Microplankton are a diverse group of planktonic organisms ranging from 0.02 to 0.2 millimeters. Since the group is defined solely by size, it spans numerous taxonomic groups, including both heterotrophs and autotrophs. Microplankton are abundant in all aquatic ecosystems and are important prey for many organisms, including bivalves, crustaceans, and fish. The San Francisco Bay is truly an estuary as saltwater enters the estuary under the Golden Gate Bridge and freshwater flows in from the Sacramento and San Joaquin Rivers. Thus, there is a gradient of salinity from freshwater (0) in the rivers to saltwater by the Golden Gate Bridge (30). This research quantified the abundance and distribution of microplankton in the San Francisco Estuary from 2010 to 2013. Microplankton were collected from nine sites within the estuary and preserved with iodine. They were then identified, measured, and counted on an inverted microscope. The data was then evaluated to determine if the distribution of microplankton was related to the salinity levels.


Marine Biology | Other Ecology and Evolutionary Biology | Terrestrial and Aquatic Ecology


Lindsay Sullivan

Lab site

Romberg Tiburon Center for Environmental Studies (RTC)

Funding Acknowledgement

This material is based upon work supported by the S.D. Bechtel, Jr. Foundation and by the National Science Foundation under Grant No. 0952013 and Grant No. 0934931. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the S.D. Bechtel, Jr. Foundation or the National Science Foundation. This project has also been made possible with support of the National Marine Sanctuary Foundation. The STAR program is administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the California State University (CSU).



URL: https://digitalcommons.calpoly.edu/star/279


To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.