical imager (WASSOC Shadowgraph) with standard environmental sensors (CTD, O2, Chl-a, CDOM, optical backscatter) on a Teledyne Webb Research Slocum G3 underwater glider. Onboard processing pipelines send data products home from the glider through Iridium satellite communication during deployment. Due to limited satellite bandwidth and surface transmission times, suites of metrics were developed to summarize acoustic backscatter (EchoMetrics) and zooplankton number, size, and shape distributions (ShadowMetrics) through the water column. Acoustic, environmental, and optic data products are visualized on web browser dashboards as data are transmitted or to review past deployments. These data products provide a near-real-time ecosystem perspective of the sampled region and can be used for ecosystem monitoring, modifying sample designs during glider deployments or, with further development, initiating autonomous adaptive sampling.
Suzu Yoshikawa, University of Washington, Microbiology
Student ROV Teams: Bridging the Gap Between Students and the Blue Economy
Co-authors: Krishna Maanasa Ramadugu, Ellen Leier, Rowan Newell
The Underwater Remotely Operated Vehicles Team (UWROV) at the University of Washington is a team of undergraduate students that use a mix of knowledge in oceanography and engineering to design and build ROVs to compete in the MATE ROV competition. The team has seen international success, placing in the top ten for the past four years. MATE gives the opportunity for students to display and get recognized for their technology, provides challenges that inspire new innovation, and creates a community that supports students and their learning. The team gives support back to our MATE community through volunteering at regional competitions, boothing at related events, and hosting educational events for nearby schools for all ages. Student teams like UWROV are crucial to growing the blue economy, equipping students with real-world problem-solving skills through hands-on design and testing, preparing them for careers. Here we show data showcasing student abilities and confidence in skills developed through UWROV; some examples of skills developed would include designing underwater technologies, troubleshooting issues, and machining parts. On top of technical skills, we will highlight employability/ “soft” skills improvement in our team, such as project management, communication, and teamwork. Additionally, we will provide insights on what students desire from industry, informing employers on how to connect with students.
SESSION B (3:00 PM – 3:45 PM)
Isabelle Brandicourt, University of Washington, Oceanography
Higher Frequency Applications for Distributed Acoustic Sensing in Ocean Acoustics
Co-authors: Samantha Juber, Kate DuFour, Shima Abadi
Distributed acoustic sensing (DAS) uses fiber-optic cables as continuous acoustic sensor arrays. This offers a new method of passive acoustic monitoring in addition to typical systems like hydrophones, often advantageous in its large spatial aperture provided by the sensing cable and real-time data accessibility via the shore connection to a DAS interrogator. While DAS has been widely adopted in the past decade for oil and gas, security, and infrastructure monitoring industries, its application for frequencies into the kilohertz range remains an active field of exploration. Our research works towards extending the effective frequency range of DAS through novel cable deployment strategies. Custom vertical and horizontal cable configurations deployed in Puget Sound and the Salish Sea enabled sampling at significantly higher frequencies than existing subsea installations. These deployments yielded clear signal detection well beyond the typical range, with detections above 2.5 kHz and up to 10 kHz. By incorporating different cable geometries along typical straight sections, we reduced directional sensitivity and increased responsiveness to higher frequency signals. This configuration captured the first vocalizations from resident and transient killer whales on a subsea DAS cable, as well as humpback whales, during the winter of 2025 - 2026. Additionally, we successfully recorded and decoded acoustic communication packets at frequencies reaching 10 kHz, demonstrating the potential of high-frequency DAS for both biological and anthropogenic signal analysis. Continued work on these signals includes denoising and data integrity as well as localization of marine mammals and sources of acoustic communications. Overall, there is much work to be done, but our results offer a promising path forward for the use of DAS in passive acoustic monitoring for higher frequencies.
Hannah Brown, University of Washington, Marine and Environmental Affairs
Investigating the Data Gap Between Larval and Abundance Estimates of Dungeness Crab (Metacarcinus magister)
The Puget Sound Dungeness crab fishery in Washington state is valuable for cultural, economic, and recreational reasons. Despite the importance of fishery, large data gaps mean that abundance estimates of Dungeness crabs are often highly uncertain; no demographic data are typically available for the several-year period between larval and adult stages. Since crabs molt in regular intervals like all arthropods, shed molts may provide a useful index of population abundance during these intermediate years, at relatively low effort and cost. While these molt data are indirect evidence of a Dungeness crab, they nevertheless provide valuable information. When paired with other datasets, this information can increase confidence in abundance estimates and determine size class distribution of Puget Sound Dungeness crab in intermediate life stages across space and time.
Marisa Campbell, University of Washington, Marine and Environmental Affairs
Implementing a Transit Hazard Index to Assess How Vessel Transit Characteristics Influence Ship-Strike Potential in Humpback Whale Critical Habitat off Washington's Olympic Peninsula
Humpback whale critical habitat was designated in 2021 and extends off the coast of Washington's Olympic Peninsula and into the Strait of Juan de Fuca, encompassing an area laden with shipping traffic accessing the major ports of Seattle, Tacoma, and Vancouver. As both shipping traffic and whale populations increase in the area, we expect a higher number of whale-vessel encounters. We developed a novel ship strike metric, the Transit Hazard Index (THI), consisting of four components: (1) the probability that a whale could successfully avoid a vessel, (2) the probability that a whale would be within vessels strike zone, (3) the probability that a strike from a vessel would be lethal, and (4) an exposure term which weights the risk metric by the area swept by a vessel transit. This risk metric does not require whale density estimates, making it a viable option for informing ship strike management in regions where whale density estimates may not be available. Instead, the THI focuses on the characteristics of vessel transits that contribute to potential hazard, while still considering whale vessel-avoidance behavior. We calculated the THI at the status quo for the months of July-September 2024 using AIS vessel traffic data. We then simulated Voluntary Speed Reduction (VSR) policy scenarios to determine potential hazard reduction, as well as the impact of reducing cargo traffic density while maintaining a similar carry capacity through the deployment of fewer, larger ships. We found that cargo ships contribute the most to the THI, and that a reduction in cargo traffic density had a greater impact on the THI than the implementation of a VSR.
Nik Giovine, University of Washington, Environmental Engineering
Development and Production of Seaglider Tracking Tool: Glider Beacon
Co-authors: Ayden van den Berg, Katie Kohlman, Wing-ho Ko
Seagliders, Autonomous Underwater Vehicles (AUVs), rely on buoyancy to maneuver in water and are subjected to strong currents over 0.25 m/s, particularly in open ocean environments. These remote areas are difficult to study but can be accessed by Seagliders to collect important oceanographic data to monitor ocean health and climate impacts. The Student Seaglider Center (SSC) is a student-run lab that pilots gliders remotely. Recently, a mission in the tropical Pacific had a glider deviate off path due to currents, disrupting the mission and requiring an emergency pickup. To minimize these mission interferences, this project creates and evaluates a predictive tool to assist Seaglider pilots in mission planning. It functions by implementing mathematical and modeling methods to visualize a seaglider path using OceanParcels, an open-source, python based lagrangian simulation framework. The Seaglider is designed as a particle that moves in space and time, simulating a glider in situ. GLORYS reanalysis water current data is inputted into the model and serves to simulate conditions that a Seaglider may experience in the real-world. To evaluate the model's effectiveness, the path of the tropical Pacific mission glider is compared to a OceanParcel-project path of a simulated Seaglider. This simulation can be analyzed prior to deployments, quantifying the distance, time and direction a Seaglider is capable of during long-term deployments. Making this tool openly accessible for Seaglider research broadly provides a means for researchers within and beyond the SSC to improve their mission planning to better achieve their scientific objectives.
Aliyaa Haan, University of Washington, Mechanical Engineering
Washington Wave
Co-authors: Emerson Lin, Spencer Lemke, Madelyn McInnis, Cali Weber, Christian Leonard, Sakina Ahmed, Lucas Tran, Jun Choe, Ziyu Wang, Brayden Gladman, Henry Crumbaugh, Dean Foral, Will Hippe, Abdelrahman Osman, Ari Howard, Reed Parker, Joseph Loi, Michael Richeson, Ophelia Chapman, Tyler Milstead, Joel Marr, John Lyons, David Rodriguez-Huerta, Jackson Price, Jaewon Song, Kacey Taylor, Caitlyn Richter, Yuto Shingai, Riley Bates, Ethan Schriner, Quinn Miller, Eanya Devasagayam, Brian Polagye, Curtis Rusch, Judy Twedt
The University of Washington's Marine Energy Club, Washington Wave, is competing in the Department of Energy's Marine Energy Collegiate Competition to design a wave energy converter (WEC) to support onshore algae farms. Our system is an offshore point absorber that converts wave energy into hydraulic power for pumping seawater into algae farms. Multiple WECs will pump water to one main pipe, creating steady flow for an in-line turbine to power environmental monitoring sensors. Energy conversion performance will be evaluated in two parts: 1) A custom actuator to mimic wave motion for testing pump flow rates; 2) A pump loop that models steady flow conditions for estimating turbine electrical power generation. The point-absorber's structural shape will be optimized by testing multiple buoy shapes to test natural frequency and heave responses in a wave tank. Surface biofouling resistance will be evaluated with two tests: 1) Hydrophobicity will be measured with a goniometer; 2) Biofouling accumulation will be quantified using a four-week field deployment of coated test coupons in both submerged and splash-zone conditions. Electrical subsystem testing will assess AC-to-DC rectification efficiency and validate embedded environmental sensors measuring temperature, turbidity, salinity, and dissolved oxygen. These experiments will quantify system performance and help make improvements to the WEC design. Guidance and interviews from professionals in the algaculture industry have inspired the WEC’s purpose of seawater pumping and water quality sensing to create a viable product for the algaculture industry.
Logan Harris, University of Washington, Oceanography
Profiler for Research in Instrumented Subsurface Monitoring
Co-authors: Lydia Kelley
The Profiler for Research in Instrumented Subsurface Monitoring (PRISM) is a waver powered profiler designed to consistently carry sensor packages to desired depths without the need of a motor. PRISM uses a ratcheting mechanism inspired from the early Wirewalker designed by Luc Rainville and Robert Pinkel. This ratchet allows PRISM to be pulled down as it falls into the trough of a wave then releases the rope and remains stationary as the rope is pulled back up with the crest of the wave. This repeats until PRISM reaches a stopper at the bottom of the rope where it floats back to the surface and starts again. The profiler consists of laser cut acrylic, PVC pipes, and a couple 3D printer parts. The rope it climbs on consists of an A2 Buoy, two stoppers on either end of the rope, dyneema rope of a desired length, and an 8-10 lb weight at the bottom (we used chain). PRISM has had one, two hour long, deployment in Puget Sound with additional deployments planned to test and push the depths PRISM is capable of reaching.
Clara Kreutziger, University of Washington, Marine Biology
Shifting Herbivory in the Aegean Sea: Assessing the Impact of Invasive Siganus spp. on Native Sarpa salpa and Posidonia oceanica Meadows in Samos, Greece
Invasive species are reshaping Mediterranean coastal ecosystems, yet their early-stage impacts on herbivory dynamics within Posidonia oceanica seagrass meadows remain poorly understood, particularly in the understudied Aegean Sea. This study represents an exploratory first step in evaluating how invasive rabbitfishes (Siganus luridus and Siganus rivulatus) influence native herbivores and seagrass structure along their potential invasion gradient. Herbivorous fish communities and benthic habitat characteristics were compared between two P. oceanica meadow sites, Avlakia (Samos) and Vroulia Bay (Lipsi), using a combination of non-extractive methods including Underwater Visual Census (UVC), Remote Underwater Video (RUV), and benthic photoquadrat analysis. Herbivorous fish abundance was estimated using maximum observed counts, while seagrass canopy height and benthic composition were quantified along standardized transects and compared between sites using non-parametric statistical analyses. Results revealed a significantly higher abundance of the S. luridus at Lipsi, coupled with a pronounced reduction in P. oceanica canopy height relative to Samos. In contrast, overall benthic composition did not differ significantly between sites, and native herbivores (Sarpa salpa and Sparisoma cretense) showed no significant differences in abundance, despite modest site-level trends. The co-occurrence of elevated invasive herbivore abundance and reduced canopy height suggests that Lipsi may be experiencing early-stage, herbivore-driven structural degradation of P. oceanica meadows preceding detectable changes in seagrass cover or benthic composition. Although limited in spatial and temporal scope, this study provides baseline evidence that invasive herbivory may act as an early driver of seagrass meadow alteration and highlights the importance of continued monitoring to detect emerging ecological change.
Ryan Luvera, University of Washington, Aquatic and Fishery Sciences & Marine Biology
Does transport of sockeye salmon eDNA affect its efficacy for enumeration in small streams?
Developing and validating new methods of enumerating species of concern is important for many conservation and management goals. Environmental DNA (eDNA) has proven to be a viable tool for obtaining non-invasive and cost-effective estimates of many organisms, including fishes in streams such as salmon. However, before eDNA can be used beyond an experimental basis, we need to understand how eDNA flows through small streams where salmon may spawn in high densities. This study aims to examine how sockeye salmon (Oncorhynchus nerka) eDNA is transported in small streams by comparing in-stream counts of salmon with spatial variation in eDNA concentrations with and among streams. Preliminary analysis shows that Eagle Creek (low stream discharge and low density of salmon) showcased significant eDNA degradation resulting in no real trend in accumulation, whereas Happy Creek (high stream discharge and high density of salmon) accumulated eDNA down the stream. Currently, these results may show the heterogeneity and importance of habitat in eDNA degradation and ultimately the implications for using eDNA for abundance analysis.
Paige McKay, University of Washington, Oceanography
Assessing the Accuracy and Long-Term Stability of the Shallow SeapHOx Oceanographic pH Sensor in an Estuarine Environment
Co-authors: Emily Betz, Sophie Monterola, Sasha K. Seroy, Charles W. Branham, Adam Newhouse
pH is an important parameter for determining the health of aquatic ecosystems and is known to be influenced by changing global conditions like climate change and fluctuations in atmospheric CO2. Recent changes have been observed in aquatic environments, particularly in marine and estuarine where climate and CO2 driven ocean acidification has decreased pH. Long-term pH monitoring is limited in these environments, largely because robust and deployable pH sensing technology is typically designed for marine environments. This gap in technology limits the technical assessment of marine pH sensors in freshwater and estuarine settings. To advance this technology into these environments, we tested the Ion Sensitive Field Effect Transistor (ISFET) pH sensing technology using the DeepSeapHOx pH sensor, manufactured by SeaBird Scientific, over three months in Portage Bay, off the University of Washington's Marine Science Building Dock. We also deployed a ShallowSeapHOx pH sensor in the Snohomish River Estuary at the port of Everett. We collected bi-weekly water samples from the deployment locations to determine pH using spectrophotometric analysis, to assess the accuracy and stability of the SeapHOx pH readings. Our findings indicated that SeapHOx models were functional in a variety of aquatic environments but required an in-situ calibration to accurately report pH values through the duration of the deployment. The sensors exhibited an offset from the spectrophotometric values and exhibited a linear drift over the test period. Both issues could be easily corrected with an in-situ calibration after the sensors had equilibrated to the environment. This study contributes to the advancement of aquatic research by expanding the technology available for monitoring changing freshwater and estuarine ecosystems.
Christopher Moon, University of Washington, Oceanography
Analyzing the Impact of Mesoscale Eddies on Coral Reefs in the Florida Keys Using Satellite Observations
The Florida Keys National Marine Sanctuary hosts vital coral reefs supporting millions of marine organisms, providing storm protection, and driving local economic activity. While mesoscale eddies (10-100 km) in the Gulf of Mexico significantly influence oceanographic conditions, their effects on the Florida Keys' extensive coral reef ecosystems remain poorly understood. This study examines how mesoscale eddies originating from the Loop Current affect temperature regimes and potentially impact coral reef health in the Florida Keys. Mesoscale eddies transport large water parcels within their cores, carrying nutrients, coral larvae, and other critical water properties while significantly influencing circulation patterns through the Florida Straits. The MUltiparameter Near real time System for Tracking Eddies Retroactively (MUNSTER) tracks eddies surrounding the Florida Keys to evaluate their potential impacts on regional coral reef health. MUNSTER eddy fields utilize the NOAA Radar Altimetry Database System (RADS) near real-time sea level anomalies, NOAA Geo-Polar Blended near real-time L4 Analysis 5 km daily grids for nighttime sea surface temperature, NOAA MSL12 near real-time VIIRS multi-sensor ocean color DINEOF gap-filled analysis 9 km daily grids for chlorophyll-a concentrations, and SMAP JPL V5.0 interpolated 0.25º × 0.25º daily grids for sea surface salinity measurements. It employs a closed contour algorithm to identify anticyclonic and cyclonic eddies (Chaigneau et al., 2008, 2009; Pegliasco et al., 2015). Additionally, this study uses in situ measurements from Argo floats and moorings to compare temperature fluctuations relative to eddy presence.
Amanda Muir, University of Washington, Landscape Architecture
Earthworks: Hydrogeologic Design Strategies for Climate Resilient Aquaculture in Skagit County
Co-authors: Nicole Loeffler-Gladstone, Karen Pacheco Garcia, Celina Balderas Guzmán
Sea level is projected to rise up to 4 feet in the next 75 years, which is a problem to many of the low lying farmlands around the Puget Sound that already exist at the high tide line, with dikes being the only obstacle to the fields experiencing flooding during concurrent high tides and storms. The isthmus connecting Samish Island to Skagit County mainland contains one such property, a historically agriculture land that connects to a high residential island that is facing sea level rise challenges. Our site analysis dove into the sedimentary history of the area, the current longshore transport of sediment from the Samish River, and the current composition of the soil. If no intervention occurs, the site will be completely mudflat in 2100, with no opportunity for the natural salt marsh in the area to migrate due to compaction of the soil, as well as cutting off connection to Samish Island. Our design proposes reconnecting people to the land through hyperlocalized aquaculture practices that will continue to produce food for the Skagit County region while building up the surrounding land through optimizing the natural sediment distribution as well as through human fill intervention optimized for native ecological species.
Rohan Rairkar, University of Washington, Mechanical Engineering
MARLIN: Modular Adaptive ROV Leveling and Interaction Nexus
Co-authors: Marcus Kwek, Emmet Van Mason, Fiona Impert, A. Rick Rupan
Remotely Operated Vehicles (ROVs) are unmanned robots that operate underwater to accomplish various tasks, such as maintenance, inspections, and research. Current ROV technology takes two approaches. Some maintain six maximum degrees of freedom (DOF) but sacrifice the ROV’s stable pitch position, which leaves inexperienced drivers unable to operate the unintuitive system effectively. Alternatively, some use four DOF, excluding pitching and rolling to stabilize the system, limiting its maneuverability and capability. This project aims to increase the mobility of small-scale ROVs while mitigating the downsides additional mobility typically causes. The Modular Adaptive ROV Leveling and Interaction Nexus (MARLIN), a novel stability arm system and tooling gantry was designed to enable precise movement while handling objects. MARLIN is composed of three subsystems: the Pitch Control Arm, the Planar Positioning System, as well as the Hot Swap Tooling Hub. This cutting edge system provides a stable, yet adjustable pitch state, and a more forgiving user experience by allowing a wider margin of alignment error. The system should allow more interaction complexity than a four DOF ROV while maintaining more pitch stability than a six DOF ROV. Integrating MARLIN into small-scale underwater vehicles allows ROVs to accomplish complex tasks while being significantly more intuitive, making it much easier to use.
Sangmin Song, University of Washington, Oceanography
Novel machine learning reconstruction of the Southern Ocean carbon sink using merged ship and float observations
Understanding the fate of excess atmospheric carbon will require accurate quantification of carbon uptake in the Southern Ocean, which acts as a central hub of exchange between the ocean and atmosphere due to its unique circulation. Although this turbulent region encircling Antarctica is thought to be responsible for capturing a quarter of anthropogenic carbon and thus slowing the effects of climate change, it remains challenging to observe directly by traditional ship sampling due to its remote nature and harsh conditions. Recent studies have shown that incorporating data from autonomously operating instruments, called Argo floats, can improve quantification of oceanic carbon uptake. Here, we leverage an increasingly large observational dataset collected by both Core- and Biogeochemical-Argo floats in a new regression framework to reconstruct the strength and variability of the Southern Ocean carbon sink over 2014–2023. Our approach identifies five overlapping classes of Southern Ocean observations, then trains distinct machine learning regression models for each cluster to learn the relationship between measured variables and surface carbon properties using known observations from both ships (Surface Ocean CO2 Atlas) and Biogeochemical-Argo floats. When applied to a large dataset of physical measurements from Core-Argo floats, the regression model generates a novel surface carbon dataset at widespread profiling times and locations across the Southern Ocean. Unlike most existing methods for estimating seawater carbon properties, our approach prioritizes using point measurements rather than monthly-averaged inputs for regression training. This preservation of variability in the training data is especially critical for learning relationships in the Southern Ocean where seawater properties can be modulated strongly at short time and space scales. Our novel reconstruction approach thus opens new possibilities to overcome observing limitations and better understand the direction, strength, and timing of air-sea carbon exchange in this important region.
James Stadler, University of Washington, Oceanography
Observations and modeling of wave - current interactions on the Oregon coast
While surface currents have long been known to modify the amplitude, direction, and steepness of surface waves, operational wave forecasts along the coast of the Pacific Northwest do not include any of the physics of surface current and surface wave interactions. The Washington and Oregon coasts are regions with both frequent and significant (O(0.5m/s)) near-inertial currents which can potentially introduce inaccuracies in existing operational wave forecasts run without current forcing. However, the magnitude of the forecast error due to neglecting these currents is currently unknown. To this end, in this work we make use of high frequency radar measurements of currents off the Oregon coast in combination with a series of wave-measuring buoys to study the impacts of near-inertial currents on surface waves in this region. Comparisons between these observations and hindcast wave models run with and without near-inertial currents allow for quantification of the impacts of these currents on coastal wave-forecast accuracy.
Hannah Tucker, University of Washington, Marine Biology
Determining the effects of altered survey design on relative abundance indices for groundfish
Co-authors: Emily Liljestrand, Amanda Hart
Long-term fishery-independent surveys provide critical data on the abundance and distribution of many species of fish and invertebrates to inform stock assessment, but changing resources and management priorities may require adjustments to sampling effort. Consistency is an important feature of long-running survey time series, so design changes tend to be infrequent and require additional analysis to assess the consequences of proposed alterations. The Northeast Fisheries Science Center’s (NEFSC) bottom trawl survey is a stratified random sample, with strata designed based on depth and latitude. This results in small strata in areas where depth changes rapidly (e.g., along the continental shelf break, along the inshore boundary of the survey) that are proportionally oversampled compared to larger strata. Revising the sampling design for small strata could help redistribute survey effort more evenly and address changing sampling resource constraints. This study examines alternative survey designs to determine how combining smaller strata and decreasing sampling effort affects the trends of abundance in groundfish stocks across both fall and spring surveys. We implemented a resampling procedure to simulate alternative NEFSC’s bottom trawl survey designs and quantified differences in relative abundance indices based on the current survey sampling design and the proposed alternatives. This work will provide a framework to assess the effects of survey design changes on the bottom trawl survey. Anticipated results will improve understanding of how sampling alterations impact uncertainty in abundance indices and stock assessments to support informed decision-making about the future of fisheries independent surveys.
Jaycee Williford, University of Washington, Marine Biology
Impacts of Ocean Alkalinity Enhancement on Pacific and Olympia Oysters
Climate change is increasing across the globe at an alarming rate. With it comes environmental impacts such as ocean warming and acidification, which negatively affect marine organisms. There are a variety of proposed techniques and solutions to combat the climate crisis, such as marine carbon dioxide removal (mCDR). Ocean alkalinity enhancement (OAE) is a highly favored mCDR method; however, there are knowledge gaps in the potential environmental impacts associated with OAE. Therefore, it is important to ensure that this novel climate solution is safe for deployment in the Salish Sea, a recommended hub of future mCDR efforts. My research focused on a local OAE project in Port Angeles Harbor, Washington, and its potential impacts on environmentally and culturally valuable species. We compared Pacific oyster (Crassostrea gigas) and Olympia oyster (Ostrea lurida) growth, survival, and shell composition directly in the OAE plume to oysters in ambient seawater conditions. Through this research, we hope to provide valuable insight into OAE impacts on species of importance, informing local stakeholders.