Fellows Study Harmful Algal Blooms and Affected Food Webs

The Delta Science Fellows program funds postdoctoral and graduate researchers to work with community and scientific mentors on targeted Delta Science program research priorities. In this issue, Science News spotlights Fellows Cécile Mioni and Monika Winder who are both making presentations at the upcoming Bay-Delta Science Conference.

Cécile Mioni is a postdoctoral researcher from the University of California, Santa Cruz, whose research goals are to apply her expertise in microbial ecology to health-related and other environmentally relevant applications in aquatic and marine environments. For the past two years she has been monitoring harmful algae in the San Francisco Bay in collaboration with the U.S. Geological Survey, the California Department of Water Resources Environmental Monitoring Program, and the Interagency Ecological Program (IEP).

Microcystis, a type of cyanobacteria-also called blue-green algae-typically found in freshwater environments such as lakes and bogs is increasingly being discovered in the Sacramento-San Joaquin Delta. Some strains of Microcystis produce toxins that can be harmful to both humans and animals.

“There are many factors that are promoting the growth of Microcystis,” Mioni said. “Based on my data, it appears that temperature is one of the dominant factors. I also believe that another type of cyanobacteria could be associated with Microcystis growth and/or toxicity, and I am currently trying to find funding to explore this hypothesis in depth.”

In Mioni’s samplings this year, she didn’t observe Microcystis colonies until August and only at some stations in the Delta. “The abundance was well below what I observed in previous years,” she said, adding that June-July is usually when the bloom starts. “Temperatures have been lower than in the previous year, which tends to confirm that this is a very important physical factor for the initiation of Microcystis blooms,” Mioni said. “Data collected by Peggy Lehman (DWR) before I started my study showed that she also observed a relationship between temperature and Microcystis blooms.”

Mioni earned a doctorate in microbiology from the University of Tennessee in 2004 doing fundamental, non-applied research. “I became very sick during my PhD,” she said. “Although I fully recovered and am healthy now, this unfortunate episode has shifted my focus to more applied microbiology research. I wanted to apply my knowledge and skills to a field of research that was more related to public health.”

In her free time-which is rare-Mioni enjoys Brazilian jiu jitsu, no gi grappling (another form of jiu jitsu) and boxing. She also surfs and is learning rock climbing.

Mioni will be giving a presentation on “What Controls Microcystis Bloom and Toxicity in the San Francisco Bay-Delta?” at the Science Conference, Sept. 27 at 3:40 p.m. in Room 311-313.

Monika Winder, a research ecologist with the John Muir Institute of the Environment, at the University of California, Davis, studies the effects of environmental change on ecosystems and adaptation to environmental variation, with special emphasis on planktonic organisms (microscopic animal and plant life found floating or drifting in bodies of water).

In her Delta (formerly CALFED) Science project, she is analyzing a 37-year record of plankton taxonomy in the San Francisco Bay-Delta collected by the IEP to identify long-term trends, patterns and interactions among the region’s phytoplankton and zooplankton-the major food source for native fish species.

To date, Winder reports that a major shift in the zooplankton community occurred during the extended drought of 1987-1994, when several species of non-native copepods (crustaceans found in freshwater and marine environments) and mysids (shrimp-like crustaceans) were introduced.

She said another major shift happened in the early 1990s, with the establishment of a small-sized copepod from Asia-Limnoithona, which took over and colonized the upper part of the estuary displacing the local fauna.

And what does this mean for the future?

“Retrospective analysis of the last four decades clearly shows past regime shifts in the Delta,” Winder said. “This tells us that future regime shifts in zooplankton dynamics are most likely. Species invasions are unpredictable, although it seems that the timing of zooplankton invasions occurred during unusually dry periods, which suggests that droughts may open a window for exotic zooplankters to become established, which is the current focus of my research. There might be continuing strong and unpredictable invasions, which will greatly complicate the long-term prediction of zooplankton dynamics in this ecosystem and management of this estuarine ecosystem.”

Winder earned a doctorate in zooplankton ecology from the Department of Limnology, Swiss Federal Institute of Technology, Zurich, in 2002. Originally from Austria, she misses her family back home and traditional Austrian food and discovered when she came to the States that “everything is bigger in the U.S. The pace of life feels much faster-although Davis might be an exception.” Yet she appreciates that people in the U.S. are open to new ideas and welcome collaborations. “People also take more risks here,” she said.

Winder will have a poster at the science conference entitled “Shifts in Zooplankton Community Structure: Implications for Food-Web Processes in the San Francisco Estuary.”

List of Fellows Presenting at the Science Conference

Oral Presentations:

Monday, Sept. 27

2:40 p.m., Room 314 - Understanding the Strategies and Decision Making of California’s Urban Water Agencies, Sara Hughes, UC Santa Barbara

3:40 p.m. Room 311-313 - What Controls Microcystis Bloom and Toxicity in the San Francisco Bay-Delta?, Cecile Mioni, UC Santa Cruz

4:00 p.m. Room 306 - Assessment of the Potential for Using Iron Amendments to Decrease Net Methylmercury Exports from Tidal Wetlands in San Francisco Bay, Patrick Ulrich, UC Berkeley

4:20 p.m., Room 307 - Distribution and Implications of Alien Clams in Suisun Marsh, CA, Robert Schroeter, UC Davis

Tuesday, Sept. 28

8:40 a.m., Room 314 - An Integrated Genetic Stock Identification and Parentage-Based Tagging Program for Chinook Salmon Using SNPs, Anthony Clemento, UC Santa Cruz

9 a.m., Room 311–313 - Reconstructing Inter-Annual Variability of Delta Smelt Life History with Otoliths, James Hobbs, UC Davis

9:40 a.m., Room 308-310 - When to Bolt? Fry or Smolt: Reconstructing the Survivorship of Juvenile Migratory Life Histories for Chinook Salmon on the Stanislaus River Relative to Flow Regimes, Rachel Barnett-Johnson, US Bureau of Reclamation/UC Santa Cruz

11:00 a.m., Room 314 - Multiscale Validation of a Spatially Explicit Demographic Model of Fremont Cottonwood on the Sacramento River, Elizabeth Harper, SUNY-ESF

11:40 a.m., Room 311–313 - Biogeochemical Processing of Anthropogenic Ammonium in the Sacramento River and the Northern San Francisco Estuary, Alexander Parker, SF State University-RTC

1:35 p.m., Room 308-310 - Effects of Tides, River Flow, and Gate Operations on Entrainment of Juvenile Chinook Salmon into the Interior Sacramento-San Joaquin Delta, Russell Perry, University of Washington

3:35 p.m., Room 308-310 - Fine Scale Movement, Life History and Survival of Wild Oncorhynchus mykiss of the Mokelumne River, CA, Walter Heady, UC Santa Cruz

Wednesday, Sept. 29

9:20 a.m., Room 306 - From Otoliths to Oocytes: A Three-Tiered Investigation into Estrogenic and Androgenic Effects in a California Estuary, Susanne Brander, UC Davis

9:20 a.m., Room 308-310 - Potential Responses of Sierra Nevada Flood Frequencies to Climate Change, Tapash Das, Scripps Institution of Oceanography

10:20 a.m., Room 314 - Nutrient Loading and Benthic Native-Invasive Species Dynamics, Heidi Weiskel, UC Davis

2:00 p.m., Room 314 - Water Resources Sensitivity to Climate Change, Land Use Change, and Population Growth in the Stanislaus, Tuolumne and Merced Basins, Michael Kiparsky, UC Berkeley

3:00 p.m., Room 314 - Survival of Juvenile Late-fall Chinook Salmon using Different Migration Routes to Negotiate the Sacramento-San Joaquin River Delta, Russell Perry, University of Washington

3:20 p.m., Room 311–313 - Going With the Flow or Staying Close to Home? Population Connectivity, Freshwater Flow, and Native Oyster Restoration in San Francisco Bay, Andrew Chang, UC Davis

Posters:

Fish Biology, Ecology and Protection

Sacramento River Steelhead Trout: Comparing Natural and Hatchery Smolts, Philip Sandstrom, UC Davis

Flood Management

Scenarios for Restoring Ecologically Functional Floodplains and Providing Ecosystem Services in the Sacramento-San Joaquin Delta, Mary Matella, UC Berkeley

Food Webs

Shifts in Zooplankton Community Structure: Implications for Food-Web Processes in the San Francisco Estuary, Monika Winder, UC Davis

Integrative Applied Science

Control and Management of Perennial Pepperweed Invasion: An Obtainable Goal?, Christine Whitcraft, CSU Long Beach (Former Fellow)

Physical Processes

Holocene Hydrologic Variability in the Western Sierra Nevada From D/H Ratios in Leaf Waxes, Joseph Street, UC Santa Cruz

Species and Communities

Cryptic Spartina alterniflora x foliosa Hybrids: The Challenge of Eradicating Invasive Hybrids in a Widespread Native Plant Population, Laura Feinstein, UC Davis

Tidal Wetland Vegetation Diversity Gradients Across and Within Sites in the San Francisco Bay Estuary, Lisa Schile, UC Berkeley

Sustainable Habitats and Ecosystems

Incorporating Economic Costs into Wildlife Habitat Management: Examples from Central Valley Riparian Restoration and Wetlands, Nathaniel Seavy, PRBO Conservation Science

Water and Sediment Quality

Factors Affecting the Bioavailability of Methylmercury to Phytoplankton and Amphipods, Allison Luengen, USF