"Effectiveness of aerial monitoring of spatial and temporal changes of Santa Catalina Island Rhodoliths"
A Thesis Defense by Charnelle Wickliff
March 1st, 2023 at 9:30 am PDT
March 1st, 2023 at 9:30 am PDT
February 24th, 2023 at 10:00 am PDT
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February 27th, 2023 at 4:00 pm PDT
Watch the recording here
February 23rd, 2023 at 12:00 pm PDT
Zoom | Live-Stream | November 30th, 2022 at 4:00 pm PDT
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.
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.
October 28th, 2022 at 3:00 pm PDT
Zoom | Live-Stream | September 2nd, 2022 at 12:00 pm PDT
Zoom | Live-Stream | August 30th, 2022 at 2:00 pm PDT
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.
Marine Environmental Physiology Lab | Invertebrate Ecology Lab
Zoom | Live-Stream | August 22nd, 2022 at 3:00 pm PDT
Caroline Rodriguez graduated from Duke University with a B.S. in Environmental Sciences in 2013 and completed internships at the North Carolina Coastal Federation and the Maryland Sea Grant Research Experience for Undergraduates (REU) program. After graduating, Caroline was chosen for the Chesapeake Conservation Corps program and spent two years working as a water quality technician and outreach coordinator for the Arundel Rivers Federation in Edgewater, Maryland. Caroline then spent two and a half years serving as a Peace Corps Volunteer in Nicaragua where she co-taught natural science courses in rural elementary schools and co-led environmental projects including school gardening and environmental summer camps.
After the Peace Corps, Caroline began her M.S. in Marine Science in the Marine Environmental Physiology Lab at California State University Monterey Bay and the Invertebrate Ecology Lab at Moss Landing Marine Labs. Caroline was awarded the NOAA Center for Coastal Marine Ecosystems (CCME) Graduate Fellowship, which funded her thesis research. During her time in the CCME Fellowship program, Caroline completed a NOAA Experiential Research and Training Opportunity (NERTO) at NOAA Pacific Islands Fisheries Science Center in Honolulu, Hawaii where she developed a workflow to generate accurate growth, survival, and recruitment estimates for thousands of coral colonies using large-area imagery. She built on this work for her master’s thesis and investigated coral population dynamics for the dominant coral species across the Hawaiian archipelago and assessed the impact of thermal stress on coral populations. In addition to her research work, Caroline worked at the MLML Front Desk throughout her time at MLML, helped lead the Future Leaders in Marine Science mentorship program at the North Monterey County High School, and served as the CSUMB representative on the MLML Student Body. In 2022, Caroline was selected for the John A. Knauss Marine Policy Fellowship Program and moved to Washington, D.C. to work with NOAA’s Office of International Affairs. She hopes to continue working with diverse communities at the intersection of science and policy to advance equitable ocean and coastal policy.
Zoom | Live-Stream | August 12th, 2022 at 1:00 pm PDT
Katie graduated from CSU Monterey Bay in 2016 with a B.S. in Marine Science. While there, Katie worked for a few MLML Ichthyology lab graduate students. Her undergrad research included two main projects: "Investigating the condition of surgeonfish along a nutrient gradient in the southern line islands" and "Examining the effects of size-selective mortality on sex change in a protogenous hermaphrodite species of goby, rhinogobiops nicholsii". Following her graduation, Katie worked for California Department of Fish and Wildlife (CDFW) as a Scientific Aid and collected data for the California Recreational Fisheries Survey in Santa Cruz, CA.
Alternative feeds for finfish aquaculture are critical for the sustainable expansion of the aquaculture industry. Fish that are farmed for human consumption are often carnivorous; therefore, the industry uses wild-caught forage fish as a primary ingredient in farmed fish feeds in the form of fish meal (FM) and fish oil (FO). With the aquaculture industry expanding, alternative ingredients are needed to safeguard fisheries' sustainability and future aquaculture development. While some alternative feed ingredients have been identified, it is necessary to improve the existing options and identify alternative ingredients with higher concentrations of omega-3 polyunsaturated fatty acids (PUFAs). This study was designed with six feed treatments to test a microalga, Schizochytrium sp., as an alternative feed ingredient for sablefish (Anoplopoma fimbria). The two fish ingredient control diets are called +FM+FO (contains both FM and FO) and -FM+FO (contains FO). The fish-free diets completely replace FO with flax oil (FF Flax) or a combination of flax oil and low, moderate, or high inclusion of Schizochytrium sp. (FF LowSc, FF ModSc, and FF HighSc) in the feeds. After a five-month feeding trial, sablefish condition metrics, whole-body proximate composition, and apparent digestibility coefficients were not different across diet treatments. In contrast, sablefish growth was influenced by treatment, with the high microalga-inclusion diet (FF HighSc) performing as well as the fish-ingredient controls. Fillet fatty acid profiles were also influenced by diet treatment, generally reflecting the fatty acid profiles of the feed. Total PUFAs were higher in the fish-free diets than in the controls. These results suggest Schizochytrium sp. can increase PUFA concentrations in fish fillets, while not compromising fish health and growth, making it a viable ingredient for alternative sablefish feeds.