Distribution and thickness of salt in the Paradox basin of southwestern Colorado and southeastern Utah : a preliminary report
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Trace Elements Investigations↗
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Snake River fall Chinook salmon life history investigations, 1/1/2012 - 12/31/2012: Annual report 2002-032-00
Executive Summary a. Fish Population RM&E This annual report describes the data collected and analyses conducted during calendar years 2012-2013 by staff of project 20023200. The USGS contributed only to the predation research and reservoir invertebrate work described in this report and the presentation of their results is consistent with USGS policy guidelines. The USGS is not responsible for the content provided by other contributing authors. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. The main goal of this project is to better understand juvenile Snake River fall Chinook salmon life history diversity and the factors that influence it. This is called for in RPA 55.4 “Investigate key characteristics of Snake River fall Chinook salmon early life history.” We 3 investigated the importance of estuary entry and rearing to various Snake River fall Chinook salmon life histories. Otoliths were used to examine differences in estuary use between subyearlings and yearlings, and to determine natal habitats, rearing habitats, and overwintering habitat for returning adults. Estuary growth was best explained by estuary residence time and natal location. b. Predation and Invasive Species Management RM&E We investigated the extent of smallmouth bass predation on juvenile fall Chinook salmon in Lower Granite Reservoir as called for in the Fish and Wildlife Program, “The federal action agencies should work cooperatively with NOAA Fisheries, states, tribes, and the Council to review, evaluate, develop, and implement strategies to reduce non-native piscivorous predation on salmon and steelhead, especially by smallmouth bass, channel catfish, and walleye” (Page 52). Smallmouth bass stomach contents were collected and analyzed for the presence of juvenile salmon. Smallmouth bass abundance was estimated with mark-recapture techniques, and salmon consumption by bass was expanded based on bass abundance to determine the annual loss of juvenile fall Chinook salmon for the study period and area. The estimated loss of juvenile fall Chinook salmon to predation in Lower Granite Reservoir exceeded 109,000 fish in 2012. This information could be used to adaptively formulate better hatchery release strategies to reduce the effects of predation. Obtaining better estimates of smallmouth bass abundance and distribution in future years would reduce the uncertainty of estimates. This study will be completed by 2017. We also examined the effects of various field temperature scenarios resulting from summer flow augmentation on juvenile fall Chinook salmon susceptibility to smallmouth bass predation in laboratory trials. Predation susceptibility of juvenile salmon acclimated at cool temperatures (10°C) was highest when exposed to predators at 24°C. These results indicate that predation susceptibility may be higher when a relatively large temperature difference exists between the Clearwater and Snake rivers; that is, when cool water flow augmentation occurs in summer. Finally, we examined the role of different invasive invertebrates in lower Snake River reservoir food webs that are food, or competitors for food, for juvenile fall Chinook salmon. The Siberian prawn, a relatively new invader, is relatively abundant but its role on the food web is largely unexplored. Prawns are successfully reproducing and their diet is 81% Neomysis (an invasive opossum shrimp) which is heavily used at times by juvenile salmon for food. Neomysis has become very abundant in lower Snake River reservoirs in recent years and may be a profitable food item for many fish species.
Oregon, Washington↗
Groundwater conditions in Utah, spring of 2015
This is the fifty-second in a series of annual reports that describe groundwater conditions in Utah. Reports in this series, published cooperatively by the U.S. Geological Survey and the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality, provide data to enable interested parties to maintain awareness of changing groundwater conditions. This report, like the others in the series, contains information on well construction, groundwater withdrawals from wells, water-level changes, precipitation, streamflow, and chemical quality of water. Information on well construction included in this report refers only to new wells constructed for withdrawal of groundwater. Supplementary data are included in reports of this series only for those years or areas that are important to a discussion of changing groundwater conditions and for which applicable data are available. This report includes individual discussions of selected significant areas of groundwater development in the State for calendar year 2014. Most of the reported data were collected by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights, and the Utah Department of Environmental Quality, Division of Water Quality. This report is also available online at http://www.waterrights.utah.gov/techinfo/ and http://ut.water.usgs.gov/publications/GW2015.pdf. Groundwater conditions in Utah for calendar year 2013 are reported in Burden and others (2014) and are available online at http://ut.water.usgs.gov/publications/GW2014.pdf. The water-level change maps in this report show the difference between water levels measured in the same well at two distinct times: in the spring of 1985 and the spring of 2015. Throughout the state, many groundwater levels were near their peak in or around 1985 following a multiple-year period of above average precipitation in the early 1980s. Conversely, consecutive years of significant drought have contributed to low groundwater levels in 2015. For these reasons, the difference between 1985 and 2015 groundwater levels may not accurately portray long-term changes in an aquifer. An evaluation of water-level trends should also include consideration of the annual water-level measurement plots provided for each of the major areas of groundwater development in this report.
Utah↗
Final data report for factors controlling DDE dechlorination rates on the Palos Verdes Shelf: A field and laboratory investigation
This data report provides a compilation of information developed over the last 6+ years by a multi-disciplinary, multi-institutional research team. The overall goal of this work has been to identify the biological, chemical, and physical factors that control rates of reductive dechlorination of DDE and DDMU in sediments of the Palos Verdes Shelf (PVS). More specific questions and objectives are delineated in the Scope of Work (section 12.1., Appendix 1). The study was composed of two parts: 1) field characterization studies, and 2) laboratory microcosm experiments. The goal of the field characterization studies was to define the conditions under which reductive dechlorination of DDE (and DDMU) is occurring in PVS sediments. This involved two separate cruises (2009, 2010) during which sediment cores, bottom water and other real-time field measurements (e.g., conductivity, temperature, depth of the water column) were acquired. The sediment cores were distributed among research team members for detailed chemical (R. Eganhouse, B. Orem, M. Reinhard), microbiological (A. Spormann), and physical (B. Edwards) analysis as well as for laboratory microcosm experiments (M. Reinhard). A team of collaborating USGS scientists generously contributed valuable information pertaining to geochronology (P. Swarzenski), the character of sedimentary geosorbent phases (P. Hackley), mineralogy (D. Webster), and grain-size characteristics (C. Sherwood) of PVS sediment samples. Together, this information will serve as framework for a conceptual model of natural degradation processes in the DDT-contaminated sediments on the PVS. These findings will enable the USEPA to gain a better understanding of the controls on reductive dechlorination and how dechlorination rates vary spatially and temporally. This, in turn, should facilitate decision making concerning the progress of natural attenuation and when monitoring at the site can be terminated. Toward that end, a brief Synthesis Report, summarizing and interpreting the acquired data, is being prepared and will be released in the coming year.
Palos Verdes Shelf↗
Brookian sequence well log correlation sections and occurrence of gas hydrates, north-central North Slope, Alaska
Gas hydrates are naturally occurring crystalline, ice-like substances that consist of natural gas molecules trapped in a solid-water lattice. Because of the compact nature of their structure, hydrates can effectively store large volumes of gas and, consequently, have been identified as a potential unconventional energy source. First recognized to exist geologically in the 1960s, significant accumulations of gas hydrate have been found throughout the world. Gas hydrate occurrence is limited to environments such as permafrost regions and subsea sediments because of the pressure and temperature conditions required for their formation and stability. Permafrost-associated gas hydrate accumulations have been discovered in many regions of the Arctic, including Russia, Canada, and the North Slope of Alaska. Gas hydrate research has a long history in northern Alaska. This research includes the drilling, coring, and well log evaluation of two gas hydrate stratigraphic test wells and two resource assessments of gas hydrates on the Alaska North Slope. Building upon these previous investigations, this report provides a summary of the pertinent well log, gas hydrate, and stratigraphic data for key wells related to gas hydrate occurrence in the north-central North Slope. The data are presented in nine well log correlation sections with 122 selected wells to provide a regional context for gas hydrate accumulations and the relation of the accumulations to key stratigraphic horizons and to the base of the ice-bearing permafrost. Also included is a well log database that lists the location, available well logs, depths, and other pertinent information for each of the wells on the correlation section.
Alaska↗
Report on progress of investigations of mineral resources of Alaska in 1904
During the last two years the United States Geological Survey has met the demand of the mining public for early publication of economic results by issuing an annual bulletin entitled "Contributions to Economic Geology." Though these volumes have made no attempt to treat exhaustively any of the subject discussed, and while many of the included papers have been but the barest outlines, they have met a cordial reception from those interested in developing the mineral resources of the country. Among the many papers in these bulletins were a number devoted to the mineral deposits of Alaska. In view of the rapid extension of the Alaskan work of the Geological Survey and its segregation in a distinct division, it has seemed desirable to issue a separate publication containing the papers summarizing the previous year's work.
Alaska↗
Ground-Water Levels in the Ozark Aquifer along the Viburnum Trend, Southeastern Missouri, 2001-05
During 2001, eight monitoring wells were installed along the Viburnum Trend to determine if dewatering of lead-zinc mines in the St. Francois aquifer affected water levels in the surficial Ozark aquifer. The well locations were chosen specifically to investigate the effects of different mining scenarios. Before data collection, much of southern Missouri, including the Viburnum Trend area, experienced a drought that began in late 1999. Dry conditions existed in the area until early 2002, about the time data recorders were installed in the monitoring wells. The water-level data indicate no long-term, continuous water-level declines occurred from 2002 to 2005 at five monitoring wells (VT-2, VT-3, VT-5, VT-6, and VT-7), four of which are over active mining areas. Conversely, these five wells had increasing water levels with time. Another well (VT-4) placed over an active mining area, did have a long-term water-level decline (about 30 foot) that developed during the study. On a local scale, the water-level data from this well reinforces conclusions of previous investigations that report small areas of drawdown in the Ozark aquifer may be present along the Viburnum Trend as the result of mine dewatering. A monitoring well (VT-1) installed over an abandoned mine where flooding is occurring showed an increasing water-level trend. Another well (VT-8) installed in an area where mining was expected to occur after well installation showed a lowering ground-water trough in 2004 and 2005. Comparing monthly precipitation and daily mean water-levels differences at these two wells indicates that for most of the period from 2002 to 2005, the converging water-level difference that occurred can be explained by local precipitation differences rather than being mining induced. Local precipitation differences, however, do not explain the 15-foot decrease in water-level difference that was observed during the period January through June 2004.
Scientific Investigations Report↗
Hydrogeology and flow of water in a sand and gravel aquifer contaminated by wood-preserving compounds, Pensacola, Florida
The sand and gravel aquifer in southern Escambia County, Florida , is a typical surficial aquifer composed of quartz sands and gravels interbedded locally with silts and clays. Problems of groundwater contamination from leaking surface impoundments are common in surficial aquifers and are a subject of increasing concern and attention. A potentially widespread contamination problem involves organic chemicals from wood-preserving processes. Because creosote is the most extensively used industrial preservative in the United States, an abandoned wood-treatment plant near Pensacola was chosen for investigation. This report describes the hydrogeology and groundwater flow system of the sand and gravel aquifer near the plant. A three-dimensional simulation of groundwater flow in the aquifer was evaluated under steady-state conditions. The model was calibrated on the basis of observed water levels from January 1986. Calibration criteria included reproducing all water levels within the accuracy of the data (one-half contour interval in most cases). Sensitivity analysis showed that the simulations were most sensitive to recharge and vertical leakance of the confining units between layers 1 and 2, and relatively insensitive to changes in hydraulic conductivity and transmissivity and to other changes in vertical leakance. Applications of the results of the calibrated flow model in evaluation of solute transport may require further discretization of the contaminated area, including more sublayers, than were needed for calibration of the groundwater flow system itself. (USGS)
Water-Resources Investigations Report↗
Interim report on the scientific investigations in the Animas River watershed, Colorado to facilitate remediation decisions by the U.S. Bureau of Land Management and the U.S. Forest Service, March 29, 2000 meeting, Denver, Colo.
INTRODUCTION The joint U.S. Department of the Interior and U.S. Department of Agriculture Abandoned Mine Lands Initiative (AMLI) was developed as a collaborative effort between the Federal land management agencies (FLMA, that is the U.S. Bureau of Land Management and the U.S. Forest Service) and the U.S. Geological Survey (USGS) in 1996. The stated goal of the AML Initiative was to develop a strategy for gathering and communicating the scientific information needed to develop effective and cost-efficient remediation of abandoned mines within the framework of a watershed. Four primary objectives of the AMLI are to: 1. Provide the scientific information needed (in the short-term) by the FLMAs to make decisions related to the design and implementation of cleanup actions, 2. Develop a multi-disciplined, multi-division approach that integrates geologic, hydrologic, geochemical and ecological information into a knowledge base for sound decision making, 3. Transfer technologies developed within the scientific programs of the USGS to the field and demonstrate their suitability to solve real, practical problems, and 4. Establish working relationships among involved members of land management and regulatory agencies within the framework of a watershed approach to the cleanup of abandoned mines. Long-term process-based research, including development of analytical tools, is recognized as being critical to the long-term success in remediating watersheds impacted by historical mining activities (AML 5-year plan, http://amli.usgs.gov/amli). In a meeting of Federal agencies (U.S. Bureau of Land Management [BLM], U.S. Bureau of Reclamation [BOR], U.S. National Park Service [NPS], U.S. Forest Service [USFS], the U.S. Environmental Protection Agency [EPA], the U.S. Fish and Wildlife Service [F&WS]), and State agencies (Colorado Division of Public Health and Environment, Colorado Division of Mines and Geology), several watersheds were examined within the state whose water quality was presumed to be impacted by historical mining activities. The Animas River watershed (fig. 1) was selected by the State and Federal agencies as one of two watersheds in the U.S. to be studied in detail by the USGS in the AML Initiative. Beginning in October 1997, each of the four Divisions of the USGS (Water Resources, Geologic, Biological Resources, and National Mapping) initiated a collaborative integrated science study of the watershed. Funds were provided from USGS base funding to each of the four Divisions in response to the priorities set by Congressional action and within the flexibility provided by the budgetary framework funding individual research programs. The AML Initiative provides for a five-year focused scientific effort in the two watersheds with final synthesis of the scientific results from each to be published in 2001. Publications are released on the AML web site on a regular basis (http://amli.usgs.gov/amli). On March 29, 2000, the USGS hosted a meeting for the BLM and USFS to discuss remediation options that were under consideration for the summer of 2000. The purpose of this report is to provide an overview of the scientific rational provided by the USGS to meet objective one above, and to summarize our preliminary interpretations of our data. Additional information from sites on private lands have been collected by the State of Colorado, EPA, and the ARSG. Unfortunately, these data have not been fully supplied to the USGS so our conclusions are based only upon our data. These interpretations provide science-based constraints on possible remediation options to be considered by the FLMA, the State, and local property owners in the Animas River watershed. The report is presented in outline format to facilitate discussion of remediation options at the March 29, 2000 meeting. Not all historical mining sites within the watershed are on public lands. This should not be construed to be a final report of the USGS
Denver↗
Cruise report for a seismic investigation of gas hydrates in the Mississippi Canyon region, northern Gulf of Mexico: Cruise M1-98-GM
During June 1998, the U.S. Geological Survey (USGS) and the University of Mississippi Marine Minerals Technology Center (MMTC) conducted a 12-day cruise in the Mississippi Canyon region of the Gulf of Mexico (Fig. 1). The R/V Tommy Munro, owned by the Marine Research Institute of the University of Southern Mississippi, was chartered for the cruise. The general objective was to acquire very high resolution seismic-reflection data across of the upper and middle continental slope (200-1200-m water depths) to study the acoustic character, distribution and potential effects of gas hydrates within the shallow subsurface, extending from the sea floor down to the base of the gas-hydrate stability zone. The Gulf of Mexico is well known for hydrocarbon resources that include petroleum and related gases. Areas of the Gulf that lie in waters deeper than about 250 m potentially have conditions (e.g., pressure, temperature, near-surface gas content, etc.) that are right for the shallow-subsurface formation of the ice-like substance (gas and water) known as gas hydrate (Kvenvolden, 1993). Gas hydrates have previously been sampled in sea-floor cores and observed as massive mounds in several parts of the northern Gulf, including the Mississippi Canyon region (e.g., Anderson et al., 1992). Extensive seismic data have been recorded in the Gulf, in support of commercial drilling efforts, but few very high resolution data exist in the public domain to aid in gas-hydrate studies. Studies of long-term interest include those on the resource potential of gas hydrates, the geologic hazards associated with dissociation and formation of hydrates, and the impact, if any, of gas-hydrate dissociation on atmospheric warming (i.e., via release of methane, a "greenhouse" gas). Several very high resolution seismic systems (surface-towed, deep-towed, and sea-floor) were used during the cruise to test the feasibility of using such data for detailed structural (geometric) and stratigraphic (physical property) analyses based on the acoustic data. The cruise was conducted in two regions, on opposite flanks of the Mississippi Canyon, where gas hydrates are known and suspected from prior coring and seismic operations (e.g., Neurauter and Bryant, 1989). The regions are also characterized by thick surficial, relatively young (Pleistocene and younger) sediments. Swath-bathymetry data (Fig. 2) show extensive sea-floor faults, piercement features, and slumps—features whose development could potentially be related to gas hydrates. The specific objectives of the cruise were (a) to image the gas-hydrate stability zone across the continental margin to document bottom-simulating reflections (BSRs) and changes in geometry of the hydrate stability zone; (b) to image known hydrate features (with several seismic systems) to estimate physical properties for hydrate and non-hydrate areas; (c) to outline the shallow structures of the hydrate stability zone to ascertain their potential effects on the formation/distribution of hydrates and on stability of the sea floor; and (d) to estimate, if possible, the amounts of hydrates present in the shallow sub surface. During the cruise about 850 km of multichannel and single-channel seismic data were recorded. Seismic measurements at nine ocean-bottom seismometer (OBS) stations were recorded for several of the multichannel tracklines (see Fig. 3 in report). The following report describes the field operations and equipment systems employed, gives two examples of ship-board seismic records, and outlines a few preliminary results.
Open-File Report↗
Geology and evaluation of tungsten anomalies, Buhairan-Abu Khurg area, southeastern part of the Uyaijah ring structure, Kingdom of Saudi Arabia
Previous geochemical exploration has indicated areas in the Precambrian Al Uyaijah ring structure for further investigation. This report encompasses the results of geologic and geochemical investigations made in a 40 square kilometer area located on the southeast perimeter of the ring structure, an area where previous geochemical exploration revealed anomalous tungsten and molybdenum values. Igneous rocks exposed in the area include batholithic plutonic rocks, intrusive rocks of the ring dike, hypabyssal dike rocks, and late epithermal quartz veins; remnants of metamorphosed, prebatholithic rocks are also exposed. About two-thirds of the area is covered with a veneer of surficial debris. Structural patterns of the area are dominated by the ring structure. The principal mineralization consists of powellite and scheelite in high-temperature, quartz-rich veinlets and pods and in contact metamorphic rocks. Although the areas of metallization account for the previously discovered sediment geochemical anomalies, mineralization is sparse, and no currently valuable mineral deposits are known or thought to be present in the area.
Open-File Report↗
Talc investigations in Vermont, preliminary report
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Circular↗
The Role of Fuel Breaks in the Invasion of Nonnative Plants
Executive Summary Fuel reduction projects have become an increasingly important component of state and federal fuels management programs. However, an unintended result of some pre-fire fuel manipulation projects may be the introduction of nonnative invasive plants. The establishment of nonnative plants within fuel breaks is a serious concern because the presence of invasive species in areas treated to reduce fuels could make adjacent wildland areas more susceptible to invasion, particularly following widespread disturbances such as fires. This report presents the results of a research project investigating the relationship between fuel reduction treatments and the invasion of nonnative plants. Throughout the rest of this document, we will collectively refer to these treatments as fuel breaks, although we sampled a range of fuel breaks described variously as fuel breaks, shaded fuel breaks, defensible fuel reduction zones, defensible fuel profile zones, fuel reduction projects, fuel management zones, wildfire protection zones, and community protection zones.
Scientific Investigations Report↗
Green Bay walleyes: a report on the scientific investigation of the marked increase in abundance of walleyes in Green Bay
Abstract has not been submitted
The Fisherman↗
The occurrence of zeunerite in the Russian mountains, Alaska : interim report [Part 4]
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Trace Elements Investigations↗
Fault trace mapping and surface-fault-rupture special study zone delineation of the Wasatch Fault Zone, Utah and Idaho
The Wasatch fault zone (WFZ) is a 220-mile-long (350-km) fault zone divided into 10 structural segments extending from southeastern Idaho to central Utah. The central five segments of the WFZ underlie the densely populated Wasatch Front region, where the majority of Utah’s population and economy are proximal to the fault zone. The West Valley fault zone (WVFZ) is an antithetic structure related to the WFZ and runs through the Salt Lake Valley. Communities on or adjacent to the WFZ are at risk of earthquake damage, due to their proximity to the fault zones. During 2016–2018, the Utah Geological Survey and a U.S. Geological Survey collaborator performed updated fault mapping of 39 7.5' quadrangles along the WFZ using recently acquired high-resolution topographic data derived from airborne light detection and ranging (lidar) elevation data. Previous geologic mapping, paleoseismic investigations, historical aerial photography, and field investigations were also used to identify and map surface fault traces and infer fault locations. Special study zones were delineated around fault traces to facilitate understanding of the surface-rupturing hazard and associated risk. Defining these special study zones encourages the creation and implementation of municipal and county geologic-hazard ordinances dealing with hazardous faults. We identified potential paleoseismic investigation sites where fault scarps appear relatively pristine, are located in geologically favorable settings, and where additional earthquake timing data would be beneficial to the continued earthquake research of the WFZ. The fault geometries, attributes, and special study zones were published in the online Utah Geologic Hazards Portal simultaneously with this Report of Investigation (RI). This report contains supplementary material describing the data and methods used to perform the mapping and in locating potential paleoseismic investigation sites in the study area. This work is critical to raise awareness of earthquake hazards in areas of Utah experiencing rapid growth.
Idaho, Utah↗
Water-quality response to changes in phosphorus loading of the Winnebago Pool Lakes, Wisconsin, with special emphasis on the effects of internal loading in a chain of shallow lakes
The Winnebago Pool is a chain of four shallow lakes (Lake Poygan, Lake Winneconne, Lake Butte des Morts, and Lake Winnebago) that are fed primarily by the Fox and Wolf Rivers, two large agriculturally dominated rivers in Wisconsin, United States. Because the lakes have received extensive phosphorus inputs from their watershed, they have become highly eutrophic with much phosphorus in the water column as well as trapped in their sediments. Each of the four Winnebago Pool lakes has been included on the Wisconsin Department of Natural Resources impaired waters list because of their high total phosphorus concentrations, water-quality use restrictions, and excess algal growth. The study described in this report is part of a Total Maximum Daily Load investigation to determine what actions are needed to improve the water quality (trophic status) of these lakes and thus be able to be removed from the impaired waters list and restore their designated uses. As part of this study, data were collected to describe the existing water quality of the lakes, detailed phosphorus budgets were developed for each of the lakes to describe the different sources of the phosphorus, and two eutrophication models (BATHTUB and Jensen models) were used to determine how much of the phosphorus being input to the lakes needs to be reduced for the lakes to be removed from the impaired waters list and restore their designated uses. In-lake water-quality data indicated that each of the lakes had extensive vertical mixing that resulted in their water quality deteriorating throughout summer. Each of the lakes had mean summer total phosphorus concentrations exceeding 0.088 milligram per liter (mg/L), well above the 0.040 mg/L criterion for the lakes. Detailed phosphorus budgets for the lakes indicated that the primary sources of phosphorus were from their tributaries (for the most upstream lake in the Winnebago Pool–Lake Poygan) or from a combination of input from the upstream lakes and phosphorus release from the bottom sediment when only the summer months were considered (for the other three lakes). Model simulations with the BATHTUB and Jensen models indicated that (1) the lakes should have almost linear response in their total phosphorus concentrations to changes in their phosphorus inputs; (2) phosphorus inputs need to be reduced by about 60 percent to the Upper Pool Lakes and 69–73 percent to Lake Winnebago to reduce their mean summer total phosphorus concentrations to 0.040 mg/L; and (3) if all the anthropogenic phosphorus inputs to the lakes could be eliminated, their best possible mean summer total phosphorus concentrations should decrease to about 0.022–0.028 mg/L in the Upper Pool Lakes and to 0.032–0.033 mg/L in Lake Winnebago. The effects of any reduction in phosphorus loading will take many years (50 to more than 75 years) to be fully realized in lake water quality because of phosphorus release from the lake sediments. The effects of nutrient reductions in the watershed of a chain of lakes, such as the Winnebago Pool, gradually cascades down the chain, which has beneficial and detrimental effects. Any action made in the watershed of upstream lakes to reduce phosphorus inputs should improve the water quality of all downstream lakes; however, the upstream lakes delay the response in the downstream lakes, especially in lakes where internal phosphorus loading is important.
Wisconsin↗