(1) Adapt leaf-scale models for relating plant reflectance indices to wetland ammonia concentrations, identified in our previous and on-going research, to field-scale canopy reflectance measurements of freshwater tidal marsh plant communities; (2) Design, build and test a boat-borne platform for rapidly collecting canopy hyperspectral reflectance of marshes, which can be used in the canopy-scale reflectance/ammonia models to quantify marsh nitrogen status, & (3) Demonstrate our technology to state agencies to consider it as a wetland monitoring tool.