Characterization of Virus-Host Interactions in Galveston Bay

with Jessica Labonte

On average one order of magnitude more abundant then their microbial hosts, viruses are the most abundance biological entity on the planet. Every day, nearly 20% of all microorganisms in the ocean are killed by viral infections, making viruses essential in microbial mortality and at the center of nutrients recycling. With their tremendous genetic diversity and capacity to act as vectors of horizontal gene transfer, they also play an integral role in microbial evolution and adaptation to environmental changes. The aim of this project is to characterize viral activity and virus-host interactions in the dynamic estuarine environment that is Galveston Bay.

The student will participate in a bi-weekly time-series aiming at the study of virus-host dynamics in Galveston Bay. Following sampling, they will filter prokaryotes and concentrate viruses. They will measure viral activity, count viral and prokaryotic cell abundances using epifluorescence microscopy, and use metagenomics and metatranscriptomics to look at the genomic potential and activity.

Student that have an interest in microbial ecology, an enthusiasm for research, and motivation to learn bioinformatics and molecular virology are especially encouraged to apply.

Movement and Feeding Ecology of Predatory Fishes

with David Wells and Jay Rooker

Identifying habitat use and movement patterns of top predators is critical in order to identify biodiversity hotspots that are used as nursery and/or feeding areas, particularly in the face of increasing environmental stressors. Current research in the newly established Gulf Research Institute for Highly Migratory Species (GRIHMS) is focusing on examining movement patterns and the feeding ecology of common predators (fishes and sharks) in estuarine and coastal waters. This specific project is using acoustic telemetry techniques to track fine-scale movements of predators in estuaries and offshore environments, while also analyzing the stomachs and tissue for stable isotope analysis to better understand how movement and feeding habitats are linked to the environment. Ultimately, information generated from this study will enable us to better understand habitat use and trophic interactions of top predators, which can then be used to assist in ecosystem-based fishery management.

PFAS and Natural Phytoplankton Communities: Pollutant Insight from the Base of Aquatic Food Webs

with Antonietta Quigg

Perfluorinated alkylated substances (PFASs) are synthetic chemicals that have been ubiquitously used in industrial and commercial products which has resulted in their emission into environments globally. This is of great ecological concern as several chemicals in the group are toxic and persistent including perfluorooctane sulfonate (PFOS), which is the most abundant PFAS found in natural systems. PFOS is observed to negatively impact many aquatic species, however its impact on phytoplankton communities is relatively unknown. The same can be said for 6:2 FTS.

This research investigates the impact of 6:2 FTS on two natural phytoplankton communities collected from the Texas coast, one of high salinity (Gulf of Mexico coastal zone) and one of low salinity (Trinity River). Five-day bioassays were conducted with these communities in triplicates of increasing 6:2 FTS concentrations [0-30 (mg/L) ppb]. Photosynthetic efficiency, biomass, nutrients, and stress response materials [transparent exopolymer particles (TEP) and extracellular polymeric substances (EPS)] will be monitored during the study. Determining the way PFOS impacts the base of the food web in different aquatic environments will aid in understanding the holistic effect of PFOS on aquatic ecosystems.

Students that have strong interests and skills in biochemistry, biology, and/or chemistry, combined with a desire to work on marine related questions and concerns are especially encouraged to apply.

Plant-Animal Interactions in Salt Marshes

with Anna Armitage

This project will explore the interactions between infauna (small organisms that burrow in the soil) and salt marsh plants. We seek to understand how positive interactions between plants and animals could boost salt marsh health and improve restoration and management outcomes. We hypothesize that higher infauna abundance will result in higher plant biomass and soil organic content. We will conduct a mesocosm study with marsh plants (Spartina alterniflora) and varying levels of infauna abundance. To assess how infauna may benefit marsh health, we will record measures of Spartina fitness (such as growth and biomass) and soil organic content and nutrient concentrations.

Students with interests in coastal wetland ecology or ecosystem restoration are encouraged to apply.

Sampling and Examining Ecosystem Indicators of Pelagic Communities of Estuaries

with Hui Liu

Effects of increased frequency of tropical storms often cause massive flooding and storm surge that have significant impacts on pelagic communities of estuaries (Liu et al. 2021). To evaluate subsequent impacts of external disturbances on natural populations in estuaries, we need baseline data of ecosystem indicators. Zooplankton consist of ecosystem indicators of water quality and provide the principal conduits for energy transfer from phytoplankton to higher trophic levels. Currently a data gap on zooplankton exists in Galveston Bay, Texas, when compared to other ecological indicators as stated in the State of the Bay. Our research has demonstrated that abundance of zooplankton is significantly related to salinity (freshwater inflow) and water temperature, and exhibited a strong bottom-up control for juvenile forage fish in Galveston Bay (Liu et al. 2017). Another recent study disclosed that zooplankton communities exhibited distinct spatial responses to storm-surge and flooding caused by hurricanes in the bay with different recovery time in the abundance and diversity index (Liu et al. 2021). This project will continue to generate time series of zooplankton, oyster larvae and hydrographic factors as ecological indicators for tracking the ecosystem health of Galveston Bay.

We use an integrated method including the field sampling and lab experiment, and microscopic identification and data analysis. Each month we will conduct a research cruise onboard RV/Trident of Texas A&M University to sample zooplankton and oyster larvae and hydrographic factors in Galveston Bay. At sea we deploy plankton nets with 100 µm and 200µm mesh sizes. Animals collected on the sieve will be back-rinsed into sample jars and preserved in 5% formaldehyde/seawater solution. Concurrently, temperature, salinity, dissolved oxygen, and pH will be obtained using a calibrated YSI sampler. Surface water will be collected for analysis of chlorophyll a concentration. Zooplankton and oyster larvae will be identified following the reference keys in Boltovskoy et al. (1999), Johnson and Allen (2012) to quantify abundance and size of oyster larvae and zooplankton. In the laboratory, samples will be processed according to Liu et al. (2017&2021), and enumerated and sorted to species or genera where possible under a dissecting microscope (Leica 205C). Data analysis will be conducted to examine the relationship between the zooplankton density and the environmental condition in view of climate change.

Students that have a major in oceanography, marine ecology, fisheries, or related undergraduate program, are enthusiastic on gaining experience on zooplankton research, oceanographic cruises and processing zooplankton samples in the lab, as well as quantitative skills of data analysis, are especially encouraged to apply.

Cnidarian Symbiosis under Disrupted Sphingolipid Signaling

with Sheila Kitchen

Bioactive lipids play a pivotal role in determining cell fate and mediating host-microbe interactions. In the symbiosis between cnidarians and dinoflagellates of the family Symbiodiniaceae, host sphingolipid metabolism mediates partner interactions at various stages from the onset to the establishment of long-term associations. Modulation of intracellular sphingolipids by the key enzyme sphingosine kinase (SPHK) in the host creates an environment to support the survival of the host and its symbionts. The biosynthesis of sphingolipids is not limited to the cnidarian host, but is highly conserved among eukaryotes. Thus, symbiont-derived sphingolipids could also be important for symbiont entry into the cnidarian host. In this study, the student will explore the importance of SPHK in the early stages of symbiosis by disrupting its function through pharmacological inhibition and/or RNA silencing in two symbiotic cnidarians, the jellyfish Cassiopea and the sea anemone Exaiptasia, and their symbiotic dinoflagellates. The objectives of this study are to identify downstream pathways related to SPHK-mediated lipid signaling that contribute to the onset and maintenance of cnidarian-dinoflagellate partnerships and overlap in these pathways between the two symbiotic systems.

The student will incubate polyps of both cnidarian hosts and their respective cultured symbionts in pharmacological reagents and track symbiont densities over time using fluorescent microscopy. The student will collect polyps and symbiont cultures for transcriptomic analysis to find divergent expression patterns in the treatment conditions. The student will also perform RNA interference (RNAi) experiments, from construct design through experimentation, to silence SPHK expression in both cnidarians hosts.

Reconstructing Hurricane Strikes in the Bahamas over the Last 5000 Years

with Pete van Hengstum

Intense hurricane strikes represent one of the greatest natural hazards to North American coastlines. Our undertanding of long-term hurricane activity is limited to the short historical and instrumental record, which is 100-150 years ago, at most, in the North Atlantic region. Our understanding of climate-hurricane interactions can be improved with a better long-term understanding of regional hurricane strikes. This project will use sediment cores collected from blue holes in the Bahamas to study intense hurricane strikes in the northern Bahamas over the last 5000 years.

Students will learn skills in classic sedimentology (e.g., textural analysis), micropaleontology (foraminifera) and some numerical analysis. More specificially, students will use the ecological shifts in benthic foraminifera to study hurricane-induced changes to hydrology and dissolved oxygen concentrations in the blue hole water column. Benthic foraminifera are part of the benthic meiofuana and they secrete a simple shell, or test, that becomes part of the sediment record after their death. Over long periods of time, a record of blue hole environmental changes is preserved in the sediment layers.

Students with an interest in coastal hazards, sedimentology, paleo climate and environmental science, benthic ecology and tropical carbonate landscapes are especially encouraged to apply. No prior experience is required.

Antarctic Tourism Sustainability

with Jenna Lamphere

Antarctic tourism doubled over the past decade, with a record-high 74,000 visitors making the voyage during the 2019 astral summer. This year, visitation is expected to exceed 100,000. Although the International Association of Antarctica Tourism Operators (IAATO) reports 360 tourist landing sites, 98 percent of visitor activity occurs along a 300-mile section of the Antarctic Peninsula shoreline. Rapid and concentrated growth has caused scientists to raise alarms about the ecological effects of tourism in a region that is already threated by climate change. The Antarctic Peninsula is among the world’s fastest warming regions, and should emission trends continue, sea ice covering will be halved and ice shelves quartered within the next 30 years. The relationship between climate change and tourism, however, is complex. Some researchers, for example, have found climate change to grow polar tourism by increasing site access and visitor demand. The term “last-chance tourism” was coined to capture this paradoxical relationship, whereby tourist desire to experience destinations threatened by climate change drives industry expansion while also accelerating ecological decline. Antarctic protection against tourism impacts is also complicated by disputes over territorial sovereignty and patchwork protective agreements.

To address Antarctic tourism sustainability, research is needed to better understand post-pandemic industry trends and socio-ecological challenges. This research is mixed methods, including survey, interview, and IAATO data. The student will familiarize themselves with existing literature on Antarctic tourism and assist with the collection and analysis of data. Ultimately, this research will result in policy recommendations for protecting the region against tourism impacts.

Students with a background in social science and interest in polar tourism are encouraged to apply. Quantitative and/or qualitative research skills are a plus but not required.