Mary Efird (Ph.D.), University of Maryland College Park, Anthropology, Isotopic Analysis of Icelandic Cod Atlases: Tracing Trophic Changes Over a Millennium, Iceland. 

As climate change intensifies and human exploitation of fish stocks escalates, there is an urgent need to monitor the state of global fisheries. Both climate change and human activities can disrupt marine ecosystems by altering trophic webs, intricate networks of predation and energy transfer among organisms. Trophic web alterations can lead to biodiversity loss and ecosystem instability. Despite this, deep-time trophic changes in Iceland’s Atlantic cod population remain poorly understood. This dissertation seeks to address this research gap by employing zooarchaeological methods. However, to contextualize archaeological findings, understanding the trophic life histories of modern Atlantic cod is crucial. Samples of Atlantic cod (Gadus morhua) atlas vertebrae will be collected from four fish processing plants across Iceland. These modern specimens will serve as analogs for previously collected archaeological vertebrae, forming the basis for carbon and nitrogen stable isotope analysis. Through comparing stable isotope signatures of modern and archaeological vertebrae spanning Iceland’s history, this study aims to elucidate historical shifts in the marine trophic webs of Iceland. The deep-time insights provided by this research can mitigate the common fisheries issue of shifting baseline syndrome and inform more effective fisheries management strategies for Iceland’s Atlantic cod fishery, which holds considerable socioeconomic and ecological significance.

 

Abdulwahab Omokolade Omigbule (Ph.D.), University of Virginia, Anthropology, The Bonny Island – Old Calabar Archaeological Project, Nigeria. 

The transatlantic economy has been extensively researched since the mid-20th century, with archaeologists contributing significantly on both sides of the Atlantic basin. While West African archaeologists have extensively explored the Senegambian region and the Bight of Benin, the Bight of Bonny has received little attention despite its centrality to transatlantic history. Old Calabar and Bonny Island served as crucial points in the transatlantic slave trade, facilitating complex African-European interactions and accounting for a substantial portion of enslaved captives transported through the region. Their geographical proximity to the Atlantic, access to trading posts via the Niger Delta, and unique political-economic structures positioned these ports strategically within the regional economy. This doctoral research focuses on daily life and material histories during the transatlantic and post-abolition periods in the Niger Delta area of the Bight of Bonny, Nigeria. By examining the lives of African traders and local inhabitants at Bonny Island and Old Calabar, this study aims to elucidate the global experiences and contributions of West Africans from the 17th to 19th centuries CE. Previous historical archaeological endeavors in West Africa have primarily emphasized the European perspective, making this interdisciplinary project vital in highlighting the role and agency of African elites and non-elites in shaping the modern world, particularly in Nigeria.

 

Robert Salerno (M.S.), University of Maryland College Park, Entomology, Soil Arthropod Diversity and Ecosystem Services in Response to Ecological Intensification of Agricultural Cropping Systems, Clarksville, Maryland. 

Modern agricultural practices, such as intensive soil tillage, crop monocultures, and overfertilization pose sustainability challenges in forage and livestock farming, impacting soil quality and ecosystem stability. Throughout the world, studies have revealed that agricultural intensification has imposed negative consequences on aboveground arthropods, prompting interest in ecologically intensified forage systems for agricultural sustainability. Belowground, soil arthropods provide many essential ecosystem services on the farm, including decomposition, biological control, and bioturbation however, these organisms are usually overlooked. Understanding their response to ecological intensification is vital for sustainable agriculture. Therefore, this project aims to assess how different land use types in forage cropping systems influence soil arthropod biodiversity, their ecosystem services, and soil quality. Sampling across various treatments using subterranean pitfall traps will provide insights into soil arthropod biodiversity and its connection to soil properties and land use type. This research aligns with broader efforts aiming to transform the agricultural landscape dominated by conventional monocultures into a landscape possessing ecologically intensified perennial forage systems. By bridging knowledge gaps, this project seeks to promote ecologically intensified forage systems, benefiting farmers and fostering agricultural resilience while also exploring soil arthropod biodiversity, a group of organisms vital to agriculture but usually overlooked.

 

Ronita Sequeira (M.S.), University of Maryland Baltimore County-IMET, Marine, Estuarine and Environmental Sciences, Measuring the Abundance, Diet and Condition of Piscifauna Near Restoration Projects in an Urban Estuary, Baltimore, Maryland. 

The proposed study explores the impact of shoreline and floating wetland resiliency projects on fish ecology in Baltimore’s Inner Harbor and Middle Branch areas. Although wetlands are known to have many ecological benefits, it is relatively unknown how beneficial they are in urban estuaries. This study aims to address this knowledge gap by quantifying fish abundance and conditions adjacent to restoration efforts and evaluating habitat restoration’s influence on juvenile fish diversity. Focusing on mummichogs and silversides, the research will assess abundance, condition, and potential diet variations near restoration sites compared to reference areas, including stands of Phragmites australis. By conducting statistical analyses and collecting biological specimens, the study will provide insights into the interaction between habitat restoration projects and fish communities in urban estuarine environments. Anticipated results of this exploration include identifying correlations between fish abundance, condition, and restoration efforts, crucial for guiding future restoration initiatives and supporting sustainable fish populations. Moreover, the study will establish a baseline for future research on fish diet, biodiversity, and mercury content, while also fostering outreach activities to engage youth and collaborate with relevant stakeholders and organizations invested in estuarine conservation and restoration.

 

Matthew Stefanak (Ph.D.), University of Maryland-UMCES, Marine, Estuarine and Environmental Sciences, Exploring the Offshore Estuary: Applying Stable Isotopes to Understand Fish Trophic Dynamics in the Chesapeake Bay Plume, Chesapeake Bay and Solomons, Maryland. 

The Chesapeake Bay offshore estuary is an important transitional zone that transports large amounts of nutrients and organic matter from the estuary onto the continental shelf. These “plume” zones have been shown to be areas of enhanced biological activity, yet the magnitude and mechanisms by which the Bay plume influences fishery production in the adjacent inner continental shelf ecosystem is poorly understood. In this project, my objectives are to use measurements of carbon and nitrogen stable isotope composition of basal resources, benthic invertebrates, and several juvenile fish species to 1) characterize the primary sources of production in the plume system (i.e., marine, autochthonous, and (or) estuarine), and 2) estimate the relative contribution of these various energy sources to higher trophic level productivity. Sampling will occur during June 2024 to build on previous collections from April/September 2023 at multiple stations across an inshore-offshore gradient within the plume using a variety of gears. All prepared samples will be analyzed for δ13C and δ15N signatures using a continuous flow isotope ratio mass spectrometer coupled with an elemental analyzer. Findings from this study will elucidate the spatiotemporal role of the Chesapeake Bay plume as a structuring agent of the nearshore food web and its higher trophic level dynamics.