This study monitored soil surface elevation change from mangrove forests fertilized with nitrogen and phosphorus from 2018-2021. The mangroves selected at Ding Darling National Wildlife Refuge (NWR) have been previously exposed to high nutrient loading from agricultural discharge into the Caloosahatchee River, which elevated soil phosphorus levels to 3-4 times ambient before treatments were impose. Sea-level rise vulnerability with additional nitrogen and phosphorus is a concern for these mangrove ecosystems.