Marine Biology Commons^™

Assessing The Significance Of Substrate Color And Temperature On Balanus Glandula Growth And Survivorship, Nhi Phan

CMC Senior Theses

The body temperatures of intertidal species are strongly dependent on the temperature of their external environment. This study sought to understand the impact of a substrate’s color and subsequent temperature on Balanus glandula in order to predict the potential effects of warming temperatures from climate change on intertidal species. Barnacles were allowed to settle and grow on three differently colored plates and were photographically monitored over the course of eleven weeks. Settlement and survivorship were recorded on-site, while growth was tracked utilizing digital imaging software. It was hypothesized that barnacles on peach plates would perform the best since the ambient …

Population Dynamics And Demographics Of Spotted Seatrout, Cynoscion Nebulosus, Through Spatial Analysis: Towards An Integrative Management Approach, Ashley Melancon Baer

LSU Doctoral Dissertations

Spotted seatrout (Cynoscion nebulosus) is one of the most highly prized sportfish along the Gulf of Mexico coast, particularly in Louisiana. Although spotted seatrout are considered to be well managed and sustainably fished according to the state’s most recent stock assessment, the spatial ecology of this species is largely understudied in Louisiana waters. Acoustic telemetry is an innovative technology that is commonly used to assess the movements and behavior of aquatic species, and can be used as a tool to address the paucity of information on the spatial dynamics of spotted seatrout. The focus of this study was …

Adult Atlantic Sturgeon Population Dynamics In The York River, Virginia, Jason E. Kahn

Graduate Theses, Dissertations, and Problem Reports

Sturgeon first appear in the fossil record in the Triassic Period just over 200 million years ago and are among the most primitive of the bony fishes. Despite their large size and historic presence along the East Coast, Atlantic sturgeon were not targeted for their meat and caviar as a commercial fishery until 1880. By 1905 they had declined to less than one percent of their pre-fishing abundance but the fishery continued. Prior to 1980, there had been very little research on Atlantic sturgeon, primarily limited to documenting landing location and poundage, maximum longevity, or weight of eggs per fish. …

Indirect Effects Of Ocean Warming And Acidification On The Realized Recruitment Of Agaricia Agaricites, Allan Anderson

HCNSO Student Theses and Dissertations

Over the past few decades, coral cover has declined worldwide due to overfishing, disease, and storms, and these effects have been exacerbated by ocean warming and acidification. Corals are extremely susceptible to these changes because they are already living close to their thermal and aragonite saturation thresholds. Ocean warming and acidification (OAW) may also impact coral survival and growth by impacting their settlement cues. Coral larvae use crustose coralline algae (CCA) and their associated biofilms as cues for settlement, i.e., habitat selection. Settlement cues can also be negatively affected by increased water temperature and acidity. It was hypothesized that the …

Variation In Coral Recruitment And Juvenile Distribution Along The Southeast Florida Reef Tract, Leah M. Harper

HCNSO Student Theses and Dissertations

Coral recruitment in Southeast Florida is being outpaced by mortality, resulting in population declines in many species. Identifying the coral species most likely to recruit and survive on Southeast Florida reefs and evaluating spatial variation in recruitment and survivorship is crucial for managing decreasing coral populations. This study focuses on 12 sites in Broward and Miami-Dade counties that have served as long-term stations for monitoring adult coral cover and demographics. At each site, thirty-two 225cm² grooved terracotta settlement tiles were attached to the substrate in winter of 2015 and retrieved in winter of 2016 to evaluate scleractinian and octocoral …

Coral Vs. Macroalgae: Relative Susceptibility To Sedimentation And Ocean Warming, Ashton J. Galarno

HCNSO Student Theses and Dissertations

Sedimentation and ocean warming are two major anthropogenic stressors that directly affect coral recruitment and recovery. Many coral-dominated reefs have undergone phase shifts becoming macroalgae-dominated because of the coral population’s inability to tolerate these increasing stressors. Predicting these phase shifts requires a determination of the relative susceptibility of coral and macroalgae to these stressors. The objective of this study was to quantitatively assess the synergistic effects of sedimentation and elevated temperature on the survival and growth of Montastraea cavernosa newly settled coral juveniles, and fragments of the macroalgae, Dictyota ciliolata. A crossed experimental design tested the two temperatures and …

Population Ecology Of Colonially Breeding Seabirds: How Intrinsic Processes, Mediating Influences, And Individual Heterogeneity Affect Population Vital Rates, Aly Mcknight

Electronic Theses and Dissertations

Seabirds have great potential to serve as marine indicators. However, before we can interpret seabird trends with confidence, we need a better understanding of the role of intrinsic processes, mediating influences, and lifetime experience in modulating relationships between prey availability and seabird population dynamics.

Intrinsic processes, mediating influences, and seabird productivity. I assessed productivity (chicks per breeding attempt) at Black-legged Kittiwake (Rissa tridactyla) colonies in Prince William Sound, AK and managed Common Tern (Sterna hirundo) colonies in the Gulf of Maine. Both systems showed evidence of intrinsic control; factors mediating access to prey were also important.

Mediating influences, individual heterogeneity, …

Transgenerational Effects Of Thermal Stress: Impacts On And Beyond Coral Reproduction, Alyson Kuba

HCNSO Student Theses and Dissertations

Ocean warming causes stress to corals and records reveal that periods of thermal stress are increasing in frequency and severity. Previous studies show that thermal stress negatively impacts the reproductive output of corals. However, the transgenerational impacts of coral bleaching have never been quantified. As a consequence, it is unclear how ocean warming may alter population dynamics due to effects on reproduction and recruitment. This study quantified the transgenerational impacts of thermal stress in Montastraea cavernosa. To assess transgenerational effects of temperature stress during gametogenesis, colonies were exposed to elevated temperature for two weeks four months prior to spawning, …

Assessment Of A Hatchery Based Rainbow Smelt Supplementation Effort, Andrew O'Malley

Electronic Theses and Dissertations

Rainbow Smelt (Osmerus mordax) are an important fish distributed throughout northeastern North America with both anadromous and landlocked populations. Abundance, size at age, and maximum size vary widely among populations and life histories. In order to compare anadromous and landlocked populations, we collected spawning adults in 2014 from four anadromous and three landlocked populations. Scales and otoliths from the anadromous fish were examined and compared for estimates of bias and precision in ageing. Analysis of both scales and otoliths provided age estimates that were acceptable, but estimates from scales were more precise and had less bias. Otoliths were …

Effects Of Sedimentation On The Physiology And Oxidative Stress Of Two Common Scleractinian Corals, Margaret E. Rushmore

HCNSO Student Theses and Dissertations

This study examined the effect of a growing environmental stressor, sedimentation, on the physiology and oxidative stress throughout the different life stages of two common scleractinian corals Montastraea cavernosa and Porites astreoides. Physiology, oxidative stress, and settlement success of newly released P. astreoides larvae were measured after exposure to various turbidity treatments. No significant effects were seen on larval settlement and photosynthetic efficiency, however carbonyl content and catalase activity were significantly higher in 2015 compared to 2014; highlighting a possible inter-annual variability in susceptibility. Larval settlement deterrence in the presence of a layer of accumulated fine- or coarse-grained sediment …

Natural Vs. Anthropogenic Sedimentation: Does Reducing A Local Stressor Increase Coral Resilience To Climate Change?, Francesca Fourney

HCNSO Student Theses and Dissertations

Corals face serious worldwide population declines due to global climate change in combination with direct anthropogenic impacts. Global climate change is difficult to manage locally, but policy makers can regulate the magnitude of local stressors affecting reefs. The objective of this experiment is to investigate if reducing sedimentation will enable reef corals to better endure global climate change. It has been shown that some coral species can handle climate change stress when provided with additional energy resources. Here I tested if the capacity of corals to cope with climate change can be improved when their ability to feed and photosynthesize …