Coastal & Marine Sciences

Session I

Natalie Askew, "Shedding Light on Seagrass: How Light Affects Seagrass Seed Development"

Zostera marina, or eelgrass, is a major seagrass species in the Chesapeake Bay that has undergone significant declines over the last few decades. In response to this decline, several groups around the bay have begun participating in restoration efforts. These efforts involve collecting reproductive Zostera shoots, allowing the seeds to develop in tanks, and planting the seeds in targeted restoration areas. Recently, some facilities have noted poor seed quality, possibly correlated with the construction of shades over their seed tanks. This project examines whether light is important to the development of Zostera marina seeds. To do so, seeds were placed into three different treatments, including full shade, partial shade, and no shade. It was found that treatments with the most access to light had the highest percentage of viable seeds, suggesting that light is essential to the proper development of Zostera marina seeds.

Student Major/Minor: Biology Major, Coastal & Marine Sciences Minor

Advisor: Dr. Alex Bijak

Krish Bommakanti, "Automated Classification of Fish Liver Pathology Using Machine Learning for Environmental Assessment"

The goal of this study was to apply machine learning techniques to create a model that can accurately classify images of cancerous lesions. This was undertaken in the hopes that the ongoing Elizabeth River health assessment done by VIMS might be automated in the future. Currently, researchers have to examine fish liver histologies manually, which requires a lot of time and effort. Using an initial dataset of 100 images, a locally stored machine learning model was able to classify images as specific precancerous lesions or cancerous lesions. This project paves the way for future uses of machine learning in marine science and in microbiology.

Student Major/Minor: Biology Major, Computer Science Minor

Advisor: Dr. Hamish Small

Nicholas Goodman, "Trace and Heavy Metal Distribution Along the Amazon River–Ocean Continuum: Assessing Anthropogenic Influence from River to Continental Shelf"

The Amazon River is the largest single source of freshwater, dissolved material, and sediment to the global oceans and exerts a major influence on Earth system processes. Increasing human activity within the basin is driving significant geochemical change. Despite this, the Amazon’s tidal component and its coastal mud banks—which serve as an important transition zones between riverine and marine environments—remain insufficiently characterized. Data on elemental concentrations and their distribution across different sediment grain-size classes (e.g., clay, silt) are particularly lacking in the literature. This study quantifies heavy (Cr, Cd, Pb) and trace (Al, Fe, Ti, Mn, Ba, V, Zn, Ni, Cu, Ga, Co) metal concentrations along pronounced environmental gradients between Óbidos and Suriname, including the Amazon estuary. Sediment samples were broken down with mineral acids under an ultra-clean environment and analyzed using inductively coupled plasma mass spectrometry (TQ-ICP-MS). To discriminate recent anthropogenic inputs from natural sources, deeper sediments retrieved from core catchers and radiocarbon dated to 1,980–9,480 yr BP (before present) were used as a robust pre-anthropogenic baseline to reliably distinguish whether observed variations reflect consistent historical trends or recent environmental alterations. Characterizing the concentrations, spatial distribution, and mobility of trace and heavy metals addresses a critical knowledge gap in Amazon elemental cycling and provides the first comprehensive assessment of human impacts along this extensive, spatially continuous system. 

Student Major(s)/Minor: Coastal & Marine Sciences Major, Chemistry Minor

Advisor: Dr. Manuel Colombo

Maya Littman, "Uncovering the Origin of Organic Carbons in a Tidal Inlet"

The nutrient-rich salt marshes that form behind barrier islands (in the backbarrier), provide a range of ecosystem services and are critical storage areas for organic carbon. However, barrier islands are vulnerable to large-scale erosion from sea-level rise, leading to faster migration towards the mainland, and subsequent exposure and erosion of long-buried marsh carbons. What happens next to that carbon is unknown: one unstudied pathway is the possible recycling of that carbon back into the backbarrier via tidal inlets, helping to feed remaining salt marshes. This project uses geochemical analyses to determine the age and subsequent origin of carbon moving through inlets and relates it to the erosion of marsh sediments on an adjacent island. Preliminary results reveal pre-storm and post-storm ages similar to the backbarrier and outcropping marsh, while mid-storm ages are younger due to an influx of offshore material. 

Student Majors: Geology and Environmental Policy Major

Advisor: Dr. Chris Hein

Darius McCallum, "Life History of Bowfin (Amia calva) in the Piankatank River, Eastern Virginia"

Recently Bowfin has been designated into two distinct species. The first being Bowfin (Amia calva) which inhabits the Atlantic coastal plain/ Gulf Coast, and the second being Bowfin (Amia ocellicauda) which includes the Great Lakes, Mississippi basin, and northern regions. Due to most of the research of this species being conducted on Amia ocellicauda, there is a research gap on those that reside in the coastal plain region. This project will explore the life history of Bowfin (Amia calva) in a river located in the coastal plain region. The methodology includes electroshocking in the study area, dissection of the collected fish, and analysis of aspects such as gut contents, eggs, and aging via otoliths. These methods will allow for an accurate assessment of Amia Calvas' life history, therefore helping to close the knowledge gap. 

Student Major(s)/Minor: Coastal & Marine Sciences Major, Integrative Conservation Minor

Advisor: Dr. Eric Hilton

Matilde Quilici, "Bones on the Move: Hogchoker Cranial Development and Metamorphosis"

Hogchokers (Trinectes maculatus) are flatfishes native to the East Coast of the U.S. As Hogchoker larvae develop, their left eye migrates across the top of the head to join the right, resulting in an asymmetrical head structure. This project revealed previously unknown skull morphology and development from larval to adult life stages. Specimens treated with a chemical procedure of clearing and staining were dissected to visualize bones and cartilages. The shape and interactions between bones in the skull, jaws, and gills were detailed through drawing, photography, and written observations. CT scans provided 3D digital models of the specimens, which revealed the architecture of structures not apparent through dissection. This study produced a complete anatomical description of Hogchoker cranial morphology, offering a foundational understanding of the emergence, distortion, and movement of bones during metamorphosis. Future directions could include expanding these data in comparative, biomechanical, or evolutionary studies of flatfishes. 

Student Major(s)/Minor: Biology Major

Advisor: Dr. Eric Hilton

Isabel Volden, "Population Genetics of the Lessepsian Migrant Galaxaura lessepsiana"

The Lessepsian migration is an ongoing mass-movement event whereby marine species primarily cross from the Red Sea to the Mediterranean Sea. The red macroalga Galaxaura lessepsiana is one migrant that is now common in the Levantine region of the Mediterranean. Red algae undergo complex alternations between macroscopic haploid and diploid phases. During invasions, these alternations can be disrupted, often leading to the loss of one of the phases. Galaxaura lessepsiana presents an opportunity to further investigate the consequences of invasions on haploid-diploid life cycles. Using samples collected along the Israeli coast in 2019, this study developed microsatellite loci to explore population structure and patterns of genetic diversity. These patterns can aid in our understanding of the underlying processes driving the population dynamics of organisms with complex life cycles during invasions.

Student Major and Minor: Coastal & Marine Sciences Major, Biology Minor

Advisor: Dr. Stacy Krueger-Hadfield