Marine Biology Commons^™

Toxicity And Effectiveness Of A New Two-Part Underwater Adhesive For Coral Restoration, Matthew Rojano

All HCAS Student Capstones, Theses, and Dissertations

As coral cover decreases around the world due to disease, bleaching events, and anthropogenic effects, coral restoration projects become increasingly important. A crucial part of many coral restoration projects is the attachment of corals to substrates in nurseries or reef substrates during outplanting. The effective anchoring of transplants is a critical phase in coral restoration and the adhesive used for attachment is crucial. Commonly used adhesives have several drawbacks: there are long mixing times, low substrate adhesion, and lengthy hardening times. To address these issues and provide an effective alternative for coral restoration activities, a new two-part Mixed Adhesive was …

Using Deep Learning And Uav Imagery To Detect Elkhorn Coral In St. Croix’S East End Marine Park, Samuel Wyatt

Master's Theses

Elkhorn coral, or Acropora palmata, is an important reef building species that promotes species abundance and other ecological services to the communities in the US Virgin Islands. We captured high resolution imagery of a reef in St. Croix’s East End Marine Park using a Wingtra One UAV. We then used deep learning techniques to detect individual coral colonies. We compared two deep learning models, FasterRCNN and MaskRCNN, and found that the models achieved accuracy shores up to 0.78. These scores improved when examining only larger corals in shallow waters. The model was able to both detect Elkhorn coral and …

Optimization Of Grow-Out Of Bouldering Coral Microfragments: Land Vs. Offshore Nursery, Ashlee A. Steinberg

All HCAS Student Capstones, Theses, and Dissertations

Corals along the Florida Reef Tract and the wider Caribbean have been declining for decades. Low densities of adult colonies hinder the ability of corals to replenish themselves through sexual reproduction, thus reef managers are focusing on restoration actions that increase coral biomass. Microfragmentation is a way to quickly increase the biomass of bouldering corals by cutting the coral into small pieces which forces the coral to allocate its resources away from reproduction and back into growth, increasing its growth rate. This study assessed the optimal location for grow-out (land vs. offshore nursery) and its synergy with size of fragment …

The Roles Of Host Species, Geographic Scale And Environmental Stressors In Shaping The Composition Of Coral Microbiomes, Alicia Marie Riegel Parker

LSU Doctoral Dissertations

Reef-building corals are long-lived and may take many centuries to adapt, making them especially susceptible to climate change. However, corals host microbial symbionts that can change quickly, potentially speeding acclimation. My dissertation aimed to determine the degree of coevolution and flexibility between corals and their microbiomes among hosts, across space, and in response to stress.

Microbial communities are usually surveyed by sequencing the 16S rRNA gene, however the PCR primers used also amplify coral DNA, thereby limiting prokaryotic read coverage. To mitigate this contamination, I designed a peptide nucleic acid clamp that increased the recovery of bacterial reads by 2-11x …

Reproductive Effort Of Montastraea Cavernosa Across Depth In The Context Of Both Climate Change Refugia And Emergent Disease, Jeanne Bloomberg

LSU Master's Theses

As coral populations on shallow reefs decline globally, mesophotic coral ecosystems (MCE) have been suggested as potential coral refugia in the face of climate changes, leading to the development of a comprehensive deep reef refugia hypothesis. The current study assesses the climate and disease refuge potential of MCEs in the U.S. Virgin Islands (USVI) for the gonochoric, broadcast-spawning species Montastraea cavernosa. Polyp, population, and total habitat fecundities were estimated across the species’ depth range, and changes to population oocyte production over time due to recent ecosystem disturbances were considered. The number of gonads producing oocytes in each polyp and oocyte …

Desperate Coral Larvae? Behavioral Responses To Settlement Cues In Aging Agaricia Agaricites Larvae, Helena Sasha Fulmore

HCNSO Student Theses and Dissertations

The global stressors of ocean warming and acidification, as well as local stressors such as eutrophication, overfishing, and coastal construction, have all contributed to the severe decline in coral populations worldwide. Recovery of coral reefs depends partly on recruitment, which relies on the response of larvae to settlement cues indicative of habitat quality; however, it remains unclear whether recruitment in disturbed areas will be compromised. Specifically, as reefs become more disturbed and dominated by macroalgae, it is important to understand larval behavior in response to changes in habitat quality. In this study, we first assessed the settlement success of newly …

Optimizing Lighting Regimes For Rearing Orbicella Faveolata And Acropora Cervicornis Recruits, Paul D. Kreh

HCNSO Student Theses and Dissertations

Coral reef decline worldwide has led to the need for coral reef restoration. The use of sexual reproduction in restoration efforts is required to increase genetic diversity; however, the procedures for rearing newly-settled coral recruits ex situ still need to be optimized. Recruits initially require low light irradiance, but it is unclear when higher irradiances are required to enhance growth and survival. Here we determined the optimal light regime for Orbicella faveolata and Acropora cervicornis recruits. Newly settled recruits were reared under treatments with varied rates of increasing irradiance (after reaching 5 weeks of age), and their survival, growth, and …

Outplanted Acropora Cervicornis Enhances The Fish Assemblages Of Southeast Florida, Ellen Dignon Goldenberg

HCNSO Student Theses and Dissertations

Acropora cervicornis, commonly known as the staghorn coral has historically been a major contributor to reef structural complexity, providing habitat for many functionally important fish species throughout Florida and the Caribbean. Unfortunately, due to disease, bleaching, and local anthropogenic stressors, A. cervicornis populations have suffered drastic declines that have negatively impacted associated reef fish populations. In order to promote recovery, A. cervicornis fragments can be cultivated in nurseries and outplanted back onto reefs. This practice can effectively increase A. cervicornis abundance, but the long-term effects on local fish assemblages, and specifically functionally important grazing fishes, has not been assessed. …

Effects Of Deposited Sediment And Turbidity On Survival And Growth Of Orbicella Faveolata Recruits, Morgan Stephenson

HCNSO Student Theses and Dissertations

Corals are frequently exposed to elevated turbidity and deposited sediment caused from coastal construction, dredging, and/or beach renourishment. This study addresses the effects of turbidity and deposited sediment on the survival and growth of newly settled and 6-week-old Orbicella faveolata recruits and disentangles the effects of turbidity and deposited sediment. We conducted two experiments in which newly settled coral recruits were reared in one of ten different turbidity and deposited sediment treatments for five weeks (0 NTU/ 0 mg cm^-2, 3.4 NTU/ 0 mg cm^-2, 8.2 NTU/ 0 mg cm^-2, 16 NTU/ 0 mg …

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 …

Optimization Of Light Irradiance During The Early Life Of Sexually-Produced Porites Astreoides And Agaricia Agaricites Recruits, Nicholas J. Mcmahon

HCNSO Student Theses and Dissertations

Current solutions of coral restoration rely mainly on fragmentation. Though a reliable technique, this asexual form of reproduction does not benefit the genetic diversity of the coral reef. With many global and local stressors threatening corals’ existence, the resiliency of corals to future ocean conditions depends highly on sexual reproduction to produce new genotypes. New technology allows coral spawning/larval release, larval settlement and rearing to be carried out in an aquarium system. Many of the techniques necessary to maintain coral recruits are well-established, however the effects of light intensity remain to be studied for these early life stages. Newly …

Spatiotemporal Change In The Benthic Community Of Southeast Florida, Nicholas P. Jones

HCNSO Student Theses and Dissertations

High-latitude reefs have been postulated as refugia, centers for resilience or the first areas to undergo re-organization under climate change. The Southeast Florida Reef Tract (SEFRT) is a high-latitude reef system (>25 °N) running parallel to the highly urbanized coastline of southeast Florida. With a benthic community comprised of a mixture of coral reef associated assemblages, the SEFRT is towards the northern limit of stony coral cover due to temperature constraints. This study analyzed spatial variations in benthic cover, spatiotemporal changes in the benthic community and the impact of spatial and temporal fluctuations in temperature on benthic cover on …

Effects Of Ocean Warming, Sedimentation, And Parental Genotype On The Post-Settlement Survival And Growth Of Acropora Cervicornis Recruits, Jena Robbins

HCNSO Student Theses and Dissertations

Ocean warming and increased sedimentation from coastal activities are major threats to coral persistence. This study assessed the effects of increased temperature and sedimentation on the survival and growth of Acropora cervicornisrecruits. The potential for adults from different regions and genotypes to confer their offspring with higher or lower tolerance to heat and/or sediment was also determined. Gametes were collected and brought to the laboratory for cross fertilization of different genotypes within the regions collected. Larval rearing and settlement were then performed in the laboratory. Newly settled recruits were reared at 29 and 31°C (current summer temperature for August …

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 …

Patterns In Caribbean Coral Spawning, Anna C. Jordan

HCNSO Student Theses and Dissertations

Most corals worldwide are broadcast spawners that rely on synchronous gamete release for successful fertilization. Spawning synchrony may also decrease the probability of heterospecific fertilization that may produce maladaptive hybrids. Despite the importance of reproductive timing, researchers have only recently begun to collect spawning data across coral species in the Caribbean, but these data remain to be analyzed. This study investigates interannual, seasonal, and environmental patterns that may influence Caribbean scleractinian spawning times. The number of spawning observations varies widely among location and species. Most spawning observations were collected in Florida, Curaçao, and Flower Garden Banks National Marine Sanctuary. Acropora …

A Phylogeographic Analysis Of Black Coral (Antipatharia) On Artificial And Natural Reefs In The Northwestern Gulf Of Mexico, Heather Otte

Theses and Dissertations

NOAA's Islands in the Stream concept (IitS) of designating networks of marine protected areas as refugia in the Gulf of Mexico depends on genetic connectivity. Isolated habitats like those proposed by the IitS occur naturally off the Texas coast where hard-bottom structures protrude from mudflats, offering a small-scale study of the IitS feasibility. Two sequences, mitochondrial 16S ribosomal RNA and nuclear internal transcribed spacer, were used to build haplotype networks of Antipatharians (Anthozoa: Hexacorallia), corals with planktonic larvae that can act as a proxy for connectivity of other organisms. Two species showed no significant genetic differentiation or pattern of genetic …

"The Effects Of Ocean Warming And Sedimentation On The Survival And Growth Of Acropora Cervicornis" And "Differential Prevalence Of Chimerism During Embryogenesis In Corals", Hayley De Marchis

HCNSO Student Theses and Dissertations

Part I:

Coral reefs are essential to coastal economies, protecting coastlines from storms, and harboring high biodiversity. However, reefs are declining due to local anthropogenic stressors and ocean warming. Sedimentation, a local stressor, aggravates the impacts of warming on corals and hinders their survival and growth. Therefore, it is important to investigate whether sedimentation and temperature have a synergistic effect on vulnerable coral species, especially during earlier stages of development. To quantify these effects, survival and growth of newly settled Acropora cervicornis corals were measured at two temperatures (29 and 31°C, representing current and predicted for 2050 Summer temperatures) and …

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 …

Bacterial Communities Associated With Healthy And Diseased Acropora Cervicornis (Staghorn Coral) Using High-Throughput Sequencing, Charles Walton

HCNSO Student Theses and Dissertations

Coral diseases were first noted in the 1960s and 1970s and have had major impacts globally on coral reef community structures. In the Caribbean, a major outbreak of white band disease has been considered responsible for the drastic decline of Caribbean Acroporids since the 1970s. In addition to white band disease, another more recently described condition known as rapid tissue loss (RTL) has had major impacts on Acropora cervicornis populations, specifically offshore Broward County Southeast Florida. While these diseases have contributed to the population decline, determining their etiologies has been elusive.

Coral diseases have been characterized by shifts in their …

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, …

Resurgence Of Acropora Corals On Mid Shelf Patch Reefs, Southwater Caye Marine Reserve, Central Belize, Jillian J. Keefer

Undergraduate Honors Thesis Projects

Acropora cervicornis (staghorn) and Acropora palmata (elkhorn) are ecologically important corals that grow quickly and provide topography and refuges for fish and invertebrates. Historically, Acropora was the most abundant coral in shallow patch reef zones in the Caribbean. During the 1980s, white band disease eliminated most Acropora causing a loss in rugosity and an increase of macroalgae on many reefs. Although Acropora remains rare throughout most of the Caribbean, this study documents its partial comeback and possible limiting factors in Southwater Caye Marine Reserve (SWCMR), Central Belize. Patch reefs in the reserve averaged 19% live coral cover with A. palmata …

Modeling Of Epizootics On Four Genera Of Arabian Gulf Corals, John Alexander Kluge

HCNSO Student Theses and Dissertations

Coral colonies, from a reef near Abu Dhabi, United Arab Emirates (UAE), were counted and assessed for condition using photo-transects. An epidemic model, used to track how a communicable disease moves through a population, was constructed to help predict the future condition of this coral reef. In situ data from a disease outbreak that occurred in September 2011 provided a baseline for the model. Coral Populations of Porites, Platygyra, Acropora and Dipsastrea were modelled using condition categories that included Healthy, Black Band Disease Infected, Cyanobacteria Infected, Recovered, Recruits or Dead. Results from the modelling indicate that populations of Platygyra and …