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


"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


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)

New Blog Post: Does science have market value? Understanding the influence of science on the economy

The editors of The MLML Drop-In Blog are pleased to present a new blog post by Jason Gonsalves (MLML Physical Oceanography Lab): “Does science have market value? Understanding the influence of science on the economy”, in which Jason delves into the economics of science and perspectives on its value by companies, governments, and the public.
You can access Jason’s piece here, and catch up on older blog posts here.
Happy Fall 2022 and keep reading,
The Drop-In Blog Editorial Team (Kali, Keenan, and Grace)

Founded in 2008 by a small group of MLML students looking for a platform to write candidly about their experiences as grad students, The Drop-In now has over 600 posts written by Moss grad students past and present. The editorial team invites submissions for blog posts from current MLML students. Please email any editor with a pitch for your piece and we will help you develop it into a post for publication.

Seminar – How spatial processes influence coastal fish population and community dynamics – October 6th


Dr. Mallorie Yeager, UC Santa Cruz

Hosted by the Physical Oceanography Lab

Presenting: "How spatial processes influence coastal fish population and community dynamics"

MLML Seminar | October 6th, 2022 at 4pm

Watch the Live Stream here or here


Mallarie is a postdoctoral researcher at UCSC working with Dr. Pete Raimondi, Dr. Mark Carr and Dr. Will White at Oregon State University. She is broadly interested in how spatial processes interact with local factors to shape both population and community dynamics. For her seminar she will first share some of her past work from her Masters and Doctorate, looking at how factors like local landscape features and functional diversity influence trophic interactions and stability of fish communities. Then, she will present on ongoing findings from her work at UCSC using demographic population models parameterized by ROMS and fish survey data to assess connectivity of kelpforest fisheries across the California MPA network.

Seminar – Jaws, Lost Sharks, and the Legacy of Peter Benchley – September 29th


Dr. Dave Ebert, Pacific Shark Research Center/Moss Landing Marine Laboratories

Hosted by the Ichthyology Lab

Presenting: "Jaws, Lost Sharks, and the Legacy of Peter Benchley"

MLML Virtual Seminar | September 29th, 2022 at 4pm

Watch the Live Stream here or here

Dr. Dave Ebert, Director of the Pacific Shark Research Center, has devoted his life to studying the ocean’s most elusive, dangerous and yet fascinating predator - the shark! Author of 35 books, including the popular “Sharks of the World”, and over 700 publications, Dave holds numerous positions including past President of the American Elasmobranch Society, Scientific Advisor to the United Nations Food and Agriculture Organization, Research Associate at the California Academy of Sciences and South African Institute for Aquatic Biodiversity, and the IUCN Shark Specialist Group. A popular television guest, Dave has appeared on various programs for the BBC, Discovery Channel, National Geographic, ABC’s Good Morning America, NBC’s Today Show and NBC News. As a regular on Shark Week, Dave has lead expeditions in search of the rarest, most elusive sharks in the world. He has even discovered new shark species while filming on location. Dave is co-host of the popular podcast Beyond Jaws, where he shares stories from his latest explorations and interviews leaders in the field.

Virtual Seminar – Biomimetic Technologies Based on Charismatic Marine Fauna – September 22nd


Dr. Frank Fish, West Chester University

Hosted by the Visiting Scientist, Dr. Roxanne Banker

Presenting: "Biomimetic Technologies Based on Charismatic Marine Fauna"

MLML Virtual Seminar | September 22nd, 2022 at 4pm

Watch the Live Stream here or here

Frank Fish is a Professor of Biology at Westchester University, he received his BA from SUNY at Oswego and both his M.S. and Ph.D. from Michigan State University. His research focus on the energetics and hydrodynamics of vertebrate swimming, with particular regard to propulsive modes and the evolution of aquatic mammals. This research is accomplished by examination of morphological structures with computer tomography (CT scans), biomechanics with motion analysis and computer digitizing, and exercise physiology by measurement of metabolic performance with oxygen consumption. His research has been funded by the National Science Foundation (NSF), Office of Naval Research (ONR), and Defense Advanced Research Projects Agency (DARPA), and has applications in the field of biomimetics and bioinspiration of engineered systems.

Virtual seminar – Inventing and applying technology to improve blue, green, and brown carbon and other water quality monitoring approaches – September 15th *SPECIAL TIME* 12pm


Dr. Phillip Bresnahan, University of North Carolina Wilmington

Hosted by the Chemical Oceanography Lab

Presenting: "Inventing and applying technology to improve blue, green, and brown carbon and other water quality monitoring approaches"

MLML Virtual Seminar | September 15th, 2022 at 12pm

Watch the Live Stream here or here


Phil Bresnahan is an Assistant Professor in the Department of Earth and Ocean Sciences at the University of North Carolina Wilmington and member of the Center for Marine Science. He has recently taken over as PI for the Sustained Ocean Color Observations with Nanosatellites (SOCON) Project and he leads R&D for Smartfin, a citizen science/ocean literacy collaboration with surfers. Bresnahan enjoys working on many aspects of ocean sensor networks, including sensor innovation (electrical and mechanical design as well as laboratory and field analysis), cloud data management, and, ultimately, data analysis and visualization. He seeks to invent and apply novel marine sensing techniques and analytical approaches in the (mostly coastal) ocean in order to investigate and communicate natural and human-caused phenomena, especially acidification, deoxygenation, and eutrophication.

Seminar – Climate-resilient fisheries management in the California Current – September 8th


Dr. Chris Free, UC Santa Barbara

Hosted by the Ichthyology Lab

Presenting: "Climate-resilient fisheries management in the California Current"

MLML Virtual Seminar | September 8th, 2022 at 4pm

Watch the Live Stream here or here

Chris is Research Faculty at the Bren School at University of California, Santa Barbara. He has a BA in Conservation Biology from Middlebury College and a PhD in Oceanography from Rutgers University. His research is focused on understanding the impacts of climate change on marine fisheries and on designing and testing management strategies that are adaptive to these impacts. He is also interested in bycatch avoidance, harmful algal blooms, and the role of seafood in human nutrition.

Dr. Chris Free Presents: Climate-resilient fisheries management in the California Current

Virtual seminar – The role of biogenic habitat in controlling local seawater chemistry – September 1st


Dr. Aaron Ninakawa, University of Washington: Friday Harbor

Hosted by Scientific Diving

Presenting: "The role of biogenic habitat in controlling local seawater chemistry"

MLML Virtual Seminar | September 1st, 2022 at 4pm

Watch the Live Stream here or here

Aaron is an NSF postdoctoral fellow working at the University of Washington Friday Harbor Laboratories and is interested in understanding how aquatic organisms interact with their chemical environment. He earned a B.S. in Biology and a B.A in Chemistry from Cal State Fullerton before starting a Ph.D. in Ecology at the UC Davis Bodega Marine Lab. His research focuses on understanding how habitat forming species alter chemistry, the consequences of those alterations for associated species, and how those interactions change given natural and human driven variability in background water chemistry.

Virtual seminar – Wave-driven changes in beach sand levels – August 25th


Dr. Bonnie Ludka, California State Polytechnic University: Humboldt

Hosted by the Physical Oceanography Lab

Presenting: "Wave-driven changes in beach sand levels"

MLML Virtual Seminar | August 25th, 2022 at 4pm

Watch the Live Stream here or here

Dr. Ludka is a coastal scientist with a background that spans physics, oceanography, geology, data science and engineering. They are interested in how coastal physical processes interact with environmental management and ecological functioning, on time scales of storms to decades. Her team uses fieldwork, data analysis and modeling to help build more resilient coasts. Dr. Ludka has a B.S. in Physics from James Madison University and a Ph.D. in Physical Oceanography from Scripps Institution of Oceanography. She has held postdoctoral positions at the Institute for Geophysics and Planetary Physics at Scripps and in the Coastal Engineering Department at Delft University of Technology in the Netherlands. They also were a California Sea Grant fellow at the California Coastal Commission. Now she is an assistant professor in the Geology Department at San Jose State.

Dr. Bonnie Ludka Presents: Wave-driven changes in beach sand levels

Thesis defense by Caroline Rodriguez – August 22nd (Zoom)


"Measuring the Impact of Thermal Stress on Coral Reef Resilience in Hawaii Using Large-Area Imagery"
A Thesis Defense by Caroline Rodriguez

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.

Thesis Abstract

Coral reefs worldwide are declining due to several anthropogenic stressors, but rising ocean temperature is the most serious threat to coral reef persistence. Developing models that document changes in coral communities following thermal stress events and project trends in reef recovery is crucial in identifying resilient reefs. Traditional approaches to generating the coral vital rates necessary for demographic modeling are time consuming and field intensive; however, by leveraging Structure from Motion photogrammetry, we can accurately track populations over time at a large spatial scale. In this study, we assessed the population dynamics of the dominant coral species across the Hawaiian archipelago and investigated the impact of thermal stress on coral populations. The annual growth, survival and recruitment of 3,852 coral colonies (5,636 unique colony-level transitions) for 3 genera was recorded at 16 sites spanning the Hawaiian archipelago across 14 intervals from 2013 to 2019, including 3 bleaching events. These data were used to parameterize integral projection models to determine the impact of thermal stress on population growth. Degree Heating Week output from the NOAA Coral Reef Watch daily global 5km satellite was used to estimate thermal conditions at each site by calculating temperature stress severity (the mean of all maximum thermal anomalies) and frequency (number of thermal stress events per 10 years). We found that all three coral genera, which have different morphologies and life-history strategies, had negative population growth rates. As expected, smaller colonies experienced faster growth, but large colonies had a high probability of shrinking, due to partial mortality. Therefore, it may be biologically advantageous for larger colonies to fragment into smaller pieces and avoid total mortality. Population dynamics were primarily driven by coral growth and survival and should be targeted in future restoration and adaptation projects. Additionally, across all taxa, population growth rates (λ) varied spatiotemporally, but most sites exhibited a declining population growth rate (λ < 1). While increased severity and frequency of thermal stress events negatively impacted the population growth rate of massive Porites corals, there was no signal of this effect on encrusting Montipora corals. We demonstrate that despite variations in the responses observed among taxa, there is an overall expected population decline across the Hawaiian archipelago. While coral population growth rates are higher following bleaching events, signifying recovery, the projected increase in both the severity and frequency of thermal anomalies may overwhelm corals’ ability to recover and threaten coral population persistence.

Caroline Rodriguez Presents: “Measuring the Impact of Thermal Stress on Coral Resilience in Hawaii Using Large-Area Imagery”