Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 7 of 7

Full-Text Articles in Life Sciences

Salinity And Temperature Distribution Of Jellyfish In The San Francisco Estuary, Trisha Huynh, Brooke Bemowski, Lindsay Sullivan, Wim Kimmerer Aug 2014

Salinity And Temperature Distribution Of Jellyfish In The San Francisco Estuary, Trisha Huynh, Brooke Bemowski, Lindsay Sullivan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

Jellyfish are generally characterized by their jelly-like bodies and internal lining (two tissue layers). They found both in the phylum Ctenophora and the phylum Cnidaria. Ctenophores differ from cnidarians primarily due to the rows of “combs”, or cilia, which are used for transportation. Additionally, ctenophores possess sticky cells while cindarians possess stinging cells. Jellyfish depend on zooplankton (small floating aquatic animals) as a food source; as a result, they are potential competitors and predators to plankton-eating fish and may negatively impact fish populations.

As recently as 1950, jellyfish have entered the San Francisco Bay from the Mediterranean Sea (probably in ...


Salinity Distribution Of Microplankton In The San Francisco Estuary, Carrie Ann Sharitt, Lindsay Sullivan, Wim Kimmerer Aug 2014

Salinity Distribution Of Microplankton In The San Francisco Estuary, Carrie Ann Sharitt, Lindsay Sullivan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

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 ...


Jellyfish Identification And Quantification In The San Francisco Estuary, Amalia Borson, Lindsay L. Sullivan, Wim Kimmerer Aug 2013

Jellyfish Identification And Quantification In The San Francisco Estuary, Amalia Borson, Lindsay L. Sullivan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

As potential predators and competitors of plankton-eating fish, jellyfish have the potential to negatively impact fish populations. Jellyfish were collected weekly with plankton tows from the RombergTiburonCenterpier in Tiburon, CA. Since some jellyfish were too small to identify, one tow was collected and preserved to record abundances, and a second tow was collected to rear jellyfish until distinguishing characteristics were visible enough for identification. Jellyfish in the preserved tows were then identified, measured, and counted, and their abundance (number m-3) was calculated. Jellyfish from the second tows were reared in plastic buckets that were lightly bubbled using aquarium pumps ...


Feeding Ecology Of Delta Smelt During A Seasonal Pulse Of Turbidity, William A. Hilton, Aaron Johnson, Wim Kimmerer Aug 2013

Feeding Ecology Of Delta Smelt During A Seasonal Pulse Of Turbidity, William A. Hilton, Aaron Johnson, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

The delta smelt (Hypomesus transpacificus) is a small, pelagic fish endemic to the San Francisco Estuary (SFE) and protected under federal and state endangered species acts. This study examines the diet of adult delta smelt during their spawning migration in the winters of 2010 and 2012. Delta smelt and their zooplankton prey were sampled concurrently during a seasonal pulse of turbidity at sites along their migratory route from the low salinity zone in Suisun Bay to the fresher waters of the Sacramento/San Joaquin Delta. Gut contents were identified to the lowest possible taxon and counted, along with zooplankton from ...


Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan Jan 2013

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR (STEM Teacher and Researcher) Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on ...


Functional Response Of Protected Larval Stage Delta Smelt (Hypomesus Transpacificus), Jorge Ruiz, Lindsay Sullivan, Wim Kimmerer, Joan Lindberg Aug 2012

Functional Response Of Protected Larval Stage Delta Smelt (Hypomesus Transpacificus), Jorge Ruiz, Lindsay Sullivan, Wim Kimmerer, Joan Lindberg

STAR (STEM Teacher and Researcher) Presentations

Delta smelt (Hypomesus transpacificus) is a protected slender-bodied fish endemic to the San Francisco Estuary. Smelt prey upon various zooplankton including the copepods such as Pseudodiaptomus forbesi. This experiment studied the prey maximum feeding rate of 2 larval stages (21 DHP, 35 DPH) of Delta smelt on various concentrations of P. forbesi. The copepod prey was offered at 7 different concentrations (2No./L–120No./L). After feeding was terminated the free prey and ingested prey were counted and analyzed to find the feeding rate of Delta smelt. Maximum feeding rate was found to be at much higher prey densities than ...


Using Stable Isotope Analysis To Study Zooplankton Trophic Ecology In San Francisco Estuary, Steven C. Westbrook, Julien Moderan, Wim Kimmerer Aug 2012

Using Stable Isotope Analysis To Study Zooplankton Trophic Ecology In San Francisco Estuary, Steven C. Westbrook, Julien Moderan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

Zooplankton biomasses in estuaries are often high and represent an important food source for fish, like theendangered Delta Smelt. Human interferences (nitrates from crops, freshwater flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. Every living thing has a specific isotopic signature. For example, in the plankton we study exists Carbon 13 and Carbon 12. Carbon 13 is different only because it has one extra neutron ...