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Full-Text Articles in Life Sciences

Zooplankton Trophic Ecology In The San Francisco Estuary During Summer As Determined By Stable Isotope Analysis, Kyla Bradylong, Steven Westbrook, Julien Moderan, Wim Kimmerer Aug 2013

Zooplankton Trophic Ecology In The San Francisco Estuary During Summer As Determined By Stable Isotope Analysis, Kyla Bradylong, Steven Westbrook, Julien Moderan, Wim Kimmerer

STAR Program Research Presentations

Declines in the abundance of several pelagic fish species in the upper San Francisco Estuary have prompted investigation into food web interactions within the estuary and delta (the lower Sacramento and San Joaquin Rivers). This area is characterized by low primary production and pelagic food webs much longer and reticulated than previously thought, implying low efficiency in the energy transfers from primary producers to planktivorous fish. We determined the carbon and nitrogen stable isotope (SI) composition of zooplankton samples collected monthly between June 2012 and February 2013 at eight stations along the salinity gradient. As consumers SI composition reflects that …


Big Babies, Big Mammas?: Relationship Of Leatherback Hatchling Size And Mother Size, Shane Morales, Violet Campbell, Kelly Stewart Aug 2013

Big Babies, Big Mammas?: Relationship Of Leatherback Hatchling Size And Mother Size, Shane Morales, Violet Campbell, Kelly Stewart

STAR Program Research Presentations

Individual leatherback hatchlings vary in size when compared to individuals from other nests, as well as individuals from the same nest. It is thought that many factors affect hatchling size but that one of the most influential factors is maternal size. Of all the aspects of a mother which could affect hatchling size, evidence for question concerning influence of mother size is determinable within the field using minimal tools and basic statistical analysis. If a direct correlation exists between mother size and hatchling size then the claim can be made that larger mothers produce larger offspring while smaller mothers produce …


Behavioral Variation Between Two Clades Of Leptasterias Spp., Ashley N. Contreras Aug 2013

Behavioral Variation Between Two Clades Of Leptasterias Spp., Ashley N. Contreras

STAR Program Research Presentations

Leptasterias spp. are six-rayed sea stars found along the rocky intertidal of the northeast Pacific Alaska to Santa Catalina Island, southern California. In central California, three clades of Leptasterias are found in separate or mixed populations, in diverse habitats that range from shallow pools of seagrass and algae to bare rock exposed to crashing waves. Initial field observations of two clades from different locations suggested that behavioral variation may relate to habitat differences among clades. To measure differences in activity, the righting response was timed at both field sites. As a result of behavioral variation observed in the field, more …


Assessing Physiological Thresholds For Eelgrass (Zostera Marina L.) Survival In The Face Of Climate Change, Carolyn Jane Ewers Jun 2013

Assessing Physiological Thresholds For Eelgrass (Zostera Marina L.) Survival In The Face Of Climate Change, Carolyn Jane Ewers

Master's Theses

Seagrasses are well known for the important ecological roles they play in coastal marine waters worldwide. However, the severe rate of decline observed in seagrasses this century is expected to accelerate with climate change. Conservation efforts can be improved by quantifying physiological thresholds of seagrasses and using these estimates in modeling to forecast changes in distribution. This study examines the response of eelgrass (Zostera marina L.) across current temperatures to look for early warning signs of vulnerability and to evaluate the ways we determine critical thresholds for survival. Whole eelgrass ramets, collected from three beds in Morro Bay, California, …