Hydrologic and Aquatic Ecology Studies at Clear Lake, California Active
The USGS California Water Science Center conducts a variety of research activities at Clear Lake, California, including surface-water monitoring and water quality and aquatic habitat studies.
Clear Lake is the largest natural lake entirely within California. It is in the California Coast Range, approximately 60 miles (100 kilometers) north of San Francisco Bay. The lake supports a wide variety of fish and bird species and is a very popular sport-fishing destination.
Water Quality
Clear Lake is hypereutrophic (has excess algal growth), and as such has a severe problem with harmful algal blooms (HABs). Excess algae and HABs can be detrimental to aquatic life because when the algae die, sink, and decay, the lake is deprived of the dissolved oxygen that fish need to breathe. A driving factor of these conditions are the nutrient loads being carried into the lake by soil erosion and the transport of sediment and dissolved nutrients via the lake’s tributaries. Nutrients are also recycled from the lake bed, especially when wind conditions drive sediments from the bed to the surface.
The USGS is monitoring and modeling the Clear Lake watershed to better understand these nutrient sources. USGS scientists are also studying the way in which nutrient dynamics affect the cycling, transport, and bioaccumulation of mercury in the Clear Lake food web. Quantifying the contributions of nutrients and mercury coming from the lake’s watershed is essential for effective remediation (restoration) through implementation of best management practices.
Clear Lake Hitch
The Clear Lake Hitch was formerly highly abundant and a staple food for the Pomo tribes of the Clear Lake region. The original abundance of this fish species is unknown but is believed to have declined 100-fold. To better understand Clear Lake Hitch behavior and habitat use, USGS biologists have conducted extensive sampling of the lake and its tributaries, as well as detailed analysis of various parts of the fish, including otoliths (ear bones), eye lenses, and fish muscle. These findings are important for identifying critical habitat, an important element of endangered species conservation and management.
Studying Threatened Fish Species in Clear Lake, CA
Monitoring and Modeling of Nutrients and Other Water-Quality Constituents in Tributaries to Clear Lake, California
Scotts Creek Nutrient Erosion Study, Lake County, California
Mercury studies at Sulphur Bank Mercury Mine and Clear Lake, California
Detection range and efficiency of acoustic telemetry receivers in Clear Lake, Lake County, California
Mercury in fishes from Clear Lake, California, 2019 and 2020 (ver. 2.0, February 2022)
The Geochemistry of Mercury and Other Constituents in Redox Manipulated Sediment cores from Clear Lake, Lake County, California
Isotopic Analysis of Clear Lake Hitch collected from Clear Lake, Lake County, California, 2017
Surface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019
Abundance and Distribution of Clear Lake Hitch in Clear Lake, Lake County, California, 2017-2022 (ver. 4.0, December 2022)
Water Temperature of Selected Tributaries of Clear Lake, Lake County, California
Water Quality Vertical Profiles in Clear Lake, Lake County, California, 2017-2019 (ver. 3.0, January 2022)
Photographs and video clips of Clear Lake Hitch
Clear Lake Hitch Otolith Data
Eye lenses reveal ontogenetic trophic and habitat shifts in an imperiled fish, Clear Lake hitch (Lavinia exilicauda chi)
First record of pughead deformity in the threatened Clear Lake Hitch
Observations of the spawning ecology of the imperiled Clear Lake Hitch Lavinia exilicauda chi
Dissolved oxygen controls summer habitat of Clear Lake Hitch (Lavinia exilicauda chi), an imperilled potamodromous cyprinid
Strontium isotopes reveal ephemeral streams used for spawning and rearing by an imperiled potamodromous cyprinid--Clear Lake hitch Lavinia exilicauda chi
Watershed Monitoring in Clear Lake Tributaries
Data viewer that allows users to see the streamflow and water quality monitoring sites at Clear Lake and its tributaries. Data is from the USGS National Water Information System and California Department of Water Resources and Lake County databases.
- Overview
The USGS California Water Science Center conducts a variety of research activities at Clear Lake, California, including surface-water monitoring and water quality and aquatic habitat studies.
Clear Lake is the largest natural lake entirely within California. It is in the California Coast Range, approximately 60 miles (100 kilometers) north of San Francisco Bay. The lake supports a wide variety of fish and bird species and is a very popular sport-fishing destination.
Water Quality
Clear Lake is hypereutrophic (has excess algal growth), and as such has a severe problem with harmful algal blooms (HABs). Excess algae and HABs can be detrimental to aquatic life because when the algae die, sink, and decay, the lake is deprived of the dissolved oxygen that fish need to breathe. A driving factor of these conditions are the nutrient loads being carried into the lake by soil erosion and the transport of sediment and dissolved nutrients via the lake’s tributaries. Nutrients are also recycled from the lake bed, especially when wind conditions drive sediments from the bed to the surface.
The USGS is monitoring and modeling the Clear Lake watershed to better understand these nutrient sources. USGS scientists are also studying the way in which nutrient dynamics affect the cycling, transport, and bioaccumulation of mercury in the Clear Lake food web. Quantifying the contributions of nutrients and mercury coming from the lake’s watershed is essential for effective remediation (restoration) through implementation of best management practices.
Clear Lake Hitch
The Clear Lake Hitch was formerly highly abundant and a staple food for the Pomo tribes of the Clear Lake region. The original abundance of this fish species is unknown but is believed to have declined 100-fold. To better understand Clear Lake Hitch behavior and habitat use, USGS biologists have conducted extensive sampling of the lake and its tributaries, as well as detailed analysis of various parts of the fish, including otoliths (ear bones), eye lenses, and fish muscle. These findings are important for identifying critical habitat, an important element of endangered species conservation and management.
- Science
Studying Threatened Fish Species in Clear Lake, CA
The Clear Lake Hitch ( Lavinia exilicauda chi ) population, which once flourished in great abundance, has been decimated by loss of spawning habitat, nursery areas, and the encroachment of non-native species. In order to make an informed decision, the California Water Science Center has been asked by the U.S. Fish and Wildlife Service to conduct studies into the fish’s habitat, specifically...Monitoring and Modeling of Nutrients and Other Water-Quality Constituents in Tributaries to Clear Lake, California
Clear Lake, the largest natural lake entirely within California, has a severe problem with harmful algal blooms (HABs). HABs can be detrimental to aquatic life because when the algae dies, sinks, and decays, the lake is deprived of the dissolved oxygen that fish need to breathe. A driving factor of these conditions are the nutrient loads being carried into the lake by soil erosion and the...Scotts Creek Nutrient Erosion Study, Lake County, California
Clear Lake, the largest natural lake entirely within California, has a severe problem with harmful algal blooms which can be detrimental to aquatic life by depriving it of oxygen when the algae dies, sinks, and decays. A driving factor of these conditions are the nutrient loads being carried into the lake by soil erosion and the transport of sediment from the lake’s tributaries. Recently, an...Mercury studies at Sulphur Bank Mercury Mine and Clear Lake, California
The abandoned Sulphur Bank Mercury Mine on the shores of Clear Lake in Northern California has been designated as a "Superfund Site" by the U.S. Environmental Protection Agency (EPA). This means that the EPA has determined that the area is contaminated by hazardous waste and requires cleanup because it poses a risk to human health and/or the environment. One of the chief contaminants at the site... - Data
Detection range and efficiency of acoustic telemetry receivers in Clear Lake, Lake County, California
Data on the detection range and efficiency of VR2W-69 kHz acoustic receivers (Innovasea Marine Systems Canada Inc., Bedford, Nova Scotia, Canada; https://www.vemco.com/) were collected to guide the development of telemetry studies of the Clear Lake Hitch (Lavinia exilicauda chi), an imperiled fish species endemic to Clear Lake, Lake County, California. The study took place June 21, 2021 through JuMercury in fishes from Clear Lake, California, 2019 and 2020 (ver. 2.0, February 2022)
Comma-separated values (.csv) file containing data related to mercury in fishes collected from Clear Lake, California.The Geochemistry of Mercury and Other Constituents in Redox Manipulated Sediment cores from Clear Lake, Lake County, California
Clear Lake, located within the Coast Range west of California's Central Valley, is the largest natural freshwater lake contained fully within the state and geologically is considered to be the oldest lake in North America. Clear Lake is popular for recreation and provides critical habitat to a wide variety of fish and bird species. Water quality in Clear Lake is degraded by both by mercury contamiIsotopic Analysis of Clear Lake Hitch collected from Clear Lake, Lake County, California, 2017
This dataset includes data from isotopic analysis of eye and muscle tissue from fish collected in Clear Lake, Lake County, California during June and July 2017. This data release includes all biological measurements and fish taxa included in the analysis.Surface-Water Geochemistry of Mercury, Methylmercury, Nutrients, and other Constituents in Clear Lake, Lake County, California, July 2019
Clear Lake is a 180 km2 freshwater lake located in the California Coast Range, approximately 120 km northwest of Sacramento. The lake supports a wide variety of fish and bird species and is a very popular sport-fishing destination. However, fish consumption advisories associated with mercury (Hg) contamination exist for several popular recreational species. The lake is comprised of three main regiAbundance and Distribution of Clear Lake Hitch in Clear Lake, Lake County, California, 2017-2022 (ver. 4.0, December 2022)
Field data for fishes sampled using bottom and surface gill nets during daylight hours in Clear Lake, California, USA. This data release includes all measured environmental parameters and fish taxa included in the analysis.Water Temperature of Selected Tributaries of Clear Lake, Lake County, California
The dataset includes water temperature and atmospheric pressure data collected from selected key tributaries Clear Lake, Lake County, California, used for spawning by the Clear Lake Hitch (Lavinia exilicauda chi): Kelsey Creek, Siegler Creek, Middle Creek, Adobe Creek, and Cole Creek. Data were collected with ONSET HOBO Model U20L-002 loggers.Water Quality Vertical Profiles in Clear Lake, Lake County, California, 2017-2019 (ver. 3.0, January 2022)
The datasets consist of principal fact information of gravity data and density and magnetic properties of hand samples in the Chico and Willows 1:100,000-scale quadrangles, California.Photographs and video clips of Clear Lake Hitch
This data release includes a collection of photographs and video clips. Above water observations were taken with with a Nikon D5300 digital camera and underwater observations were taken with a SOOCOO S100Pro digital camera. All observations were made on April 1, 2018 in Kelsey, Creek, Lake County, California. Further details can be found in: Feyrer, F. 2018. Rapid potamodromy into ephemeral streamClear Lake Hitch Otolith Data
The dataset includes four seperate files of data for a project that examined the strontium isotopic composition of otoliths of Clear Lake Hitch. Otoliths examined in this study were from randomly-sampled individual Clear Lake Hitch that recruited into the adult population in Clear Lake. The fish were collected in June and July 2017. Strontium isotopic composition (87Sr/86Sr ) in otoliths was deter - Publications
Eye lenses reveal ontogenetic trophic and habitat shifts in an imperiled fish, Clear Lake hitch (Lavinia exilicauda chi)
Stable isotopes recorded in fish eye lenses are an emerging tool to track dietary shifts coincident with use of diverse habitats over the lifetime of individuals. Eye lenses are metabolically inert, sequentially deposited, archival tissues that can open avenues to chronicle contaminant exposures, diet histories, trophic dynamics and migratory histories of individual fishes. In this study, we demonAuthorsMatthew J. Young, Veronica Larwood, Justin Kinsey Clause, Miranda Bell-Tilcock, George Whitman, Rachel C. Johnson, Frederick V. FeyrerFirst record of pughead deformity in the threatened Clear Lake Hitch
No abstract available.AuthorsJessica Catherine Kathan, Matthew J. Young, Frederick V. FeyrerObservations of the spawning ecology of the imperiled Clear Lake Hitch Lavinia exilicauda chi
Migrations for the purposes of reproduction are widely documented across the animal kingdom and are particularly common in fishes and other aquatic organisms (Dingle 2014). One important migration strategy in fishes is potamodromy, which is the movement from one location to another entirely within freshwater (Morais and Daverat 2016). Thurow (2016) estimated that worldwide there are approximatelAuthorsFrederick V. FeyrerDissolved oxygen controls summer habitat of Clear Lake Hitch (Lavinia exilicauda chi), an imperilled potamodromous cyprinid
The Clear Lake Hitch is an imperiled minnow endemic to Clear Lake, Lake County, California, USA that is listed as threatened under the California Endangered Species Act (ESA) and is a candidate for listing under the United States ESA. It exhibits a potamodromous life cycle whereby adults, which reach up to 6+ years in age and over 350 mm in length, migrate into Clear Lake’s ephemeral tributariesAuthorsFrederick V. Feyrer, Matthew Young, Oliver Patton, David E. AyersStrontium isotopes reveal ephemeral streams used for spawning and rearing by an imperiled potamodromous cyprinid--Clear Lake hitch Lavinia exilicauda chi
Identification of habitats responsible for the successful production and recruitment of rare migratory species is a challenge in conservation biology. Here, a tool was developed to assess life stage linkages for the threatened potamodromous cyprinid Clear Lake hitch Lavinia exilicauda chi. Clear Lake hitch undertake migrations from Clear Lake (Lake County, CA, USA) into ephemeral tributary streamsAuthorsFrederick V. Feyrer, George Whitman, Matthew J. Young, Rachel C. Johnson - Web Tools
Watershed Monitoring in Clear Lake Tributaries
Data viewer that allows users to see the streamflow and water quality monitoring sites at Clear Lake and its tributaries. Data is from the USGS National Water Information System and California Department of Water Resources and Lake County databases.
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