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At least 1,423 records · Page 79Linked to original sources
USGS2011

Diet and population metrics of the introduced blue catfish population in the Altamaha, River, GA

Blue catfish (Ictalurus furcatus) were first detected in the Altamaha River, Georgia, during an access creel survey in 2005 and subsequently in 2006 during annual ictalurid sampling. Introduction of this species in the Altamaha River is believed to have occurred via escape from normal upstream reservoir releases from Lake Sinclair and Lake Oconee. Relative abundance, as indexed by electrofishing catch rate (fish per hour), has increased from 2.9±1.0 SE in 2006 to 38.8±8.2 SE in 2011. The size of blue catfish captured ranged from 56 to 820 mm total length and 0.001 to 7.7 kg. Using otoliths obtained in 2010 (n=214), age of fish ranged from 0 to 6 yrs, which indicated a relatively young population. The catch-curve analysis resulted in an instantaneous mortality rate (Z) of 0.75. Despite concerns of blue catfish predation on native fishes and mussels, a diet analysis of blue catfish (n=257) obtained in 2010 revealed that diets of fish in all size groups were dominated by the introduced Asiatic clam (Corbicula fluminea). This study describes a recently introduced blue catfish population in an Atlantic coastal plain river and provides insight on possible ecological effects during the early phases of establishment. These results offer an early status assessment of the invasion dynamics before the system has had time to reach a new equilibrium state.

Conference Paper↗
USGS1974

Population trends, growth, and movement of bigmouth buffalo, Ictiobus cyprinellus, in Lake Oahe, 1963-70

The bigmouth buffalo, Ictiobus cyprinellus, is the most important commercial species in Lake Oahe, a reservoir in the upper Missouri River. The population was dominated by three strong year classes (1959, 1960, and 1962). Estimated population in the fall of 1964 was 540,000 fish of the combined 1959-60 year classes and 5 million of the 1962 year class (equivalent to 81 kg per hectare). Abundance declined irregularly during 1964-70. Annual landings of these two dominant groups during 1965-70 ranged from 149 to 271 metric tons. The total landings during the period amounted to about 151,800 fish of the 1959-60 year classes and 313,000 fish of the 1962 year class. Growth rate was high during the first few years of impoundment and then declined. Males and females grew at about the same rate for the first 4 yr of life, but females were longer and heavier than males at ages V-VIII. At these ages, fish of the 1962 year class were about 10% shorter and 36% lighter than those of the 1959 year class. Growth of tagged and untagged fish was similar. The number of females per male increased with age. Age at maturity increased slightly as growth rate declined. Movement of marked fish was extensive and the recapture of marked fish was directly related to size of fish, location of release, and subsequent fishing pressure; 44% were recaptured downstream from the point of release, and 38% upstream. Females showed a stronger tendency to move downstream than males. Maximum distance traveled was 380 km and maximum rate of travel was 6.4 km per day. Successful reproduction appeared to be associated with flooding of shoreline vegetation during spring and early summer. Inasmuch as little such flooding is expected in the future, annual landings of bigmouth buffalo will probably continue to decline sharply.

Technical Paper↗
USGS1970

Water resources of Racine and Kenosha Counties, southeastern Wisconsin

Urbanization and changes in regional development in Racine and Kenosha Counties are increasing the need for water-resources information useful for planning and management. The area is fortunate in having abundant supplies of generally good quality water available for present and projected future needs. Lake Michigan and ground-water reservoirs have great potential for increased development. Lake Michigan assures the urbanized area in the eastern part of the two counties of a nearly inexhaustible water supply. In 1967 the cities of Racine and Kenosha pumped an average of 32.6 mgd (million gallons per day) from the lake. Water from Lake Michigan is of the calcium magnesium bicarbonate type, but it is less hard than water from other sources. Discharge from Racine and Kenosha Counties into Lake Michigan is low and has little effect on the lake. The Root and Pike Rivers and a number of smaller streams contribute a mean flow of about 125 cfs (cubic feet per second) to the lake. Ground water, approximately 5 cfs, enters the lake as discharge from springs or as seeps. The Des Plaines, Root, and Pike Rivers drain areas of relatively impermeable silty clay that promotes rapid surface runoff and provides little sustained base flow. Sewage sometimes accounts for most of the base flow of the Root River. In contrast, the Fox River, which drains the western half of the area, has steady and dependable flow derived from the sand and gravel and the Niagara aquifers. Sewage-plant effluent released to the Fox River in 1964 was about 5 percent of the total flow. A 5-mile reach of the Root River loses about 30,000 gpd (gallons per day) per mile to the local ground-water reservoir and is a possible source of ground-water contamination. Thirty-five of the 43 lakes in the area are the visible parts of the groundwater table, and their stages fluctuate with changes in ground-water levels. The rest of the lakes are perched above the ground-water table. Flooding is a recurring but generally minor problem along occupied reaches of flood plains of all the streams. However, in 1960 a flood on the Fox River, which had a recurrence interval of 60 years, caused considerable damage near the village of Silver Lake. At the same time, a flood on the Root River, which had a recurrence interval of 100 years, caused damage in Racine. The sandstone aquifer, a major artesian reservoir underlying all of Racine and Kenosha Counties, is used as a water supply for industries, institutions, and three communities. Pumpage for these uses was about 3.3 mgd in 1967. The greatest decline of water levels, attributed to both local and regional pumping, was 7 feet per year at Burlington. The specific capacities of wells developed in the Mount Simon Sandstone are about 5 gpm (gallons per minute) per foot of drawdown; in the Galesville and Franconia Sandstones, about 4 gpm per foot of drawdown; and in the St. Peter Sandstone, about 1 gpm per foot of drawdown. Yields of more than 1,000 gpm are obtained from wells tapping the Galesville and Franconia Sandstones and penetrating large crevices in the Trempealeau Formation near Burlington and Union Grove. About 2.5 mgd of ground water in the sandstone aquifer was diverted from the two-county area toward the Milwaukee and Chicago pumping centers in 1963--about 1.7 mgd moving from Racine County toward Milwaukee and 0.8 mgd moving from Kenosha County toward Chicago. Recent regional waterlevel declines in the sandstone aquifer have ranged from about 3 to 5 feet per year. This decline in water levels represents a ground-water depletion of about 0.5 mgd; however, the aquifer is not being dewatered, nor are water levels declining in the recharge area. The sandstone aquifer receives about 80 percent of its recharge from its outcrop area west of the two counties. In 1963 about 3.5 mgd moved eastward laterally from the recharge zone in western Walworth County, and about 1 mgd leaked downward through the overly

Wisconsin↗
USGS1998

Lake Hickory, North Carolina: Analysis of ambient conditions and simulation of hydrodynamics, constituent transport, and water-quality characteristics, 1993-94

From January 1993 through March 1994, circulation patterns and water- quality characteristics in Lake Hickory varied seasonally and were strongly influenced by inflows from Rhodhiss Dam. The upper, riverine portion of Lake Hickory was unstratified during much of the study period. Downstream from the headwaters to Oxford Dam, Lake Hickory thermally stratified during the summer of 1993. During stratification, releases from Rhodhiss Dam plunged beneath the warmer surface waters of Lake Hickory and moved through the reservoir as interflow. During fall and winter, Lake Hickory was characterized by alternating periods of mixing and weak stratification. Water-quality conditions in the headwaters of Lake Hickory were largely driven by conditions in water being released from Rhodhiss Dam. In general, water clarity increased, and concentrations of suspended solids, phosphorus, and summertime chlorophyll a decreased in a downstream direction from the headwaters of Lake Hickory to Oxford Dam. Two chlorophyll a samples from the upper portion of Lake Hickory exceeded the North Carolina water-quality standard of 40 micrograms per liter during the investigation. Downstream from the headwaters, dissolved oxygen was rapidly depleted from Lake Hickory bottom waters beginning in May 1993, and anoxic conditions persisted in the hypolimnion throughout the summer. During summer stratification, concentrations of nitrite plus nitrate, ammonia, and orthophosphate were low in the epilimnion, but concentrations of ammonia near the bottom of the reservoir increased as the hypolimnion became anoxic. Concentrations of fecal coliform bacteria exceeded 200 colonies per 100 milliliters in only one of 60 samples collected from Lake Hickory. In contrast, concentrations of fecal coliform bacteria exceeded 200 colonies per 100 milliliters in 40 percent of samples collected from the Upper Little River, and in 60 percent of samples collected from the Middle Little River, two tributaries to Lake Hickory. Load estimates for the period April 1993 through March 1994 indicated that releases from Rhodhiss Dam accounted for most of the suspended solids, nitrogen, and phosphorus entering the headwaters of Lake Hickory. Loads of nitrogen and phosphorus from point-source discharges were potentially important, but loads of suspended solids from these discharges were insignificant relative to other sources. The CE-QUAL-W2 model was applied to Lake Hickory from the U.S. Highway 321 bridge to Oxford Dam?a distance of 22 kilometers?and was calibrated by using data collected from April 1993 through March 1994. During the simulation period, measured water levels varied a total of 1.14 meters, and water temperatures ranged from 4 to 31 degrees Celsius. The calibrated model provided good agreement between measured and simulated water levels at Oxford Dam. Likewise, simulated water temperatures were generally within 1 degree Celsius of measured values; however, water temperatures were oversimulated for the fall of 1993. Simulated dissolved oxygen concentrations generally agreed with measurements; however, the model tended to oversimulate dissolved oxygen concentrations during the late summer and early fall. There was good agreement between simulated and measured frequency of occurrence of dissolved oxygen concentrations less than 4 milligrams per liter. Simulations of tracer dye releases demonstrated the effects of stratification on dilution and rate of transport in Lake Hickory. Simulations were made of the effects of changes in nutrient loads from inflows and from bottom sediments. A simulated 30-percent reduction in inflow concentrations of orthophosphate, ammonia, and nitrate at the U.S. Highway 321 bridge delayed the initial springtime pulse of algal growth by about 2 weeks, but had little effect on dissolved oxygen concentrations. Likewise, a reduction in the release rate of orthophosphate and ammonia from bottom sediments had very little effect on simulated algae

North Carolina↗
USGS2023

Bathymetric contour maps, surface area and capacity tables, and bathymetric change maps for selected water-supply lakes in northeastern Missouri, 2021

Bathymetric data were collected at 12 water-supply lakes in northeastern Missouri by the U.S. Geological Survey (USGS) in cooperation with the Missouri Department of Natural Resources (MoDNR) and various local agencies, as part of a multiyear effort to establish or update the surface area and capacity tables for the surveyed lakes. The lakes were surveyed in March through May 2021. Ten of the lakes had been surveyed previously by the USGS, and the recent surveys were compared to the earlier surveys to document the changes in the bathymetric surface and capacity of the lakes. Bathymetric data were collected using a high-resolution multibeam mapping system mounted on a boat. Supplemental depth data at five of the lakes were collected in shallow areas with an acoustic Doppler current profiler on a remote-controlled boat. Data points from the various sources were exported at a gridded data resolution appropriate to each lake, either 0.82 foot, 1.64 feet, or 3.28 feet. Data outside the multibeam survey extent and greater than the surveyed water-surface elevation were obtained from data collected using aerial light detection and ranging (lidar) point cloud data. A linear enforcement technique was used to add points to the dataset in areas of sparse data (the upper ends of coves where the water was shallow or aquatic vegetation precluded data acquisition) based on surrounding multibeam and upland data values. The various point datasets were used to produce a three-dimensional triangulated irregular network surface of the lake-bottom elevations for each lake. A surface area and capacity table was produced from the three-dimensional surface for each lake showing surface area and capacity at specified lake water-surface elevations. Various quality-assurance tests were conducted to ensure quality data were collected with the multibeam, including beam angle checks and patch tests. Additional quality-assurance tests were conducted on the gridded bathymetric data from the survey, the bathymetric surface created from the gridded data, and the contours created from the bathymetric survey. If there were data from a previous bathymetric survey for a given lake, a bathymetric change map was generated from the elevation difference between the previous survey and the 2021 bathymetric survey data points. After reconciling any vertical datum disagreement between the previous survey data and the 2021 survey datum, coincident points between the surveys were identified, and a bathymetric change map was generated using the coincident point data. The mean elevation change between all repeat surveys at most lakes was positive, indicating sedimentation. Relative to previous surveys, the change in capacity at the primary spillway elevation ranged from a 7.7-percent decrease at Memphis Reservoir to a 3.9-percent increase at Old Lake (Bowling Green West). The mean bathymetric change ranged from 0.03 foot at Hazel Creek and 0.07 foot at Shelbina Lake and Bowling Green Reservoir (Jack Floyd Memorial Lake) to 0.63 at Memphis Lake (Lake Showme) and 0.88 at Memphis Reservoir. The time-averaged mean bathymetric change ranged from 0.002 foot per year at Hazel Creek Lake to 0.044 foot per year at Memphis Reservoir. The computed volumetric sedimentation rate generally ranged from 0.14 to 6.80 acre-feet per year at Shelbina Lake and Memphis Lake (Lake Showme), respectively; however, Forest Lake had a substantially larger sedimentation rate of 17.0 acre-feet per year. Some changes observed in some bathymetric change maps are believed to result from the difference in data collection equipment and techniques between the previous and present bathymetric surveys, whereas other erosional features around the perimeter of certain lakes may be the result of wave action during low-water years.

Missouri↗
USGS2015

Control of nitrogen and phosphorus transport by reservoirs in agricultural landscapes

Reservoirs often receive excess nitrogen (N) and phosphorus (P) lost from agricultural land, and may subsequently influence N and P delivery to inland and coastal waters through internal processes such as nutrient burial, denitrification, and nutrient turnover. Currently there is a need to better understand how reservoirs affect nutrient transport in agricultural landscapes, where few prior studies have provided joint views on the variation in net retention/loss among reservoirs, the role of reservoirs apart from natural lakes, and differences in effects on N versus P, especially over time frames >1 year. To address these needs, we compiled water quality data from many rivers in intermediate-to-large drainages of the Midwestern US, including tributaries to the Upper Mississippi River, Great Lakes, and Ohio River Basins, where cropland often covers >50 % of the contributing area. Incorporating 18 years of data (1990–2007), effects of reservoirs on river nutrient transport were examined using comparisons between reservoir out- flow sites and unimpeded river sites (N = 869, including 100 reservoir outflow sites) supported by mass balance analysis of individual reservoirs (n = 17). Reservoir outflows sites commonly had 20 % lower annual yields (mass per catchment area per year) of total N and total P (TP) than unimpeded rivers after accounting for cropland coverage. Reservoir outflow sites also had lower interannual variability in TP yields. The mass balance approach confirmed net N losses in reservoirs, suggesting denitrification of agricultural N, or N burial in sediments. Net retention of P ranged more widely, and multiple systems showed net P export, providing new evidence that legacy P within reservoir systems may mobilize over the long-term. Our results indicate that reservoirs broadly influence the downstream transport of N and P through agricultural river networks, including networks where natural lakes and wetlands are relatively scarce. This calls for a more complete understanding of agricultural reservoirs as open, connected features of river networks where biogeochemical processes are often influential to downstream water quality, but potentially sensitive to changes associated with sedimentation, eutrophication, infrastructure aging, and reservoir management.

Biogeochemistry↗
USGS1982

Dams, reservoirs, and withdrawals for water supply; historic trends

The U.S. Geological Survey (USGS) from time to time has published an inventory of major reservoirs and controlled natural lakes. The latest available USGS report indicated that as of 1963, usable capacity in major reservoirs (those having 5 ,000 acre-ft of usable capacity) totaled 359 million acre-ft. The growth rate for total capacity averaged about 80%/decade until the early 1960's. Since then, reservoir capacity has increased at a markedly slower rate, the effects of approaching an asymptotic limit on capacity in some areas, compounded, by increasing public aversion toward reservoir construction. The trend toward non-structural measures places greater dependence on management skill and on better forecasts. At some point, the potentials of conservation and better management will become less effective than reservoirs and there will again be an upward trend in reservoir capacity. (Lantz-PTT)

Open-File Report↗
USGS2013

Chronological history of zebra and quagga mussels (Dreissenidae) in North America, 1988-2010

An unprecedented invasion began in North America in the mid-/late-1980s when two Eurasian mussel species, Dreissena polymorpha (zebra mussel) and Dreissena rostriformis bugensis (quagga mussel), became established in Laurentian Great Lakes. It is believed that Lake Erie was the initial location of establishment for both species, and within 3 years, zebra mussels had been found in all the Great Lakes. Since 1986, the combined distribution of two dreissenids has expanded throughout the Great Lakes region and the St. Lawrence River in Canada and also in the United States from the Great Lakes to the Mississippi Basin including Arkansas, Cumberland, Illinois, Missouri, Ohio, and Tennessee river basins. The distribution of dreissenid mussels in the Atlantic drainage has been limited to the Hudson and Susquehanna rivers. In the western United States, the quagga mussel established a large population in the lower Colorado River and spread to reservoirs in Arizona, California, Colorado, Nevada, and Utah. Overall, dreissenid species have been documented in 131 river systems and 772 inland lakes, reservoirs, and impoundments in the United States.

Book chapter↗
USGS2018

Development of new information to inform fish passage decisions at the Yale and Merwin hydro projects on the Lewis River, Washington—Final report, 2018

The reintroduction of extirpated salmonids to historically occupied areas is becoming increasingly common as a conservation and recovery strategy. Often, reintroductions are implemented after the factors that originally led to species extirpation have been reduced, eliminated, or mitigated. For anadromous Oncorhynchus spp. (Pacific salmon) and O. mykiss (steelhead), addressing barriers to migration, which have been a primary factor in the decline and extirpation of many populations, has been an integral component of recovery efforts. Mitigation has included barrier removal, developing fish passage opportunities, and (or) actively trapping and hauling juvenile and adult anadromous salmonids around barriers. With any reintroduction, there are a number of concerns regarding the ecological impact of the reintroduction efforts. Three of the main tenets to consider when assessing reintroductions are (1) the potential benefits if reintroduction is successful, (2) the biological risk through interactions of reintroduced strains with existing populations, and (3) the factors potentially limiting a successful reintroduction. This report focuses on information and data to address the second and third factors as they apply to the upper Lewis River in Washington. The upper Lewis River historically contained wild populations of O. tshawytscha (Chinook salmon), O. kisutch (coho salmon), and steelhead. These populations were extirpated after completion of hydropower facilities on Lake Merwin in 1932, Yale Lake in 1953, and Swift Reservoir in 1958, which prevented fish from migrating to and from ocean environments. However, recent licenses issued by the Federal Energy Regulatory Commission require the installation and operation of an upstream fish passage facility at Lake Merwin and a downstream fish passage facility at Swift Reservoir. The licenses were developed in consultation with the National Marine Fisheries Service and the U.S. Fish and Wildlife Service. The overarching goal of this fish reintroduction project is to establish viable, self-sustaining, naturally reproducing, harvestable populations of spring Chinook salmon, winter steelhead, and coho salmon at levels higher than minimum viable populations. This report uses a combination of field data and existing information to address six key objectives related to the reintroduction in order to inform decisions about passage at the Yale Lake and Lake Merwin hydropower projects. The objectives are (1) a review of information relevant to anadromous fish reintroduction and full fish passage; (2) a habitat assessment of tributaries to Swift Reservoir, Yale Lake, and Lake Merwin; (3) a field study to assess adult potential for spawning success; (4) an assessment of juvenile production and outmigration success; (5) a Lake Merwin predator impact study; and (6) a set of studies assessing interactions between anadromous and resident fish.

Washington↗
USGS2025

Framework developed for geomorphic mapping of Fern Ridge Lake, Oregon, 2023

The construction and operation of large reservoirs in the Willamette River Basin, Oregon, influences important cultural, biological, and other natural or economic resources in affected river corridors. The present-day landforms and cover within the reservoirs have been shaped by a variety of processes, including the pre-dam valley setting and geomorphic processes related to dam operations. Maps of reservoir geomorphic process domains, landforms, and cover provide a foundation for understanding how erosion and deposition processes in or near the reservoirs may affect cultural resources. Detailed geomorphic mapping of Fern Ridge Lake in 2023 provides a basis for evaluating geomorphic processes and patterns of sediment transfer within the reservoir. These processes are related to geomorphic and hydroclimatic conditions as well as annual lake level fluctuation for seasonal flood-control operations. This geomorphic mapping also provides an inventory of existing landforms from which to evaluate the spatial and temporal geomorphic change over time. Digital maps based on high-resolution digital surface models and orthophotographs acquired during low-pool conditions in 2023 extend over an area of about 30 square kilometers (km) upstream of the Fern Ridge Dam. The mapping framework has 3 main components consisting of several subtypes: 5 process domains, 18 landforms, and 7 cover categories. The overarching classification structure is tied to the process domains, which correspond to dissimilar regions of the reservoir that have distinct landforms and broadly similar suites of geomorphic processes. This document describes the geomorphic mapping framework for the reservoir at Fern Ridge Lake and provides mapping unit descriptions including delineation criteria, hypothesized formation processes inferred from remote-sensing and field observations and the literature, and relevance during drawdown operations.

Oregon↗
USGS1991

Physiological response of largemouth bass to angling stress

The physiological effects of catch-and-release fishing on largemouth bass Micropterus salmoides from Lake Powell and Mantua Reservoir, Utah, were evaluated, and an estimate of the time needed for recovery from hooking stress was obtained. Fatigue in Lake Powell fish, as indicated by elevated blood lactate, was directly proportional to hooking time (1–5 min) and water temperature, but recovery from the hyperlacticemia was relatively rapid (about 24 h). Hyperglycemia, an indicator of stress hormone production, did not occur in largemouth bass hooked and played for 1–5 min in the coldest water (11–13°C), was moderate in fish hooked and played at l6–20°C, and was severe in fish played for 5 min at 28–30°C. Fish held for recovery in live cages suffered further hyperglycemia, presumably because of the stress of confinement. Ionoregulation, as indicated by relatively stable plasma chloride values, was not immediately affected in largemouth bass caught at water temperatures of 11–13°C or 28–30°C, but an unusual hyperchloremia developed in fish hooked and played at 16–20°C. During recovery, the expected progressive hypochloremia developed. Plasma osmolality was somewhat affected by hooking at all water temperatures tested, but recovery was almost complete within about 8 h. Mantua Reservoir fish were hooked and played only at water temperatures of 23–26°C. The hyperlacticemia and hyperglycemia that occurred were generally more severe than in the Lake Powell fish hooked and played at either 16–20°C or 28–30°C. However, effects on plasma chloride and osmolality were similar to those occurring in Lake Powell fish.

Transactions of the American Fisheries Society↗
USGS2013

Estimation of reservoir storage capacity using multibeam sonar and terrestrial lidar, Randy Poynter Lake, Rockdale County, Georgia, 2012

The U.S. Geological Survey, in cooperation with the Rockdale County Department of Water Resources, conducted a bathymetric and topographic survey of Randy Poynter Lake in northern Georgia in 2012. The Randy Poynter Lake watershed drains surface area from Rockdale, Gwinnett, and Walton Counties. The reservoir serves as the water supply for the Conyers-Rockdale Big Haynes Impoundment Authority. The Randy Poynter reservoir was surveyed to prepare a current bathymetric map and determine storage capacities at specified water-surface elevations. Topographic and bathymetric data were collected using a marine-based mobile mapping unit to estimate storage capacity. The marine-based mobile mapping unit operates with several components: multibeam echosounder, singlebeam echosounder, light detection and ranging system, navigation and motion-sensing system, and data acquisition computer. All data were processed and combined to develop a triangulated irregular network, a reservoir capacity table, and a bathymetric contour map.

Georgia↗
USGS2016

The Water-Quality Partnership for National Parks—U.S. Geological Survey and National Park Service, 1998–2016

The U.S. Geological Survey (USGS) and the National Park Service (NPS) work together through the USGS–NPS Water-Quality Partnership to support a broad range of policy and management needs related to high-priority water-quality issues in national parks. The program was initiated in 1998 as part of the Clean Water Action Plan, a Presidential initiative to commemorate the 25th anniversary of the Clean Water Act. Partnership projects are developed jointly by the USGS and the NPS. Studies are conducted by the USGS and findings are used by the NPS to guide policy and management actions aimed at protecting and improving water quality. The National Park Service manages many of our Nation’s most highly valued aquatic systems across the country, including portions of the Great Lakes, ocean and coastal zones, historic canals, reservoirs, large rivers, high-elevation lakes and streams, geysers, springs, and wetlands. So far, the Water-Quality Partnership has undertaken 217 projects in 119 national parks. In each project, USGS studies and assessments ( http://water.usgs.gov/nps_partnership/pubs.php ) have supported science-based management by the NPS to protect and improve water quality in parks. Some of the current projects are highlighted in the NPS Call to Action Centennial initiative, Crystal Clear, which celebrates national park water-resource efforts to ensure clean water for the next century of park management ( http://www.nature.nps.gov/water/crystalclear/ ). New projects are proposed each year by USGS scientists working in collaboration with NPS staff in specific parks. Project selection is highly competitive, with an average of only eight new projects funded each year out of approximately 75 proposals that are submitted. Since the beginning of the Partnership in 1998, 189 publications detailing project findings have been completed. The 217 studies have been conducted in 119 NPS-administered lands, extending from Denali National Park and Preserve in Alaska to Everglades National Park in Florida, and from Acadia National Park in the Northeast to park lands in Hawaii and Pacific Island territories in the West. Project goals range from periodic stream monitoring, to determining the occurrence and concentrations of contaminants and the potential for them to exceed human health or aquatic life criteria, to conducting interpretive studies to evaluate the effect(s) on or vulnerability of national park resources to visitor usage and other natural and anthropogenic activities.

Fact Sheet↗
USGS2007

Sediment storage and severity of contamination in a shallow reservoir affected by historical lead and zinc mining

A combination of sediment-thickness measurement and bottom-sediment coring was used to investigate sediment storage and severity of contamination in Empire Lake (Kansas), a shallow reservoir affected by historical Pb and Zn mining. Cd, Pb, and Zn concentrations in the contaminated bottom sediment typically exceeded baseline concentrations by at least an order of magnitude. Moreover, the concentrations of Cd, Pb, and Zn typically far exceeded probable-effects guidelines, which represent the concentrations above which toxic biological effects usually or frequently occur. Despite a pre-1954 decrease in sediment concentrations likely related to the end of major mining activity upstream by about 1920, concentrations have remained relatively stable and persistently greater than the probable-effects guidelines for at least the last 50 years. Cesium-137 evidence from sediment cores indicated that most of the bottom sediment in the reservoir was deposited prior to 1954. Thus, the ability of the reservoir to store the contaminated sediment has declined over time. Because of the limited storage capacity, Empire Lake likely is a net source of contaminated sediment during high-inflow periods. The contaminated sediment that passes through, or originates from, Empire Lake will be deposited in downstream environments likely as far as Grand Lake O' the Cherokees (Oklahoma). ?? 2007 Springer-Verlag.

Environmental Geology↗
USGS1983

Fish abundance and population stability in a reservoir tailwater and an unregulated headwater stream

Fish abundance and population stability were compared in the tailwater and in an unregulated tributary of Barren River Lake, a flood control reservoir in south central Kentucky. Fish abundance was greater in the tailwater near the dam and was dominated by three species common in the reservoir: gizzard shad ( Dorosoma cepedianum ), bluegills ( Lepomis macrochirus ), and white crappies ( Pomoxis annularis ). Three riverine suckers were less abundant in the tailwater than in the unregulated stream: northern hog suckers ( Hypentelium nigricans ), black redhorse ( Moxostoma duquesnei ), and golden redhorse ( Moxostoma erythrurum ). The fish populations in the tailwater, particularly common carp ( Cyprinus carpio ), northern hog suckers, black redhorse, and golden redhorse, were less stable than those in the unregulated stream. Population stability is defined as the extent to which fish remain in a stream section. This study suggests that the occurrence of reservoir species in the tailwater was the result of fish passage from the reservoir during high discharges in fall and winter. Reservoir operations (altered flow, low summer water temperature, and poor summer water quality) probably were responsible for the unstable populations of common carp and riverine suckers in the tailwater.

Kentucky↗
USGS2023

The Colorado River water crisis: Its origin and the future

During much of the 21st century, natural runoff in the Colorado River basin has declined, while consumption has remained relatively constant, leading to historically low reservoir storage. Between January 2000 and April 2023, the amount of water stored in Lake Mead and Lake Powell, the two largest reservoirs in the United States, declined by 33.5 million acre feet (41.3 billion cubic meters). As of April 2023, total basin-wide storage was sufficient to support the 21st century average rate of basin-wide consumption for only 15 months. Runoff in spring 2023 is predicted to be large, providing a short-term reprieve. However, it will take four to five additional unusually wet years in succession to refill Lake Powell and Lake Mead if basin-wide water use remains unchanged. Increasing evapotranspiration and dry soils associated with global climate change makes such a scenario unlikely. To stabilize reservoir storage, basin-wide use needs to equal modern runoff. To recover reservoir storage, basin-wide use needs to decline even more. Based on 21st century average runoff, a 13%–20% decline in basin-wide use would allow for stabilization and some reservoir storage recovery. Future policy debate about reservoir operations will inevitably concern whether most, or all, reservoir storage should be in Lake Mead or in Lake Powell. The choice of one or the other will result in significantly different environmental and recreational outcomes for Glen Canyon and the Grand Canyon.

Arizona, Baja California, California, Colorado, Ne↗
USGS2008

Assessing contribution of DOC from sediments to a drinking-water reservoir using optical profiling

Understanding the sources of dissolved organic carbon (DOC) in drinking-water reservoirs is an important management issue because DOC may form disinfection by-products, interfere with disinfection, or increase treatment costs. DOC may be derived from a host of sources-algal production of DOC in the reservoir, marginal production of DOC from mucks and vascular plants at the margins, and sediments in the reservoir. The purpose of this study was to assess if release of DOC from reservoir sediments containing ferric chloride coagulant was a significant source of DOC to the reservoir. We examined the source-specific contributions of DOC using a profiling system to measure the in situ distribution of optical properties of absorption and fluorescence at various locations in the reservoir. Vertical optical profiles were coupled with discrete water samples measured in the laboratory for DOC concentration and optical properties: absorption spectra and excitation emission matrix spectra (EEMs). Modeling the in situ optical data permitted estimation of the bulk DOC profile in the reservoir as well as separation into source-specific contributions. Analysis of the source-specific profiles and their associated optical characteristics indicated that the sedimentary source of DOC to the reservoir is significant and that this DOC is labile in the reservoir. We conclude that optical profiling is a useful technique for understanding complex biogeochemical processes in a reservoir.

Lake and Reservoir Management↗