SFEWS

San Francisco Estuary and Watershed Science Volume 23, Issue 4 | December 2025 is online now escholarship.org/uc/jmie_sfews/…

McGill & Lacy found sediment bulk density in the #SFEstuary can be accurately predicted (93% of variation) by the % of fine particles. Models are system-specific; local conditions (tides & waves) affect density & erodibility, improving sediment budgets & restoration planning.

Pesticides in the Delta show complex patterns: H20 carried more hydrophilic pesticides, zooplankton absorbed more hydrophobic ones. Higher flows, esp. from Ag tailwater, ⬆️ pesticide conc. in #YoloBypass but ⬇️ in #SacRiver, highlighting risk of unintended effects from H20 mgmt.

Pelagic zooplankton is a key food source for endangered #DeltaSmelt, positively affecting their condition across all habitats. McCormick et al. found increasing zooplankton availability benefits #DeltaSmelt, regardless of proximity to tidal wetlands.

Peterson et al. find flooded wetlands in Suisun Marsh increased ~45% over 38 years due to a few sites. Spring/summer water availability varies annually & depends more on local mgmt than rainfall or river outflow. Making more wetlands semi-permanent may benefit breeding waterfowl.

Chapple et al. track progress across 4 key ecosystems to meet #DeltaPlan goals of restoring 60K-80K acres by 2050. Tidal wetland restoration leads, driven by ESA mitigation. Progress is promising, yet faster project planning & securing funding is critical to achieve targets.

Jensen et al. modeled how water flow, temperature, and exports affect endangered Sacramento winter-run #Chinook salmon migrating through the #CADelta. They found these factors are tied to their survival and routing, but key knowledge gaps remain on pathways and pump entrainment.

Using legacy hydrologic data, Hutton and Roy extended a monthly time-series of freshwater inflow to the #SFEstuary by 60 yrs to California’s Gold Rush era, revealing an increasing trend in systemwide water use that was preceded by a decline in the latter half of the 19th century.

How does risk of entrainment into Barker Slough Pumping Plant vary in space & time? If Nobriga et al.'s use of a 1-D model to estimate fish transport is accurate, then #DeltaSmelt & #LongfinSmelt spawned in Barker or Lindsey sloughs face a meaningful risk of entrainment at BSPP.

Gershunov et al. review AR science & their projected enhancement in a warming climate. Challenges for water mgmt may be mitigated by better & longer lead-times in weather and climate-forecasts, w/ modernized infrastructure, maintenance & improved observational networks.

Dahm et al. on how global change affects the forests & wildlands of California through rising temps, earlier snowmelt, more rain, less snow, greater vapor-pressure deficits & forest dieback, resulting in increased frequency, size, & severity of wildfires. bit.ly/41iYQp0

Colombano et al.'s essay presents five perspectives to advance science-informed decision-making in the era of climate change and extreme events.

SFEWS Vol. 23 Issue 3 is Now Online - mailchi.mp/ucdavis/sfews-…

SFEWS Special Issue, Vol. 23 Issue 2 Now Online - mailchi.mp/ucdavis/sfews-…

SFEWS Special Issue: The State of Bay-Delta Science, 2025 Extreme Events Edition: Vol. 23 Iss 1 is Now Online - mailchi.mp/22df8cd1570a/s…

Ritter et al. studied fish habitat in Richardson Bay in a dry winter & a wet winter using Dual-frequency Identification Sonar for (1) finfish & ray abundance & size distribution, (2) putative ray foraging pit size & abundance, & (3) eelgrass presence. bit.ly/41DOHT1

Mahardja et al. examine heatwaves, an extreme event of climate change expected to ⬆️ in duration, intensity, & frequency. Heatwaves cause wide-ranging human health effects: dehydration & heat exhaustion, ⬇️ birth weight, mental health problems, & violence. bit.ly/4iH3vHA

#BayDelta residents rely on water exports, yet droughts increase drinking water cost, decrease Ag production, & negatively affect Ag & labor markets. Hartman et al. describe tools to respond to droughts to increase supply, reduce demand, & mitigate actions bit.ly/4iF7Rio

Rudnick et al. review #BayDelta climate governance & study how it operates, broadly distilling two key dimensions that scholars suggest influence efficacy: the structure of a governance system & the degree of reactivity or proactivity in its processes. bit.ly/4kJ4V6b

The State of Bay–Delta Science reports on science & policy topics relevant to management of the #SFBay & #SacDelta. Part 1 of this edition begins the topics covering extreme events: an introduction, governance droughts, & heatwaves. bit.ly/41DygWY