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Full-Text Articles in Life Sciences

The Evaluation Of The Response Of American Eels To Rapid Decompression, Christina Macmillan, Alison Colotelo, John Stephenson, Briana Rhode, Trevor Macduff Sep 2016

The Evaluation Of The Response Of American Eels To Rapid Decompression, Christina Macmillan, Alison Colotelo, John Stephenson, Briana Rhode, Trevor Macduff

STAR (STEM Teacher and Researcher) Presentations

Hydropower dams are used throughout the world to generate electricity and dams can negatively affect fish, as they can hinder or block migration or be a source of injury and mortality during passage. When moving downstream, fish can pass through the turbines instead of other routes (e.g. spillway and juvenile bypass system)where there is a sudden decrease in pressure that can cause barotraumas, injuries from the changes in barometric pressure, (e.g., hemorrhaging, embolism, ruptured organs) due to internal gases expanding. To determine the response of American eels, Anguilla rostrate, to rapid decompression, testing was conducted in the ...


Winter Freeze Decreases The Emergence Of Fauna And Flora In California Vernal Pools, Korena S. Hendryx, Jamie Kneitel Aug 2015

Winter Freeze Decreases The Emergence Of Fauna And Flora In California Vernal Pools, Korena S. Hendryx, Jamie Kneitel

STAR (STEM Teacher and Researcher) Presentations

Impacts of global climate change is observed in many ecological systems. Temporary aquatic ecosystems, including California vernal pools, are especially sensitive to climatic variation, but most species are adapted to the annual fluctuations in precipitation and temperature. Since vernal pools experience an inundation and desiccation every year, species that occupy the ecosystem have adaptations to this cycle. Many species survive drought by creating resting eggs to then re-emerge upon inundation However, climate changes outside the typical range may have deleterious effects on these populations. Moreover, climate variation can have secondary effects on the community. For example, the amount of precipitation ...


Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman Aug 2015

Radiocarbon Isotopic Classification Of Deep Tropical Forest Soils, Brooke Butler, Karis J. Mcfarlane, Jennifer Pett-Ridge, Katherine A. Heckman

STAR (STEM Teacher and Researcher) Presentations

Tropical forest soils have an important role in global carbon (C) stocks. Small changes in the cycling of C could drastically affect atmospheric carbon dioxide (CO2) concentrations and active cycling of carbon in a forest community. Currently, little is understood of how tropical forest soils will respond to the increasing global temperatures. To examine the effects of warming/ drought on losses of older versus younger soil C pools, we implemented radiocarbon (14C) isotopic characterization of various soil plot samples and depths from the Luquillo Experimental Forest, Puerto Rico. 14C was measured using Accelerated Mass Spectrometry (AMS) from catalytically condensed carbon ...


Do Marine Protected Areas Affect Emerging Fisheries Population Density?, Jennifer Greene, Katherine O. Grady, Crow White, Danielle Zacherl Aug 2015

Do Marine Protected Areas Affect Emerging Fisheries Population Density?, Jennifer Greene, Katherine O. Grady, Crow White, Danielle Zacherl

STAR (STEM Teacher and Researcher) Presentations

Kellet’s whelk, Kelletia kelletii, were observed at sample sites throughout their range from Baja California, Mexico, to Monterey, CA to determine patterns of population density. Sample sites in each region were either located within California marine protected areas where take of the Kellet’s whelk in prohibited, or in non-protected areas where the whelks can be fished both commercially and recreationally. Kellet’s whelk population density was compared between all MPA and non-MPA sample sites. These mean densities were also found for sites in Santa Barbara and San Diego near active fishing ports and compared to data from the ...


Monitoring Abundance Of Carcinus Maenas Developmental Stages In Seadrift Lagoon, Andrea M. Fieber Aug 2015

Monitoring Abundance Of Carcinus Maenas Developmental Stages In Seadrift Lagoon, Andrea M. Fieber

STAR (STEM Teacher and Researcher) Presentations

Able to tolerate a wide range of habitats, temperatures, and salinities, Carcinus maenas thrives in much of its non-native range, out-competing native crabs for resources while diminishing food supplies for a variety of marine and estuarine organisms. In Seadrift Lagoon, a manmade inlet of Bolinas Lagoon in Marin County, California, green crabs comprise a significant portion of benthic fauna, and trapping efforts began in 2009 to eradicate them. We analyzed several years of trapping data to monitor demographic changes for this closed population, performed larvae and megalopae sampling with pot scrubbers, and counted eggs on ovigerous females captured in Seadrift ...


The Pioneer Of Santa Rosa Island, Andrea Martinez, Michael Perez, Kathryn Mceachern, Sarah Chaney, Ken Niessen Jul 2015

The Pioneer Of Santa Rosa Island, Andrea Martinez, Michael Perez, Kathryn Mceachern, Sarah Chaney, Ken Niessen

STAR (STEM Teacher and Researcher) Presentations

Santa Rosa Island which is part of the Channel Islands in California has a ranching history that goes as far back as the year 1843. While rich in history, the island is no longer “rich” in native plant populations due to the sheep, cattle and other livestock that once occupied the island. As a result of these grazers that the ranchers livelihood depended on, a great disturbance in the native plant population took place. It is up to plants such as Baccharis pilularis, commonly known as Coyote brush, to assist these endangered and threatened plants to once again flourish on ...


Are Circadian Cycles The Dominant Proteome Rhythym In The Intertidal Mussel Mytilus Californianus?, Kristina M. Koster, Cory Elowe, Lars Tomanek Jan 2015

Are Circadian Cycles The Dominant Proteome Rhythym In The Intertidal Mussel Mytilus Californianus?, Kristina M. Koster, Cory Elowe, Lars Tomanek

STAR (STEM Teacher and Researcher) Presentations

Mytilus californianus, also known as the California mussel, is a marine bivalve that is abundant along the West coast from Alaska to southern Baja California. They mainly reside in the upper-middle intertidal zone and cling to pier pilings and surf exposed rocks. They create multi-layered beds, which form a habitat for algae and many species of invertebrates. Intertidal mussels live in a naturally dynamic environment. It has previously been reported (Connor and Gracey, 2011) that the 24-hour circadian (day to night) rhythm of the intertidal mussel Mytilus californianus is primarily responsible for its rhythmic gene expression, as opposed to the ...


Jellyfish Throwdown: Invasive Versus Native, Brooke Bemowski, Trisha Huynh, Lindsay J. Sullivan, Wim Kimmerer Aug 2014

Jellyfish Throwdown: Invasive Versus Native, Brooke Bemowski, Trisha Huynh, Lindsay J. Sullivan, Wim Kimmerer

STAR (STEM Teacher and Researcher) Presentations

The San Francisco Bay Estuary is home to many species of marine and wildlife that create a delicate ecological balance. Invasive jellyfish introduced to the bay though cargo shipping are believed to be competing with the endangered delta smelt for the same food source of copepods. Samples of zooplankton were taken from high and low salinity zones in the San Francisco Bay over three years in months June through February to correlate with the peak of the jellyfish lifecycle. The preserved samples are looked through and jellyfish are removed and recorded. The species of jellyfish is determined using features such ...


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 ...


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 (STEM Teacher and Researcher) 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 ...


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 ...


Informing Carbon In Arctic Reservoirs Vulnerability Experiment Flight Schedule Based Upon Soil And Vegetation Freeze And Thaw Event Variation Along The Alaska Ecological Transect, Jessica Potter, Kyle Mcdonald, Erika Podest Aug 2011

Informing Carbon In Arctic Reservoirs Vulnerability Experiment Flight Schedule Based Upon Soil And Vegetation Freeze And Thaw Event Variation Along The Alaska Ecological Transect, Jessica Potter, Kyle Mcdonald, Erika Podest

STAR (STEM Teacher and Researcher) Presentations

Established in the 1990s, the Alaska Ecological Transect (ALECTRA) is composed of a series of ground stations extending from the Franklin Bluff on Alaska’s North Slope to the Kenai Peninsula, south of Anchorage. At each station, sets of thermistors are deployed to monitor vegetation tissue temperature, air temperature, and soil profile temperatures. Also sensors are deployed for monitoring sap flow in individual trees. The stations are automated, with data loggers recording this data approximately every two hours. Dates marking the spring thaw and fall freeze transitions in soil and vegetation tissues from sites in Coldfoot, Dietrich Valley, and Bonanza ...


Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley Aug 2011

Interspecies Comparison Of Αii-Spectrin Abundance Between Chinook Salmon And Steelhead, Brielle D. Kemis, Ann L. Miracle, Katie A. Wagner, Christa M. Woodley

STAR (STEM Teacher and Researcher) Presentations

Salmonids, such as Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss), are a staple economic, recreational, tribal, and environmental resource, yet many populations are unsustainable. This study was part of a broad scale effort to monitor the impact of downstream migration obstacles on juvenile salmonid health and survival, which is an essential step towards increasing Smolt-to-Adult Return ratios (SARs). The objective of this study was to determine if juvenile Chinook salmon and steelhead exhibit differing quantities of alphaII-Spectrin Breakdown Products (SBDPs) over two consecutive spring migration periods, indicative of neurogenesis rate and/or biological response to head injury. AlphaII-Spectrin is ...


Relationship Of Maternal Flow Environment To Offspring Size In Botrylloides Violaceus, Damion J. Delton, Sarah Cohen Aug 2011

Relationship Of Maternal Flow Environment To Offspring Size In Botrylloides Violaceus, Damion J. Delton, Sarah Cohen

STAR (STEM Teacher and Researcher) Presentations

Colonial botryllid tunicates, such as Botrylloides violaceus, brood large, non-feeding offspring with extremely limited larval life spans of minutes to perhaps one day. Despite the importance of this transitory life history stage, there is little information on how environmental factors such as ambient water flow affect larval size among invertebrates. Since adult tunicates feed by filtering particles from the water flowing around the siphons, we reasoned that colonies of B. violaceus in high water flow may produce larger offspring due to greater food availability. We tested to see whether there was a relationship between larval size and water motion in ...


Contrasting Effects Of Flow On Adult And Juvenile Ascidian Life History Stages, Including The Global Invasive Didemnum Vexillum, Tren C. Kauzer, C Sarah Cohen Jan 2011

Contrasting Effects Of Flow On Adult And Juvenile Ascidian Life History Stages, Including The Global Invasive Didemnum Vexillum, Tren C. Kauzer, C Sarah Cohen

STAR (STEM Teacher and Researcher) Presentations

Few studies have quantified a relationship between recruitment, growth, survival and flow with colonial filter feeders. In this study, the growth of D. vex and larval recruitment were evaluated under different local flow conditions in Half Moon Bay, California, USA. Tunicates were subjected to four different flow conditions, three of which included objects to differentially obstruct flow, and growth and recruitment were measured. A direct relationship was seen between increases in flow and adult growth, and an inverse relationship was seen between increases in flow and recruitment. These trends suggest that optimal flow conditions differ for juveniles and adults. The ...