Tidal & Estuary Dynamics

A fragile ecosystem exists where rivers meet the ocean. The flora and fauna particular to the estuary and tidal environments have evolved to withstand the many water quality issues (from salinity to sediment) that come into play within this zone straddling freshwater and marine habitats. Stillwater approaches these brackish environments as extensions of the upstream watershed and have expertise in questions related to:

  • Lagoon/marsh geomorphic dynamics: sedimentation dynamics and local topographic change; groundwater elevation; mouth breaching
  • Hydraulic modeling: bathymetry evolution
  • Marsh vegetation: establishment, recruitment, and changes in zonation
  • Sea level rise, salt-water encroachment, and climate change
  • Fish rearing and spawning habitat: listed salmonids, smelt, spilltail, and tidewater goby)
  • Shorebird surveys and monitoring
  • Eelgrass habitat restoration and monitoring
  • Wetland habitat planting plans and fisheries habitat development
  • Nutrient and macroalgae synoptic sampling
  • Point source pollution: development of comprehensive water quality sampling plans and assessment of narrative and numeric compliance with regional, statewide, and national water quality criteria for coastal and inland waters.


Our watershed-wide perspective helps link upstream activities with downstream outcomes.


Noah Hume
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Energizing the Ocean

Wave energy has the potential to provide an economical energy supply that would lessen our reliance on coal. Stillwater was a part of a multi-disciplinary team assisting PG&E with a draft pilot license application for their Humboldt WaveConnectTM Project.

Tidewater Goby Restoration “Toolbox”

Stillwater developed hydrologic and biologic guidelines to assist resource managers as they implement tidal habitat restoration or enhancement activities for the federally listed endangered tidewater goby (Eucyclogobius newberryi).

Wastewater Discharge: Good or Bad?

Stillwater is helping to assess whether the treated wastewater discharge to the Santa Clara River Estuary by the City of Ventura’s Water Reclamation Facility provides ecological enhancement or harm both now and in the future.

Eelgrass Restoration

An idle fuel pipeline removal in Humboldt Bay included restoration of 1 acre of eelgrass habitat to satisfy various permit stipulations. Eelgrass was transplanted from neighboring natural beds into the disturbed site. Successful colonization by anemones, octopus, and crabs was observed soon thereafter.