Executive Summary
This report summarizes waterbird and water quality monitoring efforts by the San Francisco Bay Bird
Observatory between September 2024 and May 2025 at 82 ponds within the South Bay Salt Pond
Restoration Project (SBSPRP) and remaining nearby salt production ponds. For over two decades the
SBSPRP has been restoring 15,000 acres of former salt evaporation ponds to a mix of tidal marsh and
enhanced managed pond habitats. Monitoring has shown declines in some taxa but evidence of cyclical
trends in others, which might be the result of external flyway-level climatic or habitat factors or
density-dependent regulation. It is important to assess if observed declines were driven by SBSPRP
actions or these other factors. As restoration proceeds, understanding waterbirds’ habitat use to adaptively
manage ponds and restoration planning can help maintain and recover waterbirds in the South Bay.
We examined species richness, abundance, and behavior of waterbird assemblages within pond
complexes based on either foraging guild (e.g., diving ducks) or specific species of special concern (e.g.,
Ruddy Ducks). Multi-year abundances in each taxa’s target season (fall, winter, or spring) were compared
to baseline values from near the start of the project (2005–2007) to assess long-term trends. To understand
the drivers of observed changes we developed and applied a model relating changes in seasonal
abundance of each species/guild’s abundance to changes in habitat conditions, annual weather, and static
site characteristics. For the first time this year, these models were expanded to cover fisheaters, gulls,
herons and egrets, and terns, which do not have formal management triggers set.