The goal of this project is to identify and monitor long-term trends and variability in seagrass-dominated ecosystems in and around the Gulf Islands National Seashore (GUIS) and identify drivers of change in biodiversity and productivity of these systems. GUIS is comprised of discontinuous areas in Mississippi and Florida that span ~250 km from its western end at Cat Island, MS to its eastern end at Okaloosa Island, FL. Across this distance are distinct gradients in salinity, water clarity, and seagrass species composition. This project takes an integrated and sustainable approach to characterize and identify shifts in ecological baselines and integrate data to support management needs in GUIS. Research questions are as follows: (1) How do the seagrass-dominated ecosystems of GUIS (including both the seagrasses and the associated nekton community) respond to environmental/weather variability and extreme events? (2) How are these ecosystems changing over time? (3) What are the primary drivers of change in biodiversity and productivity of these systems?