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Full-Text Articles in Life Sciences
Beyond Cortisol: Indicators Of Stress And Negative Feedback In Plasma And Blubber Of Marine Mammals, Jessica Avalos
Beyond Cortisol: Indicators Of Stress And Negative Feedback In Plasma And Blubber Of Marine Mammals, Jessica Avalos
University of the Pacific Theses and Dissertations
Marine mammals play an important role in ecosystem stability. However, anthropogenic activity is compounding pressure on many already vulnerable populations. A potential consequence of anthropogenic disturbance is physiological stress, which can impact metabolism, immunity, and reproduction, especially if it occurs repeatedly. Previous studies on marine mammals have focused on acute stress, but the impacts of repeated stress are poorly understood. Due to its accessibility on land during haul-outs, the northern elephant seal (Mirounga angustirostris) is a good system in which to study the effects of stress in marine mammals. Stress stimulates the release of glucocorticoid hormones, primarily cortisol. Elevated cortisol …
Impacts Of Plastic Pollution On A Pelagic Marine Mammal, The Northern Elephant Seal, Lauren M. Kashiwabara
Impacts Of Plastic Pollution On A Pelagic Marine Mammal, The Northern Elephant Seal, Lauren M. Kashiwabara
University of the Pacific Theses and Dissertations
As plastic pollution increases, top marine predators such as marine mammals are becoming increasingly susceptible to plastic particles and their additives. Plastic particles have been found in gastrointestinal tracts and scat of many marine mammals, and quantifying plastic pollution in those that are pelagic can provide insight into plastic pollution in mesopelagic ecosystems that are just beginning to be analyzed. Adapting well-developed laboratory techniques for microplastic (MP) isolation (i.e. density separation and chemical digestion), I isolated MPs from the scat of the deepest diving pinniped, the northern elephant seal (NES), and found that100% of scat samples (n=11) contained high counts …
How Do They Do It? Using Omics Approaches To Explore Metabolic Responses Associated With Hypoxia And Exercise Tolerance In The Deepest Diving Pinniped, Elizabeth R. Piotrowski
How Do They Do It? Using Omics Approaches To Explore Metabolic Responses Associated With Hypoxia And Exercise Tolerance In The Deepest Diving Pinniped, Elizabeth R. Piotrowski
University of the Pacific Theses and Dissertations
Marine mammals such as northern elephant seals (NES) routinely experience hypoxemia and ischemia-reperfusion events to many tissues during deep dives with no apparent adverse effects. Adaptations to diving include increased antioxidants and elevated oxygen storage capacity associated with high hemoprotein content in blood and muscle. Despite experiencing decreased oxygen tensions during diving, NES likely rely on the mobilization of large lipids stores and catabolism of fatty acids to provide energy to exercising muscle while diving. To identify potential regulatory mechanisms that may underly hypoxia and exercise tolerance in diving mammals, this study used system-wide approaches to characterize changes in genes …
To Feed Or Not To Feed: Examining The Effects Of Provisioning Tourism On Nurse Sharks In Caye Caulker, Belize, Carlee Jackson
To Feed Or Not To Feed: Examining The Effects Of Provisioning Tourism On Nurse Sharks In Caye Caulker, Belize, Carlee Jackson
All HCAS Student Capstones, Theses, and Dissertations
Wildlife tourism is increasing in popularity around the world, creating the need to understand alterations in animal behavior and spatial distributions that may occur due to associated anthropogenic disturbances. Nurse sharks (Ginglymostoma cirratum, Bonnaterre 1788) are commonly used for wildlife tourism within the Caye Caulker Marine Reserve in Belize. Shark and Ray Village (SRV) is a site within the reserve where nurse sharks are consistently fed by tour/snorkel boats to create an interactive experience with tourists, termed provisioning tourism. Prior to this experiment, no studies had been conducted in SRV to evaluate the impact of provisioning tourism (tourism …
A Review Of The Global Commercial Cephalopod Fishery, With A Focus On Apparent Expansion, Changing Environments, And Management, Corey Clark
HCNSO Student Capstones
Cephalopods are both important predators and prey in many marine environments and important fishery resources in many countries. The global fishery has expanded almost continuously from landings of 580,000 metric tonnes in 1950 to over 4 m.t. in 2007. Cephalopods are ecological opportunists with highly plastic biological characteristics and varied population dynamics. Nearly all commercially harvested species are short-lived and can reproduce quickly, enabling them to evolve more rapidly under high selection pressure relative to many fish competitors and predators. As a result, they may have the biological means to be successful under conditions of long-term global climate change. This …
Development Of A Biomarker Panel For Identifying Stressed Marine Mammals, Laura Pujade
Development Of A Biomarker Panel For Identifying Stressed Marine Mammals, Laura Pujade
University of the Pacific Theses and Dissertations
Increasing anthropogenic disturbance in marine ecosystems such as fishing, oil-drilling, and noise pollution can have detrimental effects on the reproduction and survival of apex predators such as marine mammals. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, resulting in increased circulating glucocorticoid (GCs) hormones, which alter expression of target genes encoding metabolic enzymes and other mediators of stress. Prolonged HPA axis stimulation may increase catabolism of nutrient stores and suppress immune and reproductive functions, impacting the fitness of marine mammals. GCs measurements are used to identify wild animals experiencing stress. However, these measurements may not be sensitive enough to distinguish between an …
Resurgence Of Acropora Corals On Mid Shelf Patch Reefs, Southwater Caye Marine Reserve, Central Belize, Jillian J. Keefer
Resurgence Of Acropora Corals On Mid Shelf Patch Reefs, Southwater Caye Marine Reserve, Central Belize, Jillian J. Keefer
Undergraduate Honors Thesis Projects
Acropora cervicornis (staghorn) and Acropora palmata (elkhorn) are ecologically important corals that grow quickly and provide topography and refuges for fish and invertebrates. Historically, Acropora was the most abundant coral in shallow patch reef zones in the Caribbean. During the 1980s, white band disease eliminated most Acropora causing a loss in rugosity and an increase of macroalgae on many reefs. Although Acropora remains rare throughout most of the Caribbean, this study documents its partial comeback and possible limiting factors in Southwater Caye Marine Reserve (SWCMR), Central Belize. Patch reefs in the reserve averaged 19% live coral cover with A. palmata …
Comparison Of Guekensia Demissa Populations Along A Nitrogen Loading Gradient In Narragansett Bay, Ri, Janis Hall
Comparison Of Guekensia Demissa Populations Along A Nitrogen Loading Gradient In Narragansett Bay, Ri, Janis Hall
Master's Theses, Dissertations, Graduate Research and Major Papers Overview
Anthropogenic eutrophication of coastal estuaries impacts these vital ecosystems by increasing primary production, hypoxic conditions, pathogen concentration, and greenhouse gas emissions, all of which are leading to the degradation of shorelines, disease transmission, and hypoxia-related fish kills. Narragansett Bay is a prominent feature of Rhode Island, making up over 500 km of coastline and acting as a watershed for over 2,000 square meters of land in both Massachusetts and Rhode Island. This estuary is important to both the economy of the state of Rhode Island and its fringing ecosystems are necessary for a healthy shoreline. The beaches of Narragansett Bay …
Family Matters: An Analysis Of Genetic Relatedness Of Tetraclita Rubescens (The Pink Volcano Barnacle) Over Several Spatial Scales At Monterey And Bodega Bay, California, Kelly N. Chang
Scripps Senior Theses
Inbreeding involves the mating of closely related individuals at a higher frequency than at random; this can decrease the average fitness of populations and individuals by reducing the presence of heterozygotes and augmenting the expression of deleterious genes. Since marine invertebrates exhibit widespread dispersal, their potential for inbreeding is often disregarded. The adult sessile state of barnacles creates the potential for inbreeding as a result of necessary copulation between neighboring individuals. Depending on the degree of mixing that occurs during dispersal, closely related individuals or siblings may settle in close proximity, generating the possibility of kin aggregation and consequent inbreeding. …