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Christopher Churchill

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In cooperation with Dallas Water Utilities (DWU), the U.S. Geological Survey (USGS) measures nutrient and major-ion concentrations in selected reservoirs in north Texas. This data release documents water-quality data obtained from Ray Hubbard Lake, Grapevine Lake, Ray Roberts Lake, and Lake Lewisville during water years 2016-20. In addition to nutrient and major-ion concentrations, water-quality field properties and other selected constituents measured in the water-quality samples collected from these reservoirs are documented. The study began in water year 2016 (WY16) with monthly sampling of Ray Hubbard Lake. A water year is defined as the 12-month period from October 1 through September 30 and is designated...
Aquatic invasive species (AIS) present major ecological and economic challenges globally, endangering ecosystems and human livelihoods. Managers and policy makers thus need tools to predict invasion risk and prioritize species and areas of concern, and they often use native range climate matching to determine whether a species could persist in a new location. However, climate matching for AIS often relies on air temperature rather than water temperature due to a lack of global water temperature data layers, and predictive power of models is seldom evaluated. We developed 12 global lake (water) temperature-derived “BioLake” bioclimatic layers for distribution modeling of aquatic species and compared “climatch” climate...
Categories: Publication; Types: Citation
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Dispersal, establishment, and spread of aquatic invasive species such as the zebra mussel (Dreissena polymorpha) can be influenced by riverine velocities and volumetric flows in invaded lake-stream ecosystems. Zebra mussels, which have a planktonic larval form (veliger), disperse rapidly downstream from a source population. Concentrations, dispersal, and body conditions of zebra mussel veligers were studied under different volumetric flow, or discharge, conditions in a coupled lake-stream ecosystem in northern Texas, USA. Veliger densities in lotic environments were strongly related to population dynamics in upstream lentic source populations. A strong exponential decrease in veliger density was observed through...
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This data release documents water-quality data obtained as part of an assessment of compounds of emerging concern (CECs) measured in samples collected at potable water and wastewater treatment plants in Dallas and downstream from Dallas in the Trinity River from August 2009 to December 2013 by the U.S. Geological Survey in cooperation with the City of Dallas, Dallas Water Utilities. Targeted CECs (120 total) included human-health pharmaceuticals (prescription and non-prescription), antibiotics, steroidal hormones, stanols, sterols, detergents, personal-use products (flavors and fragrances), pesticides and repellents, industrial wastewater compounds, disinfection compounds, PAHs, flame retardants, and plasticizers....
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