Urea is typically less toxic than ammonia. Ammonia is a direct irritant to the respiratory system and can cause damage upon inhalation, while urea is less likely to cause immediate harm. However, both substances can be harmful in high concentrations and should be handled with caution.
Species in the salt marsh community use cordgrass (Spartina alterniflora) for various purposes. It provides habitat and food for many organisms, including marsh animals like fiddler crabs and marsh periwinkles. Cordgrass also helps stabilize the marsh sediments and protects the shoreline from erosion.