The Bay: Where We're Watching
Explore how WRMP monitors the San Francisco Estuary across regions, networks, and restoration sites.
The data runs deeper
This exhibit is one layer. WRMP's monitoring lives inside a larger data ecosystem — from the Bay-wide EcoAtlas toolset to the raw datasets scientists work with every day.
Explore the data ecosystem
The Estuary
The San Francisco Estuary is the largest on North America's Pacific coast — a vast network of tidal marshes, sloughs, and open water where freshwater rivers meet the sea.
It's home to over 250 species of fish and invertebrates, including several listed for protection: Winter-run Chinook Salmon, Delta and Longfin Smelt, Green and White Sturgeon.
The Wetland Regional Monitoring Program (WRMP) watches over this system with a network of monitoring stations stretching from Suisun Bay to the southern tip of the South Bay.
Three Worlds
You can't study the estuary as one thing. It's three distinct ecological zones, shaped by a single force: salinity.
Suisun Bay in the east is nearly fresh — fed by the Sacramento and San Joaquin rivers. It hosts freshwater species like Threespine Stickleback and Siberian Prawn.
North Bay is the mixing zone — brackish water where freshwater and marine species overlap. The most dynamic habitat, shifting with the tides and seasons.
South Bay is the most saline, connected to the Pacific. Here you find marine species — jellyfish, tunicates, English Sole — alongside estuary residents.
The Network
Scientists cover this vast territory through nine sampling networks — circuits that field crews run by research vessel, timed to the tides.
Each circuit is sampled with otter trawls — nets towed behind the boat for 10 minutes, sweeping up fish and invertebrates from the channel bottom. A single quarter produced 244 trawl samples across the Bay.
Shallow stations require spring tides for access. Crews plan around weather, tidal windows, and even submerged hazards — one network lost a propeller to an unmarked rock wall.
Restoration in Progress
The South Bay is home to the largest tidal wetland restoration in the United States — 15,000 acres of former salt ponds being returned to tidal marsh habitat.
The monitoring network is designed to answer a critical question: is restoration working?
By sampling at restored project sites alongside natural reference sites and long-term benchmarks, scientists can directly compare fish communities.
What Comes Next
Across the Bay, 17 planned restoration sites mark where the next chapter of recovery will unfold. Baseline monitoring at these locations will begin before construction starts — establishing what's there before transformation.
As data accumulates, each station on this map will grow to reflect what was found there — species abundance, community diversity, seasonal patterns.
The map becomes a living portrait of the estuary's ecological health — showing not just where we look, but what we find.