EOS Center

Wim Kimmerer, Adjunct Professor Emeritus, EOS Center, SFSU

Apparent competition among four copepod species in the San Francisco Estuary, an estuarine food desert 

Abstract: The San Francisco Estuary (SFE) is home to nine copepod species, most introduced 3-4 decades ago. We analyzed potential interactions among four of these introduced species that are abundant during spring-summer in the Low-Salinity Zone (LSZ), the rearing habitat for larval delta and longfin smelt. Since 1987, grazing by the introduced clam Potamocorbula amurensis reduced summer phytoplankton biomass and productivity in the LSZby ~10-fold. The resulting chronic food limitation, together with consumption of copepod nauplii by clams, restricted copepod abundance to low levels during summer of every year since 1987, and produced a “food desert” for young smelt. Eurytemora carolleeae, introduced to the Estuary before monitoring began, was highly abundant year-round in the LSZ until it declined sharply in 1987, and it is now abundant only in spring. The other three copepod species are subtropical and most abundant during summer: Pseudodiaptomus forbesi (detected in 1988) at salinity less than ~2, and Limnoithona tetraspina (1993) and its predator Acartiella sinensis (1993)in salinity of 0.5–10. Since 1993 abundance patterns of these four copepods overlap in season and salinity, superficially suggesting competition. However, this is a case of “apparent competition”, because competition for food is ruled out by the distinct diets and incomplete spatial overlap among the four species. Rather, abundance of each species is influenced by a combination of temperature, freshwater flow, feeding by clams on microplankton and copepod nauplii, and predation. The ability of estuarine copepod species to co-occur may generally be explained better by considering the broader hydrodynamic, thermal, and predatory environment than by competition. 

Bio: Dr. Wim Kimmerer is a Research Professor of Biology (Emeritus) at the Estuary and Ocean Science Center of San Francisco State University. He has a Bachelor’s degree in chemistry from Purdue University and a Ph.D. in biological oceanography from the University of Hawaii. Previous positions include a stint in U.S. Navy nuclear submarines, a three-year fellowship at the University of Melbourne, Australia, and a position at a consulting firm in central California. In 1994 he established a zooplankton laboratory at the EOS Center focused mainly on the San Francisco Estuary, studying both the basic ecology of zooplankton and fishes in the estuary, and management concerns such as the maintenance of declining and listed species and the influence of human activities. Current focuses of the laboratory include interactions between physical dynamics of the Estuary and the distribution and dynamics of planktonic organisms, the planktonic food web effects of introduced species, and effects of variation in freshwater flow on fishes, particularly the endangered longfin smelt. He is Principal Investigator of several large projects in the Estuary, including a study of the dynamics of longfin smelt, temporal transitions among a suite of introduced estuarine copepods, and a study of copepod movements into and out of a large tidal wetland. He served as Co-founder and later President of the California Estuarine Research Society, Chair of the Estuarine Ecology Team, Interagency Ecological Program (1995–2015), Co-Chair of the Science Board, CALFED Bay-Delta Ecosystem Restoration Program, and Science Advisor to the San Francisco Bay Subtidal Habitat Goals Project. In 2012 he received the Brown-Nichols Science Award presented by the Delta Science Program for significant research and application of science to manage the estuary, and in 2013 received the Conservation Achievement Award from the Cal-Neva Chapter of the American Fisheries Society. He is a Fellow of the California Academy of Sciences.

Zachary Gold, Lead Molecular Ecologist - Ocean Molecular Ecology Program, NOAA Pacific Marine Environmental Laboratory

Leveraging eDNA to Survey Large Marine Ecosystems in the Northeast Pacific

Abstract: Environmental DNA (eDNA) is a powerful, cost effective, and scalable tool enhancing marine ecosystem monitoring programs across NOAA. This talk highlights our progress operationalizing eDNA approaches at scale across the West Coast Ocean Acidification, Ecosystem Fisheries Oceanography Coordinated Investigations (EcoFOCI), and California Cooperative Oceanic Fisheries Investigation (CalCOFI) cruises to generated robust marine biodiversity inventories co-located with high resolution physical and chemical hydrographic measurements. Our work highlights the power of eDNA approaches to better characterize marine ecosystem shifts across key environmental thresholds. Critical to enhancing these efforts are the integration and synthesis of eDNA data sets across ocean observing platforms being led by the West Coast Ocean Biomolecular Observation Network. Ultimately, rigorous adherence to open science principles and wide spread adoption of standards and best practices are critical to effectively mobilize trusted biomolecular observations of marine biodiversity. Such efforts directly support the National Aquatic eDNA and National Ocean Biodiversity Strategies. 

Bio: Dr. Zachary Gold is the Ocean Molecular Ecology Program Lead at the NOAA Pacific Marine Environmental Laboratory in Seattle. His research seeks to leverage the advances in molecular biology to scale biological analyses with physical and chemical processes and allow for characterization of marine ecosystems response to climate change.  

Sarah Cohen – Coastal Estuarine Population Connectivity and Environmental Stress

Julie Gonzalez – Towards More Holistic Conservation and Restoration Approaches

Ellen Hines – Bycatch Risk Assessment for Chilean Fisheries and Marine Mammals with Varying Data

Michelle Jungbluth and Sean Jungbluth – Marine and Estuarine (Zoo)plankton Ecology

Wim Kimmerer – Density Dependence in Pelagic Estuarine Populations

Stuart Siegel – Nature-Based Shoreline Protection Along the Mid and Upper Intertidal

Anne Simonis – You Can Learn a Lot by Listening…

Frances Wilkerson – Nutrients, Phytoplankton, HABs and Primary Productivity

Jaime Jahncke, PhD, Director, California Current Group, Point Blue Conservation Science and Adjunct Professor at San Francisco State University’s Estuary & Ocean Science Center

From Peru to California: How ocean processes influence prey and predator abundance in coastal areas? 

Abstract: This presentation examines the interplay between ocean processes and the abundance of prey and predators in coastal ecosystems, with a focus on regions in Peru and California. The talk explores how physical oceanographic processes influence prey availability and seabird distribution, highlighting findings from long-term studies on seabird diet, foraging ecology, and ecosystem dynamics. The work of Point Blue Conservation Science, particularly at the Farallon Islands and within the Greater Gulf of the Farallones, is showcased as a model for understanding and addressing environmental challenges. Research emphasizes the impacts of climate change, marine heatwaves, urban pollution, and human activities on marine biodiversity and ecosystem health. Dr. Jahncke also discusses innovative approaches, including automated surveys, drones, and machine learning, to enhance data collection and analysis. The talk concludes with a call for collaborative, science-based strategies to advance ocean conservation and build resilience in the face of climate and human pressures. 

Bio: Dr. Jaime Jahncke is the Director of the California Current Group at Point Blue Conservation Science and an Adjunct Professor at San Francisco State University’s Estuary & Ocean Science Center. With over 30 years of experience in marine bio-oceanography, Jaime’s work focuses on understanding and conserving marine wildlife and ecosystems. He collaborates with diverse partners to develop science-based solutions for ocean resilience, sustainable fisheries, and biodiversity conservation. Committed to advancing equitable and innovative approaches, Jaime strives to integrate research, policy, and community engagement to protect marine habitats and support coastal communities.