Aquatic Health Program

News & Events

2005-2009 Pelagic Organism Decline: Effects of Toxic Contaminants on Invertebrates and Fish in the Sacramento-San Joaquin Delta.

2007-2008 Surface Water Quality Monitoring - Orestimba and Del Puerto Creek Watersheds.

2007 Toxicity of Checkmate® LBAM-F and Epiphyas postvittana Pheromone to Ceriodaphnia dubia and Fathead Minnow (Pimephales promelas) Larvae.

2005-2008 Water Quality Benefits of Vegetated Agricultural Drainage Ditches as a Viable Management Practice.

2004-2008 California State Water Resources Control Board: Surface Water Ambient Monitoring Program.

2007-2008 Toxicity of runoff from new road surface materials.

2001-2003 The New River and Alamo River Project focuses on identifying specific chemical causes and sources of toxic contaminants in the New and Alamo Rivers. Monthly monitoring is conducted on samples taken from four sites and tested with P. pimephales, C. dubia, and Neomysis. Phase I and Phase II TIEs are conducted on toxic samples.

2001-2003 The Bioassessment Study of Effluent and Agricultural-Dominated Waterbodies will establish a baseline for aquatic biological community structure and physical habitat conditions in the Central Valley using the US EPA’s rapid bioassessment protocols.

2000-2003 The Cal Trans State-wide Monitoring project monitors run-off waters collected from 37 sites across California. All samples are tested with P. pimephales, C. dubia and S. capricornutum. Phase I and Phase II TIEs are conducted on toxic samples.

2002 The Dormant Spray and In-Season Monitoring of the San Joaquin River Basin focuses on organophosphate and pyrethroid pesticide toxicity. The lower San Joaquin River has been listed in the Clean Water Act 303(d) list of impaired waterways for elevated concentrations of diazinon and chlorpyrifos. Samples are employed in C. dubia toxicity testing, sediment testing, and bioassessment.

2001-2002 The US EPA Study of the San Joaquin River at Vernalis augmented existing projects by conducting baseline studies before rain and then conducting two event-based studies. Samples were tested with P. pimephales, C. dubia and S. capricornutum Phase I TIEs were conducted on toxic samples.

2000-2001 The Los Angeles River Project focused on toxicity due to organophosphorus pesticides. Monthly monitoring included six sites in the Los Angeles River Watershed. Toxicity tests were conducted with P. pimephales and C. dubia, and Phase I TIEs were conducted on toxic samples.

2000-2001 The Lake Elsinore Project was a study to determine if there was toxicity in the lake. It had previously been placed on the Clean Water Act 303(d) list of impaired waterways. All samples were tested with P. pimephales, C. dubia and S. capricornutum.

2000-2001 Phytotoxicity in the Sacramento River, San Joaquin and Delta was a study to monitor toxicity to S. capricornutum in these watersheds and to develop TIE methods.

1999-2000 Toxicity of Unknown Cause was a study investigating the cause of anomalous toxicity found in P. pimephales toxicity testing. The anomalous toxicity occurred throughout the Sacramento River, San Joaquin River, Delta and Big Chico Creek watersheds and was associated with high variability among replicates.

1999-2000 Alternative Practices for Reducing Pesticide Impacts on Water Quality compared the pest control efficiency and water quality influences of traditional applications of diazinon and chlorpyrifos to a variety of alternative practices in Stanislaus County. Monitoring was conducted with P. pimephales and C. dubia, as well as newly developed toxicity tests employing organisms indigenous to the area (a rotifer, a benthic midge, a cladoceran, a cycloid copepod and an amphipod).

1998-2000 The City of Modesto focused on indicating if toxicity found in Dry Creek and the lower Tuolumne River could be attributed to organophosphate pesticides. Toxicity testing was performed with C. dubia and Phase I and Phase II TIEs were performed on toxic samples. Chlorpyrifos and diazinon have been chemicals identified as chemicals causing mortality to C. dubia during the wet season.

1998-1999 The Integrated Pest Management Project was a comprehensive study which looked at alternative pest control practices, their efficacy as pest deterrents and their impact on aquatic species.

1998-1999 The DeltaKeeper Sacramento-San Joaquin Delta Project was a continuation of previous Bay Protection and Toxic Cleanup Program efforts. Intensive sampling schedules was used to take a closer look at toxicity seen in previous years. This project's emphasis was to determine the chemical cause of toxicity through the use of Toxicity Identification Evaluations (TIEs).

1996-1999 The Sacramento River Watershed Project focused on the Sacramento River and its major tributaries. Water samples were screened using EPA three species bioassays. Also, Phase I TIEs were conducted on toxic samples. Future work will focus on P. pimephales and C. dubia assays since these species have proven to be more sensitive to Sacramento River toxicity in previous tests. Diazinon and nickel have been identified as chemicals causing mortality to C. dubia within this watershed.

1998-1999 The Cache Creek and Putah Creek Watersheds Monitoring Project focused on land use and inputs into the watersheds. Agricultural, mine, NPDES, and urban runoff inputs were evaluated using EPA three species bioassays. Water sampling took place over a complete hydrologic cycle. TIEs will identified constituents when toxicity was observed.

1998 The Gasoline Additive Study evaluated MTBE and ethanol toxicity to an indigenous shrimp and rotifer.

1997-1998 The Revolon Slough Project was a follow-up study intended to identify toxic chemicals and highlight geographic sources of organophosphorous and carbamate insecticides. In addition, this project evaluated the adverse impact of these insecticides to Mugu Lagoon which is both an ecological preserve and a Revolon Slough discharge.

1996-1998 The DeltaKeeper Urban Runoff Project examined water samples from five Stockton waterways. The project's objective was to characterize toxicity in storm water runoff located within the statutory boundaries of the Delta and downstream of the city's monitored outfalls. Toxicity Identification Evaluations were used to determine the chemicals present in toxic samples. Organophosphorus pesticides have been identified as the primary cause of toxicity to C. dubia..

1996-1998 The San Diego Creek Project characterized toxicity from storm water runoff in San Diego Creek. Phase I TIEs were used to identify toxicants causing toxicity to C. dubia. Also, Enzyme Linked Immunosorbant Assays were used as a technique to analyze water samples for diazinon and chlorpyrifos.

1997 The Dormant Spray Study was designed to identify dormant spray pesticides. Several samples were collected in the Sacramento and San Joaquin Rivers following storm events. Samples underwent microfiber filtering, C-8 column solid phase extraction, and USGS pesticide analysis. Diazinon was identified as a primary cause of toxicity to C. dubia.

1997 The Yolo County Agricultural Runoff Project evaluated toxicity from agricultural runoff where chlorpyrifos was applied according to manufacturer's instruction. The project also helped evaluate the ability of tailwater ponds to prevent pesticides from moving off site and into major waterways.

1997 The Rainbow Trout Embryo Study focused on the Sacramento River and its major tributaries from Redding to Sacramento. Sampling sites included areas of spawning and nursery for anadromous fishes. The lab adapted Canaria and Bailey's protocol to a 7-day static-renewal bioassay initiated at fertilization.

1997 The Rotifer Toxicity Study focused on the Sacramento River and its major tributaries from Redding to Sacramento. The study employed rotifer bioassays to better represent variations in sensitivities among zooplankton.

1997 The In Season Orchard Spray Study focused on waterways impacted by off-site movement of pesticides applied to orchards. Samples were collected weekly from April to September 1997. Sampling events alternated between Sacramento River watershed sites and San Joaquin River watershed sites. The initial screen followed EPA protocols for C. dubia toxicity tests. Phase I, II, and III TIEs were conducted on toxic samples. Chlorpyrifos and other pesticides were identified as the primary causes of toxicity.

1996 - 1997 The Salton Sea Pesticide Runoff Project was designed to determine if the Alamo River is discharging toxic concentrations of pesticides into the Salton Sea. The Alamo River and various sites within the Salton Sea were sampled and analyzed for pesticides. Samples were screened for pesticides using Enzyme Linked Immunosorbant Assays. In addition, samples underwent microfiber filtering, C-8 column solid phase extraction, and pesticide analysis.

1995 The Pesticide Transport in Air Project studied the movement of sprayed pesticides from dormant orchards to the Greater Sacramento and Stockton areas. Urban samples were analyzed using Enzyme Linked Immunosorbant Assays. The project showed clear patterns of elevated diazinon concentrations in rain samples after dormant orchards were sprayed with pesticides.

1994-1995 The Urban Storm Runoff Toxicity Study characterized toxicants from urban runoff waters in the cities of Sacramento and Stockton. Toxicity was evaluated using EPA three species bioassays. Also, Toxicity Identification Evaluations were conducted on toxic samples to identify the cause of toxicity.

1993-1995 The Sacramento-San Joaquin Delta Monitoring Project focused on the Delta's inputs, across-estuary pathways, island drains, and back sloughs. Special attention was given to identifying Toxic Hot Spots as instructed by the Bay Protection and Toxic Cleanup Program. We assessed toxicity using EPA three-species bioassays. The lab also conducted Phase I, II and III TIEs on various samples to identify toxic constituents. Diazinon, chlorpyrifos, carbaryl and carbofuran were identified as compounds primarily responsible for toxicity to C. dubia.

1995 The Sediment Toxicity Study was conducted in cooperation with Pacific Eco-Risk Laboratories to investigate sediment associated toxicity in waters collected from the San Joaquin and Cache Basins.

1995 The Reconnaisance Pesticide Snow Melt Study was conducted in cooperation with the US Geological Survey to evaluate pesticide concentrations in snow collected from the Sierra Nevada range downwind of major orchard areas. Samples were microfiber filtered, extracted with C-8 solid phase columns, and sent to USGS for pesticide analysis.

1993-1994 The North Valley Study focused on metal toxicity in the upper Sacramento River watershed from Shasta Dam to Hamilton City. Toxicity was assessed using EPA three-species bioassays. TIE manipulations on toxic samples included extraction with cation-exchange resin columns to determine the role metals played in the observed toxicity.

1993 The Dormant Spray Insecticides Study tracked dormant spray pesticide transport through the Delta. Samples were microfiber filtered, extracted with C-8 solid phase columns, and sent to USGS for pesticide analysis.

1991-1992 The Central Valley Orchard and Alfalfa Study characterized off-site movement and toxicity of pesticides applied to orchards and alfalfa.

1991-1992 The Walker Mine Toxicity Study evaluated the efficacy of remedial structures at the Walker Mine. Impacts to Little Grizzly and Dolly Creeks were evaluated using EPA three species bioassays. Toxicity Identification Procedures and analytical chemistry demonstrated that copper was the cause of toxicity to all three test species.

1991-1992 The Sacramento Reservoir Survey evaluated metal contributions from major reservoir releases to the Sacramento River. Significant copper and zinc toxicity were identified downstream of Keswick Dam.

1988-1989 The Sacramento Point Source Discharge Survey evaluated the impact of several NPDES discharges on the lower Sacramento and American Rivers. Water samples were taken at sites upstream and downstream of discharges. Toxicity was assessed using EPA three species bioassays.

1988-1990 The Sacramento River Toxicity Survey focused on the Sacramento River and its major tributaries. The study's objective was to characterize the spacial and temporal distribution of toxicity in the Sacramento River Basin, as well as to identify toxic constituents. Twenty-five sites were sampled for 18 consecutive months and tested with EPA three species bioassays.

1988-1989 The Colusa Basin Drain Rice Season Biotoxicity Project evaluated toxicity in the Colusa Basin Drain using EPA three species bioassays. This project highlighted rice fields as a source of toxic inputs into agricultural drainage.

1986-1987 The Lower Sacramento Toxicity Survey evaluated toxicity in the lower Sacramento River and its major tributaries using EPA three species bioassays.