Life Sciences Commons^™

Evaluating The Foraging Ecology And Energetics Of Atlantic Bluefin Tuna (Thunnus Thynnus) In The Gulf Of Maine, Samantha Nadeau

Electronic Theses and Dissertations

Atlantic bluefin tuna (Thunnus thynnus, ABFT) have been a commercially and recreationally valuable species in the Gulf of Maine (GOM) since the early 1950s. Over the past few decades, abundance, spatial distribution, and physical condition of ABFT have shifted, possibly as a result of trophic changes including the composition, distribution, and/or condition of available prey. Historically, ABFT forage has most commonly consisted of Atlantic herring (Clupea harengus), Atlantic mackerel (Scomber scombrus), squids (Cephalopoda), bluefish (Pomatomus saltatrix), and sand lance (Ammodytes spp.). The current stock assessment for Atlantic herring, the dominant prey item for ABFT, suggests a reduction in spawning stock …

Use Of The New England Aquarium To Evaluate Environmental Dna Metabarcoding Of Gulf Of Maine Vertebrates And Invertebrates, Samantha Silverbrand

Electronic Theses and Dissertations

Environmental DNA (eDNA) metabarcoding is a tool that has been used to characterize biodiversity in a range of diverse systems. However, blind application of eDNA metabarcoding primer sets to new regions and species pools can result in poor taxon coverage and unaccounted detection biases. For the Maine-eDNA EPSCoR program, one of the main focuses is to understand and characterize community assemblages in the Gulf of Maine (GoM) using eDNA to further inform conservation, monitoring, and sustainability. In this study, I selected a subset of the best performing vertebrate and invertebrate metabarcoding assys to test against GoM species present in the …

Evaluation Of The Effectiveness Of Ventless Trap Survey In Capturing Sublegal American Lobster Abundance In The Inshore Gulf Of Maine, Shiyue Zhao

Electronic Theses and Dissertations

The stock assessment of American lobster (Homarus americanus) plays an important role in managing the fishery in the Gulf of Maine (GOM). Various fishery-dependent and fishery-independent data are required in the stock assessment to estimate key fisheries parameters that define the population dynamics of American lobster. In the 2015 benchmark stock assessment, ventless trap survey (VTS) data were included for the first time to provide information about the sublegal lobster (carapace length < 83 mm) dynamics. However, the effectiveness of VTS data in monitoring sublegal lobsters has not been evaluated and we have little information on whether the VTS sampling design can capture sublegal lobster dynamics. The primary goal of this thesis research was to evaluate and determine whether the data collected from the Maine VTS provide robust estimation of design-based sublegal lobsters abundance index in the inshore GOM. To achieve this goal, I (1) estimated and evaluated variations in catch rates derived, respectively, from the first, second, and third ventless trap per site; 2) predicted sublegal lobster population at a high spatial resolution using generalized additive models (GAMs); (3) sampled the simulated sublegal lobster population following the sampling protocol used in the VTS program to derive a simulated VTS abundance index; and 4) compared the simulated VTS abundance index with the

predicted population abundance index in the simulated sublegal lobster population. The spatial scale of the study was defined by the National Marine Fisheries Service (NMFS) statistical areas in …

The Development And Application Of Targeted Edna Metabarcoding For Monitoring Freshwater And Marine Ais, Yueyang Wu

Electronic Theses and Dissertations

Species invasions are of critical concern due to their significant impacts on ecosystems and social economies, of which aquatic invasive species (AIS) often pose significant challenges in their control and management, notably because of difficulties in early detection. Environmental DNA (eDNA) provides a promising tool in advancing the detection of newly introduced aquatic organisms because of its high sensitivity and ease of use compared to traditional capture-based methods. Although eDNA-based methods are increasingly used worldwide, especially in aquatic ecosystems, most studies focus on a limited number of target species despite a pressing need for broad taxonomic monitoring for conservation and …

Environmental Impacts On The Reproduction Of Three Cold-Water Corals, With Implications For Their Vulnerability To Ocean Warming And Climate Change, Julia Johnstone

Electronic Theses and Dissertations

Cold-water corals are important habitat builders in the deep ocean worldwide. Despite being known for centuries, recent technological advances and deep-sea exploration has revealed cold-water corals thriving at depths of up to 6000m. Similar to their warm-water relatives, cold-water corals are hotspots of diversity, with their structures creating habitat for thousands of associated species. Some cold-water corals create bioherms that stretch for tens of kilometers, while others come together to form vast undersea forests. These habitats are often home to commercially important fisheries species, and conservation efforts have recently begun to regulate fishing in cold-water coral ecosystems to protect them …

The Impacts Of Embryonic Arsenic Exposure Of Fundulus Heteroclitus, Torey Bowser

Electronic Theses and Dissertations

Arsenic is a toxic metalloid that exceeds safe drinking water standards in groundwater in many locations worldwide. Arsenic exposure in fish has been linked to destruction of gill tissues, impairment of growth, decreased muscle mass, memory impairment, increased aggression, and avoidance behaviors. We examined the behavior of mummichogs (Fundulus heteroclitus) following arsenic exposure during development in two studies. Embryos were collected from fish from three reference sites: Scorton Creek (SC), Massachusetts, Wells Harbor (WE), Maine, and Block Island (BLOC), Rhode Island and two contaminated sites: Callahan Mine (CM), Brooksville, Maine, and New Bedford Harbor (NBH), Massachusetts. Embryos were …

The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang

Electronic Theses and Dissertations

The Gulf of Maine northern shrimp (Pandalus borealis) once supported a significant winter fishery for the Gulf of Maine (GOM). Although the shrimp fishery is not comparable to the lobster business, it provided fishermen and many coastal communities jobs and incomes in winters after lobster seasons. However, a moratorium has been put on the shrimp fishery since 2014 due to record low population abundance and perceived recruitment failures. The recruitment failures have been correlated with warming water temperatures over the past decade. The GOM has been recognized as experiencing rapid warming as a result of global climate change. …

Examining Scale-Dependent, Nonstationary Environmental Effects On American Lobster (Homarus Americanus) Spatial Distribution And Habitat Suitability In A Changing Gulf Of Maine, Jamie Behan

Electronic Theses and Dissertations

The Gulf of Maine (GOM) is a highly complex environment and previous studies have suggested needs to account for spatial nonstationarity in species distribution models for the American lobster (Homarus americanus). Spatial nonstationarity can be defined as the presence of variation in relationships between independent and dependent variables across space (Windle et al., 2012). To explore impacts of spatial nonstationarity on species distribution, models with the following three assumptions were compared: (1) stationary relationships between species distributions and environmental variables; (2) nonstationary density-environment relationships between eastern and western GOM, and (3) nonstationary density-environment relationships across eastern, central, and western GOM. …

Marine Aquaculture In Maine: Understanding Diverse Perspectives And Interactions At Multiple Scales, Melissa L. Britsch

Electronic Theses and Dissertations

Coastal oceans are changing and experiencing increased use. The social and ecological benefits of healthy coastal oceans are well documented and include habitats for marine species, storm protection, and recreational opportunities (MEA, 2005). As the impacts of human activities are recognized, questions about how ocean spaces should be used are becoming more common. These questions are complex and involve many tradeoffs. Understanding the values people hold about uses, and how activities and ecosystems overlap, is critical for weighing tradeoffs and improving future management. I use the northeastern U.S. state of Maine to study human interactions with coastal oceans. Maine is …

Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin

Electronic Theses and Dissertations

Among bony vertebrates, the melanocortin-2 receptor ortholog is unique among the family of five melanocortin receptors on the basis that it is dependent on its accessory protein, MRAP1, for trafficking and activation, and is selective for activation by ACTH alone. Previous studies on the MC2R orthologs of select cartilaginous fish, the elephant shark (Callorhinchus milii) and the red stingray (Dasyatis akajei), revealed divergent traits in a less obligatory relationship on MRAP1 and its ability to be activated by ACTH or the MSH-sized peptides. However, observed traits were not consistent between these two cartilaginous fish species, posing …

Novel Quantification And Localization Of Water And Solute Transporters In The Tissues Of The Spiney Dogfish (Squalus Acanthias), Tolulope B. Ojo

Electronic Theses and Dissertations

The dogfish, Squalus acanthias is a marine cartilaginous elasmobranch found in the North Atlantic and Pacific oceans. Dogfish synthesize and excrete urea as a product of nitrogen metabolism. They also convert ammonia into urea and retain this urea, such that their plasma is isosmotic or slightly hyperosmotic to the surrounding seawater. To facilitate the regulation of body fluid and to maintain ionic concentrations and osmotic pressure, Dogfish use ion and solute transporters (e.g., NCC, UT-1) and aquaporin water channel proteins. Studies have identified some of the aquaporin genes in the elasmobranch genome, but their functions are mostly uncharacterized. Recent transcriptomic …

Assessing The Utility Of Environmental Dna Techniques To Monitor White Shrimp (Litopenaeus Setiferus) Abundance On The Georgia Coast, Raven Hurt

Electronic Theses and Dissertations

Environmental DNA (eDNA) surveys have developed over the last decade from once being a novel tool to now acting as an effective technology often used in complement to traditional capture surveys for assessing the distribution of organisms in freshwater and marine environments. However, many uncertainties on how to properly develop, operate, and analyze eDNA based techniques still hinder this technology effectiveness in the field. The white shrimp, Litopenaeus setiferus, is a common, commercially and recreationally important species in the United States, with landings exceeding $254 million in 2020. L. setiferus is also used as a key indicator species to changes …

Assessing Habitat Suitability Of Ribbed Mussels (Geukensia Demissa) In Georgia Salt Marshes By Examining Predicted Mussel Densities And Mussel Population Parameters, William K. Annis Jr

Electronic Theses and Dissertations

Geukensia demissa (ribbed mussel) is an ecology important bivalve that has the potential to contribute to salt marsh restoration. Understanding the factors that contribute to the distribution of mussels can help inform managers on choosing locations to optimize the survivorship of mussels in restoration projects. This study sought to model mussel densities across the coast of Georgia and to compare predicted mussel densities with mussel population parameters as means to gauge habitat suitability. Mussel densities were collected through field surveys across a range of salt marshes along the coast of Georgia and were compared with spatial data such as distance …

Disease Prevalence And The Population Genetic Structure Of Crassostrea Virginica Along The Georgia Coast, Sarah Batchelor

Electronic Theses and Dissertations

The Eastern Oyster, Crassostrea virginica, is an ecologically important species that plays a role in protecting shorelines, water filtration, and providing habitat and food for various fish species. Perkinsus marinus and Haplosporidium nesloni are two pathogens currently affecting oyster populations. These pathogens have both been documented as causes of mass mortality events along the East coast. They greatly diminish the health of oysters, resulting in the degradation of oyster tissue, reduction in growth and reproductive ability, and may cause death. In this study, wild oysters were collected from eleven locations along the Georgia coast to investigate the presence, intensity, …

The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson

Electronic Theses and Dissertations

Ocean acidification (OA) caused by CO₂ emissions is projected to decrease seawater pH to 7.6 by 2100. Scleractinian corals are at risk because excess H⁺ in seawater binds to carbonate (CO₃^2-), reducing its availability for CaCO₃ skeletons. The energy demand for skeletal growth increases as pH decreases because corals must actively purge excess H⁺ from their seawater sourced calcifying fluid to maintain high calcification rates. In scleractinian corals it is hypothesized that photosynthesis by symbiotic algae is critical to meet this increased energy demand. To test this hypothesis, I conducted laboratory and field …

Lipid Metabolites As Energy Stores In Four Stingray Species, Lauren Moniz

Electronic Theses and Dissertations

Assessing macronutrient transfer is important for estimating ecosystem health and structure. This nutrient transfer is facilitated through trophic position interactions and the consumption of biomass. Lipids are macronutrients that can be used to assess energy flow. Triglyceride (TAG) and free fatty acids (FFA) are important lipids that are obtained from diet and integrate into tissues. They are representative of energy stores and potential energy available for metabolic processes. In marine ecosystems, stingrays occupy the mesopredator niche, facilitating nutrient transfer from lower to higher trophic positions. Stingrays consume a variety of prey items ranging in lipid content, but how lipid metabolites …