Marine Biology Commons^™

The Path To The Sea: Leatherback Hatchling Orientation At Sandy Point National Wildlife Refuge, Christina Macmillan, Kelly Stewart

STAR Program Research Presentations

Once sea turtle hatchlings emerge from their nest, they must find their way to the ocean by using cues such as a bright horizon and the slope of the beach. While moving toward the water, hatchlings often must navigate past predators and through vegetation, sticks, footprints in the sand, and other dangers such as ghost crab holes. Sometimes hatchlings become confused (or disoriented) and turn in circles to find the right route to the water. Sea turtle hatchlings also may become disoriented as a result of human impacts such as town lights or trash. The purpose of our experiment was …

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

STAR Program Research 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 Gate Bridge …

Habitat Preference Of The Introduced Green Crab Carcinus Maenas, Brittany Susan Daum, Andy Chang

STAR Program Research Presentations

The aim of this experiment was to determine if Carcinus Maenas (European Green Crab) hhas a habitat preference in Seadrift Lagoon located in Stinson Beach, California. This experiment was accomplished by placing crab traps on the two types of substrate in Seadrift (sand and algae). The traps were pulled up every 24 hours and the size and sex of crabs was recorded. The data was analyzed to see if there was a difference in habitat preference based upon size, sex, and number of crabs. Using a Poisson Regression model, the size and sex of crabs were not significantly different between …

Sex Ratio Assessment Of Endangered Kemp’S Ridley Sea Turtle Foraging Populations: Validation Of A Testosterone Elisa For Juvenile Sex Determination, William A. Hilton, Camryn D. Allen

STAR Program Research Presentations

Currently all species of sea turtles are listed as threatened or endangered with extinction under the U.S. Endangered Species Act. In order to effectively construct management approaches we need as much information on various sea turtle populations as possible including demography, genetic origin, and critical habitat. One demographic piece of data that is lacking is the sex ratio of turtle populations in foraging habitats, as this information is integral in determining overall population abundance. Because secondary sex characteristics (i.e. males have longer tails) are not evident until turtles start to reach sexual maturity, the sex of juvenile turtles cannot be …

Ultraviolet Led Biofouling Mitigation, Andrew Lam

Computer Engineering

The goal is to determine if low-cost UV LEDs can mitigate marine biofouling on small glass or acrylic camera lenses. A microprocessor-controlled experimental setup to control the illumination of low-cost UV LEDs of various wavelength and packaging was fashioned. The system consists of a programmed microcontroller, a manufactured LED breakout interface, and a submergible UV LED array enclosed in a borosilicate glass tube. A preliminary qualitative assessment of four different UV LEDs was conducted during a three-week deployment of the experimental setup in the raw seawater system at the Cal Poly Center for Costal and Marine Sciences in Avila Beach, …

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

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

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

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, …

An Analysis Of Human Disturbance To Rocky Intertidal Communities Of San Luis Obispo County, Grant Tyler Waltz

Master's Theses

ABSTRACT

An Analysis Of Human Disturbance To Rocky Intertidal Communities Of San Luis Obispo County

Grant Tyler Waltz

The number of coastal areas open to public access in California and San Luis Obispo County is increasing due to the acquisition by California State Parks of land previously owned by private entities. For example, California State Parks acquired property from the Hearst Corporation in 2005, which included 18 miles of coastline. California State Parks is responsible for providing public access in these newly acquired areas and also for maintaining the health of the natural systems found on these properties. Part of …

A Genetic Survey Of English Sole Populations In The Salish Sea, Elizabeth S. Gutierrez, Gary A. Winans, Jon Baker, Amanda Cope

STAR Program Research Presentations

This summer I interned at the Northwest Fisheries Science Center in Seattle, WA and participated in NOAA’s Salish Sea Project. The Salish Sea Project’s goal is to identify genetically distinctive groups of species in the Salish Sea that may have unique evolutionary and/or adaptive backgrounds. These findings will allow NOAA to promote and monitor the natural production of species in the Salish Sea, to select representative populations for experimental work regarding pollution, ocean acidification and climate change, to contribute to managing the ecosystem for intra- and inter-species diversity, and to help make informed decisions about adaptive management and marine protected …

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

STAR Program Research 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, …

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

STAR Program Research 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 …

Developing Monitoring Methods For Leptasterias Spp. As Sentinel Species In Detecting Local Environmental Changes, Zachary Sturbaum, Kathryn Nuessly, Riley J. Smith, C. Sarah Cohen

STAR Program Research Presentations

Leptasterias spp., a six-rayed sea star, is found in rocky intertidal habitats ranging from Alaska to central California. Leptasterias spp. can be monitored on a broad scale throughout their range by a variety of means using timed counts and random plot censusing in order to detect both large-scale and local-level changes in the environment due to climate change, land-based human activity, or other environmental events. Leptasterias brood their young externally until the embryos grow into fully developed juveniles. These juveniles disperse by crawling away, limiting their dispersal potential. This localized dispersal provides an opportunity to use Leptasterias spp …

Testing The Salinity Tolerance Levels Of Similar Invasive Species Found In The San Francisco Bay, Julia M. Smith, C. Sarah Cohen, Elizabeth Sheets

STAR Program Research Presentations

Testing the salinity tolerance levels of similar invasive species found in the San Francisco Bay

Julia Smith^1,2, Elizabeth Sheets², and C. Sarah Cohen²

¹Department of Teacher Education, California State University, Sacramento ²Department of Biology and Romberg Tiburon Center, San Francisco State University

Three non-indigenous colonial ascidian species, Botrylloides violaceus, Botrylloides diegensis, and Botryllus schlosseri, have become well established in San Francisco Bay. Two species, B. violaceous and B. schlosseri, are globally distributed, and understanding the salinity ranges and tolerances of these successful invaders in their introduced habitats is important for …

Nutritional Content Of Rhinoceros Auklet (Cerorhinca Monocerata) Bill Loads, Dustin Taylor, Ron Heintz

STAR Program Research Presentations

Nutritional Content of Rhinoceros Auklet Bill Loads

Dustin E Taylor

Abstract

An adult Rhinoceros Auklet (Cerorhinca monocerata) can only catch and carry a limited amount of prey to their nestlings after a foraging trip. The auklets therefore must maximize their efficiency by bringing back the most proportionally nutritious prey items to their nestlings. The prey carried back to the nesting sites (known as a ‘bill load’) can contain whole fish, as well as parts, most commonly fish heads. This study is aimed to determine whether returning with just heads to the nestlings was proportionally more nutritious than bringing …

Effects Of Pristane On Growth Of Pink Salmon (Oncorhynchus Gorbuscha), Brielle D. Kemis, Bonita Nelson

STAR Program Research Presentations

Pristane is a naturally occurring hydrocarbon that is generated by copepods in marine ecosystems. Organisms that eat copepods do not readily metabolize pristane, which causes it to accumulate throughout the marine food web. Understanding how pristane affects marine fish is essential because pristane is often used as a bioindicator in lab studies and may be influencing results in those studies. Also, this hydrocarbon may significantly reduce growth of marine fish in the wild. A previous study indicated that pristane is an appetite suppressant and growth retardant in fish. However, the study implemented a feeding regime with unnaturally high levels of …

Brody-Bertalanffy Growth Curves From Tag And Recapture Studies On Cabezon (Scorpaenichthys Marmoratus) And Gopher Rockfish (Sebastes Carnatus) Of The Central Coast, Christie Yorke

Biological Sciences

No abstract provided.