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Abstracts of Poster Presentations

WARM-WATER TOLERANCE OF THE DEEP-WATER GORGONIAN CORAL ADELOGORGIA PHYLLOSCLERA WITH IMPLICATIONS FROM THE 2015-2016 EL NIÑO EVENT

Gugliotti, E. (GPMB, The University of Charleston, SC), DeLorenzo, M. (NOAA), and Etnoyer, P. (NOAA)

Warm-water anomalies associated with El Niño-Southern Oscillation (ENSO) events have had major impacts on the health of marine ecosystems, particularly coral reefs. While such thermal anomalies are more pronounced on shallow-water coral reefs, few studies have examined their occurrence and impacts on adjacent deep-water coral reefs. Deep-water corals are stenothermal organisms and are thus particularly vulnerable to exposures to high temperatures. This study assessed the upper thermal limits of Adelogorgia phyllosclera, a deep-water gorgonian coral found at depths between 9-595 m off the California coast. For this purpose, several colonies of A. phyllosclera were collected at depths between 50-100 m using a remotely operated vehicle (ROV) and maintained alive in aquaria. Experiments exposed fragments from the colonies to temperatures ranging from 5-25°C over 7 d in the laboratory. The health scores of coral fragments exposed to 25°C were significantly different (p < 0.05) than those kept at 5°C and 10°C. Historical temperature records from 1949-2016 indicate that the average temperatures experienced off the California Coast from 20-100 m are between 15°C (±0.98°C) and 10°C (±0.44°C). The historical records also indicate that the 2015-2016 ENSO event involved particularly strong temperature anomalies (temperatures exceeding two standard deviations) at depths between 20-­100 m where A. phyllosclerapopulations can occur. These preliminary results represent the first study to understand the effects of warming temperatures on deep-water corals in Southern California, and are imperative in developing management strategies to conserve these crucial, yet vulnerable species.


POTENTIAL SKIN-ASSOCIATED CHEMICAL CUES FOR CYPRID SETTLEMENT OF THE EPIZOOTIC CETACEAN TASSEL BARNACLE, XENOBALANUS GLOBICIPITUS

Hall, A (GPMB, The University of Charleston, SC)

The pseudo-stalked tassel barnacle, Xenobalanus glopicipitus, is an obligate ceatacean epibiont found predominantly on the fins of dolphins and small whales in tropical and subtropical waters around the world. The life cycle and behavior of this species is relatively unknown as they are only found on cetacean hosts and are uncommon, making them difficult to study. This research will explore the potential chemical cues associated with cetacean skin that may induce or inhibit settlement of exploring cyprids. Frozen dolphin skin will be cryo-homogenized and both protein and lipid fractions will be extracted and resuspended in separate clear gel casting tubes. These gel lollipops will then be used for settlement assays performed in a large flume using X. glopicipitus larvae reared in lab from eggs collected from gravid adults. Using tandem liquid chromatography mass spectrometry, the lipidomes of various cetaceans will be examined and compared by body location, demographic, and presence of X. globicipitis. The potential influence of microbial cues will be examined by swabbing host and non-host wild dolphins and characterizing the microbe community using high throughput DNA sequencing. Additional swabs will be used to inoculate sterile tanks containing gel pops and settlement will again be assayed to determine any inhibitory or excitatory effects on cyprid attachment.


IDENTIFYING SOURCES OF MICROPLASTIC TIRE WEAR PARTICLES IN CHARLESTON

Kell, SE (GPMB, The University of Charleston, SC) and Weinstein, JE (The Citadel)

Plastic is ubiquitous in the environment today and can be found in fresh and marine waters worldwide.  It is estimated that if current production rates continue by 2050, there will be more plastic in the ocean than fish.  Recent investigations have found the majority of plastic debris in the pelagic ocean are microplastics (<5 mm diameter).  Microplastics can easily be ingested by a wide range of marine species and can serve as both a source of contaminants and act as a vector for contaminants sorbed to them from the environment.  Studies conducted within the Charleston Harbor watershed have found a high abundance of black polybutadiene (synthetic rubber) fragments believed to be tire wear particles based on Fourier Transform Infrared Spectroscopy analysis.  Tire wear particles are generated by the interaction of tires with road surfaces.  The objective of this study is to determine the pathways that tire wear particles enter Charleston Harbor by sampling nonpoint stormwater outfalls, stormwater detention ponds and adjacent receiving tidal waterbodies.  Limited data exists on tire wear particles in the marine environment and the results of this study will help fill in existing knowledge gaps as well as help make better informed stormwater management decisions.


ASSESSMENT OF ATLANTIC HORSESHOE CRAB (LIMULUS POLYPHEMUS) NESTING BEACHES AND EGG DENSITIES AVAILABLE TO FEDERALLY THREATENED SHOREBIRDS IN THE ACE BASIN, SOUTH CAROLINA

Kimelblatt, A (GPMB, The University of Charleston, SC), Kendrick, M (SCDNR), Podolsky, R (College of Charleston), Sanger, D (SCDNR), Brunson, J (SCDNR) and Kingsley-Smith, PR (SCDNR)

The Atlantic horseshoe crab, Limulus polyphemus, has played important economic and ecological roles in South Carolina, both historically and presently. The species was harvested as bait for whelk and eel fisheries up until 1991, and is currently harvested by the biomedical industry to be bled in order to derive Limulus amoebocyte lysate (LAL), which acts as a sterilization agent for medical instruments and pharmaceutical drugs. Also important is the ecological role of L. polyphemus as a food source for migratory shorebirds, including the federally threatened red knot (Calidris canutus rufa), which annually consume horseshoe crab eggs as a critical nutritional resource at migratory staging sites. Each spring, horseshoe crabs arrive at beaches to spawn around the new and full moons during high tide. Though their mass spawning events are iconic, little is known about spatial or temporal patterns in their use of shorelines for spawning. This project aims to identify preferential spawning habitat, establish a relationship between productive spawning beaches and egg availability, and assess temporal patterns among crabs, eggs, and migratory shorebirds. To determine preferred nesting shoreline characteristics, spawning surveys were conducted along marked transects around the new and full moons from April 2017 to June 2017 along 14 shorelines in the ACE Basin that varied in orientation and accretional/erosional status. Abundances of crabs ranged from zero to 1,390 per transect; data analyses are ongoing. Documenting nesting and egg density hotspots will facilitate direct management and conservation of high priority habitat that is crucial to both horseshoe crabs and migratory shorebirds.


THE REPRODUCTIVE BIOLOGY AND ECOLOGICAL IMPACTS OF AN INVASIVE CRAB, PETROLISTHES ARMATUS

Popp, TE (GPMB, The University of Charleston, SC) and Wilber, D (College of Charleston)

Although the invasive green porcelain crab, Petrolisthes armatus, has been established on intertidal oyster reefs in South Carolina for decades, its life history characteristics and potential ecological impacts are poorly understood. To investigate a population in the invasive range, I have been collecting intertidal crabs bi-weekly and noting ovigery status and size over the reproductive season. I will also be conducting two laboratory experiments. In the first experiment, I am determining the length of time females go between clutches in a reproductive season, by holding both male and female P. armatus in tanks and following individual females, noting their ovigery status over time.  Female size is a factor in this experiment because it is not known if crab size affects frequency of brood production in this species.  A second experiment will investigate how this crab affects oyster behavior.  This crab species is highly abundant on oyster reefs, occurring at densities as high as thousands of crabs per square meter.  I will test how varying densities of crabs may potentially affect gape width in oysters. Oysters protect themselves from predation, irritation, and disease by closing their valves. High crab densities may reduce the amount of time an oyster opens its shells, thus impacting its ability to feed, grow, and survive.  The goal of this study is to determine whether oysters shut their shells longer as crab densities increase.  Together, these experiments will help us better understand the role and impact of this non-native species in its invasive range.


STRUCTURE-FORMING DEEP-SEA CORAL DIVERSITY ON THE WEST FLORIDA SHELF AND HABITAT SUITABILITY MODELS FOR LOPHELIA AND LEIOPATHES

Proux, Z (GPMB, The University of Charleston, SC), Sautter, L (College of Charleston), Etnoyer, P (NOAA), Ballenger, J (SCDNR) and Wilber, P (NOAA)

Structure forming deep-sea corals are a foundational ecological group common in deep-sea habitats on the West Florida Shelf. The distribution of these corals depends primarily on depth, presence of hard substrate, and vertical relief of the seafloor, but less is known about how deep-sea coral assemblages vary with different geomorphologic features. The primary goal of this study is to compare diversity and abundance of coral assemblages as they relate to specific geomorphologic features. The secondary goal is to evaluate existing mesoscale habitat suitability models for two prevalent genera: Lophelia and Leiopathes.  The study focuses on four Habitat Areas of Particular Concern (HAPC) proposed by the Gulf of Mexico Fishery Management Council with depths between ~200 and 1000 m. High-resolution multibeam sonar data from two surveys (2008, 2012) are used in concert with coral presence data from NOAA’s deep-sea coral database.  Additionally, coral presence-absence data from ROV images collected by NOAA Ship Nancy Foster in 2017 and NOAA Ship Okeanos Explorer in 2018 are used to enumerate and identify assemblages on flats, mounds, and ridges. Understanding the relationship between specific geomorphologic features and deep-sea coral distribution will better inform managers regarding which geographic areas are critical to the protection of these animals. Evaluating the models will shed light on if Lophelia and Leiopathes presence data are dense enough for accurate mesoscale predictive modeling


LIFE HISTORY OF COMPLEMENTAL MALES IN THE COMMENSAL BARNACLE CHELONIBIA TESTUDINARIA AND THE INFLUENCE OF SUBSTRATUM ON SEX

Reilly, ME (GPMB, The University of Charleston, SC), Zardus, JD (The Citadel), Podolsky, RD (College of Charleston), Strand, AE (College of Charleston) and Burnett, LE (College of Charleston)

Chelonibia testudinaria is an epibiotic acorn barnacle that attaches to sea turtles, manatees, and crabs. Its sexual system is androdioecy, which includes both hermaphrodites and males. Males are classified as “complemental” because they are smaller and attach to the shell of the hermaphrodite, often in the crevices between the shell plates of the hermaphrodite. The focus of this project is to describe life history characteristics of complemental males and examine the impact of substratum type on sex determination in C. testudinaria. The first objective will estimate the size of males at sexual maturity. Males will be sampled periodically, their rostro-carinal length measured, and sexual maturity assessed by the presence or absence of sperm. In addition, male attachment locations will be mapped to determine if settlement patterns are random or skewed toward shell crevices. The second objective will determine if the substratum on which a cyprid settles influences the sex of the individual. To test this hypothesis, settlement chambers will be created containing varying numbers of hermaphrodites attached to PVC. Then, 25-30 cyprids will be added to the chambers and allowed to attach, and resulting sex ratios will be calculated after a period of growth. If more cyprids develop into males in the chambers relative to the number of hermaphrodites available, the conclusion will be that substratum influences sex determination. Further description of the sexual system of C. testudinaria and complemental males could expand knowledge of androdioecy and the evolution of sexual systems.


DETERMINING TOXICOLOGICAL EFFECTS OF INORGANIC PHOSPHATE ON CORAL REEF SPECIES

Slone, A (GPMB, The University of Charleston, SC) and Woodley, CM (NOAA)

Coral reefs provide nutrients and habitats for diverse marine life, protect the coastline from erosion and are economically valuable, but coral health, reproduction and survival continue to decline. This study investigates the toxicity of inorganic phosphate on tropical marine species foundational for coral reefs. Excess phosphate concentrations have been reported to weaken skeletal structure, decrease fertilization rates and increase disease severity in coral. In previous work, measured porewater phosphorus concentrations at 8 out of 12 sites in St. Croix, U.S. Virgin Islands ranged from 51.2 – 367 µg/L, which were well above the total phosphorus water quality criteria (<50 µg/L). In addition, Acropora palmata, a critically endangered coral species, was shown to have exceedingly low reproductive effort near the locations with high phosphorus levels. Based on these findings, the present study tested the effects of phosphorus ranging in concentration from 0.1 mg/L to 2.0 mg/L (over 5 times greater than reported in the environment) on early life stages of the sea urchin (Lytechinus variegatus) and coral (Acropora palmata and Orbicella faveolata). Sea urchin trials were conducted at 25°C resulting in no adverse effect observed on embryo development. Fertilization and larval survivorship were examined for both coral species at 29°C and at 31°C. The results indicated no observable adverse effect on either fertilization rate or survivorship for either A. palmata or O. faveolata. Information garnered from quantifying the impacts of elevated phosphate concentrations on coral reef species may aid in setting appropriate nutrient water quality criteria for protected coral species.


IMPROVING DIET RESOLUTION IN THE U.S. SOUTH ATLANTIC USING MOLECULAR TECHNIQUES

Spanik, K (GPMB, The University of Charleston, SC) and Smart, T (SCDNR)

With growing research and support for Ecosystem-Based Fisheries Management (EBFM) approaches, incorporation of ecological interactions into fishery management plans is becoming more realistic, and is even mandated in some cases. Diet studies in particular provide valuable insight on competition for resources, habitat use, energy flow, natural mortality, and seasonal variability that are not considered in single-species stock assessment models. This type of information is especially important in South-Atlantic reef ecosystems, where many species exhibit high site-fidelity and co-occurrence is common. Many grouper/hind species (family Serranidae) exhibit high metabolic rates, and consequently their prey items are commonly in advanced stages of digestion and cannot be visually confirmed through traditional morphological analysis techniques. This study will aim to increase resolution for both inter- and intra-specific diet composition for several species of grouper from the U.S. South Atlantic by combining both visual and molecular diet analysis techniques. Since genomic DNA of prey items from stomach contents can be highly degraded, a portion of mitochondrial gene cytochrome oxidase subunit I will be chosen as a target amplicon because of its abundance within cells, and publicly available primers and reference sequences that can be used to achieve species-level resolution.


DETECTION OF MULTIPLE PATERNITY IN DIAMONDBACK TERRAPIN (Malaclemys terrapin) EGG CLUTCHES FROM CHARLESTON, SC THROUGH THE USE OF NOVEL MOLECULAR TECHNIQUES

Sporre, M (GPMB, The University of Charleston, SC) and Strand, A (College of Charleston)

Egg clutches sired by more than one male are common in turtles even though females do not receive direct benefits from mating with multiple males and turtles do not display strong social interactions that give rise to multiple mating. Indirect benefits of multiple paternity include sperm competition and increased genetic diversity of offspring. Past studies of diamondback terrapins have shown variation in the occurrence of multiple paternity under a range of female dominated sex-ratios. Malaclemys terrapin in the Charleston area provide a good system to investigate the relationship between population sex-ratio and multiple paternity because of a high male to female sex-ratio. The objectives of the proposed project are to (1) develop both a microsatellite panel and SNP panel for M. terrapin, (2) develop a maximum likelihood statistics program to compare mating system hypotheses, and (3) determine incidence of multiple paternity, male clutch contribution and genetic diversity in diamondback terrapin egg clutches collected from a male dominated system using microsatellite and SNP markers.  I hypothesize that the degree of multiple paternity and genetic diversity are directly correlated to the probability of male encounters, which is driven by sex-ratios in the field. Results of this study will identify mating behaviors and effective population size of diamondback terrapins in the Charleston area while shedding light on the effects that sex-ratios have on the frequency of multiple paternity within conspecifics. In addition, the methodology developed in this project will have far reaching applications to future questions about conservation and mating strategies.


HISTOLOGICAL STUDY OF THE LIFE HISTORY OF THE GOBIID FISH GOBIOSOMA BOSC

Taylor, MA (GPMB, The University of Charleston, SC), Harold, AS (College of Charleston), Roumillat, WA (College of Charleston), Wyanski, DM (SCDNR) and Smart, T (SCDNR)

Gobiosoma bosc is a cryptic, short-lived goby abundant in shallow coastal habitats, oyster reefs, and estuaries throughout the northwestern Atlantic from New York south to southern Florida, excluding the southern tip of Florida, and along the coast of the Gulf of Mexico to Campeche, Mexico. Previous studies on the life history of G. bosc failed to include age determination or histological analysis of gonadal tissues, therefore basic knowledge of its population demographics and reproductive biology remain nearly unknown. The aim of the current study is 1) to determine the age and growth rates for individuals of all size classes for both sexes of G. bosc; 2) determine the duration of the spawning season and spawning periodicity for populations within the Charleston Harbor; and 3) histologically describe their sexuality and reproductive biology. Specimens will be collected monthly using oyster shell trays, seine nets, dip nets, and hand collections from three sites within the Charleston Harbor beginning May 2017 until August 2018. Prior to fixation, sagittal otoliths will be removed for aging and growth analyses. Formalin-fixed dissected gonad tissue and surrounding viscera will be sectioned and sequentially mounted to obtain a full cross-sectional series of the gonad and accessory gonadal structures. Histological study of mounted sections will provide information about sexuality and gonadal stages and general reproductive biology of G. bosc populations in the Charleston Harbor. Results from the study will provide data necessary for population assessments of G. bosc and their ecological role within oyster reefs and estuarine ecosystems.


DYNAMIC COLOR IN A BLACK-AND-WHITE WORLD: PENGUIN BEAK SPOTS AS BIOSENTINELS IN THE ANTARCTIC

Van Skoik, B (The Citadel), Hart, T (University of Oxford) and Nolan, PM (The Citadel)

Animals’ external characteristics, including behaviors, sexually-selected ornaments, and integumentary colors, reveal details of their age, physiology, and/or body condition.  Ornamental coloration of the beak and feet, in particular, signal health status that can vary dynamically on a time frame of minutes or hours.  Gentoo penguins (Pygoscelis papua) display a deep red beak spot, with substantial variation between individuals shown experimentally to reflect concentration of carotenoid pigments.  Carotenoid pigments may be used in mating displays or in the immune system, meaning that birds showing the deepest red are in the best condition.  We sampled 50+ birds at each of 10 breeding colonies on the Antarctic peninsula, taking care not to sample the same bird twice.  Using a color standard placed next to the bird in each photo, we standardized light levels of the photos before measuring hue, saturation, and brightness.  We calculated colony-wide mean values along each of those parameters, and found substantial variation between the colonies.  We compare those means with other publicly-available data to assess possible causes of the variation, considering prey availability, tourism visits, latitude, and ambient temperature changes as possible correlates.  Our work will not only allow better management of human activities such as tourism and fishing in the Antarctic, it may help us predict future changes on the Antarctic peninsula.


AGE, GROWTH, AND REPRODUCTIVE LIFE HISTORY OF TWO DATA-DEFICIENT PARROTFISH SPECIES IN THE CARIBBEAN

Wagner, G (GPMB, The University of Charleston, SC)

Parrotfish’s grazing behavior helps control algal growth and prevents coral reefs from becoming algae-dominated. No other organism provides this service; therefore the presence of parrotfish is crucial to coral reef health. In the Caribbean, snapper and grouper species are commercially targeted, while parrotfish have historically constituted a small, subsistence based fishery. In recent years, snappers and groupers have become heavily overfished, resulting in parrotfish experiencing intense increases in fishing pressures. In 2011, the SouthEast Data, Assessment, and Review (SEDAR) stock assessment indicated severe data deficiencies regarding age, growth and reproductive life histories of several species of parrotfish, including redtail parrotfish (Sparisoma chrysopterum) and stoplight parrotfish (Sparisoma viride), the two most heavily targeted parrotfish species in the Caribbean. Due to the severe lack of data, responsible management decisions were not possible. This study aims to fill these data gaps by determining and comparing growth rates, population age structure, sex ratios, reproductive seasonality, and size and age at maturity for redtail and stoplight parrotfish in U.S. Caribbean waters. Lengths and weights will be coupled with age determined from otoliths and sexual maturity determined from reproductive histology to shed light on the life histories of redtail and stoplight parrotfish in Puerto Rico, St. Thomas, and St. Croix. The results of this study can influence management decisions such as catch limits, size and seasonality restrictions, as well as gear restrictions in order to maintain healthy parrotfish populations, and in return, allow coral reefs to continue benefiting from the grazing control that parrotfish provide.


STRESS RESPONSE AND POST-RELEASE SURVIVAL OF BLACKTIP SHARKS, CARCHARHINUS LIMBATUS, CAPTURED IN SHORE-BASED AND CHARTER RECREATIONAL FISHERIES

Weber, N (GPMB, The University of Charleston, SC), Frazier, B (SCDNR), Burnett, L (College of Charleston), Janech, M (MUSC) and Sancho, G (College of Charleston)

In recent decades, the number of recreational fishermen has increased, including those participating in shore-based and charter fishing. The stress imposed on a fish through capture, and associated post-release survival rates, are poorly understood for most marine species. In the U.S. south Atlantic, the blacktip shark (Carcharhinus limbatus) is the most commonly landed large coastal shark species, and is targeted by shore-based and charter fishermen. Despite its popularity, the effects of recreational capture and release on the blacktip shark are unknown. The present study aims to: (1) assess post-release survival rates of blacktip sharks captured in shore-based and charter fisheries; (2) quantify the stress response associated with both capture modes; and (3) investigate use of a heat shock protein (Hsp70) as an indicator of the stress response. To monitor post-release survival, sharks are fitted with acoustic transmitters and pop-up satellite tags. To quantify the stress response, blood is drawn via caudal venipuncture and analyzed using a portable blood analyzer. Comparisons of Hsp70 in the red blood cells will be assessed by semi-quantitative western blotting. Preliminary data indicate that pH, lactate, and hematocrit do not differ between the two capture modes (p>0.05). However, as fight time increases, lactate (mmol/L) increases for sharks caught from charter boats (p<0.05), and hematocrit (%) increases for sharks caught from shore (p<0.05). The present study will enhance our understanding of the blacktip shark’s physiological response to two different capture modes and will provide post-release survival estimates critical to the upcoming stock assessment of the blacktip shark.


ENERGETIC RESPONSE TO FEEDING AND TEMPERATURE IN JUVENILE RED DRUM, SCIAENOPS OCELLATUS

Welling, E (GPMB, The University of Charleston, SC), Burnett, L (College of Charleston), Denson, M (SCDNR), Watson, A (SCDNR) and McElroy, E (College of Charleston)

Fish metabolic rates depend on environmental temperatures. Standard metabolic rate (SMR) and the cost of processing a meal (specific dynamic action or SDA) both change with temperature. Increased temperature normally shortens the total duration of SDA but also amplifies the peak oxygen consumption rate. High temperatures may result in a greater overall oxygen demand, or magnitude, of SDA. Fish SDA response to higher temperatures has been found to vary by species, increasing in magnitude in species such as Atlantic cod and decreasing in others such as the common minnow. A common estuarine fish in South Carolina, red drum, Sciaenops ocellatus, is frequently exposed to elevated temperatures. This project will test the hypotheses that 1) higher temperature will shorten red drum SDA duration while increasing the peak oxygen consumption rate, and 2) high temperature will increase the magnitude of SDA. Juvenile red drum (N=40) will be randomly assigned to one of two temperature treatments that mimic natural conditions in Charleston Harbor: 25°C and 28°C. After a two-week period, metabolic rates will be measured using respirometry. SMR will be measured after a 24-hour starvation period. Then, fish will be fed ad libitum and then monitored as metabolism increases during digestion and returns to SMR. Increased oxygen demand of SDA in red drum could limit the animal’s digestion in an estuarine habitat known to frequently exhibit high temperatures and hypoxic conditions.