Marine Biology Commons^™

Sympatric Otariids Increase Trophic Segregation In Response To Warming Ocean Conditions In Peruvian Humboldt Current System, Susana Cardenas-Alayza, Michael Adkesson, Mickie Rae Edwards, Amy C. Hirons, Dimitri Gutierrez, Yann Tremblay

Marine & Environmental Sciences Faculty Articles

Determining trophic habits of predator communities is essential to measure interspecific interactions and response to environmental fluctuations. South American fur seals, Arctocephalus australis (SAFS) and sea lions Otaria byronia (SASL), coexist along the coasts of Peru. Recently, ocean warming events (2014–2017) that can decrease and impoverish prey biomass have occurred in the Peruvian Humboldt Current System. In this context, our aim was to assess the effect of warming events on long-term inter- and intra-specific niche segregation. We collected whisker from SAFS (55 females and 21 males) and SASL (14 females and 22 males) in Punta San Juan, Peru. We used …

Benthic Community Dynamics And Stony Coral Demographics In Florida In Relation To Acute Disturbances And Chronic Pressures, Nicholas P. Jones

All HCAS Student Capstones, Theses, and Dissertations

The persistence of coral reef communities is threatened by a suite of pressures operating at varying spatial and temporal scales. In general, acute disturbances (short term stochastic events such as marine heatwaves or hurricanes) and chronic pressures, such as ocean warming, have caused the most significant changes to stony coral assemblages (order Scleractinia) and continue to impair recovery potential. Additionally, many coral reefs are subject to local chronic anthropogenic pressures resulting in poor water quality or sedimentation, which further impact stony corals and shape benthic community structure, particularly near urbanized coastlines. For the viability of communities on coral reefs, a …

Relationships Between Mercury And Trophic Level In Nine Coastal Pelagic Fishes Off Southeastern Florida, Emily Akins

All HCAS Student Capstones, Theses, and Dissertations

State and federal agencies have issued consumption advisories for various fish species for many years, including in Florida. Upper-level predatory fish, such as tunas and mackerels, are especially popular with anglers but are susceptible to high levels of mercury through bioaccumulation and biomagnification. This study used two data sets over two time periods, 2010-2012 and 2020-2021, to compare mercury and trophic level relationships in nine coastal pelagic fishes is Southeastern Florida. As these species are popular in recreational fisheries, charter and tournament catches formed the base of the samples that were analyzed for total mercury along with carbon and nitrogen …

The Impacts Of Egg Chamber Depth And Clutch Size On Hatching And Emergence Success For Loggerhead Sea Turtles (Caretta Caretta) On South Florida Beaches, Curtis J. Slagle

All HCAS Student Capstones, Theses, and Dissertations

All seven extant species of sea turtle are either threatened or endangered due to a multitude of anthropogenic and environmental factors. There has been strong emphasis on reversing this trend through various conservation efforts at multiple life stages, yet, if hatchlings never develop within the nest or are unable to escape the egg chamber, then these efforts are futile. Understanding how they develop, the factors impacting this development and their ability to emerge from the egg chamber are essential for sea turtle conservation. Important factors that may impact hatching success (HS) and emergence success (ES) are egg chamber depth (ECD) …

Impacts On Fast-Start Performance: How Do Group Size And Habitat Degradation Alter The Escape Behavior Of A Schooling Coral Reef Fish?, Monica D. Bacchus

All HCAS Student Capstones, Theses, and Dissertations

Escaping predation is essential for species survival, but prey must effectively match their response to the perceived threat imposed by a predator. Fish evaluate their surroundings using several sensory stimuli, including olfactory, visual, auditory, and mechanical cues. A range of taxa use the fast-start response to evade predators, including fishes, sharks, and larval amphibians. While the fast-start response (rapid bursts of swimming) is extensively studied in solitary fishes, the factors that mediate the collective escape response in schools of fish have historically been investigated far less. To address this knowledge gap, the collective escape behavior and individual escape performance of …

Preliminary Trials To Assess Bycatch Reduction Potential For Deep-Set Pelagic Longline Gear In The U.S. Atlantic Fishery, Sean T. Wilms

All HCAS Student Capstones, Theses, and Dissertations

The U.S. Atlantic pelagic longline fishery uses a shallow-set gear configuration to primarily target swordfish (Xiphias gladius) and yellowfin tuna (Thunnus albacares) at depths of around 75-100 m. However, the fishery has been the subject of several bycatch reduction regulations due to incidental catch and mortality of sea turtles, seabirds, marine mammals, and istiophorid billfishes. An alternative deep-set technique, used by the U.S. pelagic longline fishery based in Hawaii and several non-U.S. fleets, differs from the shallow-set pelagic longline gear by deploying a greater length of mainline per unit distance using a mechanical line shooter, resulting in a deeper catenary …

Spatial Variation Of False Map Turtle (Graptemys Pseudogeographica) Bacterial Microbiota In The Lower Missouri River, United States, Joseph D. Madison, Madeline M. Butterfield, Drew R. Davis, Jacob L. Kerby

School of Earth, Environmental, & Marine Sciences Faculty Publications

Turtle populations around the world are continually confronted with changing environments that affect their ecology and conservation status. Among freshwater turtles, population dynamics are thought to be mediated by complex yet often cryptic causes. One recent direction of focus in addressing these causes is the turtle-associated microbiota. In turtles, the gut- associated microbiota is of exceptional interest due to its continual association with host species under changing conditions. Diet-based fluctuations and changes in microbial diversity may correspond to varying external environments at both the individual and population level. Environmental responses are of particular interest due to the anthropogenic changes that …

Determination Of Atlantic Shortfin Mako Shark (Isurus Oxyrinchus) Population Genetic Structure And Comparison Of Mitogenomic Markers, Marissa Mehlrose

All HCAS Student Capstones, Theses, and Dissertations

This study provides the first genomics-level, population structure and genetic diversity assessment of the shortfin mako (Isurus oxyrinchus) shark. The assessments were based on mitogenome sequences from makos distributed throughout the Atlantic Ocean, with Pacific mako mitogenomes used as a comparative outgroup. In addition to complete mitogenome-based analyses, I assessed individual mitochondrial coding gene and non-coding (Control Region) sequences for their comparative resolution properties as markers for revealing matrilineal population structure and genetic diversity. Sequencing of 125 makos in the western and eastern Atlantic across northern and southern hemispheres yielded 92 complete mitogenomes (16,698-16,702 bp) and 33 partial …

Variability In The Vertical Distributions Of Mesopelagic Fishes: Effect Of Body Size, Season, And Sampling Strategy On The Characterization Of Diel Vertical Migration, Brandon A. Brule

All HCAS Student Capstones, Theses, and Dissertations

Diel‌ ‌vertical‌ ‌migration,‌ or DVM, ‌is‌ ‌defined‌ ‌as‌ ‌the‌ large-scale changes in the depth distribution of a species or an assemblage with respect to the time of day. DVM‌ ‌is‌ ‌the‌ ‌largest‌ ‌active movement‌ ‌of‌ ‌biomass‌ on Earth, driven by the need for food balanced against predator avoidance and metabolic constraints. Asynchronous‌ ‌diel‌ ‌vertical‌ ‌migration, in the context of this study,‌ ‌refers‌ ‌to‌ the phenomenon where only a portion of a species’ population migrates upwards at night while others remain at depth. ‌The‌ extent that factors such as temporal variation, ontogenic variation, and methodological variation explain this migratory pattern is …

A Genomic Investigation Of Divergence Between Tuna Species, Pavel V. Dimens

Dissertations

Effective management and conservation of marine pelagic fishes is heavily dependent on a robust understanding of their population structure, their evolutionary history, and the delineation of appropriate management units. The Yellowfin tuna (Thunnus albacares) and the Blackfin tuna (Thunnus atlanticus) are two exploited epipelagic marine species with overlapping ranges in the tropical and sub-tropical Atlantic Ocean. This work analyzed genome-wide genetic variation of both species in the Atlantic basin to investigate the occurrence of population subdivision and adaptive variation. A de novo assembly of the Blackfin tuna genome was generated using Illumina paired-end sequencing data and …

Evaluating The Impact Of Intersecting Research And Outreach Marine Science Programs On Elementary And Undergraduate Students, Randi J. Sims

All Theses

Climate change is one of the most destructive forces our ocean is currently experiencing. Despite this, many students are not taught the basics of climate change science and ocean literacy in public school systems. My work seeks to combat these deficits through educational experiences in marine science for undergraduate and local elementary students through three studies incorporating marine-science based research and outreach. (1) Through undergraduate marine science research and outreach, students enrolled for long durations or with positive mentorship increased their conceptual understanding of marine science concepts, altered their attitudes towards climate change and science, and were more likely to …

The Effect Of Post-Harvest Storage Temperature And Drying Method On The Pathogen Load Of Edible Kelp, Jessica Vorse

All Theses And Dissertations

The American seaweed industry is growing, primarily into the edible sector, and as a result, more seaweed products are available for human consumption. It is necessary to evaluate the safety of industry’s current post-harvest storage and processing methods to ensure the risk of foodborne pathogens on edible seaweed remains low. We evaluated the pathogen load of edible kelp post-harvest under three different storage temperatures (4˚C, 10˚C, 20˚C) and two different drying methods (air- and freeze-drying). The focal pathogens for this project were six of the most common food-associated pathogens in the United States: Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, pathogenic …

Defining The Current Distribution Of The Imperiled Black-Spotted Newt Across South Texas, Usa, Padraic S. Robinson, Drew R. Davis, Sean M. Collins, Richard Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Black-spotted Newt (Notophthalmus meridionalis) is a chronically understudied salamander species, with many aspects of its natural history, ecology, and distribution poorly known. Previous studies using traditional methodologies have had limited success documenting N. meridionalis on the landscape, detecting individuals at 6% (7 of 114) and 1% (2 of 221) of sites surveyed. A novel environmental DNA (eDNA) assay was designed and implemented with the goals of assessing the current distribution of N. meridionalis across south Texas, USA, and better understanding the conditions for positive eDNA detections. We conducted eDNA sampling and traditional surveys at 80 sites throughout …

Effects Of Shoreline Development And Freshwater Discharge On Nekton Assemblage And Trophic Structure In A Northern Gulf Of Mexico Estuary, Glenn Schumacher

Master's Theses

Coastal salt marshes support a diversity of nekton and facilitate critical ecosystem functions but are threatened by shoreline development and climate change. Therefore, coastal ecosystem managers have begun incentivizing the use of living shorelines (LS), erosion control structures incorporating native plantings, to mitigate ecological consequences of marsh loss. However, post-restoration climate changes may shift habitat templates and negate positive effects of ecosystem restoration. I evaluated the ecology nekton along LS, natural marshes, hardened shorelines and greyed shorelines within Biloxi Bay, Mississippi, during a high freshwater discharge (HFD) period by comparing nekton assemblage (using species richness, Shannon-Wiener diversity, and relative abundance), …

Are Sharks Attracted To Caged Fish And Associated Infrastructure?, Charlie Huveneers, Yuri Niella, Michael Drew, Joshua Dennis, Thomas M. Clarke, Alison Wright, Simon Bryars, Matias Braccini, Chris Dowling, Stephen J. Newman, Paul Butcher, Scott Dalton

Fisheries Research Articles

Huveneers Charlie, Niella Yuri, Drew Michael, Dennis Joshua, Clarke Thomas M., Wright Alison, Bryars Simon, Braccini Matias, Dowling Chris, Newman Stephen J., Butcher Paul, Dalton Scott (2022) Are sharks attracted to caged fish and associated infrastructure?. Marine and Freshwater Research 73, 1404-1410.

https://doi.org/10.1071/MF22039

Further Flattening Of A Degraded, Turbid Reef System Following A Severe Coral Bleaching Event, Andrew G. Bauman, Fraser A. Januchowski-Hartley, Aaron Teo, Peter A. Todd

Marine & Environmental Sciences Faculty Articles

Increasing incidence of severe coral bleaching events caused by climate change is contributing to extensive coral losses, shifts in species composition and widespread declines in the physical structure of coral reef ecosystems. With these ongoing changes to coral communities and the concomitant flattening of reef structural complexity, understanding the links between coral composition and structural complexity in maintaining ecosystem functions and processes is of critical importance. Here, we document the impacts of the 2016 global-scale coral bleaching event on seven coral reefs in Singapore; a heavily degraded, turbid reef system. Using a combination of field-based surveys, we examined changes in …

Effect Of Ultraviolet Light Treatment On Microbiological Safety And Quality Of Fresh Produce: An Overview, Veerachandra K. Yemmireddy, Achyut Adhikari, Juan Moreira

School of Earth, Environmental, & Marine Sciences Faculty Publications

Fresh and fresh-cut fruits and vegetables have been associated in several foodborne illness outbreaks. Although investigations from those outbreaks reported that the contamination with pathogenic microorganisms may occur at any point in the farm to fork continuum, effective control strategies are still being widely investigated. In that direction, the concept of hurdle technology involving a sequence of different interventions have been widely explored. Among those interventions, ultraviolet (UV) light alone or in combination with other treatments such as use of organic acids or sanitizer solutions, has found to be a promising approach to maintain the microbiological safety and quality of …

Evaluation Of Nearshore Carbonate Chemistry Within Major Navigational Inlets Of The Kristin Jacobs Coral Reef Ecosystem Conservation Area, Harrison Davis

All HCAS Student Capstones, Theses, and Dissertations

The absorption of atmospheric carbon dioxide (CO₂) by ocean surface water is causing ocean acidification (OA), a process by which the reaction between water and CO₂ changes ocean carbonate chemistry. Predictions of OA trajectories modeled by the Intergovernmental Panel on Climate Change (IPCC) are based on open ocean trends and may not accurately predict changes to variable nearshore ecosystems. The dynamic nature of nearshore ocean chemistry, and prevalence of OA vulnerable species within these ecosystems complicates the process of making accurate OA impact predictions within the coastal zone. Florida’s coral reef is a nearshore ecosystem vulnerable to …

Abundance, Site-Fidelity, And Association Patterns Of Coastal Bottlenose Dolphins (Tursiops Truncatus) Off Southeast Florida, Graysen D. Boehning

All HCAS Student Capstones, Theses, and Dissertations

The coastal bottlenose dolphin is well studied throughout its natural range, however, most of the study areas comprised wide, well-protected habitats such as bays and estuaries, and not narrow coastal sandbanks. This study identifies a residential group of coastal bottlenose dolphins utilizing the narrow sandbanks within the Northwestern Atlantic waters off the coast of Palm Beach County, Florida, USA. From 2014-2020, 313 boat surveys were conducted, and 585 individual dolphins were identified using photo-ID. Twenty-four animals were determined to be full-time and 66 animals were determined to be part-time residents. Full-time and part-time residents associated in three social tribes, with …

Consequences Of Gulf Of Mexico Estuarine Tropical Cyclone Disturbance Regimes For Fish Assemblage Dynamics Conditionally Depend On Life-History Traits And Niche Characteristics, Stephen Edward Potts

LSU Doctoral Dissertations

Tropical cyclones (TC) are intense, localized disturbances that can potentially cause extensive damage to ecosystems. This dissertation is motivated by a need for interdisciplinary study of TC-ecosystem dynamics with applications to ecology, geography, and analytical methodology. I explore concept linkages between TC dynamics and ecosystems to characterize TC-ecosystem relationships as ecological disturbance regimes. This dissertation tests hypotheses and relationships of TC effects on estuarine fish assemblages in the north-western Gulf of Mexico. I explore concepts in TC-ecosystem relationships to link biotic dynamics with physical disturbance.

In Chapter 2, I compared spatial performance of generalized linear models (GLMs) and generalized additive …