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At least 793 records · Page 44Linked to original sources

USGS1982

Water resources data Mississippi, water year 1981

Water resources data for the 1981 water year for Mississippi consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. This report contains records of water discharge at 82 gaging stations; stage records for 18 of these gaging stations; stage only at 4 gaging stations; contents for 4 lakes; water quality for 33 gaging stations, and 123 wells; and water levels for 324 observation wells. Also included are peak-discharge data for 91 crest-stage partial-record stations and water quality data at 18 partial-record or miscellaneous sites. Locations of these sites are shown on Figures 3-5. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Mississippi.

Mississippi↗

USGS2003

Chemical quality of water, sediment, and fish in Mountain Creek Lake, Dallas, Texas, 1994-97

The occurrence, trends, and sources of numerous inorganic and organic contaminants were evaluated in Mountain Creek Lake, a reservoir in Dallas, Texas. The study, done in cooperation with the Southern Division Naval Facilities Engineering Command, was prompted by the Navy’s concern for potential off-site migration of contaminants from two facilities on the shore of Mountain Creek Lake, the Naval Air Station Dallas and the Naval Weapons Industrial Reserve Plant. Sampling of stormwater (including suspended sediment), lake water, bottom sediment (including streambed sediment), and fish was primarily in Mountain Creek Lake but also was in stormwater outfalls from the Navy facilities, nearby urban streams, and small streams draining the Air Station. Volatile organic compounds, predominantly solvents from the Reserve Plant and fuel-related compounds from the Air Station, were detected in stormwater from both Navy facilities. Fuel-related compounds also were detected in Mountain Creek Lake at two locations, one near the Air Station inlet where stormwater from a part of the Air Station enters the lake and one at the center of the lake. Concentrations of volatile organic compounds at the two lake sites were small, all less than 5 micrograms per liter. Elevated concentrations of cadmium, chromium, copper, lead, mercury, nickel, silver, and zinc, from 2 to 4 times concentrations at background sites and urban reference sites, were detected in surficial bottom sediments in Cottonwood Bay, near stormwater outfalls from the Reserve Plant. Elevated concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls, compared to background and urban reference sites, were detected in surficial sediments in Cottonwood Bay. Elevated concentrations of polycyclic aromatic hydrocarbons, indicative of urban sources, also were detected in Cottonwood Creek, which drains an urbanized area apart from the Navy facilities. Elevated concentrations of polychlorinated biphenyls were detected in two inlets near the Air Station shoreline. Polycyclic aromatic hydrocarbon and heavy metal concentrations near the Air Station shoreline were not elevated compared to urban reference sites. Much larger concentrations of selected heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls were detected in deeper, older sediments than in surficial sediments in Cottonwood Bay. The decreases in concentrations coincide with changes in wastewater discharge practices at the Reserve Plant. Elevated concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls also were detected in older sediments in the Air Station inlet. On the basis of dated sediment cores and contaminant discharge histories, contaminant accumulation rates in Cottonwood Bay were much greater historically than recently. Most heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls that accumulated in the central and eastern parts of Cottonwood Bay appear to have come from the west lagoon on the Reserve Plant. Treated sewage and industrial-process wastewater were discharged to the west lagoon from about 1941 to 1974. Estimated annual contaminant accumulation rates in Cottonwood Bay decreased by from 1 to 2 orders of magnitude after 1974, when most point-source discharges to the west lagoon ceased. Polychlorinated biphenyls were detected in 61 of 62 individual fish-tissue samples. The largest average concentrations were in eviscerated channel catfish and the smallest were in largemouth bass fillets. Polychlorinated biphenyl and selenium concentrations from analyses of this study were large enough to prompt the Texas State Department of Health to issue a fish-possession ban for Mountain Creek Lake in 1996. Suspended sediments in stormwater at the lagoon outfalls and at sites on Cottonwood Creek were sampled and analyzed for major and trace elements, polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls. The suspended sediments from the outfalls contained about the same mixture of heavy metals and organic compounds, in elevated concentrations compared to reference sites, as bottom sediments from the lagoons and surficial bottom sediments in Cottonwood Bay. Diagnostic ratios of polycyclic aromatic hydrocarbons indicate that uncombusted fuel sources contribute to older sediments and that pyrogenic sources of polycyclic aromatic hydrocarbons dominate recently deposited sediments in Cottonwood Bay and along the Air Station shoreline.

Texas↗

USGS2002

Water Resources Data, Florida, Water Year 2001, Volume 3A. Southwest Florida Surface Water

Water resources data for the 2001 water year in Florida consist of continuous or daily discharges for 406 streams, periodic discharge for 12 streams, continuous daily stage for 142 streams, periodic stage for 12 streams, peak stage and discharge for 37 streams, continuous or daily elevations for 11 lakes, periodic elevations for 30 lakes; continuous ground-water levels for 424 wells, periodic ground-water levels for 1,426 wells, and quality-of-water data for 80 surface-water sites and 245 wells. The data for Southwest Florida include records of stage, discharge, and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 83 streams, periodic discharge for 10 streams, continuous or daily stage for 43 streams, peak stage and discharge for 8 streams, continuous or daily elevations for 2 lakes, periodic elevations for 26 lakes, and quality-of-water data for 37 surface-water sites. These data represent the national Water Data System records collected by the U.S. Geological Survey and cooperating local, state, and federal agencies in Florida.

Water Data Report↗

USGS1992

Water resources data, Florida, water year 1991. Volume 3A. Southwest Florida surface water

Water resources data for the 1991 water year in Florida consist of continuous or daily discharge for 346 streams, periodic discharge for 27 streams, miscellaneous discharge for 50 streams, continuous or daily stage for 151 streams, continuous daily tide stage for 3 sites, periodic stage for 29 streams, peak discharge for 23 streams and peak stage for 16 streams; continuous or daily elevations for 64 lakes, periodic elevations for 67 lakes; continuous ground-water levels for 436 wells, periodic ground-water levels for 1,172 wells, and miscellaneous water-level measurements for 1,628 wells; quality-of-water data for 139 surface-water sites and 761 wells. The data for southwest Florida include records of stage, discharge, and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 56 streams, periodic discharge for 4 streams, miscellaneous discharge for 3 streams, continuous daily stage for 20 streams, peak discharge for 13 streams, continuous elevations for 19 lakes, periodic elevations for 16 lakes, and quality-of-water for 64 surface water sites. These data represent the National Water Data System records collected by the U.S. Geological Survey and cooperating, local, state and federal agencies in Florida.

Florida↗

USGS1997

Water-quality trends in the Rio Grande/Rio Bravo Basin using sediment cores from reservoirs

Water-quality trends reflect the relation between water quality and human activities, chronicling changes in concentrations of environmental contaminants, introduction of new contaminants, and successful efforts in environmental pollution remediation. Historical data available for analyzing trends often have severe limitations, from questionable accuracy to unknown sampling and analytic methodologies. Where data are unavailable or have such limitations, water-quality trends sometimes can be reconstructed using sediment cores from lakes and reservoirs. The purpose of this fact sheet is to summarize the findings of a study to assess historical changes in surface-water quality in the Rio Grande Basin (known as the Río Bravo Basin in Mexico) by analyzing changes in sediment chemistry in cores from three reservoirs: Elephant Butte Reservoir, Amistad International Reservoir, and Falcon International Reservoir (fig. 1). Sediments that erode from the land surface are transported by tributaries into the Rio Grande/Río Bravo. Metals and some persistent pesticides and industrial organic compounds sorb to these sediments, which eventually accumulate at the bottom of the reservoirs or are transported to the Gulf of Mexico. Although use of reservoir cores has limitations—for example, the cores do not record trends in non-persistent compounds—in many cases the data provide a partial historical record of water quality. In 1991, the U.S. Geological Survey (USGS) began full implementation of the National Water-Quality Assessment (NAWQA) Program (Leahy and others, 1990). Also in 1991, the State of Texas established the Clean Rivers Program (CRP) administered by the Texas Natural Resource Conservation Commission (TNRCC). The coring study reported here was a collaborative effort between the NAWQA Program and the CRP Rio Grande Border Environmental Assessment Team, with additional funding support from the El Paso County Water Improvement District No. 1.

Colorado, New Mexico, Texas↗

USGS2004

Water Resources Data, Florida, Water Year 2003, Volume 3A: Southwest Florida Surface Water

Water resources data for the 2003 water year in Florida consist of continuous or daily discharges for 385 streams, periodic discharge for 13 streams, continuous daily stage for 255 streams, periodic stage for 13 streams, peak stage for 36 streams and peak discharge for 36 streams, continuous or daily elevations for 13 lakes, periodic elevations for 46 lakes; continuous ground-water levels for 441 wells, periodic ground-water levels for 1,227 wells, and quality-of-water data for 133 surface-water sites and 308 wells. The data for Southwest Florida include records of stage, discharge, and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 103 streams, periodic discharge for 7 streams, continuous or daily stage for 67 streams, periodic stage for 13 streams, peak stage and discharge for 8 streams, continuous or daily elevations for 2 lakes, periodic elevations for 26 lakes, and quality-of-water data for 62 surface-water sites. These data represent the national Water Data System records collected by the U.S. Geological Survey and cooperating local, state, and federal agencies in Florida.

Water Data Report↗

USGS2004

Water resources data, Florida, water year 2004, volume 3A: southwest Florida surface water

Water resources data for the 2004 water year in Florida consist of continuous or daily discharges for 405 streams, periodic discharge for 12 streams, continuous daily stage for 159 streams, periodic stage for 19 streams, peak stage for 30 streams and peak discharge for 30 streams, continuous or daily elevations for 14 lakes, periodic elevations for 23 lakes; continuous ground-water levels for 408 wells, periodic ground-water levels for 1,188 wells, and quality-of-water data for 140 surface-water sites and 240 wells. The data for Southwest Florida include records of stage, discharge, and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 104 streams, periodic discharge for 6 streams, continuous or daily stage for 36 streams, periodic stage for 14 streams, peak stage and discharge for 8 streams, continuous or daily elevations for 2 lakes, periodic elevations for 3 lakes, and quality-of-water data for 58 surface-water sites. These data represent the national Water Data System records collected by the U.S. Geological Survey and cooperating local, state, and federal agencies in Florida.

Water Data Report↗

USGS2016

Groundwater exchanges near a channelized versus unmodified stream mouth discharging to a subalpine lake

The terminus of a stream flowing into a larger river, pond, lake, or reservoir is referred to as the stream-mouth reach or simply the stream mouth . The terminus is often characterized by rapidly changing thermal and hydraulic conditions that result in abrupt shifts in surface water/groundwater (sw/gw) exchange patterns, creating the potential for unique biogeochemical processes and ecosystems. Worldwide shoreline development is changing stream-lake interfaces through channelization of stream mouths, i.e., channel straightening and bank stabilization to prevent natural meandering at the shoreline. In the central Sierra Nevada (USA), Lake Tahoe's shoreline has an abundance of both “unmodified” (i.e., not engineered though potentially impacted by broader watershed engineering) and channelized stream mouths. Two representative stream mouths along the lake's north shore, one channelized and one unmodified, were selected to compare and contrast water and heat exchanges. Hydraulic and thermal properties were monitored during separate campaigns in September 2012 and 2013 and sw/gw exchanges were estimated within the stream mouth-shoreline continuum. Heat-flow and water-flow patterns indicated clear differences in the channelized versus the unmodified stream mouth. For the channelized stream mouth, relatively modulated, cool-temperature, low-velocity longitudinal streambed flows discharged offshore beneath warmer buoyant lakeshore water. In contrast, a seasonal barrier bar formed across the unmodified stream mouth, creating higher-velocity subsurface flow paths and higher diurnal temperature variations relative to shoreline water. As a consequence, channelization altered sw/gw exchanges potentially altering biogeochemical processing and ecological systems in and near the stream mouth.

California, Nevada↗

USGS2005

Water resources data, Florida, water year 2005. Volume 3A: Southwest Florida surface water

Water resources data for the 2005 water year in Florida consist of continuous or daily discharges for 429 streams, periodic discharge for 9 streams, continuous or daily stage for 218 streams, periodic stage for 5 streams, peak stage for 28 streams and peak discharge for 28 streams, continuous or daily elevations for 15 lakes, periodic elevations for 23 lakes; continuous ground-water levels for 401 wells, periodic ground-water levels for 1,098 wells, and quality-of-water data for 211 surface-water sites and 208 wells. The data for Southwest Florida include records of stage, discharge, and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains records for continuous or daily discharge for 113 streams, periodic discharge for 4 streams, continuous or daily stage for 80 streams, periodic stage for 2 stream, peak stage and discharge for 8 streams, continuous or daily elevations for 3 lakes, continous or daily elevations for 3 lakes, and quality of water for 75 surface water sites. These data represent the national Water Data System records collected by the U.S. Geological Survey and cooperating local, state, and federal agencies in Florida.

Water Data Report↗

USGS2006

Spatial and temporal dynamics of microcystin in a Missouri reservoir

Environmental factors associated with spatiotemporal variation of microcystin (MC) in Mozingo Lake, a Missouri reservoir, were studied during summer 2001, and annual MC trends were characterized from May 2001-May 2002. MC increased during summer, ranging from 20 to 1220 ng/L. Seasonal patterns in MC corresponded with chlorophyll>35 ??m (Net Chl) and cyanobacterial biovolume associated with increased dominance by Microcystis and Anabaena. MC showed strong negative correlations with dissolved nitrogen (r=-0.95) and cations (r=-0.98), and strong positive correlations with Net Chl (r=0.91). Once the lake stratified, MC and Net Chl remained uniform throughout the photic zone and decreased significantly (p<0.05) in the aphotic zone. Field experiments indicated MC did not change independently of Net Chl in response to decreased light or increased nutrients; however, enclosure effects may have substantially influenced experimental results. Mozingo Lake MC was tightly coupled with seasonal lake processes, including stratification and nutrient loss from the epilimnion, and cyanobacterial community composition, abundance and distribution in the water column. MC was detected in all monthly samples suggesting the potential for problems associated with MC exists year round, but peaks in early fall presented the greatest concern in Mozingo Lake. ?? Copyright by the North American Lake Management Society 2006.

Lake and Reservoir Management↗

USGS1988

Water resources data for Florida, water year 1987. Volume 3A. Southwest Florida-surface water

Water resources data for the 1987 water year in Florida consist of continuous or daily discharge for 320 streams, periodic discharge for 38 streams, miscellaneous discharge for 29 streams, continuous or daily stage for 94 streams, periodic stage for 48 streams, peak discharge for 76 streams and peak stage for 69 streams; continuous. Or daily elevations for 80 lakes, periodic elevations for 74 lakes; continuous ground-water levels for 477 wells, periodic ground-water levels for 562 wells, and miscellaneous water-level measurements for 2886 wells; quality-of-water data for 223 surface-water sites and 900 wells. The data for southwest Florida include records of stage, discharge and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 61 streams, periodic discharge for 5 streams, miscellaneous discharge for 4 streams, continuous daily stage for 22 streams, periodic stage for 2 streams, peak discharge for 16 streams, continuous daily tide stage for 10 sites, continuous elevation for 22 lakes and periodic elevation for 16 lakes, and quality-of-water for 80 surface-water sites. These data represent the National Water Data System records collected by the U. S. Geological Survey and cooperating local, state, and federal agencies in Florida.

Florida↗

USGS1989

Water resources data, Florida, water year 1988. Volume 3A: Southwest Florida - surface water

Water resources data for the 1988 water year in Florida consist of continuous or daily discharge for 338 streams, periodic discharge for 34 streams, miscellaneous discharge for 28 streams, continuous or daily stage for 152 streams, periodic stage for 29 streams, peak discharge for 71 streams and peak stage for 84 streams; continuous daily tide stage for 10 sites, continuous or daily elevations for 73 lakes, periodic elevations for 72 lakes; continuous ground-water levels for 490 wells, periodic ground-water levels for 1620 wells, and miscellaneous water-level measurements for 2678 wells; quality-of-water data for 158 surface-water sites and 884 wells. The data for southwest Florida include records of stage, discharge and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 59 streams, periodic discharge for 5 streams, miscellaneous discharge for 4 streams, continuous daily stage for 25 streams, periodic stage for 2 streams, peak discharge for 15 streams, continuous daily tide stage for 10 sites, continuous elevation for 22 lakes and periodic elevation for 16 lakes, and quality-of-water for 64 surface-water sites. These data represent the National Water Data System records collected by the U. S. Geological Survey and cooperating local, state and federal agencies in Florida.

Florida↗

USGS1990

Water resources data, Florida, water year 1989. Volume 3A: Southwest Florida surface water

Water resources data for the 1989 water year in Florida consist of continuous or daily discharge for 295 streams, periodic discharge for 36 streams, miscellaneous discharge for 75 streams, continuous or daily stage for 154 streams, continuous daily tide stage for 12 sites, periodic stage for 13 streams, peak discharge for 57 streams and peak stage for 30 streams; continuous or daily elevations for 73 lakes, periodic elevations for 72 lakes; continuous ground-water levels for 514 wells, periodic ground-water levels for 798 wells, and miscellaneous water-level measurements for 2687 wells; quality-of-water data for 149 surface-water sites and 827 wells. The data for southwest Florida include records of stage, discharge and water quality of streams; stage, contents, water quality of lakes and reservoirs, and water levels and water quality of ground-water wells. Volume 3A contains continuous or daily discharge for 59 streams, periodic discharge for 4 streams, miscellaneous discharge for 3 streams, continuous daily stage for 24 streams, continuous daily tide stage for 10 sites, periodic stage for 1 stream, peak discharge for 30 streams, continuous elevation for 21 lakes and periodic elevation for 16 lakes, and quality-of-water for 71 surface-water sites. These data represent the National Water Data System records collected by the U. S. Geological Survey and cooperating local, state and federal agencies in Florida.

Florida↗

USGS1986

Water resources data, Florida, water year 1985. Volume 3A: Southwest Florida - surface water

The Water Resources Division of the U.S. Geological Survey, in cooperation with State agencies, obtains a large amount of data pertaining to the water resources of Florida each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the State. To make these data readily available to interested parties outside the Geological Survey, the data are published annually in this report series entitled "Water Resources Data - Florida." This report series includes records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs, and water levels and water quality of groundwater wells. This volume contains records for continuous daily discharge at 91 gaging stations; periodic discharge at 23 stream sites; miscellaneous discharge at 57 stream sites; continuous daily stage at 30 stream sites; periodic stage at 10 stream sites; peak discharge at 20 stream sites; peak stage at 1 stream site; continuous daily elevations at 50 lakes; periodic elevations at 39 lakes; water quality at 146 surface-water sites and 287 ground-water sites; continuous ground-water elevations at 223 wells; periodic ground-water elevations at 146 wells; and miscellaneous ground-water elevations at 1,477 wells. Locations of these sites are shown on figure 1. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating State and Federal agencies in Florida.

Florida↗

USGS2019

Measurement of cyanobacteria bloom magnitude using satellite remote sensing

Cyanobacterial harmful algal blooms (cyanoHABs) are a serious environmental, water quality and public health issue worldwide because of their ability to form dense biomass and produce toxins. Models and algorithms have been developed to detect and quantify cyanoHABs biomass using remotely sensed data but not for quantifying bloom magnitude, information that would guide water quality management decisions. We propose a method to quantify seasonal and annual cyanoHAB magnitude in lakes and reservoirs. The magnitude is the spatio-temporal mean of weekly or biweekly maximum cyanobacteria biomass for the season or year. CyanoHAB biomass is quantified using a standard reflectance spectral shape-based algorithm that uses data from Medium Resolution Imaging Spectrometer (MERIS). We demonstrate the method to quantify annual and seasonal cyanoHAB magnitude in Florida and Ohio respectively during 2003-2011 and rank the lakes based on median magnitude over the study period. The new method can be applied to Ocean Land Color Imager (OLCI) on Sentinel-3 data for assessment of cyanoHABs and the change over time, even with issues such as variable data acquisition frequency or sensor calibration uncertainties between satellites. CyanoHAB magnitude can support monitoring and management decision-making for recreational and drinking water sources.

Florida, Ohio↗

USGS2007

A Dreissena Risk Assessment for the Colorado River Ecosystem

Executive Summary Nonnative zebra and quagga mussels (Dreissena polymorpha and Dreissena bugensis, respectively; see photo above) were accidentally introduced to the Great Lakes in the 1980s and subsequently spread to watersheds of the Eastern United States (Strayer and others, 1999). The introduction of Dreissena mussels has been economically costly and has had large and far-reaching ecological impacts on these systems. Quagga mussels were found in Lakes Mead and Havasu in January 2007. Given the likelihood that quagga mussels and, eventually, zebra mussels will be introduced to Lake Powell and the Colorado River at Lees Ferry, it is important to assess the risks that introduction of Dreissena mussels pose to the Colorado River ecosystem (here defined as the segment of river from just below Glen Canyon Dam to Diamond Creek; hereafter CRE). In this report, I assess three different types of risks associated with Dreissena and the CRE: (1) the risk that Dreissena will establish at high densities in the CRE, (2) the risk of ecological impacts should Dreissena establish at high densities in the CRE or in Lake Powell, and (3) the risk that Dreissena will be introduced to tributaries of the CRE. The risk of Dreissena establishing within the CRE is low, except for the Lees Ferry tailwater reach where the risk appears high. Dreissena are unlikely to establish at high densities within the CRE or its tributaries because of high suspended sediment, high ratios of suspended inorganic:organic material, and high water velocities, all of which interfere with the ability of Dreissena to effectively filter feed. The rapids of Grand Canyon may represent a large source of mortality to larval Dreissena, which would limit their ability to disperse and colonize downstream reaches of the CRE. In contrast, conditions within the Lees Ferry tailwater generally appear suitable for Dreissena establishment, with the exception of high average water velocity. If Dreissena establish within the CRE, the risks of negative ecological impacts appear low. If Dreissena are able to attain moderate densities in Lees Ferry, estimates of filtration capacity indicate they are unlikely to substantially alter the composition (e.g., nutrient concentrations, suspended organic matter concentrations) of water exported from Lees Ferry. Further, a moderate density of Dreissena within Lees Ferry may actually increase food available to fishes by increasing habitat complexity and stimulating benthic production. If Dreissena attain moderate densities in the CRE mainstem, which seems unlikely, ecological impacts will probably be comparable to Lees Ferry-an increase in benthic production. Dreissena may have ecological impacts on the CRE, if they become established in Lake Powell and substantially alter the composition of water released from Glen Canyon Dam; however, it is unclear whether changes in the composition of water released from Glen Canyon Dam will have a net positive or negative impact on food availability in the CRE mainstem. The risk of Dreissena introduction to tributaries appears low. None of the tributaries have upstream lakes or reservoirs that could actually serve as a source population for Dreissena; reservoirs on the Little Colorado River may eventually support Dreissena, but they are far up in the watershed and the segment of river connecting them with the mainstem CRE is intermittent. If the CRE mainstem is colonized by Dreissena, there are no significant vectors for transporting them upstream into the tributaries. In addition, lethally high summer water temperatures make it unlikely that Dreissena will establish in many tributaries. Lake Powell is a logical focus for management and research efforts, given that maintenance of Dreissena populations within the CRE will require an upriver source population and the uncertainty associated with the downstream impact of changes in Lake Powell water quality.

Open-File Report↗

USGS2023

Leveraging multimission satellite data for spatiotemporally coherent cyanoHAB monitoring

Cyanobacteria harmful algal blooms (cyanoHABs) present a critical public health challenge for aquatic resource and public health managers. Satellite remote sensing is well-positioned to aid in the identification and mapping of cyanoHABs and their dynamics, giving freshwater resource managers a tool for both rapid and long-term protection of public health. Monitoring cyanoHABs in lakes and reservoirs with remote sensing requires robust processing techniques for generating accurate and consistent products across local and global scales at high revisit rates. We leveraged the high spatial and temporal resolution chlorophyll-a (Chl a ) and phycocyanin (PC) maps from two multispectral satellite sensors, the Sentinel-2 (S2) MultiSpectral Instrument (MSI) and the Sentinel-3 (S3) Ocean Land Colour Instrument (OLCI) respectively, to study bloom dynamics in Utah Lake, United States, for 2018. We used established Mixture Density Networks (MDNs) to map Chl a from MSI and train new MDNs for PC retrieval from OLCI, using the same architecture and training dataset previously proven for PC retrieval from hyperspectral imagery. Our assessment suggests lower median uncertainties and biases (i.e., 42% and -4%, respectively) than that of existing top-performing PC algorithms. Additionally, we compared bloom trends in MDN-based PC and Chl a products to those from a satellite-derived cyanobacteria cell density estimator, the cyanobacteria index (CI-cyano), to evaluate their utility in the context of public health risk management. Our comprehensive analyses indicate increased spatiotemporal coherence of bloom magnitude, frequency, occurrence, and extent of MDN-based maps compared to CI-cyano and potential for use in cyanoHAB monitoring for public health and aquatic resource managers.

Utah↗

USGS2015

Status and conservation of interior Redband Trout in the western United States

In this article we describe the current status and conservation of interior (potamodromous) Redband Trout Oncorhynchus mykiss sspp. throughout its range in the western United States using extant data and expert opinion provided by fish managers. Redband Trout historically occupied 60,295 km of stream habitat and 152 natural lakes. Currently, Redband Trout occupy 25,417 km of stream habitat (42% of their historical range) and 124 lakes or reservoirs. Nonhybridized populations are assumed to occupy 11,695 km (46%) of currently occupied streams; however, fish from only 4,473 km (18%) have been genetically tested. Approximately 47% of the streams occupied by Redband Trout occur on private land, 45% on government lands, and 8% in protected areas. A total of 210 Redband Trout populations, occupying 15,252 km of stream habitat (60% of the current distribution) and 95,158 ha of lake habitat (52%), are being managed as “conservation populations.” Most conservation populations have been designated as weakly to strongly connected metapopulations (125; 60%) and occupy much more stream length (14,112 km; 93%) than isolated conservation populations (1,141 km; 7%). The primary threats to Redband Trout include invasive species, habitat degradation and fragmentation, and climate change. Although the historical distribution of interior Redband Trout has declined dramatically, we conclude that the species is not currently at imminent risk of extinction because it is still widely distributed with many populations isolated by physical barriers and active conservation efforts are occurring for many populations. However, the hybridization status of many populations has not been well quantified, and introgression may be more prevalent than documented here. We recommend (1) collecting additional genetic data and estimating distribution and abundance by means of a more rigorous spatial sampling design to reduce uncertainties, (2) collecting additional information to assess and predict the impacts of climate on populations, and (3) continuing to use this database to evaluate the status of Redband Trout and inform conservation efforts through time.

North American Journal of Fisheries Management↗