Marsh Sustainability
USGS scientists are studying sediment transport (including the supply, movement, and deposition of sediment) in the Bay-Delta system.
One reason that such studies are crucial is that sediments transported by rivers are important to building and sustaining tidal wetlands, such as marshes and mudflats. In the 1800s, unnaturally large volumes of sediment entered the Bay-Delta as a result of hydraulic mining. After accounting for the sediments from hydraulic mining, recent studies indicate that the amount of sediment entering the Bay-Delta has been steadily decreasing from expected natural levels and that current declines in sediment are in part caused by sediment retention behind dams. USGS is working toward a better understanding this decline, quantifying how much sediment input can be expected in the future and describing where sediments are being trapped or moved between different parts of Bay-Delta system. With an increased understanding of sediment transport, it may also be possible to better manage the distribution of sediments for habitat restoration, shoreline erosion control and protection, dredging projects, and related species-preservation efforts.
The survival of tidal-marsh habitats largely depends on (1) processes that contribute to the creation and elevation of marshes (such as sediment inputs and the deposition of plant remains) and (2) processes that contribute to the loss of marshes (such as sea-level rise, soil compaction, and subsidence). These factors interact in complex ways, and models accounting for this complexity developed by USGS scientists are proving to be useful tools to generate maps of tidal-marsh sustainability. To measure habitat quality, USGS is currently enhancing its existing water-monitoring network (which, for example, measures water level, flow direction and speed, salinity, temperature, and clarity) with the establishment of “super stations” at strategic locations. The enhancements include adding new sensors to existing stations, as well as installing several new stations, to collect data every 15 minutes on a variety of additional water characteristics. These characteristics include nutrients (such as phosphorus and nitrogen), phytoplankton (microscopic plants), light penetration into the water, and dissolved organic material (such as that from plant remains). These characteristics may have biological and ecological consequences for the base of the aquatic food web in the Bay-Delta, which in turn may affect the health of both aquatic and terrestrial species populations.
For more information see:
Modeling Sea-Level Rise in San Francisco Bay Estuary
Mapping and Monitoring Wetland Carbon for Climate Change Mitigation and Adaptation Planning
Back to San Francisco Bay-Delta Science
USGS scientists are studying sediment transport (including the supply, movement, and deposition of sediment) in the Bay-Delta system.
One reason that such studies are crucial is that sediments transported by rivers are important to building and sustaining tidal wetlands, such as marshes and mudflats. In the 1800s, unnaturally large volumes of sediment entered the Bay-Delta as a result of hydraulic mining. After accounting for the sediments from hydraulic mining, recent studies indicate that the amount of sediment entering the Bay-Delta has been steadily decreasing from expected natural levels and that current declines in sediment are in part caused by sediment retention behind dams. USGS is working toward a better understanding this decline, quantifying how much sediment input can be expected in the future and describing where sediments are being trapped or moved between different parts of Bay-Delta system. With an increased understanding of sediment transport, it may also be possible to better manage the distribution of sediments for habitat restoration, shoreline erosion control and protection, dredging projects, and related species-preservation efforts.
The survival of tidal-marsh habitats largely depends on (1) processes that contribute to the creation and elevation of marshes (such as sediment inputs and the deposition of plant remains) and (2) processes that contribute to the loss of marshes (such as sea-level rise, soil compaction, and subsidence). These factors interact in complex ways, and models accounting for this complexity developed by USGS scientists are proving to be useful tools to generate maps of tidal-marsh sustainability. To measure habitat quality, USGS is currently enhancing its existing water-monitoring network (which, for example, measures water level, flow direction and speed, salinity, temperature, and clarity) with the establishment of “super stations” at strategic locations. The enhancements include adding new sensors to existing stations, as well as installing several new stations, to collect data every 15 minutes on a variety of additional water characteristics. These characteristics include nutrients (such as phosphorus and nitrogen), phytoplankton (microscopic plants), light penetration into the water, and dissolved organic material (such as that from plant remains). These characteristics may have biological and ecological consequences for the base of the aquatic food web in the Bay-Delta, which in turn may affect the health of both aquatic and terrestrial species populations.
For more information see:
Modeling Sea-Level Rise in San Francisco Bay Estuary
Mapping and Monitoring Wetland Carbon for Climate Change Mitigation and Adaptation Planning
Back to San Francisco Bay-Delta Science