Estuarine Salinity Zones for 147 US Estuaries

147 estuaries in the contiguous United States are classified into three average annual salinity zones: Tidal Fresh (0-0.5 ppt), Mixing (0.5-25 ppt), and Seawater (≥25 ppt). This static geographic dataset, created by NOAA's National Estuarine Inventory and refined in the 1990s, provides a foundational spatial framework for long-term resource assessments. Its cross-platform presence on NASA Earthdata and Data.gov signals its established use in federal science and management programs.

Use Cases

• Serving as a spatial framework for the Estuarine Living Marine Resources (ELMR) Program species database.
• Providing baseline zones for National Estuarine Eutrophication Assessments.
• Analyzing long-term salinity characteristics for coastal habitat classification.
• Mapping the extent of tidal fresh, mixing, and seawater zones within specific estuaries like Baffin Bay, Texas.

Strengths

• Covers a substantial set of 147 estuaries across the contiguous U.S. coasts.
• Based on analysis of long-term salinity data, providing a stable, average-condition view.
• Has a documented history of use in key NOAA programs like ELMR and eutrophication assessment.

Limitations

• The 3-zone scheme is static and does not account for seasonal or interannual salinity variation.
• There is a conflict in the 'last updated' metadata: one source states 1999-12-31, while others list 2026-03-05, suggesting a possible metadata error or re-publication.
• Specific column names, row counts, and file formats are not provided by any source.

Provenance

Source

NOAA National Centers for Environmental Information (NCEI), originating from the National Estuarine Inventory (NEI).

Collection Method

Analysis of long-term, annual-averaged and depth-averaged salinity data to define geographic zones.

Time Range

1999-01-01 to 1999-12-31

Freshness

2026-03-05 23:02:26.741366

Geography

Estuaries of the contiguous United States (East Coast, Gulf of Mexico, West Coast).