Life Sciences Commons^™

Climate Change And An Evolving Fishery: Do Declining Maternal Size And Planktonic Foods Affect Lobster Larval Survival In The Gulf Of Maine?, Alexander J. Ascher

Electronic Theses and Dissertations

Many marine organisms exhibit bipartite life-cycles whereby reproductive adults dwell on the benthos while the larvae are pelagic. The pelagic stage is subject to mortality rates which far exceed those experienced by the organism during its benthic existence. The larval phase therefore represents an important bottleneck to larval recruitment. Small changes to survivorship in the plankton can have large consequences for subsequent year-class strength. Understanding the factors influencing successful larval recruitment is an important step towards predicting future stock abundances and maintaining healthy fisheries. The American lobster (Homarus americanus) is a large benthic crustacean which is economically and culturally important …

Are Rising Seas Pushing Ghost Crabs Out Of Their Comfort Zone?, Finn Gillette

Honors Theses

Ghost crabs (Ocypode quadrata) can be found on sandy beaches bordering the western Atlantic Ocean. These semiterrestrial crustaceans are often found between the swash zone and the dunes on beaches. Dunes are critical refuges for ghost crabs during storms and extreme tide events. This makes them a useful indicator species for monitoring the effects of global warming-induced sea level rise on beach biota, as their distribution patterns among beach zones may correlate with shifts found in other species. Beach surveys conducted from 2015 onward assessed the population density of ghost crabs on beaches of Horry and Georgetown counties …

Atlantic Surfclam (Spisula Solidissima) Population Demographics And Distribution Along The Middle Atlantic Bight, Mauricio González Díaz

OES Theses and Dissertations

The Atlantic surfclam (Spisula solidissima) is a long-lived benthic biomass dominant organism that occurs on the Middle Atlantic Bight (MAB) continental shelf between 10 m and 50 m. Trends in Atlantic surfclam population specific growth and mortality rates were analyzed using four decades of age and length observations obtained from NOAA stock surveys from the 1980s to 2010s in six regions distributed along the MAB. Atlantic surfclam specific growth rates and asymptotic lengths were estimated from the age and length observations using the von Bertalanffy growth model. The analysis showed that the Atlantic surfclam median asymptotic length in …

Modeling Life History And Population Dynamics Of American Lobster And Atlantic Sea Scallops In A Warming Gulf Of Maine, Cameron T. Hodgdon

Electronic Theses and Dissertations

Climate change is impacting many marine species distributions, life histories, and behaviors, as well as their associated fisheries and overall production. This is perhaps especially true for the Gulf of Maine (GOM). Here, warming rates are exceeding a vast majority of the world’s oceans. This highly dynamic system supports myriad species, but is both economically recognized and culturally known for its Atlantic sea scallop (Placopecten magellanicus) and American lobster (Homarus americanus) fisheries. This dissertation examines the influence of regional climate change on these species in an effort to predict how these stocks and their fisheries may …

The Effects Of Increasing Ocean Temperatures On The Survivorship Of A Subtropical Population Of The Sea Urchin Arbacia Punctulata, Rhianna Clemons

Undergraduate Theses

Most sea urchin species have critical ecological roles in their ecosystems, such as keystone grazers. There is an increasing need to understand the impacts of rising temperatures on species that are vital to the health of their environments. Studies have shown that increasing temperatures may significantly negatively affect several important biological processes including reproduction, development, and excretion in many species including sea urchins. However, very little is known about the sea urchin species Arbacia punctulata. In this study, individuals were exposed to 21˚C (control, n = 12) and 27˚C (experimental, n = 12) for seven days, and survivorship was …

Lost At Sea, Anny Oberlink

Capstones

At the end of World War I and World War II, in a new era of peace, nations confronted an unprecedented logistical problem: millions of tons of unexploded ordnance—once a wartime boon—had become a peacetime burden. Faced with a mandate to dispose of excess munitions, militaries turned to dumping their stockpiles into the sea. But now a complex and urgent issue is emerging. Increasingly, as industry looks to build offshore—wind power turbines, internet cables, oil pipelines—they are facing a potential peril: millions of tons of unexploded bombs and ammunition that are lying on the ocean floor can explode or leak …

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. …

Investigating Local Adaptation To Hypoxia Stress In The Eastern Oyster Through Comparative Transcriptomics, Heather Nichole Smith

LSU Master's Theses

Climate change represents one of the most important challenges to biodiversity, therefore it is important to understand the mechanisms that allow species to respond to rapid environmental change. Here, we compared two populations of eastern oysters, Crassostrea virginica, from the Gulf of Mexico to study the mechanisms underlying hypoxia tolerance. Using a common garden experiment and comparative transcriptomics, we identified sets of genes involved in the hypoxia response and found differences in both the timing and baseline expression of hypoxia-responsive genes between tolerant and sensitive populations, consistent with a scenario of local adaptation. These genes include the signaling transcription factor …

The Potential Influence Of Abiotic Conditions On Mussel Species Abundance In San Francisco Bay, Alexandra G. Farrell, M. Christina Vasquez Dr.

Honors Thesis

Climate change has negatively altered seawater conditions, which may have severe implications for marine ecosystems. Mussels are susceptible to environmental changes since they are primary consumers and filter-feeding bivalves. Two species of particular interest to the West Coast of the U.S. are Mytilus galloprovincialis and M. trossulus. M. trossulus is native to the California Coast and was historically prevalent from Southern California to Washington. However, with increased shipping and rising seawater temperature, M. galloprovincialis, an invasive species from the Mediterranean, pushed the species range of M. trossulus poleward. M. trossulus is more tolerant of cold seawater with variable salinity while …

Effects Of Tropical Cyclones On Incubation And Hatch Frequency Of Marine Turtles In Broward County, Fl: An Exploratory Look For Potential Cues Of Environmentally Cued Hatching (Ech), Alexis Peterson

All HCAS Student Capstones, Theses, and Dissertations

Due to climate change and warming sea surface temperatures (SST), the intensity and frequency of tropical cyclones in the North Atlantic are continuing to increase. Tropical cyclones have many direct and indirect effects on coastal and marine species, such as sea turtles. Sea turtles are extremely vulnerable to climate change, due to having life history, physiology, and behavioral traits that are heavily influenced by environmental factors (Fuentes and Porter 2013). This study examined whether tropical cyclones serve as a triggering event for environmentally cued hatching (ECH) in loggerhead (Caretta caretta) and green (Chelonia mydas) turtle nests …

Patterns And Mechanisms Of Intraspecific Trait Variation Across Thermal Gradients In A Marine Gastropod, Andrew R. Villeneuve

Masters Theses

As the earth’s climate changes due to anthropogenic emissions, it has increasingly become an imperative within the ecological community to understand existing species adaptations to climate change. Much focus has been paid to how a species might react to climate change, but the role of locally adapted traits and responsible environmental mechanisms have received less attention. Quantifying how sublethal (e.g. growth rates) and lethal (e.g. thermal tolerance) trait performance vary between populations can thus improve our understanding of how populations, and the entire species, will react to climate change. Here, I quantified the spatial patterns of performance of several traits …

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 …

Benthic Microalgae Response To A Warming Climate And Shift In Foundational Vegetation Species In A Saltmarsh-Mangrove Ecotone, Gabriela Canas

UNF Graduate Theses and Dissertations

The ecotone in Northeast Florida is experiencing rapid change as mangroves begin to encroach northward into saltmarsh dominated coastal wetlands. This is especially prevalent within the boundaries of the Guana Tolomato Matanzas National Estuarine Research Reserve where studies are attempting to understand the consequences of more mangroves. Although we are beginning to understand some of the implications of this shift in dominant vegetation, the true effects and the accompanying sustained climatic warming effects on the resilience of wetland habitats and their associated communities remains unknown. Primary producers such as benthic microalgae (BMA) are important food sources in both mangrove and …

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 …

Steady Heartbeat: Field And Laboratory Studies Indicate Unexpected Resilience To High Temperatures For The Ribbed Mussel Geukensia Demissa, Ashlyn N. Smith Ms.

Honors College Theses

Salt marshes are important ecosystems found along the coast of Georgia. Salt marshes are hosts to diverse organisms that interact with each other to promote many ecosystem services, such as storm buffering and flooding, and absorption of excess nutrients. Among these diverse organisms is the ribbed mussel, Geukensia demissa. Mussels are a foundation species in this intertidal landscape, and without them the whole salt marsh would be negatively affected. The purpose of this investigation was to explore the thermal stress response of G. demissa to rising temperatures. Mussels were collected from three locations that were landlocked, close to a …

Sea Level Rise Vulnerability Analysis Of Mangrove Ecosystems Using Gis, Kayla Caldwell

HCNSO Student Theses and Dissertations

Climate change is accelerating beyond what is natural due to excessive emissions from human activities. The sea level has been rising for many years and is currently at a rate of 3.6 mm/yr. Mangroves are known to only keep pace with a sea level rate of less than 1.2 mm/yr. Mangroves are particularly vulnerable to rising sea levels if they are not able to keep pace through vertical sediment accretion or inland migration. To test the vulnerability of the south Florida mangrove ecosystems to sea level rise, this study analyzed changes in the mangrove forest coverage of the Oleta River …

Natural Variation And Evolutionary Responses To Climate Change Stressors In Marine Invertebrates, Joanna Sarah Griffiths

LSU Doctoral Dissertations

Our rapidly changing climate is putting many species at risk of extinction and there is an urgent need to understand how species will respond to these changes. In this dissertation, I evaluate how three species of marine invertebrates (corals, oysters, and copepods) respond to stressful conditions in their current environments and how plasticity and evolutionary adaptation could alter their response to future climate change stressors. I first employed a space for time study to elucidate population differences in the response of cold-water corals, Balanophyllia elegans, to future ocean acidification. I found evidence that upwelling history (natural low pH exposure) influences …

A Troop, A Raft, A Bed, Hanna Jane Guendel

Senior Projects Spring 2020

A Troop, a Raft, a Bed tells the interwoven fictional stories of three major animals (the mountain gorilla, the Adélie penguin, and the American eel) and four transitional animals (the white stork, the humpback whale, the common octopus, and the great white shark). The stories are told from the animals' perspectives, and are written with language that considers each animal's unique intelligence, mind, and behavior. These stories seek to communicate how animals around the world may be experiencing the various effects of climate change and global warming.

The Impact Of Climate Change On The Migration Phenology Of New England’S Anadromous River Herring And American Shad, Charles K. Cobb

Honors Theses

Anadromous fish play important roles in food webs and nutrient cycling in both aquatic and marine ecosystems. As a result of climate change however, anadromous fish’s migration timing has begun to change, with potentially deleterious consequences to both anadromous fish, and the species that depend on them. Western coastal US studies have linked earlier anadromous fish returns to warming marine temperatures and changes in river flow regimes, but the exact temperatures thresholds that anadromous fish respond to, and the relative importance of temperatures and river flows, remain somewhat unknown. Additionally, there has been relatively little research on anadromous fish phenology …

What If The Key To Climate Change Is Hiding Under The Sea?, Shira Feder

Capstones

“We know more about outer space than we do the ocean,” says Vicki Ferrini, a research scientist at Columbia University with over 20 ocean expeditions under her belt. And as the woman leading Seabed 2030, the charge to map the world’s oceans—which are 85% unexplored—she knows how vital this is to combat climate change and exactly how she’s going to do it. Read it here: https://medium.com/@shira.feder/what-if-the-key-to-climate-change-is-hiding-under-the-sea-4503565c33a2

The Effects Of Seasonal Variations, El Niño-Southern Oscillation, And Climate Change On The Tuna-Dolphin Association, Caitlynn Birch, Michael D. Scott, Zhi-Yong Yin, Lisa T. Ballance

Theses

Tuna and dolphins swim together in the waters of the eastern tropical Pacific, and this association has long benefitted tuna fishermen and intrigued scientists. Although the tuna-dolphin association is often referred to as a “mystery,” much is known about the association. Yellowfin tuna are primarily caught with spotted dolphins and, to a lesser extent, spinner dolphins; historically the spotted dolphin has borne the brunt of the bycatch mortality. The tuna-dolphin association is thought to be a product of the distinct oceanography of the ETP: a shallow mixed layer, a thick oxygen minimum zone, and warm surface waters. As the mixed …

Salt Marsh Health And Biomass Responses To A Changing Environment, Gwen Joelle Miller

Theses and Dissertations

Coastal salt marshes are important ecosystems not only for their aesthetic beauty but also for their ecosystem services that they provide including improving water quality, providing protection from storm surges and hurricanes, and carbon sequestration. With climate change, including drought, warmer temperatures and sea-level rise, these systems are going to be impacted. Understanding how salt marshes will respond, or already have responded, to climate change will help us be better prepared for the future. By scripting a model to project how marshes may migrate with sea-level rise, I discover that salt marshes within Beaufort and Jasper counties, South Carolina will …

Changing Oceanic Conditions On The Foraging Patterns Of Cassin’S Auklets, Ptychoramphus Aleuticuschanging Oceanic Conditions On The Foraging Patterns Of Cassin’S Auklets, Ptychoramphus Aleuticus, Clare Flynn

Pomona Senior Theses

Cassin’s auklet (Ptychoramphus aleuticus) reproductive success has been monitored on Southeast Farallon Island (SEFI) for the past 45 years. Their productivity has varied with oceanic conditions. The purpose of this study is to connect how oceanic conditions affect Cassin’s auklet foraging behaviors. The California Current System (CCS) can normally maintain high plankton productivity, and thus high seabird productivity, because of coastal upwelling. I hypothesized that lower upwelling and/or higher sea surface temperatures (SSTs) lead Cassin’s auklets to spend more time on intensive foraging behaviors such as flying and diving, and have less time to spend resting. I also hypothesized that …

Synergistic Effects Of Temperature And Salinity On The Gene Expression And Physiology Of Crassostrea Virginica, Hollis Jones

LSU Master's Theses

Crassostrea virginica, the eastern oyster, forms reefs that provide critical services and benefits to the resiliency of the surrounding ecosystem. Changes in environmental conditions, including salinity and temperature, can dramatically alter the services oysters provide by affecting their population dynamics. Climate warming may further exacerbate the effects of salinity changes as precipitation events increase in frequency, intensity, and duration. Temperature and salinity independently and synergistically influence gene expression and physiology in marine organisms. We used comparative transcriptomics, physiology, and a field assessment experiment to investigate whether Louisianan oyster are changing their phenotypes to cope with increased temperature and salinity …

Spatial Distribution And Stock-Recruitment Analysis Of The Atlantic Surfclam, Spisula Solidissima, In The Mid-Atlantic Bight And On Georges Bank, Jeremy Timbs

Master's Theses

Atlantic surfclams, Spisula solidissima, are long-lived bivalve molluscs with dispersive larval stages. Surfclam patchiness throughout the U.S. Exclusive Economic Zone (EEZ) has declined from the 1980’s to the present in all assessed regions (Delmarva, New Jersey, Long Island, Southern New England, and Georges Banks). Warming of Mid-Atlantic bottom waters is driving the surfclam stock into new habitat and extirpating the surfclams from nearshore areas. Based on a species distribution function model, the small surfclams appear to inhabit a greater area than the large market-size surfclams across the entire stock. The wider distribution of recent recruits relative to the fishable …

Effects Of Temperature On Growth And Molting In Blue Crabs (Callinectes Sapidus) And Lesser Blue Crabs (Callinectes Similis), Abigail Ann Kuhn

Master's Theses

Temperature can exert impacts on many processes in ectotherms. With global temperatures rising due to climate change, many ectothermic species may exhibit changes in growth rates and size at maturity, and these changes can have population-level effects. Predicting responses of species to climate change will require not only knowledge of thermal tolerance limits, but also effects of temperature change on growth rates and other life history parameters. For arthropods that exhibit discontinuous growth (i.e., molting), this includes both intermolt period and growth per molt. Previous laboratory and field experiments suggest that temperature affects both intermolt period (IMP) and growth per …

Combined Effects Of Dissolved Oxygen And Temperature On Aerobic Respiration And Respiratory Recovery Responses Of The Spioniform Polychaete, Streblospio Gynobranchiata, In Relation To Body Size, Alyssa Bennett

Master's Theses

Elevated surface temperatures exacerbate the threat of hypoxia within coastal ecosystems. These two primary stressors likely interact as they elicit opposing physiological responses from marine organisms. Metabolic depression is typically associated with hypoxia, while metabolic rates increase with temperature. Moreover, physiological effects of combined stressors may not be additive. In light of increasing pressures from hypoxia, elevated ocean temperatures, and other stressors within coastal regions, studies need to examine effects of multiple stressors on physiology of coastal organisms.

Mass-specific aerobic respiration (V_O2) was characterized as a proxy for metabolic cost of Streblospio gynobranchiata, at combined levels of …

Long-Term Changes In A Spatially Subsidized Insular Ecosystem In The Archipelago Of Bahía De Los Ángeles, Baja California, Mexico, Thais Fournier

Theses

Interactions between climate change and the processes that structure coastal communities are poorly understood.Long – term weather patterns that include extreme events (e.g., El Niño Southern Oscillation, or “ENSO”) allow us to test hypotheses of how changes in weather (e.g., precipitation) will influence communities over long time frames. One system that is particularly vulnerable to climate changes is the coastal ecotone, which occupies 8% of the earth’s surface. A large exchange of resources (spatial subsidies) link habitats across this ocean – land interface, often with dramatic consequences for the recipient systems. Spatial subsidies such as marine input influence …

Growth Of Orbicella Faveolata In La Parguera, Puerto Rico, Darren B. Marshall

HCNSO Student Theses and Dissertations

Reef-building corals are subject to high amounts of stress, including pollution and rising sea surface temperatures due to climate change. These factors can affect the ability of corals to produce their calcium carbonate skeletons. Evaluation of the effects of climate change may be facilitated by evaluation of records of coral skeletal growth over a long period of time. The aim of this study was to evaluate skeletal growth of the coral Orbicella faveolata in La Parguera, Puerto Rico over a 32-year period. For this, 14 Orbicella faveolata core samples were collected from corals at two reefs (1.2 km apart) in …

Linking Rising Pco2 And Temperature To The Larval Development, Physiology And Gene Expression Of The American Lobster (Homarus Americanus), Jesica Waller

Electronic Theses and Dissertations

Anthropogenic warming and ocean acidification are occurring as CO₂ continues to accumulate in the atmosphere (OA). Few studies have evaluated the joint effects of elevated temperature and partial pressure of CO₂ (pCO₂)on marine organisms. In this study we investigated the interactive effects of Intergovernmental Panel on Climate Change (IPCC) predicted temperature and pCO₂ for the end of the 21st century on key aspects of larval development of the American lobster, Homarus americanus, an otherwise well-studied, iconic, and commercially prominent species in the northeastern United States and Atlantic Canada. Our experiments showed …