For more than three decades, the impact of anthropogenic nutrient loading in coastal ecosystems has been a major concern of scientists, coastal managers, and the public. Nutrient enrichment leads to a variety of negative ecosystem consequences including increased intensity, duration, and frequency of phytoplankton blooms, hypoxic and anoxic events, increased macroalgae blooms, losses of fish and shellfish habitat, decreased benthic diversity, and loss of eelgrass beds. Remarkably, little work has been done in intertidal areas, and very few studies have addressed the effects of nutrient enrichment on the coastal landscape or how changes in biogeochemical cycles can modify the coastline by promoting erosion, accretion, and shoreline evolution. This research determines the impact of anthropogenic nutrient loading on tidal flats and salt marshes at the Plum Island LTER site, Massachusetts. State-of-the-art field and laboratory techniques work will be used. Quantitative measurements of a wide variety of field parameters will be incorporated into coupled numerical models that will be used as a tool for examining impacts to the landscape and ecosystem over longer-time scales and at different locations. Results of the work will be generalizable and widely applicable to shallow coastal landscapes anywhere in the world. Broader impacts of the work include providing important projections of coastal erosion and wetland assessments to land managers, integration of research and education, training of significant numbers of undergraduates and a postdoc, and support of an early career researcher.