Port Royal Sound FoundationPRSound Science

PRS Watershed

AboutBoundaries
Water LevelsWeather
A Living Watershed

Water Quality

AboutMonitoring Locations

Land Cover

AboutForty Years of Change

Marsh Dynamics

AboutWetlands over Time

Biodiversity

AboutBiodiversity IndicatorsOyster Reefs

Resilience

AboutWatershed DevelopmentStrategy Explorer
Marsh Dynamics

Wetlands over Time

NWI wetlands · National Wetlands Inventory

The NWI maps 294k acres of wetland and aquatic habitat within the watershed.

NWI maps wetland and deepwater habitat at a finer resolution than NLCD land cover classes. Together they provide a more detailed picture of the watershed's hydrological fabric.

Estuarine & marine wetland · 117,374 acres

The tidal salt marshes lining every creek and sound. Among the most productive ecosystems per acre on Earth, sheltering juvenile fish, exporting organic matter, and forming the biological core of Port Royal Sound.

Freshwater forested & shrub wetland · 155,366 acres

Bottomland hardwoods and cypress swamps spanning the watershed interior. They store floodwater, transform nutrients, and provide critical habitat along connected upland-to-tidal corridors.

Freshwater emergent & pond · 15,468 acres

Interior marshes, wet meadows, and ponds. Seasonally flooded, highly productive for breeding amphibians and waterfowl, and disproportionately valuable for biodiversity relative to their acreage.

Freshwater Forested/Shrub Wetland

155,366ac

Estuarine Wetland

117,374ac

Freshwater Emergent Wetland

10,435ac

Freshwater Pond

5,033ac

Riverine

4,194ac

Lake

1,302ac

Estuarine deepwater

672,536ac · the open Sound

Estuarine deepwater is the open Sound, bays, and tidal rivers: the water body itself. It is shown for completeness and reported separately from the wetland-and-aquatic-habitat total above.

Wetland change · Annual NLCD 1985–2024

From 1985 to 2024, mapped woody wetland declined while mapped emergent wetland increased.

About 67% of the combined decline in woody wetland and increase in emergent wetland occurs after 2016. The endpoint transition matrix also identifies land that changed between these classes or to open water. Because these are 30-meter mapped classifications, determining whether the patterns reflect marsh migration, hydrologic change, vegetation disturbance, or classification effects requires additional spatial and field analysis.

Wetland classes · annual acres

Net change in annual series

Emergent wetland

+7,524ac · +7%

Woody wetland

−13,070ac · −6%

Endpoint transitions · 1985→2024

Woody → emergent wetland

8,546ac

Emergent wetland → open water

1,348ac