This layer shows a 250-meter buffer from the 45-meter buffer of the maximum extent that eelgrass has been surveyed in the San Francisco Bay. This resource is intended to be a starting point for understanding potential sites where indirect impacts to eelgrass habitat could occur as a general reference only. Further information on methods and limitations can be found at SFEI. Merkel & Associates, Inc. conducted Baywide surveys in 2003, 2009, 2014, and a Richardson Bay survey in 2019 - the 250-meter buffer was developed from all of these survey data. The 2019 results were received from Merkel & Associates, Inc directly and permission to share this publicly was granted.

Methods for developing this dataset are as follows:

Downloaded Baywide Eelgrass Surveys from SFEI done by Merkel & Associates, Inc in 2003, 2009, and 2014. Uploaded this layer and Richardson Bay 2019 survey layer (projected NAD 1983 UTM Zone 10N). Used Buffer tool to develop a single multipart shapefile with a 45-meter buffer from the input layers. Imported the Pacific Marine and Estuarine Fish Habitat Partnership (PMEP) Estuary Extent layer and clipped the 45-meter buffer over terrestrial areas based on the PEMP Estuary Extent (this represents the 45-meter eelgrass buffer layer also found in this Web Application). To create the 250-meter buffer from there, the same methods were used as follows. Used Buffer tool to develop a single multipart shapefile with a 250-meter buffer from the 45-meter buffer layer. Clipped the 250-meter buffer over terrestrial areas based on the PEMP Estuary Extent. Some minor adjustments were made where the 250-meter buffer layer resulted in fragments on land or behind levees.