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John Y Takekawa

Coastal ecosystems have been identified by the International Panel on Climate Change (2007) as areasthat will be disproportionally affected by climate change. Recent sea-level rise projections range from 0.57to 1.1 m (Jevrejeva et al. 2012) or 0.75 to 1.9 m by Grinsted et al. (2010) and Vermeer and Rahmstorf(2009) by 2100, which are contingent upon the ambient temperature conditions and CO2 emissions. Sealevelrise projections for San Francisco Bay are 1.24 m by 2100 (Cayan et al. 2008). The expectedaccelerated rate of sea-level rise through the 21st century will put many coastal ecosystems at risk,especially those in topographically low-gradient areas.Sea-level rise response modeling was conducted at 12 tidal salt...
The aim of this USGS program is to provide site specific sea-level rise predictions to land managers through the intensive collection of field data and innovative predictive modeling. In 2009 and 2010, thousands of elevation and vegetation survey points were collected in salt marsh at 12 sites surrounding San Francisco Bay. The elevation data was synthesized into a continuous elevation model for each site, providing land owners valuable baseline data. This site hosts the project report, pages describing each of the 12 marshes visited in this study, and maps and GIS data for all of the marshes including high-resolution digital elevation models.
In 2010 the U.S. Geological Survey (USGS), Coastal and Marine Geology Program completed three cruises to map the bathymetry of the main channel and shallow intertidal mudflats in the southernmost part of south San Francisco Bay. The three surveys were merged to generate comprehensive maps of Coyote Creek (from Calaveras Point east to the railroad bridge) and Alviso Slough (from the bay to the town of Alviso) to establish baseline bathymetry prior to the breaching of levees adjacent to Alviso and Guadalupe Sloughs as part of the South Bay Salt Pond Restoration Project (http://www.southbayrestoration.org). Since 2010 we have conducted four additional surveys to monitor bathymetric change in this region as restoration...
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Tracklines and associated observations were mapped and analyzed using ArcMap (ESRI, Redlands, CA). GPS data were recorded in NAD27 map datum and projected to an USGS Albers Equal Area Conic map projection for presentation and subsequent density analyses. Concatenated GPS and observation data were then used to generate point and line coverages in ArcMap (ESRI, Redlands, CA). We designed a custom analytic tool using ArcMap Model Builder that allows for the construction and export of user-specified and effort-adjusted spatial binning of species observations along continuous trackines. For the purposes of this report, we calculated seabird density estimates and marine mammal counts along continuous 3.0-kilometer and...
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This data set contains decomposition rates for litter of Salicornia pacifica, Distichlis spicata, and Deschampsia cespitosa buried at 7 tidal marsh sites in 2015. Sediment organic matter values were collected at a subset of sites. These data support the following publication: Janousek, C.N., Buffington, K.J., Guntenspergen, G.R. et al. Ecosystems (2017). doi:10.1007/s10021-017-0111-6. http://link.springer.com/article/10.1007/s10021-017-0111-6
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