The interface between groundwater and the coastal or intertidal landscape determines the location and migration path of fresh and saline wetlands. These ecosystems interact with the coastal ocean in many ways, much of which is driven by tidal exchange and groundwater discharge, both common coastal processes that deliver water, nutrients, and other materials to nearshore ecosystems, including wetlands. The Environmental Geochemistry group has led development of novel methods to constrain fluxes between coastal ecosystems using continuous, high frequency in situ measurements of water flux, physical chemistry, and optical properties. With these data it is possible to link biological feedbacks with physical drivers, including physical conditions sea-level rise, sediment supply and erosion, hydrodynamics and wave energy, tidal amplitude, salinity, and climate, including temperature, drought, and solar radiation.