Seminars

Return of the “age of dinoflagellates”: unusual dinoflagellate dominance in northern Monterey Bay detected with automated imaging flow cytometry-May 2nd

Mina Sattari

Alexis Fischer, UC Santa Cruz

Moss Landing Marine Labs Seminar Series - May 2nd, 2019

Hosted by The Invertebrate Zoology Lab

MLML Seminar Room, 4pm

Open to the public

Alexis is a Delta Science Postdoctoral Fellow who is interested in the physical, chemical, and biological factors that promote development of blooms, especially harmful algal blooms (HABs). To explore phytoplankton dynamics on daily timescales in the Monterey Bay and San Francisco Bay, she uses an Imaging FlowCytobot (IFCB), an in-situ automated submersible flow cytometer that generates high-resolution images of particles in-flow taken from the aquatic environment. Alexis completed her PhD in Biological Oceanography in the Massachusetts Institute of Technology - Woods Hole Oceanographic Institution Joint Program. Her dissertation focused on cyst dormancy cycling and bloom initiation of Alexandrium catenella, a HAB dinoflagellate that causes paralytic shellfish poisoning.

Abstract:

Monterey Bay is the largest open embayment along the U.S. West Coast and is subject to intense autumn dinoflagellate blooms, many of which are harmful algal blooms. During 2004–2007 these blooms were so dominant that it was called the “age of dinoflagellates”. In 2018, after a decade absence, these conditions returned with an abundance of dinoflagellates documented at the Santa Cruz Municipal Wharf (SCW) using an Imaging FlowCytobot (IFCB). The IFCB combines video and flow cytometric technology to capture images with chlorophyll fluorescence above a trigger threshold. A phytoplankton image training set was amassed and used to train a 28-category random forest classifier that has 90% overall accuracy. The dominant dinoflagellate was Akashiwo sanguinea, exceeding 40 cells mL-1 and 500 cells mL-1 in March and May, respectively – a time of year when dinoflagellates are characteristically rare. Also abundant were Prorocentrum spp., Ceratium spp., and Gymnodinum spp. – all “upwelling relaxation” dinoflagellate taxa (Smayda 2002). During the winter and spring, pulses of increased dinoflagellates were associated with wind reversals, relaxation of upwelling, water column stability, and river discharge, which would have created a retentive, nutrient-rich region at SCW. These daily dynamics were also reflected in interannual drivers of anomalous dinoflagellate abundance at SCW. A partial least-squares regression was applied to a 7-year de-seasonalized weekly SCW timeseries. Winds from the west and south, increased river discharge, and negative NPGO and ENSO anomalies could explain 80% of anomalous dinoflagellate chlorophyll from January through May. High-frequency IFCB sampling and our coastal phytoplankton classifier will continue to improve our understanding of harmful dinoflagellate bloom development and better inform monitoring decisions.

New laser-imaging technology elucidates form, function, and ecological impact of deep sea, giant larvacean mucus houses -May 9th

Mina Sattari

Kakani Katija, MBARI

Moss Landing Marine Labs Seminar Series - May 9th, 2019

Hosted by the Ichthyology Lab

MLML Seminar Room, 4pm

Open to the public

Kakani received her PhD in Bioengineering at the California Institute of Technology and specializes in biological fluid mechanics and in situ imaging methods. She is currently a Principal Engineer and Principal Investigator at MBARI, with funding provided by the Packard Foundation, National Geographic Society, NOAA, and NSF-OTIC/IDBR. Kakani has been named a National Geographic Emerging Explorer in 2011 and a Kavli Research Fellow in the National Academy of Sciences in 2013.

Abstract:

The midwater region of the ocean (below the euphotic zone and above the benthos) is one of the largest ecosystems on our planet, yet remains one of the least explored. Little-known marine organisms that inhabit midwater have developed life strategies that contribute to their evolutionary success, and may inspire engineering solutions for societally relevant challenges. Although significant advances in underwater vehicle technologies have improved access to midwater, small-scale, in situ fluid mechanics measurement methods that seek to quantify the interactions that midwater organisms have with their physical environment are lacking. Here we present DeepPIV, an instrumentation package affixed to a remotely operated vehicle that quantifies fluid motions from the surface of the ocean down to 4000 m depths. Utilizing ambient suspended particulate, fluid-structure interactions are evaluated on a range of marine organisms in midwater (and the benthos). Initial science targets include larvaceans, biological equivalents of flapping flexible foils, that create mucus houses to filter food. Little is known about the structure of these mucus houses and the function they play in selectively filtering particles, and these dynamics can serve as particle-mucus models for human health. Using DeepPIV, we reveal the complex structures and flows generated within larvacean mucus houses, and elucidate how these structures function. Future technologies (currently in the development pipeline) that will enable study of organismal ecomechanics in the deep sea will also be discussed.

 

 

Physiological constraints and life history trade-offs drive marine mammal behavior-January 31st

Mina Sattari

Roxanne Beltran, UC Santa Cruz

Moss Landing Marine Labs Seminar Series - January 31st, 2019

Hosted by The Vertebrate Ecology Lab

MLML Seminar Room, 4pm

Open to the public

Roxanne obtained her PhD in 2018 from the University of Alaska
Fairbanks studying behavior and life history phenology in the world’s
most southern mammal, the Weddell seal. For her postdoctoral research
at UC Santa Cruz, Roxanne hopes to better understand the strategies
that seals use to survive and thrive in the open ocean; specifically,
how their behavior and survival may be impacted by our changing
planet. With funding from National Geographic, Roxanne is deploying
trackers with a research team to learn how elephant seal pups navigate
and dive during their first ocean migration. In addition to her
research, Roxanne is passionate about science communication and
inclusion of underrepresented minority students in scientific
research. She has written a children’s book, “A Seal Named Patches”
and has visited more than 4,000 K-12 students to share her work.
www.roxannebeltran.com

Abstract:
The life histories of semi-aquatic mammals are characterized
by various challenges that arise from the conflicting dynamics of
living both on land and at sea. Animals have evolved a variety of
solutions to cope with these challenges, from flexible life history
phenologies to wide-ranging behavioral strategies. The resulting
variability within- and between-species provides an opportunity to
evaluate how trade-offs are driven by a combination of physiological
constraints and ecological processes. Using a combination of
free-ranging and captive pinnipeds, I show how animal behavior can be
used to predict potential responses to global change.

Under Pressure: Coastal upwelling and Climate Change – September 6th, 2018

Kimberly Elson
Marisol Garcia-Reyes, Farralon Institute
Moss Landing Marine Labs Seminar Series - September 6th, 2018

Hosted by the Physical Oceanography Lab

MLML Seminar Room, 4pm

Open to the public

Marisol has studied coastal upwelling for over 10 years, focusing on its variability, and how it relates to climate (García-Reyes et al., 2015) and its marine ecosystem (García-Reyes et al., 2013). She has a background on physics and atmospheric sciences, but she's an oceanographer at heart. Her current research includes a comparative study on climate impacts on the California and Benguela upwelling ecosystems (see CalBenJI project), and development and analysis of Indicators of ocean and climate variability in California (see the MOCI project)

Under Pressure: Coastal Upwelling and Climate Change

Is your research subject, life or hobbies part of the California Current or coast? Do you wonder (and get asked) how is it impacted by climate change? This seminar is for you. Back to the basis of coastal upwelling. We will explore the following questions: How coastal upwelling, the process that brings nutrient rich water to the coast and fuels a rich marine ecosystem, depends on global climate? How is this a global phenomena? How it is and will be impacted by climate variability and change? What do we know and what do not know about these changes? And how they impact our coast and our lives?

Using Transcriptomics and Reverse Genetics to Understand Cnidarian-Dinoflagellate Symbiosis – September 13th, 2018

Kimberly Elson
Phillip Cleaves, Stanford University
Moss Landing Marine Labs Seminar Series - September 13th, 2018

Hosted by the Invertebrate Zoology & Molecular Ecology Lab

MLML Seminar Room, 4pm

Open to the public

Using Transcriptomics and Reverse Genetics to Understand Mechanisms of Cnidarian-dinoflagellate Symbiosis

Phillip A. Cleves1, Cory J. Krediet1, Erik M. Lehnert1, Benjamin M. Mason1, Marie Strader2, Mikhail Matz2, and John R. Pringle1

1Department of Genetics, Stanford University, Stanford, CA, USA

2Integrative Biology, The University of Texas at Austin, Austin, TX, USA

 

The endosymbiosis between corals and dinoflagellate algae (genus Symbiodinium) is essential to the energetic requirements of coral-reef ecosystems.  However, coral reefs are in danger due to elevated ocean temperatures and other stresses that lead to the breakdown of this symbiosis and consequent coral "bleaching".  Despite its importance, the molecular basis of how corals establish and maintain a healthy symbiosis is poorly understood, in part because of the lack of a tractable genetic model organism. The small anemone Aiptasia is symbiotic with Symbiodinium strains like those in reef-building corals but has many experimental advantages over corals, making it an attractive laboratory model for cnidarian symbiosis.  To explore the possible transcriptional basis of heat-induced bleaching, we used RNA-Seq to identify genes that are differentially expressed during a time course of thermally stressed symbiotic and aposymbiotic Aiptasia strains. We observed a strong upregulation of hundreds of early stress response genes at time points long before bleaching begins in symbiotic anemones. The putative promoters of these early stress response genes are enriched for NFKB and HSP1 transcription factor binding sites suggesting that many of these stress response genes share core transcriptional inputs. The overall expression patterns were similar between the symbiotic anemones and the aposymbiotic anemones, indicating that many of the expression changes are not specific to the presence of the algae. However, blocking protein synthesis or HSP1 DNA binding with pharmacological inhibitors during this up-regulation results in more severe bleaching suggesting this symbiont-independent early stress response is protective against thermal stress and bleaching.

Genetic tools are needed to allow rigorous functional testing of the roles in symbiosis of candidate genes and pathways. As a first step in developing transgenic methods for Aiptasia, we have successfully expressed the photoconvertible Kaede fluorescent protein in larvae by microinjection of capped mRNA into 1-cell zygotes obtained by spawning in the laboratory.  This technique should allow both expression of tagged proteins for localization studies and the overexpression of candidate genes to analyze gain-of-function phenotypes.  In addition, we have promising results for two different methods for analyzing loss-of-function phenotypes in Aiptasia.  First, we have microinjected zygotes with translation-blocking morpholinos targeting the FGF1a gene, which has been shown to be required for apical-tuft formation in another anthozoan.  Preliminary results show apparent loss of apical-tuft formation in successfully injected larvae, suggesting that the Fgf1a protein was effectively knocked down.  Meanwhile, we have successfully used the CRISPR-Cas9 technology to create genetic changes in embryos of the coral Acropora millepora.  Through the establishment of both gain-of-function and loss-of-function methods in both Aiptasia and corals, Aiptasia will be a uniquely powerful genetic model organism (with year-round spawning) for the study of cnidarian-Symbiodinium symbiosis, and the discoveries made can be validated using similar technologies in corals.

 

We thank the Gordon and Betty Moore Foundation and the Simons Foundation for support.

 

Scientific Art… or Artistic Science? – September 20th, 2018

Kimberly Elson
Ron Holthuysen, Scientific Art, Inc.
Moss Landing Marine Labs Seminar Series - September 20th, 2018

Hosted by the Phycology Lab

MLML Seminar Room, 4pm

Open to the public

In 1980, Ron Holthuysen  founded Scientific Art Studio.  After teaching, biology, chemistry and physics for a few years, he decided to follow his desire to create natural history exhibits.  There was not really a job in which he could explore and combine his interests in taxidermy, wild life photography, film, design, history, paleontology, geology, sculpture, painting, engineering, teaching and be an inventor all at the same time.  Ron has always had the need to involve himself in a wide range of fields, and to challenge himself with interesting projects.  The result is Scientific Art Studio as it is now.

During the last 35 years, under the name of Scientific Art Studio He has been able to take on and, mostly to great satisfaction of his clients, finalize projects of a very wide variety.  From Natural History exhibits to special effects for motion pictures and television, from Museum taxidermy to mechanical costumes for a Las Vegas show, from the restoration of artifacts to the design of rock show stages, and much more.  The source of his inspiration and the focus of his interest has been always Nature in its broadest embrace.  It gives Ron great satisfaction to reconstruct extinct animals and plants, to work with scientific specialists and to dabble in whatever  draws his attention.

Scientific Art or Artistic Science ?

The initial reaction of members of the Scientific World and of the Art World often is to distance themselves from one another’s realm of interest.

Science:

A world of exactness and no fuzzy, artsy stuff.

Rigid discipline.

Art:

Seeking for the absolute freedom of self expression.

No restraints.

Absolute separate worlds, right ?

Think again or better: Look , listen, smell and feel again.

Science and Art are, in my opinion, co-dependent siblings.

Both realms study and investigate and interpret the world we live in.

This talk features the some of the  visualizations and interpretations of our world through Scientific Art (or Artistic Science)

Watch Ron’s MLML seminar presentation below:

Coral Reefs, Climate Change, and Atoll Sustainability: How long will atolls be able to sustain human habitation? – October 4th, 2018

Kimberly Elson
Curt Storlazzi, USGS
Moss Landing Marine Labs Seminar Series - October 4th, 2018

Hosted by the Geological Oceanography Lab

MLML Seminar Room, 4pm

(or Watch it Live here!)

Open to the public

Curt received his BSc from the University of Delaware in 1996, his PhD from the University of California at Santa Cruz in 2000, and has been a research geologist in the U.S. Geological Survey’s (USGS) Coastal and Marine Geology Program since 2003.

Curt’s research focuses on the quantitative study of hydrodynamics, sediment transport, and geomorphology in coastal and marine environments across the Pacific, Atlantic, Arctic, and Indian Oceans.

Currently, Curt is the Chief Scientist of the USGS Coral Reef Project and leads a research team of 13 PhD- and MSc-level scientists that examines the geologic and oceanographic processes that affect the sustainability of US coral reefs and reef-lined coasts, authoring more than 130 scientific papers, reports, and book chapters on these topics.

Curt is on the steering committee for the US Coral Reef Task Force and regularly contributes scientific review for the US Global Change Research Program, NOAA’s National Marine Sanctuary Program, the National Park Service, the USFWS Landscape Change Cooperatives, and theUSGS Climate Science Centers.

Coral Reefs, Climate Change, and Atoll Sustainability:
How long will atolls be able to sustain human habitation?

Although absolute rates of sea-level rise (SLR) and projected 2100 global sea levels are still under deliberation, the models consistently suggest that eustatic sea level will be considerably higher by the end of the century and rates of SLR will far outstrip vertical coral-reef accretion rates, which will have a profound impact on coral reef-lined islands. Atoll islands are low-lying carbonate Holocene features, many of which have maximum elevations of less than 4 m, that support 1000 year-old cultures, yet the amount of land and water available for human habitation, water and food sources, and ecosystems is limited and extremely vulnerable to wave-driven flooding and inundation from SLR. The USGS is leading a multi-agency, multidisciplinary effort to understand how SLR and climate change may impact low-lying atoll islands in Micronesia using field observations and global climate model outputs to drive coupled hydrodynamic and hydrogeologic models for a number of SLR and climate change scenarios. Rising sea levels and climate change will reduce the ability of coral reefs to mitigate wave-driven flooding in the future, leading to more frequent, persistent, and extreme marine flooding and overwash on atoll islands, damaging infrastructure, habitats, and agriculture. More importantly, the increased marine flooding, along with decreased precipitation, will result in salinization the islands’ limited freshwater drinking supplies with such frequency that the freshwater resources will not be able to recover. Our findings suggest that such “tipping points” – when the islands can no longer sustain a freshwater lens and thus human habitation – will likely occur in decades, not centuries as previously thought, which will result in significant geopolitical issues when it becomes necessary to abandon and relocate island-states.

More info on:

Coral Reefs: https://coralreefs.wr.usgs.gov/

Sea-level Rise and Atolls: https://walrus.wr.usgs.gov/climate-change/atolls/


Watch Curt’s MLML Seminar Presentation Below: