Project Title: Groundwater controls on microbial communities in coastal aquifers
Principal Investigator(s): Dr. James Heiss
Affiliations: UMass Lowell
Summary: Groundwater discharge from the seabed into coastal ecosystems carries nutrients and other chemicals that affect surface water quality and ecosystem health. Microbial processing of groundwater contaminants prior to discharge alters the chemistry of discharging groundwater and can be an important ecosystem service that reduces nutrient fluxes that would otherwise contribute to coastal eutrophication. The objective of this research is to understand how microbial communities process nutrients and other chemicals in coastal aquifers. The work will aid managers aiming to reduce nutrient loads to surface water bodies. Groundwater wells, water quality sensors, and porewater sampling will provide information into how groundwater hydrology affects microorganisms in the subsurface and nutrient fluxes in discharging groundwater.
Project Title: Intertidal salt marshes as an important source of inorganic carbon to the coastal ocean. Limnology and Oceanography, 61(5), 1916-1931.
Principal Investigators: Wang, Z. A., Kroeger, K. D., Ganju, N. K., Gonneea, M. E., & Chu, S. N.
Abstract: Dynamic tidal export of dissolved inorganic carbon (DIC) to the coastal ocean from highly productive intertidal marshes and its effects on seawater carbonate chemistry are thoroughly evaluated. The study uses a comprehensive approach by combining tidal water sampling of CO2 parameters across seasons, continuous in situ measurements of biogeochemically‐relevant parameters and water fluxes, with high‐resolution modeling in an intertidal salt marsh of the U.S. northeast region. Salt marshes can acidify and alkalize tidal water by injecting CO2 (DIC) and total alkalinity (TA). Read Full text: http://onlinelibrary.wiley.com/doi/10.1002/lno.10347/full
Project Title: Contemporary Methods for Quantifying Submarine Groundwater Discharge to Coastal Areas
Principal Investigators: Ray, R. L., & Dogan, A.
Summary: In Emerging Issues in Groundwater Resources (pp. 327-364). Springer International Publishing.
Submarine Groundwater Discharge (SGD), which represents subsurface exchange of water between land and ocean, is a major component of the hydrological cycle. Until the mid-1990s, it was generally believed that SGD rates were not large enough to influence ocean water budgets. Read full text… http://link.springer.com/chapter/10.1007/978-3-319-32008-3_12
Continuous measurements of dissolved Ne, Ar, Kr, and Xe ratios with a field-deployable gas equilibration mass spectrometer
Project Title: Continuous measurements of dissolved Ne, Ar, Kr, and Xe ratios with a field-deployable gas equilibration mass spectrometer
Principal Investigators: Manning, C.C., Stanley, R.H., & Lott III, D.E. (2016)
Abstract: Noble gases dissolved in natural waters are useful tracers for quantifying physical processes. Here, we describe a field-deployable gas equilibration mass spectrometer (GEMS) that provides continuous, real-time measurements of Ne, Ar, Kr, and Xe mole ratios in natural waters. Analytical chemistry, 88(6), 3040-3048. Read full text… http://pubs.acs.org/doi/abs/10.1021/acs.analchem.5b03102
Project Title: Geochemistry of redox sensitive trace elements in a shallow subterranean estuary
Principal Investigator(s): O’Connor, A. E., Luek, J. L., McIntosh, H., & Beck, A. J.
Abstract: Submarine groundwater discharge (SGD) is an important component of chemical fluxes in the coastal ocean. The composition of SGD is influenced by biogeochemical reactions that take place within the subterranean estuary (STE), the subsurface mixing zone of fresh and saline groundwaters. The STE is characterized by redox gradients that affect the speciation and mobility of redox-sensitive elements (RSEs). Read full text… Marine Chemistry, 172, 70-81. http://www.sciencedirect.com/science/article/pii/S0304420315000432
Permeable reactive barriers designed to mitigate eutrophication alter bacterial community composition and aquifer redox conditions
Project Title: Permeable reactive barriers designed to mitigate eutrophication alter bacterial community composition and aquifer redox conditions
Principal Investigator(s): Hiller, K.A., Foreman, K.H., Weisman, D., & Bowen, J.L.
Summary: Permeable reactive barriers (PRBs) consist of a labile carbon source that is positioned to intercept nitrate-laden groundwater to prevent eutrophication. Decomposition of carbon in the PRB drives groundwater anoxic, fostering microbial denitrification. Such PRBs are an ideal habitat to examine microbial community structure under high-nitrate, carbon-replete conditions in coastal aquifers. We examined a PRB installed at the Waquoit Bay National Estuarine Research Reserve in Falmouth, MA. Read full text…Applied and environmental microbiology, 81(20), 7114-7124. http://aem.asm.org/content/81/20/7114.short
PI: Hanan Karam, MIT, PhD Candidate
Advisor: Charles Harvey, MIT
Funding: EPA Star Graduate Fellowship
Sub-estuarine Groundwater Discharge (SGD), Dissolved Nutrients and the Production of Benthic Microalgae
PIs: Rachel Stanley, WHOI
Evan Howard, WHOI
PI: Meagan Gonneea, MIT / WHOI Joint Program, PhD Candidate
Advisor: Matthew Charette, Woods Hole Oceanographic Institution
Funding: NERRS Graduate Research Fellowship at Waquoit Bay NERR (current)
As groundwater flows to the coast, it meets and mixes with seawater. Mixing between these two water bodies creates a dynamic region-the coastal aquifer – where nutrients are chemically and biologically transformed. The fate of nutrients from development is a key issue in coastal areas like Cape Cod so understanding the processes in this area is of great importance. The mixing zone beneath Waquoit Bay was monitored for three years to observe how it changes with different seasons and responds to climate events such as the 2009-10 El Nino.