Seminars

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Abstract:

Deep-diving vertebrates evolve within a tri-dimensional ocean where the physical and biological conditions are dynamic. These variations are likely affecting their utilization of the vertical dimension of their environment. To obtain an accurate understanding of the habitat use of deep-diving animals, it is important beforehand to review the environmental information available to characterize this vertical dimension. The work I conducted during my Ph.D. first aimed to obtain, with the help of animal-borne active acoustics biologgers, a better characterization of the variability of the biological parameters along
the vertical dimension. An original biological characterization of the water column was made possible using small range active acoustics. From this characterization, we gained reliable insights on the biomass and behavior patterns of the mid-trophic levels organisms sampled by active acoustics. The second objective of my thesis was to develop an approach to integrate the vertical environmental information, in the form of profiles, by using functional analysis approaches. Doing so, I was able to propose habitat use models for two different species, the Southern elephant seal and the Blainville’s beaked whale. This original approach is significant as it allows the integration of the vertical dimension toward the development of tri-dimensional habitat modeling under the conditions that the spatial and temporal resolutions of the dataset are adequate. Thanks to the development of biologging tools, able to sample parameters that have been seldom obtained due to the difficulty of accessing them, more specific characterization of the water column can be conducted. This new characterization can gradually unveils the barely accessible world of deep-diving mammals by using these high-resolution environmental data to model the tri-dimensional foraging habitats of deep-diving vertebrates.

Bio:

Ocean depths have an indubitably strong fascinating power, and their appeal sparked my main research interests. My interests lie in studying diving vertebrates' behavior and, more specifically, in understanding how the oceanic dynamic environments affect their movement and foraging strategies. Dr. Tournier mostly uses data from biologging tools attached to the diving animals to model their habitat use, as they can provide high resolution on their environment. He earned my Ph.D. in France from the University of La Rochelle, where he studied the deep diving foraging behaviors of Southern elephant seals and beaked whales. By using a diverse set of biologging data, Martin was able to model their tridimensional habitat.

Martin is joining the NSF-funded project led by Dr. McDonald to investigate the habitat use of the post-breeding Emperor Penguins and infer which of the climatological and oceanic conditions affect their
diving and foraging strategies.

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Abstract:

All organisms face resource limitations that will ultimately restrict population growth, but the controlling mechanisms vary across ecosystems, taxa, and reproductive strategies. As climate change continues to alter ecosystem processes across the globe, organisms are confronted with new challenges to their ability to survive. The Northeast Pacific Blob was a multi-year marine heatwave that affected ecosystems across the Northeast Pacific, from producers to top predators. We quantified the subsurface extent and evolution of the Blob using oceanographic instruments carried by northern elephant seals (Mirounga angustirostris), a top predator that forages on the abundant biomass of the mesopelagic Northeast Pacific Ocean. We then assessed the effect of this marine heatwave on the foraging behavior of adult female northern elephant seals. We used a combination of telemetry data collected by instrumented seals (temperature, salinity, location, depth) along with body composition and energy gain metrics to examine the population-level effects of the Blob. We found significant warm anomalies throughout the top 1000m of the water column during the Blob, and that northward advection of warm, salty water at the base of the pycnocline likely played an important role in the sustained accumulation of warm water. Comparing foraging behavior during 2014 and 2015 to our 15-year tracking time series, we found evidence of a plastic behavioral response.  Females increased their use of the Alaska Gyre, increased their daytime foraging effort, and increase their use of deep water (>800m depth) during the summer months, suggesting that the prey field changed relative to previous years. Northern elephant seals are both generalist predators and capital breeders, which may buffer the effect of acute events, allowing them to adjust to environmental variability more than highly specialized or constrained predator species. Biologging technology not only increases our understanding of animal behavior, but also gives us unprecedented insight into the changing environment these animals are experiencing.

Bio:

I am an Assistant Researcher with the Institute of Marine Sciences at the University of California, Santa Cruz. I study the behavior and ecology of marine mammals and how it relates to oceanographic processes.  My work to date has primarily focused on a major marine heatwave in the North Pacific and its effects on the reproduction and foraging ecology of the northern elephant seal.  I am particularly interested in individual variability in behavior, what drives and maintains that variability, and what the ecological consequences are for a population. I have had the privilege and opportunity to work with several different pinniped species, from Antarctica to the Bering Sea, on topics ranging from cellular-level physiology to species-level behavior and ecology.  Currently, I am part of a collaborative effort to assess the consequences of multiple stressors on northern elephant seals.  We are evaluating the interacting effects of acoustic disturbance, contaminant load, varying foraging conditions, and acute physiological stress responses on reproductive success.

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Abstract:

The Greenland ice sheet is the largest mass of ice in the northern Hemisphere, comprising more than 200 glaciers and enough ice to raise sea level by over 25 feet. In the past several decades, the ice sheet has been melting, contributing to sea level rise, and causing changes in biological productivity in the regional ocean around the ice sheet. In this talk, I will start by providing an overview of the main drivers of Greenland ice loss and uncertainties in our future projections of overall sea level rise. Next, I will highlight some of my recent observational and modeling work to better constrain future sea level projections resulting from Greenland ice melt. I will conclude my talk with a description of some new efforts to investigates changes in phytoplankton growth around the ice sheet and couple regional ocean models with biogeochemistry. This talk will highlight collaborations with scientists at all levels including undergraduates at SJSU, graduate students at MLML, and scientists at MLML and NASA.

Bio:

Mike is a (relatively) new professor at MLML, starting in January 2023. He holds a joint appointment with the SJSU Department of Computer Science and is in the process of starting up a Computational Oceanography lab at MLML. Mike is interested in any topic that uses satellites observations, numerical ocean models, and in situ observation to further our understanding of the ocean and its role in climate change. His main research activities are currently focused on ice-ocean-biology interactions and sea level rise from the Greenland ice sheet. Being a California kid, Mike enjoys surfing and climbing when he can get a break from prepping classes or debugging code.

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Abstract:

With the climate, biodiversity, and inequity crises squarely upon us, never has there been a more pressing time to rethink how we conceptualize, understand, and manage our relationship with nature. This is acutely true among the world’s coastal oceans where marine ecosystems provide the nutrition, livelihood, climate regulation, and well-being for over 3 billion people globally. While it is conventionally assumed that the alteration of marine ecosystems by people is a recent phenomenon and inherently destructive, human societies have been intentionally shaping, enhancing, and sustaining biodiversity across the planet’s coastal oceans for millennia. In fact, for thousands of years people have been developing innovative practices to maintain resilient relationships within coastal ecosystems amid predator disturbance and extreme climatic events. By weaving ecological, archaeological, and Indigenous knowledge, I will share recent discoveries from Canada’s west coast kelp forests and ancient clam gardens revealed only by considering people as fundamental components of nature, looking back through time, and democratizing ocean science itself. Expanding our models of nature and modes of science will help disrupt scientific paradigms, illuminate novel interactions, and guide us towards more ecologically sustainable and socially just ocean policies.

Bio:

Anne Salomon is a Professor of Applied Marine Ecology and Social-Ecological System Science at Simon Fraser University working at the nexus of applied ecology, sustainability science, and marine policy. She seeks to discover what makes the relationships between people and other components of nature resilient to disturbance to inform ecologically sustainable and socially just conservation policies. She is deeply committed to working across disciplines and sectors to catalyze transdisciplinary research that addresses environmental challenges of concern to global society. She links science to policy by co-designing and co-delivering research with Indigenous knowledge holders, resource users, and government agencies, with knowledge mobilization as a fundamental goal of her research program. Her ecological research incorporates archaeological and Indigenous knowledge to provide greater time-depth to her analyses of coastal system dynamics and to democratize ocean science and governance. Anne was elected to the Royal Society of Canada College in 2019, named a Pew Fellow in marine conservation in 2013, and awarded the International Prize in of Professional Excellence in Ecology in 2013.

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Abstract:

Biological dinitrogen (N2) fixation is a critically important component of the marine N cycle, as it supplies readily-available nitrogen (N) and can support primary productivity. N2 fixation is mediated by some Bacteria and Archaea, referred to as diazotrophs. These specialized single-celled organisms convert nitrogen gas from the atmosphere and convert it to biologically available nitrogen via nitrogen fixation. Marine nitrogen-fixing microbes inhabiting the well-lit surface ocean have diverse physiologies, from free-living autotrophs to particle-bound heterotrophs to symbiotic associations with eukaryotes, and few cultivated marine nitrogen-fixers are available to study in isolation. Their distributions and nitrogen-fixing activities are controlled by a complex interplay between physical and chemical controls and biological interactions that vary from species to species. My research uses cultivation-independent techniques and biogeochemical rate measurements to advance our understanding of the environmental drivers behind the distribution and activity of some of the most enigmatic nitrogen-fixing taxa. Today I will talk about some recent research centered on the importance of enigmatic marine nitrogen-fixing symbioses in both oligotrophic and coastally-influenced ecosystems.

Bio:

Kendra is a marine microbial ecologist studying specialized microbes that convert nitrogen gas into bioavailable nitrogen, which is a vital process supporting oceanic primary productivity. Her research focuses on understanding the ecophysiology of poorly understood nitrogen-fixing microbes, an effort fundamental for improving our ability to predict the magnitude and distribution of nitrogen fixation in contemporary and future oceans. Many nitrogen-fixers have yet to be isolated in culture, so Kendra’s research relies on extensive field work and applying cultivation-independent techniques to detect and study these cryptic microbes. Kendra’s uses single-cell rate measurements, targeted molecular techniques, metagenomics, and biogeochemical rate measurements to enable integration across huge spatial scales in the ocean.

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Abstract:

Cal Poly Humboldt has a culturally diverse student body that has led its faculty and staff to pursue the creation of a culturally sustaining environment. In order to achieve this goal, Humboldt first partnered with ESCALA, a professional development organization, to transform our instructional culture to benefit Latinx and Hispanic students, and then, developed an internal program called Creando Conciencia (Create Awareness, in Spanish) to continue this effort. Besides these university-wide efforts, in our lab we have partnered with tribal nations, and city, state and federal institutions in order to provide our diverse students with the best learning environment possible. In this presentation, I will discuss two projects describing the status of Night Smelt and Redtail Surfperch in sandy beach surf zones in Humboldt and Del Norte counties, that our students are currently carrying out. These two fish species are of cultural, commercial and ecological importance, who despite inhabiting the same habitat appear to be experiencing opposite population trends. Finally, I will briefly introduce a new program funded by a University of California Office of the President California Climate Action Seed grant that will allow us to expand our collaborations to five coastal tribal nations and will provide capacity building and priority species research in marine and estuarine habitats.

Bio:

I am originally from Guayaquil, Ecuador where I obtained a B.Sc. in Biology at the University of Guayaquil. Thanks to a Fulbright Scholarship, I moved to Charleston, Oregon to pursue a M.Sc. in Marine Biology at the University of Oregon’s Oregon Institute of Marine Biology. I then moved two hours north, to Newport Oregon, where I obtained a Ph.D. in Fisheries Science from Oregon State University’s Hatfield Marine Science Center. After finishing my Ph.D., my family and I moved to Mount Pleasant Michigan, where I was a postdoctoral fellow at Central Michigan University, and Guayaquil, Ecuador, where I was a research and teaching fellow at Escuela Superior Politecnica del Litoral. Before joining Cal Poly Humboldt, I worked at the Charles Darwin Research Station (CDRS) in Galapagos, Ecuador, as a Senior Fisheries Ecologist. During that time, I was also the interim science coordinator for CDRS for nine months, and participated in the sharks, seabirds, seamounts and climate change programs. These experiences have led me to pursue research geared towards high-use and/or low-information/data-limited fisheries species, and towards the provision and analysis of vital early and adult life history data of fishes and crustaceans, especially with respect to impacts from local fishery pressures and climate change. In order to achieve this goal, I use a combination of field, laboratory analysis and numerical modeling approaches.

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Abstract:

Due to the public health risks of wastewater contamination of coastal waters worldwide, there is a need for rapid tracking of sewage-laden flows. Fluorescence-based submersible sensors have been used for monitoring organic contaminants in natural waters; however, their potential to serve as a real-time warning of high bacteria concentrations and wastewater pollution under estuarine conditions with tidal influence remains to be evaluated. The Tijuana River Estuary has been plagued by decades of cross-border sewage flow that poses major public health risks for beach goers, Navy Seals, and border patrol agents, and has resulted in long-term beach closures on both sides of the US-Mexico border. This study assessed the use of submersible, in-situ tryptophan-like (TRP) and humic-like (CDOM) fluorescence sensors for tracking fecal indicator bacteria (FIB) concentrations in real-time in the Tijuana River Estuary during three conditions: 1) dry weather without cross-border sewage flow, 2) dry weather with cross-border flow, and 3) wet weather with cross-border flow. FIB concentrations of samples collected during scenario #2, dry weather with cross-border flow, were most significantly correlated with submersible TRP and CDOM sensor fluorescence. TRP and CDOM fluorescence were also measured using a benchtop, scanning fluorometer with instrument corrections, which yielded significant correlation (p < 0.001) with FIB concentrations under all hydrologic conditions, reflecting the superior performance of the benchtop instrument. Regular maintenance conducted weekly or fortnightly was required to minimize sensor fouling. Also, the presence of high strength wastewater resulted in an inner filter effect, which requires post-processing corrections or data flagging as part of quality control efforts. Overall, we conclude that TRP and CDOM sensors are currently able to provide real-time warning of sewage contamination. However, quantifying the magnitude of contamination is not yet possible in real-time, and efforts are underway in our research groups to achieve this goal.

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Dr. Liz Alter is a marine evolutionary biologist, Assistant Professor of Biology at California State University, Monterey Bay and a Research Associate at the American Museum of Natural History in New York. Her research focuses on understanding how biodiversity is generated and maintained, particularly in oceans, estuaries and rivers, using the tools of genomics. Dr. Alter serves as a Commissioner on the Fish and Wildlife Advisory Commission of Santa Cruz County, as well as the Scientific Advisory Board of the Billion Oyster Project, which seeks to restore coastal ecosystems while training high school students in marine science. She holds a PhD from Stanford University’s Hopkins Marine Station, and an MS from UC Berkeley.