Thesis Defense by Victoria Dickey – November 30th


"The Distribution of Microplastics in Marshlands Surrounded by Agriculture Fields: Elkhorn Slough (CA)"
A Thesis Defense by Victoria Dickey

Geological Oceanography Lab

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.

Thesis Abstract

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.

2 MLML Students Awarded at WSN 2022

Two of Moss Landing's own graduate students in the Invertebrate Ecology lab were awarded at the conclusion of the WSN 2022 conference this Sunday for the work they presented over the weekend!

Keenan Guillas was awarded the runner-up for best poster for the print of his work: "The bigger they are, the harder they sneeze: contraction behaviours in the temperate demosponge Tethya californiana". His poster will be hung in the hall for viewing.

Sydney McDermott was awarded Best Community Ecology Talk for her incredible presentation on the effect of lost shipping containers: "Colonization and succession on experimental natural and artificial substrates in the deep sea", for which she was awarded a cash prize of $250.

A huge congratulations to both of them for recognition of their work!

Seminar – Consequences of calcification for coralline algal ecology and evolution – November 17th

Dr. Patrick Martone, University of British Columbia
Presenting: "Consequences of calcification for coralline algal evolution and ecology"

MLML Seminar | November 17th, 2022 at 4pm

Watch the Live Stream here or here

Dr. Patrick Martone is a professor and phycologist in the Botany Department at the University of British Columbia (UBC). For nearly twenty years, Patrick has been studying the biology and biodiversity of seaweeds in the NE Pacific. Research in his lab focuses on a wide range of topics from cell wall chemistry and tissue development, through ecophysiology and evolution, to ecological interactions and community structure. Patrick is passionate about teaching the wonders of seaweed, inspiring hundreds of students at UBC and the Bamfield Marine Sciences Centre. He has developed a mobile app for iPhone and Android called the “Seaweed Sorter” that helps users identify (and fall in love with) more than 100 seaweed species along the NE Pacific coast. Patrick is the Vice-President / President-Elect of the Phycological Society of America.

In-Person Seminar – Marine ecosystem forecasting along the U.S. west coast – November 10

Dr. Michael Jacox, NOAA SWFSC
Presenting: "Marine ecosystem forecasting along the U.S. west coast"

MLML In-Person Seminar | November 10th, 2022 at 4pm

Watch the Live Stream here or here

Mike Jacox is a physical oceanographer working for NOAA at the Southwest Fisheries Science Center in Monterey, CA and the Physical Sciences Laboratory in Boulder, CO. His primary research focus is on physical-biological interactions in the ocean and their connections to climate, particularly in the northeast Pacific. Recently, he has focused on ocean variability and change off the US West Coast, including extreme events such as marine heatwaves, and the response of marine ecosystems from phytoplankton to top predators. Dr. Jacox is currently leading new efforts to develop end-to-end assessments of climate impacts on US west coast fisheries, including seasonal forecasts and centennial-scale projections of ocean conditions, distributions of targeted and bycatch species of interest to US fisheries, socio-economic impacts of changing living marine resources, and evaluations of fisheries management strategies in a changing climate. He holds a Ph.D. in Ocean Sciences from the University of California, Santa Cruz, and a B.S. in Aerospace Engineering from the University of Colorado.