Thesis Defenses

Thesis Defense by Parker Forman – July 19th

Taylor Azizeh
"Influence of intrinsic factors on at-sea behavior of late chick-rearing emperor penguins (Aptenodytes forsteri) at Cape Crozier, Ross Island, Antarctica"
A Thesis Defense by Parker Forman

Vertebrate Ecology Lab

Zoom | Live-Stream | July 19th, 2022 at 12:00 pm PDT

Abstract

I described the at-sea behavior of emperor penguins (Aptenodytes forsteri) during late chick-rearing at Cape Crozier. Analyzing data from eight penguins, I investigated how intrinsic factors, including sex, size, and body condition influenced their behaviors. Penguins exhibited mean trip durations of 10.6±3.4 days, covering a daily distance of 55.7±8.0 km. Penguins predominantly performed dives within the upper 200 meters of the water column (90.7±26.5%), with a smaller proportion of dives (9.3±2.0%) reaching greater depths. Deeper dives were typically associated with shallow bathymetry. Penguins conducted an average of 1,860±681 dives with maximum depths of 455.8±32.6 m and durations of 12.9±2.4 minutes. Penguins spent 66.4±14.8% and 43.9±4.4% of their time at sea resting and diving.

Penguins with similar behaviors were categorized into groups: Group I foraged near the continent and traveled to the Ross Bank, and Group II predominantly foraged near the continent. I found significant differences in foraging behaviors between the groups and sexes. The composition of these groups was influenced by sex. Group I mostly comprised males, while Group II were females and one unknown sex. Females displayed higher dive frequencies per day (Females (F):186±17, Males (M):151±4), shallower maximum depths (F: 432.2±29.4 m, M: 476.8±12.8 m), and shorter durations (F: 3.2±0.7, M: 3.9±0.3). Possible explanations for the observed differences between male and female penguins include energetic requirements, prey preference, physical characteristics, and niche differentiation, which can shape their distinct foraging behaviors.

Furthermore, results from this study indicate that penguin behaviors were also influenced by the physical characteristics and condition of their bodies. This finding suggests that there may be an optimal body condition for achieving greater diving depths. Penguins with intermediate body conditions may possess a more efficient physiological adaptation for sustained deep diving, enabling them to access resources inaccessible to individuals with lower or higher body compositions.

This study advances our understanding of late-chick-rearing penguins and the influence of intrinsic factors on their behavior. The findings indicate that emperor penguins exhibit divergent strategies influenced by sex and physical condition, leading to variations in dive behavior and bathymetry use. These sex-based disparities in penguin behavior highlight distinct ecological roles for each sex within the species. These findings provide a novel description that underscores the remarkable adaptations of emperor penguins in successfully navigating dynamic environments at Cape Crozier.

Bio

Parker Forman is an ecologist recognized for his creative application of datalogging technology to study cryptic species. With a solid understanding of behavioral ecology, Parker illuminates the hidden complexities of these creatures' lives and their interactions with their environments.

After completing his undergraduate studies, Parker embarked on a hands-on role as a biological field technician. His work encompassed diverse demographic studies, contributing to our knowledge of marine and terrestrial vertebrates, including Northern spotted owls, native Hawaiian birds, Northern elephant seals, and fur seals.

In 2018, Parker joined the Vertebrate Ecology Lab at MLML, which marked a turning point in his career. He researched the frigid landscapes of Cape Crozier, Antarctica, focusing on studying the at-sea behavior of emperor penguins. Living in such an isolated location alongside his study subjects provided Parker with firsthand experiences of the lives of these deep-diving seabirds.

Guided by his passion for nature, data analysis, and commitment to conservation, his experiences reinforce his dedication to expanding conservation efforts in ecological discovery.

Thesis Defense by Katie Cieri – April 19th

Jackson Hoeke
"Composition and Distribution of Fish Assemblages in Cap de Creus Natural Park in Relation to Marine Protection, Depth, and Habitat"
A Thesis Defense by Katie Cieri

Fisheries and Conservation Biology Lab

Zoom | Live-Stream | Arpil 19th, 2022 at 4:00 pm PDT

Bio

Katie got her B.S. in Biology from the University of Virginia. After graduating, she pursued many different opportunities. She completed a Research Apprenticeship at Friday Harbor Laboratories investigating the foraging ecology and diet of Pacific Sand Lance. She also worked as an intern with the Virginia Aquarium Stranding Network in the Humpback Whale identification program. Prior to her enrollment in MLML, Katie worked as a research technician and lab manager in the Farmer Lab at the University of Utah, where she conducted investigations into the respiratory physiology of Tarpon and American Alligators. While completing her Master’s thesis, the composition and distribution of fish assemblages in Cap de Creus Natural Park in relation to marine protection, depth, and habitat, at MLML Katie worked as a research technician in the Fisheries and Conservation Biology Lab under Dr. Rick Starr. She was involved in many projects, including the Monitoring & Evaluation of Mid-Depth Rocky Reef Ecosystems, the Benthic Observation System Survey (BOSS), and the California Collaborative Fisheries Research Program (CCFRP). Through these projects and her own thesis, Katie explored how different survey methodologies including video landers, remotely operated vehicles, and hook-and-line surveys, can be utilized to assess nearshore fish and invertebrate communities and to monitor the effectiveness of Marine Protected Areas. Katie is also passionate about outreach and inclusion and continues to explore avenues to make marine science more accessible. While at MLML, she was a member of the leadership committee for the Monterey Bay Chapter of the Society for Women in Marine Science. She also contributed to MLML Open House through leading crowdfunding, participating in the puppet show, and heading up the donations committee. Katie is interested in exploring the best solutions for marine conservation through science, user engagement, and collaborations in her new position as a California Sea Grant Fellow for the California Ocean Protection Council's Biodiversity Program. In her free time, Katie enjoys kayaking, scuba diving, hiking, and adventures with her husband and dog.

Katie Cieri (Right) and Rick Starr (Left) prepare for a research dive in the Medes Islands, Spain.

Katie (right) holds up a Copper Rockfish (Sebastes caurinus) caught by her mom, Mary Pat, (Left) on a catch-and-release CCFRP trip. Photo Credit: Fisheries and Conservation Biology Lab

Katie operates the winch during a BOSS research cruise to San Clemente Island. Photo Credit: Fisheries and Conservation Biology Lab

Thesis Defense by Victoria Dickey – November 30th

Jackson Hoeke

 

"The Distribution of Microplastics in Marshlands Surrounded by Agriculture Fields: Elkhorn Slough (CA)"
A Thesis Defense by Victoria Dickey

Geological Oceanography Lab

Zoom | Live-Stream | November 30th, 2022 at 4:00 pm PDT

Bio

Victoria joined Moss Landing Marine Labs in 2018 after earning a BS in Oceanography at Hawaii Pacific University. She is in the Geological Oceanography lab under Ivano Aiello’s advisement and has enjoyed building skills in GIS, grain size analysis, and operating the Scanning Electron Microscope. Victoria came up with the idea to sample sediment to find microplastics after driving past the fields of plastic mulch on her way to school every day. She is a strong advocate for ocean conservation and has played a role in the local chapter of the Surfrider Foundation as well as on the advisory council for the Monterey Bay National Marine Sanctuary. Victoria believes strongly in the necessity of communicating science and conservation to people of all ages and demographics and hopes to continue to build that skill in her future careers.

Thesis Abstract

The wide-spread use and subsequent recycling of plastics in the agriculture industry promotes improper disposal and poses a threat to important wetland habitats. When plastics degrade, they break up into smaller pieces that pose serious threats to organisms that ingest them and to habitats they settle in. This study quantifies the estimated concentration, types, and lengths of microplastics (< 5mm plastic particles) in the marsh environments of Elkhorn Slough, California’s second largest estuary. Replicate samples of marsh soil samples were extracted from seven Elkhorn Slough marshes at varying distances from the head and the mouth of the estuary and potential sources of agricultural plastic. Using a safe and cost-effective density separation technique, microplastics were separated from the soil, identified, and counted on micro-filters using a dissecting microscope, then further analyzed with a Scanning Electron Microscope equipped with an Energy-Dispersive Spectrometer (SEM/EDS) to analyze surface microstructures and the elemental compositions of the particles. Two main microplastic morphotypes, fragments and fibers were observed. The average concentration of microplastics estimated by this study is ~1600 particles per kg of wet soil, which is comparable to the average concentration of microplastics found in the sediment of the Venice Lagoon. Fragments are statistically smaller but more abundant (making up 85% of microplastics found) than fibers and with an average length of ~85 µm and ~500 µm respectively. Fragment lengths at agriculture sites are larger than the rest of the sampling sites, indicating a shorter residence time in these locations and highlighting agriculture plastics as a potential source. All microplastics found in collected samples exhibit signs of weathering, like pitting and fractures on the surface.  This study explores the particle size distributions of microplastics and the sediment they were sampled from to highlight the similarities in the physical influences controlling their distributions. Importantly, the federally protected Monterey Bay National Marine Sanctuary exchanges an extensive tidal range with Elkhorn Slough. This study identifies potential sources of microplastics to the Monterey Bay National Marine Sanctuary and the surrounding shores with an emphasis on the agriculture industry.

Thesis Defense by Hannah Bruzzio – August 30th (Zoom)

Taylor Azizeh

 

"Effects of Ocean Acidification and Hypoxia on Stress and Growth Hormone Responses in Juvenile Blue Rockfish (Sebastes mystinus)"
A Thesis Defense by Hannah Bruzzio

Ichthyology Lab

Zoom | Live-Stream | August 30th, 2022 at 2:00 pm PDT

Bio

Hannah Bruzzio is a graduate student in the Ichthyology Lab at Moss Landing Marine Labs. In the spring of 2018, she got her BS from the College of William & Mary in Williamsburg, VA. While there she completed her honor’s thesis researching particle interactions with the gill arch/gill raker morphology of the American shad to investigate the fluid dynamics of filter-feeding fish. She joined MLML in the fall of 2018. 
For her master’s thesis, Hannah looked at how the environmental stressors of ocean acidification and hypoxia affects the hormonal stress response of juvenile blue rockfish. In addition to her research, Hannah worked as the MLML Environmental, Health and Safety assistant under Jocelyn Douglas. She also designed the open house t-shirts for 2019, 2020 and 2022. She also volunteered at the Monterey Bay Aquarium where she worked with the jellyfish and schooling fish husbandry staff. In April of 2022, Hannah returned to the east coast to accept a job at the Institute of Marine and Environmental Technology (IMET) as the Senior Biological Technician for their Aquaculture Research Center (ARC) in Baltimore, MD. There she maintains populations of Atlantic salmon, Tilapia, Rainbow trout, Nurse Shark, Blue gill, Hybrid striped bass, Blue crab, White-leg shrimp and Zebrafish for use in a wide range of RAS-aquaculture based research projects.

Thesis Abstract

Global climate change is causing increasing ocean acidification (OA) and deoxygenation (hypoxia) of coastal oceans. Along the coast of California, where upwelling is a dominant seasonal physical process, these environmental stressors often co-occur and are intensified in nearshore ecosystems. For juvenile nearshore fishes, who spend a crucial developmental life stage in coastal kelp forests during the upwelling season, these stressors are experienced concurrently and may have large implications for fitness. Environmental stress can set off an endocrine response, which impacts physiology, energy allocation, growth, and behavior. To test the effects of climate change on juvenile blue rockfish, I measured the endocrine response to single and combined stressors of OA and hypoxia after one week of exposure. Assays of cortisol and IGF-1 hormone responses, served as proxies for stress and growth, respectively. Full organismal effects of environmental stressors were evaluated using a scototaxis (i.e., light/dark anxiety) behavior test, and measures of physiological changes in maximum metabolic rate (MMR) and body condition (i.e., Fulton’s K condition index). I found that peak (~1 hour) cortisol levels were highest in the single stressor low pH (7.3 pH), followed by the combined stressor (7.3 pH and 2.0 mg/L O2) and then the single stressor hypoxic treatment (2.0 mg/l O2). This high peak cortisol associated with low pH may indicate the role of cortisol in acid-base regulation. Only the low DO (dissolved oxygen) group did not exhibit a recovery of cortisol levels by the end of one week. There was no observable difference in IGF-1 in juvenile blue rockfish after a week of exposure to any of the pH or DO stressors. When cortisol levels were high, the same fish had low levels of IGF-1, and when cortisol levels were lower, the same fish had highly variable levels of IGF-1. At one-week of exposure, cortisol exhibited a positive relationship with MMR, such that higher stress levels were associated with greater oxygen consumption by the fish. MMR values themselves were highest in the low DO fish, which subsequently also had slightly higher cortisol levels at one-week. Juvenile blue rockfish were largely robust to any behavioral changes associated with stress across treatments. Hypoxic treatment fish had significantly lower body condition than fish from treatments with ambient DO levels after one week. Overall, the results indicated that pH levels influenced hormonal stress physiology, while DO levels contributed to observed differences in metabolism, body condition, and behavioral anxiety in juvenile blue rockfish. I was unable to tease apart and classify whether OA and hypoxia work in an additive, antagonistic, or synergistic way. Continued research should include more experimental stressor treatment levels of varying intensity of both individual and combined treatments as well as upwelling/relaxation fluctuating treatment levels. Elucidating the effects of climate change on fish endocrine response and physiology is important for fish population management and can help inform stock assessment models of blue rockfish in a rapidly changing ocean.

 

Hannah Bruzzio Presents: Effects of Ocean Acidification and Hypoxia on Stress and Growth Hormone Responses in Juvenile Blue Rockfish (Sebastes mystinus)