The data release contains data for the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll. Data-collection cruises were conducted over two days in March 2017 during a high flow event when Sacramento Valley flood waters inundate the Yolo Bypass.

This data release documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll . Data-collection cruises were conducted under three different environmental/flow conditions in August, September, and October 2018 that coincided with conditions prior to, during, and following a directed flow action or pulse of agricultural return water organized by the California Department of Water Resources and California Natural Resources Agency .

This data release documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll . Data-collection cruises were conducted under three different environmental/flow conditions in August, September, and October 2018 that coincided with conditions prior to, during, and following a directed flow action or pulse of agricultural return water organized by the California Department of Water Resources and California Natural Resources Agency .

Largely supported by the Interagency Ecological Program (IEP), California Department of Water Resources (DWR) has operated a fish monitoring program in the Yolo Bypass, a seasonal floodplain and tidal slough, since 1998. The objectives of the Yolo Bypass Fish Monitoring Program (YBFMP) are to: 1. Collect baseline data on water quality, chlorophyll, lower trophic level biota, and fish in the Yolo Bypass to monitor spatial and temporal changes in trends and abundance. 2. Analyze and communicate Yolo Bypass data with interested parties and the scientific and management communities to address pertinent management-related questions. 3. Provide technical expertise on Yolo Bypass aquatic ecology and monitoring and sampling methods. The YBFMP operates a rotary screw trap and fyke trap and conducts biweekly beach seine and lower trophic surveys in addition to maintaining water quality instrumentation in the bypass. The YBFMP informs the restoration actions that are mandated or recommended in these plans and provides critical baseline data on the ecology of the bypass and how it interacts with the broader San Francisco Estuary. YBFMP’s data is often accompanied by information on whether the Yolo Bypass is inundated, as water quality, and species composition and abundance can be greatly altered during inundation. This dataset was created to consistently estimate inundation over time. Estimating inundation in the Yolo Bypass is usually done by referencing stage height in the Sacramento River at Fremont Weir. Stage height is the water level of the river. Fremont Weir is upstream of the Yolo Bypass and when Fremont Weir overtops, or reaches its monitoring stage, the Yolo Bypass is considered inundated. This dataset is originally published on EDI and linked to this CNRA open data portal.

Yolo Bypass is an ecological feature of the Bay-Delta ecosystem in California that provides floodplain habitat for spawning and rearing of Sacramento Splittail (Pogonichthys macrolepidotus) and rearing of juvenile Chinook Salmon (Oncorhynchus tshawytscha) when inundated. We used outputs from 10 climate change models for two Representative Concentration Pathways (RCPs) for greenhouse gas concentrations to assess the effects of climate change on the frequency, duration, and timing of flood flows in Yolo Bypass. We also assessed a planned notched weir modification to the primary weir that controls inflow from the Sacramento River into Yolo Bypass that has been designed to allow the bypass to be inundated at lower river flows.

The dataset documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta of the Sacramento-San Joaquin River Delta of California, USA. The dataset includes surface mapping, depth profile, and discrete data for nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, and chlorophyll as well as information about phytoplankton community composition. Data-collection cruises were conducted over two time periods in July and October 2018 across two flooded islands with dense submerged aquatic vegetation beds. Little Hastings Tract received an herbicide treatment by the California Department of Boating and Waterways and French Island was the untreated control site.

The dataset documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta of the Sacramento-San Joaquin River Delta of California, USA. The dataset includes surface mapping, depth profile, and discrete data for nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, and chlorophyll as well as information about phytoplankton community composition. Data-collection cruises were conducted over two time periods in July and October 2018 across two flooded islands with dense submerged aquatic vegetation beds. Little Hastings Tract received an herbicide treatment by the California Department of Boating and Waterways and French Island was the untreated control site.

This report documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll. Data-collection were conducted over one day in July 2017 when continuous monitoring stations detected elevated chlorophyll concentration and decreasing nitrate concentrations.

This report documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll. Data-collection were conducted over one day in July 2017 when continuous monitoring stations detected elevated chlorophyll concentration and decreasing nitrate concentrations.

This dataset includes shallow surface sediment (top 0–2 cm interval) constituent concentration data (primarily) and microbial methylmercury production potential rate data (limited) collected from the Cache Creek Settling Basin (CCSB), Yolo County, California, between April 2010 and November 2019. The dataset includes up to 723 observations (including field replicates) per sediment parameter, reflecting 93 unique sampling locations, with each location having been sampled from 1 to 29 times (excluding field replicates) over this 10-year period. There were four spatially intensive field campaigns conducted (February–March 2013, May 2013, October–November 2014, and January–March 2015), during which at least 90 sites were sampled. A sub-set of 13 sites were sampled intensively (20–29 times, primarily during 2015–2017, and 2019) to create a more detailed monthly time-series at these locations. Sampling was conducted over a range of hydrologic conditions, from periods when the basin was essentially dry (no overlying water, even in ‘open-water’ habitats) to periods when the basin was nearly fully flooded (most sites with overlying water). Analyses in this dataset include: bulk sediment: total mercury, methyl mercury, reactive mercury(ll), iron speciation, total reduced sulfur, loss on ignition, dry weight, bulk density, porosity, grain-size (sieved), grain size distribution; pore water: total mercury, methyl mercury, dissolved organic carbon, sulfate, chloride, sulfide, and isotopic delta 34-S of sulfate. This data release is a revision, which includes six data tables given both as excel (*.xlsx) and machine readable (comma-separated values, *.csv) format: 1) ‘T1_CCSB_SED_data_dictionary _ver2.0’, the Data Dictionary, which provides definitions and details related to the other five data tables and includes citations of analytical methods; 2) ‘T2_CCSB_SED_ver2.0’, the primary dataset with spatial/temporal sediment and pore water analyses; 3) ‘T3_CCSB_SED_seq_extr’, a sub-set of sediment samples (33 sites collected during May 2013) assayed for Hg using a 5-fraction sequential extraction procedure; 4) ‘T4_CCSB_SED_grain_size_ver2.0’, data on detailed sediment grain-size distribution (by laser-scattering) for 630 unique samples (plus n=67 field duplicates); 5) ‘T5_CCSB_SED_size_frac’, a sub-set of sediment samples (33 sites collected during May 2013) size-fractioned into 5 size classes and assayed for total mercury and limited suite of parameters, including particulate surface area (15 of the 33 sites); and 6) ‘T6_CCSB_SED_QA_ver2.0’, quality assurance data summary. The mapping of the physical site locations can be found on the companion child page associated with this product (https://www.sciencebase.gov/catalog/item/607625f2d34e018b3201cc1b) First posted – October 16, 2018 (available from author) Revised – July, 2021 (version 2.0)