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Trends and habitat associations of waterbirds using the South Bay Salt Pond Restoration Project, San Francisco Bay, California

Open-File Report 2018-1040

By:
https://doi.org/10.3133/ofr20181040

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Executive Summary

The aim of the South Bay Salt Pond Restoration Project (hereinafter “Project”) is to restore 50–90 percent of former salt evaporation ponds to tidal marsh in San Francisco Bay (SFB). However, hundreds of thousands of waterbirds use these ponds over winter and during fall and spring migration. To ensure that existing waterbird populations are supported while tidal marsh is restored in the Project area, managers plan to enhance the habitat suitability of ponds by adding islands and berms to change pond topography, manipulating water salinity and depth, and selecting appropriate ponds to maintain for birds. To help inform these actions, we used 13 years of monthly (October–April) bird abundance data from Project ponds to (1) assess trends in waterbird abundance since the inception of the Project, and (2) evaluate which pond habitat characteristics were associated with highest abundances of different avian guilds and species. For comparison, we also evaluated waterbird abundance trends in active salt production ponds using 10 years of monthly survey data.

We assessed bird guild and species abundance trends through time, and created separate trend curves for Project and salt production ponds using data from every pond that was counted in a year. We divided abundance data into three seasons—fall (October–November), winter (December–February), and spring (March–April). We used the resulting curves to assess which periods had the highest bird abundance and to identify increasing or decreasing trends for each guild and species.

Suggested Citation

De La Cruz, S.E.W., Smith, L.M., Moskal, S.M., Strong, C., Krause, J., Wang, Y., and Takekawa, J.Y., 2018, Trends and habitat associations of waterbirds using the South Bay Salt Pond Restoration Project, San Francisco Bay, California: U.S. Geological Survey Open-File Report 2018–1040, 136 p., https://doi.org/10.3133/ofr20181040.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Executive Summary
  • Introduction
  • Study Area
  • Methods
  • Results
  • Discussion
  • Acknowledgments
  • References Cited

Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Trends and habitat associations of waterbirds using the South Bay Salt Pond Restoration Project, San Francisco Bay, California
Series title:
Open-File Report
Series number:
2018-1040
DOI:
10.3133/ofr20181040
Year Published:
2018
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Western Ecological Research Center
Description:
viii, 136 p.
Country:
United States
State:
California
Other Geospatial:
South San Francisco Bay
Online Only (Y/N):
Y