When we appreciate the brilliant blue of the Chesapeake Bay, salted water silently invades lands that we live on due to global warming. This phenomenon is referred as saltwater intrusion (SWI), when saline water moves into fresh aquifers and surface water. New research is showing that SWI can disrupt nutrient cycling in coastal regions (Ardón et al 2013; Ardón et al 2017). In the Lower Eastern Shore of Maryland along the Chesapeake Bay, coastal farmland is subject to severe SWI and extensive agricultural areas will be lost in the coming decades (Shepard et al 2013). These coastal farmlands and adjacent areas (i.e. forests and marshes) provide important economic, social, and environmental functions in the region (Tully et al 2019).
Don’t worry, we researchers in AgroEcoLab, are here to investigate and solve this pressing problem! My work with Dani Weissman this semester is to further investigate the impact of saltwater intrusion on nutrients (i.e. nitrogen and phosphate) in active farm fields on the Lower Eastern Shore of Maryland. By reading all research papers provided by Dani, I learned that the saltwater includes rich ionic components (i.e. sulfate, sodium, etc.) that can bind to iron in soils stimulate the release of nutrients into soil porewater and surface water (Chambers and Odum 1990). It inspired me to develop an independent summer study on answering how the ionic components of saltwater affect nutrients in soils.
Thanks for this great opportunity offered by AgroEcoLab, I can experience working in a professional laboratory and apply my chemistry knowledge in practice. Until now, I have helped with sample preparation, experiment set-ups and data analysis. I still remembered the exciting moment when I obtained a perfect calibration for pipets (Figure 1); the cheerful moment when Dani and I finally resolved the instrumental issues (Figure 2). Participating in this saltwater intrusion projects not only provides me joys and self-fulfilling but also helps me develop professional research skills and enhances my understanding of environmental knowledge. My time in the AgroEcoLab is giving me an important foundation for me to attend graduate school in the future.
Ardón M, Helton AM, Scheuerell MD, Bernhardt ES (2017) Fertilizer legacies meet saltwater incursion : challenges and constraints for coastal plain wetland restoration. Elementa: Science of the Anthropocene 5:41. doi:10.1525/elementa.236
Ardón M, Morse JL, Colman BP, Bernhardt ES (2013) Drought-induced saltwater incursion leads to increased wetland nitrogen export. Global Change Biology 19:2976–2985. doi:10.1111/gcb.12287
Chambers RM, Odum WE (1990) Porewater oxidation, dissolved phosphate and the iron curtain- Iron-phosphorus relations in tidal freshwater marshes. Biogeochemistry 10:37–52. doi:10.1007/BF00000891
Shepard A, Curson D, Patton K, Dubois N (2013) Sea-level Rise Is for the Birds: Landscape-level Conservation Planning to Protect Communities, Coastal Wetlands and Salt Marsh Birds. 20.
Tully KL, Weissman D, Wyner WJ, Miller J (2019) Soils in transition : saltwater intrusion alters soil chemistry in agricultural fields. Biogeochemistry. doi:10.1007/s10533-019-00538-9
- By Tia Ouyang
On an uncharacteristically warm couple of days in early February, Kate, Elizabeth, and Dani attended the first annual Marsh Resilience Summit hosted by the Virginia Institute of Marine Science (VIMS) in Williamsburg, Virginia. This event was organized to bring together researchers, non-profit groups, wetland restoration practitioners, and other stakeholders to address issues related to coastal marsh restoration in the face of climate change. There was so much interest in the summit that VIMS had to move it off their campus to a nearby hotel to accommodate all the attendees. Over 200 people were present! A large portion of the event was dedicated to discussing the Chesapeake Bay Sentinel Site Cooperative. Sentinel sites are research stations where scientists measure changes in coastal ecosystems throughout the Bay. The summit was in part organized by Keryn Gedan, Assistant Professor of Biology at George Washington University and one of our very close project collaborators!
Kate gave a wonderful talk entitled Agroecosystems in transition: sea level rise and saltwater intrusion alter biogeochemical cycling in coastal farmlands and Dani and Elizabeth presented posters on their current research. Dani’s poster was on her three summers of work collecting water sample data from coastal farms, marshes, and forests. Elizabeth’s poster was on carbon fractions on farm fields undergoing saltwater intrusion. (Shout out—she won the Outstanding Student Presentation Award for her talk, based on this poster, at the annual American Geophysical Union conference). There she is below with her awesome poster and the newest little ecologist—Toby Gedan! Of course, Toby told us that he loved all of the wetland talks that Keryn took him to during the conference.
The summit included many discussion-stimulating talks related to marsh migration, opportunities to enhance conservation policies, coastal community resilience, wetland ecosystem services, management and restoration techniques, dredge materials, living shorelines, and relationships between marshes, agriculture and industry. Though this summit wont be held for another few years, it certainly sparked a great amount of sharing of ideas and collaboration between people interested in protecting the marshes, in the Chesapeake Bay and worldwide!
-By Dani Weissman and Elizabeth de la Reguera