This web-based application was created by BCDC to
support the Long Term Management Strategy for the Placement of Dredged Material
in the San Francisco Bay Region (LTMS)
program and the National Marine Fisheries Service’s 2011 LTMS Programmatic Essential Fish Habitat (EFH) consultation. The web application
can assist project planners in identifying potential impacts of dredging
projects in San Francisco Bay to eelgrass based on the LTMS EFH consultation. Once inside
the application, click on the “about” button to learn more about assessing impacts
and make sure to refer to the EFH consultation linked above for more specific information.
Layers in this application include: 1) the
maximum extent of eelgrass beds that have been surveyed in San Francisco Bay
shown in green; 2) a 45-meter growth buffer for potential bed expansion shown
in blue; 3) Polygons demonstrating where dredging occurs within San Francisco Bay; and 4) a 250-meter turbidity buffer around dredging footprints. The eelgrass survey data used in this web
application represents the best available data on comprehensive eelgrass extent
throughout San Francisco Bay as of 2021. The original eelgrass survey data were
developed by Merkel & Associates, Inc. (Merkel) using a combination of
acoustic and aerial surveys and site-specific ground truthing. This web
application may be used to determine potential direct and indirect impacts to
eelgrass habitat from dredging projects as described in the LTMS EFH
consultation. These data do not replace the need for site-specific eelgrass
surveys as directed by the regulatory and resource agencies.Data from the 2003, 2009, and 2014 baywide eelgrass
surveys and associated Merkel reports, which include information on mapping methodology,
are available for download on the San Francisco Estuary Institute’s (SFEI) website. Data from a Richardson Bay survey conducted by Merkel in 2019 is also included
in this application. For further
information on methods used here please enter the application by clicking “View
Application” on the right, then click the “…” next to each layer, and then
select “Show item details" in the drop-down menu for each individual layer.
