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Effects Of Increasing Temperature And Acidification On The Growth And Competitive Success Of Alexandrium Catenella From The Gulf Of Maine, Drajad Seto Dec 2018

Effects Of Increasing Temperature And Acidification On The Growth And Competitive Success Of Alexandrium Catenella From The Gulf Of Maine, Drajad Seto

Electronic Theses and Dissertations

The increases in ocean temperature and pCO2 due to climate change are projected to affect the growth and future prevalence of Harmful Algal Blooms (HABs) in nearshore waters, but systematic studies on the effects these climate drivers have on harmful algal species are lacking. In particular, little is known about how future climate scenarios will affect the growth of the toxic dinoflagellate Alexandrium catenella, which produces the toxins responsible for paralytic shellfish poisoning (PSP) that threaten the health and economy of coastal communities in the Gulf of Maine. I examined growth responses of A. catenella and two other naturally co-occurring …


Thermal And Microbial Effects On Brown Macroalgae: Heat Acclimation And The Biodiversity Of The Microbiome, Charlotte Tc Quigley Nov 2018

Thermal And Microbial Effects On Brown Macroalgae: Heat Acclimation And The Biodiversity Of The Microbiome, Charlotte Tc Quigley

Electronic Theses and Dissertations

This dissertation examines effects of stress on brown algal biology from a macroscopic scale by examining the whole aquaculture crops, and at a microscopic level by examining the macroalgal microbiome, across the vertical stress gradient of the intertidal zone and across the latitudes of their biogeographic ranges. Thermal stress negatively affected seedstock gametophytes of the kelp Alaria esculenta isolated from northern and southern locations in Maine. However, previous thermal stress had a positive effect on growth of the next-generation sporophytes. Alaria esculenta has potential as a kelp crop in Maine’s sea vegetable aquaculture sector and implementing this protocol may allow …


Investigating Present-Day Health Issues Of The American Lobster (Homarus Americanus), Deborah A. Bouchard May 2018

Investigating Present-Day Health Issues Of The American Lobster (Homarus Americanus), Deborah A. Bouchard

Electronic Theses and Dissertations

The American lobster, Homarus americanus, H. Milne Edwards, 1837, supports the most economically valuable fishery along the North Atlantic coast of North America. A collapse in lobster populations in Southern New England (SNE) has coincided with increasing ocean temperatures and emerging diseases. This research investigated the etiologies of limp lobster disease (LLD) and epizootic shell disease (ESD), two diseases that continue to cause significant mortality in natural lobster populations. Mortality from LLD is associated with the bacteria Photobacterium indicum and is more intense in impounded lobsters. To more clearly define the community ecology of this suspected opportunistic pathogen, the microbial …


Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish May 2018

Spatio-Temporal Dynamics Of Atlantic Cod Bycatch In The Maine Lobster Fishery And Its Impacts On Stock Assessment, Robert E. Boenish

Electronic Theses and Dissertations

Of the most iconic fish species in the world, the Atlantic cod (Gadus morhua, hereafter, cod) has been a mainstay in the North Atlantic for centuries. While many global fish stocks have received increased pressure with the advent of new, more efficient fishing technology in the mid-20th century, exceptional pressure has been placed on this prized gadoid. Bycatch, or the unintended catch of organisms, is one of the biggest global fisheries issues. Directly resulting from the failed recovery of cod in the GoM, attention has been placed as to possible sources of unaccounted catch. Among the most …


Modeling And Simulation Of American Lobster In The Gulf Of Maine: Spatial Distribution, Monitoring, And Conservation, Bai Li May 2018

Modeling And Simulation Of American Lobster In The Gulf Of Maine: Spatial Distribution, Monitoring, And Conservation, Bai Li

Electronic Theses and Dissertations

In spite of the high fishing pressure and landings, the Gulf of Maine (GOM) American lobster (Homarus americanus) population abundance has increased dramatically since the early 1990s. Various hypotheses have been developed to explain such an increase, ranging from improved habitat to conservation measures that protect female spawners. However, no systematic study has been done to evaluate these hypotheses. This study aims to examine roles of environmental drivers and conservation measures in regulating the dynamics of lobster population, and evaluate the performance of monitoring programs. A geographical weighted regression model was developed to examine the non-stationary environmental effects …


The Effects Of Ocean Acidification On The Gametogenesis Of The Red Tree Coral, Primnoa Pacifica, Ashley Rossin May 2018

The Effects Of Ocean Acidification On The Gametogenesis Of The Red Tree Coral, Primnoa Pacifica, Ashley Rossin

Electronic Theses and Dissertations

Primnoa pacifica, otherwise known as the Red Tree Coral, is one of the most ecologically important corals in the North Pacific. This species is an ecosystem engineer, providing essential habitat for commercially important fish and invertebrate species. Ocean acidification (OA) threatens corals and all calcifying organisms and is more prevalent in polar and sub-polar regions as the concentration of CO2 is higher and there is a lowered buffering capacity due to low alkalinity in colder waters. The impact from a chemical shift in the oceans could alter the role of P. pacifica as an ecosystem engineer in predicted ocean …


Polyp To Population: A Tale Of Two Corals, Christopher T. Fountain May 2018

Polyp To Population: A Tale Of Two Corals, Christopher T. Fountain

Electronic Theses and Dissertations

Deep-sea corals are of conservation concern in the North Atlantic due to prolonged disturbances associated with the exploitation of natural resources and a changing environment. As a result, the recovery rates of deep-sea coral communities are of heightened interest. These recovery rates are suggested to be on the order of decades to millennia, based on slow growth rates and longevity, of various deep-sea coral species. In 2014 and 2017 two research cruises in the Gulf of Maine, collected samples of two locally dominant species, Primnoa resedaeformis and Paramuricea placomus. These specimen collections were coupled with video surveys, conducted by …


Changes In The Microbial Community Of Lubomirskia Baicalensis Affected By Red Sponge Disease, Colin Rorex May 2018

Changes In The Microbial Community Of Lubomirskia Baicalensis Affected By Red Sponge Disease, Colin Rorex

Electronic Theses and Dissertations

Lake Baikal is the oldest known lake and a unique ecosystem, home to several species of fresh water sponge. A disease outbreak affecting the dominant species, Lubormirskia baialensis, was recently reported. The cause of the disease has not been determined but one of the current hypothesis is that the increase in methane concentration is correlated to the disease outbreak. This pilot study characterized the microbiomes of sick and healthy sponges through the use of 16S rRNA sequencing. Sick sponge microbiomes shared a conserved group of taxa while the healthy sponge microbiomes had greater diversity. Indicator species analysis identified two significant …


Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams May 2018

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein …


Assessing Economic Performance Of Maine's Lobster Fleet Under Changing Ecosystem Conditions In The Gulf Of Maine, Alexa Dayton May 2018

Assessing Economic Performance Of Maine's Lobster Fleet Under Changing Ecosystem Conditions In The Gulf Of Maine, Alexa Dayton

Electronic Theses and Dissertations

This thesis explores the inter-disciplinary space that lies between fisheries management and stock conservation, resource extraction and economic return at the individual producer level, balanced with societal welfare. It considers policy implications in support of changing marine ecosystems and considers the values of the Maine lobster communities, which depend on it. We conducted a comprehensive lobster industry survey to assess costs and effort expended at the producer level for a representative fishing year, and establish a series of production function performance baselines for future comparison. The demographic data, attitudes and valuations collected allow us to characterize the fishing effort and …


An Investigation Into The Physiological Impacts Of Ocean Acidification On Recruits Of The Temperate Coral, Oculina Arbuscula, Brianne Varnerin Jan 2018

An Investigation Into The Physiological Impacts Of Ocean Acidification On Recruits Of The Temperate Coral, Oculina Arbuscula, Brianne Varnerin

Electronic Theses and Dissertations

Ocean acidification is well-researched with respect to adult scleractinian corals, however information on whether adults and recruits of the same species respond similarly to this environmental stress is lacking. I investigated the responses to increased pCO2 of recruits of the temperate coral, Oculina arbuscula, whose adults are known to withstand high levels of pCO2 with no depression in calcification (up to 1000 ppm CO2). I addressed the hypothesis that O. arbuscula recruit health is not affected by increased pCO2 by exposing small colonies (5-12mm diameter) to 475, 711, and 1270 ppm CO2 for …


Evaluating Elasmobranch Bycatch And Shark Depredation In The Georgia Shrimp Fishery, Matthew M. Scanlon Jan 2018

Evaluating Elasmobranch Bycatch And Shark Depredation In The Georgia Shrimp Fishery, Matthew M. Scanlon

Electronic Theses and Dissertations

The Georgia shrimp fishery has seen a dramatic decrease in profit and productivity since the 1980’s due to a number of economic factors. Additional, yet undocumented, pressures on this fishery include interactions between foraging sharks with trawl gear. Fishermen report that sharks frequently bite nets in an attempt to prey on netted fish, resulting in large holes in the gear. Further elasmobranch interactions with trawl gear occur as bycatch; shrimp trawls represent nearly 100% of elasmobranch commercial bycatch in Georgia state waters, the species composition of which is largely unstudied. Shark interactions with nets were detailed through fishery-dependent observations on …


Environmental And Physiological Regulation Of Yellow Stingray Color Change, Theresa Rose Gunn Jan 2018

Environmental And Physiological Regulation Of Yellow Stingray Color Change, Theresa Rose Gunn

Electronic Theses and Dissertations

Many reef fishes exhibit dynamic coloration and body patterns that can change under nervous or hormonal control. Several species of benthic sharks and rays likely alter melanin in the skin to provide background matching for camouflage. The yellow stingray (Urobatis jamaicensis) is a benthically-oriented elasmobranch with elaborate spot patterns that provide effective camouflage within its habitats. This patterning, when coupled with the ability to alter melanin in response to background color, could increase background matching effectiveness in these species. The yellow stingray has been anecdotally noted to lighten or darken skin color.However, it is unclear whether this type …


Environmental Factors Affecting Hatch Success In The Loggerhead Sea Turtle (Caretta Caretta), Mattie J. Whitesell Jan 2018

Environmental Factors Affecting Hatch Success In The Loggerhead Sea Turtle (Caretta Caretta), Mattie J. Whitesell

Electronic Theses and Dissertations

The loggerhead turtle (Caretta caretta) is a species federally listed as “threatened” whose global populations are declining. Georgia Department of Natural Resources conservation protocols for this species require the daily monitoring of nesting activity and permit physical relocation of nests which are at risk of being eroded or flooded by storms and high tides in order to increase hatch success--the proportion of hatched to unhatched eggs. Relocated nests are moved to an area with higher elevation in order to avoid flooding, but other variables such as increased temperature and decreased moisture are introduced when relocating. For years temperature …