Seminar – Ecophysiology of ecosystem engineers: bioenergetic effects of climate and food on dominant consumers and their consequences for coastal ecosystems

Nate Spindel, MLML | San José State University
Presenting: "Ecophysiology of ecosystem engineers: bioenergetic effects of climate and food on dominant consumers and their consequences for coastal ecosystems"

MLML Seminar | February 21st, 2024 at noon

Watch the Live Stream here or here

Abstract:

Kelp forests host tremendous biodiversity and provide essential ecosystem services but increasingly face direct and indirect threats from rapid global change. Environmental stressors like ocean warming and marine heatwaves impose direct physiological stress on foundational kelp species as well as indirect threats via impacts on primary consumption by grazers. However, it may be impossible to generalize the impacts combined ocean warming, acidification, and other drivers have on critical ecological interactions like herbivory due to complex energetic impacts on both consumers and their resource(s). Therefore, it is advantageous to focus on understanding specific consumer responses to multiple drivers and dynamic conditions in ecologically key taxa, such as the purple sea urchin, Strongylocentrotus purpuratus. As with all consumers, the abundance and quality of available food constrains the energy budgets of sea urchins, mediating their responses to stressors. Here I will discuss how changes in the abundance and composition of macroalgae, S. purpuratus’s primary food, as well as contemporary abiotic stressors affect physiology, performance, and subsequent ecological impacts. I will reference case studies in British Columbia, Canada utilizing field and laboratory-based experiments. These empirical studies provide basic insights to inform applied restoration of degraded kelp forests, improved energetic modeling based on first principles, and expectations for consumer-resource interactions in the context of rapid global change.

Bio:

I study basic and applied marine science emphasizing physiological ecology, fisheries, and global change. As a Postdoctoral Researcher at Moss Landing Marine Laboratories, I investigate the influences of marine protected areas (MPAs), benthic habitat, and species traits on spatiotemporal trends of fishery performance. As a National Science Foundation Ocean Sciences Postdoctoral Research Fellow (NSF OCE 2308398), I study independent and combined impacts of temperature, acidification, and deoxygenation on the physiology, performance, and population dynamics of sea urchins whose grazing shapes nearshore ecosystems. To this end, I apply field experiments in the natural laboratory provided by geographic gradients of upwelling intensity in coastal California paired with manipulative experiments in a controlled laboratory setting. I aim to formalize and scale up insights from these studies using mechanistic modeling which leverages energetic theory to improve our ability to predict coastal ecological dynamics in a context of rapid global change. Some of my happiest moments involve exploration, whether it is foraging in cloudy coastal redwood forests with my family or breathing underwater in emerald kelp forests bathed in filtered golden sunlight.

Seminar – Observing Carbon Export During NASA’s EXPORTS Field Campaign

Leah Johnson | University of Washington
Presenting: "Observing Carbon Export During NASA’s EXPORTS Field Campaign"
Hosted by the Physical Oceanography Lab

MLML Seminar | March 13th, 2024 at noon

Watch the Live Stream here or here

Abstract:

In this presentation, I will overview NASA’s EXport Processes in the Ocean from Remote Sensing 2021 Field Campaign in the North Atlantic (EXPORTS NA) focusing on the physical processes modulating water transformations and carbon export during the study. A major programmatic goal was to conduct the sampling in a Lagrangian mode so that ocean ecological and biogeochemical changes can be observed independent from physical advective processes. To accomplish this goal, EXPORTS NA conducted a multi-ship, multi-asset field sampling program within a retentive, anticyclonic mode water eddy. Lagrangian sampling assets remained within the eddy core throughout the experiment, demonstrating that the mode water eddy was retentive. Outside the retentive eddy core, the rich mesoscale flow field advected biogeochemical tracers around the periphery of the eddy. Additionally, strong westerly winds from four storm events deepened the mixed layer (ML) above the eddy’s mode water and exchanged surface waters outside of the eddy via Ekman transport. Within this environment, two major carbon export events were observed: 1) Gravitational sinking of organic matter out of the ML in the retentive eddy core, and 2) organic matter advected vertically along isopycnals along the eddy edge.  Combined these illustrate two examples of export pathways in dynamical regions such as the North Atlantic.

 

Bio:

I am a Physical Oceanographer at the Applied Physics Lab, University of Washington. My research focuses on processes at the atmosphere-ocean interface that influence the distribution of heat, salt, momentum, and biogeochemical tracers in the upper ocean. Studying the physics of the near surface ocean is essential for understanding how the upper ocean communicates with the atmosphere as well as with the interior circulation. This is a multi-scale problem, requiring detailed studies to explore mechanisms at play, along with an understanding of how these processes integrate to impact the weather and climate system. My research combines observations, numerical models, geophysical fluid dynamics theory, and applied mathematics across scales to address these topics. I received an MS from San Francisco State University and a PhD from the University of Washington. After a postdoctoral appointment at Brown University, I returned to UW as a Senior Oceanographer at the Applied Physics Lab and an Affiliate Assistant Professor within the School of Oceanography.

Seminar – Characterization and modeling of the Southern elephant seals’ vertical habitat

Martin Tournier, MLML | San José State University
Presenting: "Characterization and modeling of the Southern elephant seals' vertical habitat"

MLML Seminar | February 7th, 2024 at noon

Watch the Live Stream here or here

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.

Seminar – Oceanographic Measurements of a Marine Heatwave and the Behavioral Response of a Top Predator: The Northeast Pacific Blob 2014-2017

Dr. Rachel Holser, University of California: Santa Cruz
Presenting: "Oceanographic Measurements of a Marine Heatwave and the Behavioral Response of a Top Predator: The Northeast Pacific Blob 2014-2017"

MLML Seminar | November 16th, 2023 at 4pm

Watch the Live Stream here or here

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.

Seminar – Ice melt and biological productivity at the edge of the Greenland ice sheet

Dr. Mike Wood, San Jose State University
Presenting: "Ice melt and biological productivity at the edge of the Greenland ice sheet"

MLML Seminar | November 2nd, 2023 at 4pm

Watch the Live Stream here or here

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.

Remote Seminar – Expanding Our Models of Nature and Modes of Science for a Safe and Just Future

Dr. Anne Salomon, Simon Fraser University
Presenting: "Expanding Our Models of Nature and Modes of Science for a Safe and Just Future"

MLML Seminar | October 26th, 2023 at 4pm

Watch the Live Stream here or here

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.

Seminar – Dynamics of Coastal Upwelling Fronts

Dr. Thomas Connolly, Moss Landing Marine Laboratories
Presenting: "Dynamics of Coastal Upwelling Fronts"

MLML Seminar | October 19th, 2023 at 4pm

Watch the Live Stream here or here

Abstract:

The seminal work of Ekman during the early twentieth century showed that wind blowing parallel to the coast and the effects of the Earth’s rotation can produce offshore transport in the surface boundary layer and upwelling of cold, dense water near the coast. This process stimulates high primary productivity by supplying nutrient-rich water to the euphotic zone. Ekman’s theory and many modern studies predict that the upward transport associated with coastal upwelling occurs over a shallow region near shore known as the inner shelf. However, these theories do not account for sharp gradients in velocity and density near the front that separates cold, dense water near shore from the warmer, lighter water farther offshore. Observations, idealized modeling experiments and a new theory are presented to explain how the cross-shore distribution of upwelling changes in different situations. A simple ecosystem model illustrates the potential effects on plankton distributions and primary productivity.

Bio:

Tom is a physical oceanographer at Moss Landing Marine Labs who studies the dynamics and ecological impacts of circulation in the coastal zone. Tom received his Ph.D. in Oceanography from the University of Washington in 2012, where he studied shelf and slope circulation off the coasts of Washington and British Columbia. As a postdoctoral scholar at Woods Hole Oceanographic Institution from 2012-2015, he used a wide range of observations to study nearshore currents along the US east coast. At Moss Landing, he has continued his research in the shallow waters near the coast, while also returning to some of his favorite topics in the California Current System: seasonal currents, submarine canyons, and biogeochemical impacts of coastal upwelling.

Seminar – Marine N2 fixation: Importance of enigmatic nitrogen-fixing symbioses in open ocean and coastal ecosystems

Dr. Kendra Turk-Kubo, UC Santa Cruz
Presenting: "Marine N2 fixation: Importance of enigmatic nitrogen-fixing symbioses in open ocean and coastal ecosystems"

MLML Seminar | October 12th, 2023 at 4pm

Watch the Live Stream here or here

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.

Remote Seminar – Star Track: Sea star wasting disease, sunflower sea star recovery, and potential consequences for kelp forest health

Dr. Sarah Gravem, Oregon State University
Presenting: "Star Track: Sea star wasting disease, sunflower sea star recovery, and potential consequences for kelp forest health"

MLML Seminar | September 28th, 2023 at 4pm

Watch the Live Stream here or here

Bio:

I am a marine ecologist that works at the intersection of community and behavioral ecology. I focus on rocky intertidal and kelp forest ecosystems and am interested in how species interactions and communities are affected by climate change, environmental variation, and marine diseases. I study how predators affect prey populations and prey behavior, and am particularly interested in the resulting consequences of these key interactions for the rest of the players in the ecosystem.

As a leading member of the Pycnopodia Recovery Working Group, I was a lead author on the listing of the sunflower sea star as an endangered species through the IUCN Red List after its severe declines from wasting disease. I am actively working to understand and restore this species. This large predator has over 20 arms and can grow to the size of an extra large pizza. It is also a top predator, and its decline was followed by a rapid increase in its herbivorous sea urchin prey and a decline in kelp forests. I am working to understand basic demographic information on this star, and to understand whether it truly can support healthy kelp forests.

As a science advisor to the Oregon Kelp Alliance (https://www.oregonkelp.com/), I am working to actively restore Oregon's once lush kelp forests by working with a diverse group of researchers, commercial divers, aquaculture specialists, marine tourism businesses, restaurants, local tribes, and more. We are testing and implementing several tools to reduce sea urchin densities and support kelp recovery.