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USGS2003

Occurrence and Transport of Diazinon in the Sacramento River and Selected Tributaries, California, during Two Winter Storms, January?February 2001

Diazinon, an organophosphate insecticide, is applied as an orchard dormant spray in the Sacramento Valley during the winter months when the area receives most of its annual rainfall. During winter rainstorms that frequently follow dormant spray applications, some of the applied pesticide is transported in storm runoff to the Sacramento River and its tributaries. Diazinon is also used to control insect pests on residential and commercial properties in urban areas and is frequently detected in urban storm runoff draining into the Sacramento River system. Between January 24 and February 14, 2001, diazinon concentrations and loads were measured in the Sacramento River and selected tributaries during two winter storms that occurred after dormant spray applications were made to orchards in the Sacramento Valley. Water samples were collected at 21 sites that represented agricultural and urban inputs on a variety of scales, from small tributaries and drains representing local land use to main-stem river sites representing regional effects. Concentrations of diazinon ranged from below laboratory reporting levels to 1,380 nanograms per liter (ng/L), with a median of 55 ng/L during the first monitored storm and 26 ng/L during the second. The highest concentrations were observed in small channels draining predominantly agricultural land. About 26,000 pounds of diazinon were reported applied to agricultural land in the study area just before and during the monitoring period. About 0.2 percent of the applied insecticide appeared to be transported to the lower Sacramento River during that period. The source of about one third of the total load measured in the lower Sacramento River appears to be in the portion of the drainage basin upstream of the city of Colusa. About 12 percent of the diazinon load in the lower Sacramento River was transported from the Feather River Basin, which drains much of the mountainous eastern portions of the Sacramento River Basin. Diazinon use in the study area during the 2000?2001 dormant spray season continued a declining trend observed since 1993. The maximum concentrations of diazinon observed during the last 2 years of monitoring were lower than concentrations observed in previous years when larger amounts of diazinon had been applied as dormant sprays.

Water-Resources Investigations Report↗
USGS2003

Environmental Setting and the Effects of Natural and Human-Related Factors on Water Quality and Aquatic Biota, Oahu, Hawaii

The island of Oahu is the third largest island of the State of Hawaii, and is formed by the eroded remnants of the Waianae and Koolau shield volcanoes. The landscape of Oahu ranges from a broad coastal plain to steep interior mountains. Rainfall is greatest in the mountainous interior parts of the island, and lowest near the southwestern coastal areas. The structure and form of the two volcanoes in conjunction with processes that have modified the original surfaces of the volcanoes control the hydrologic setting. The rift zones of the volcanoes contain dikes that tend to impede the flow of ground water, leading to high ground-water levels in the dike-impounded ground-water system. In the windward (northeastern) part of the island, dike-impounded ground-water levels may reach the land surface in stream valleys, resulting in ground-water discharge to streams. Where dikes are not present, the volcanic rocks are highly permeable, and a lens of freshwater overlies a brackish-water transition zone separating the freshwater from saltwater. Ground water discharges to coastal springs and streams where the water table in the freshwater-lens system intersects the land surface. The Waianae and Koolau Ranges have been deeply dissected by numerous streams. Streams originate in the mountainous interior areas and terminate at the coast. Some streams flow perennially throughout their entire course, others flow perennially over parts of their course, and the remaining streams flow during only parts of the year throughout their entire course. Hawaiian streams have relatively few native species compared to continental streams. Widespread diverse orders of insects are absent from the native biota, and there are only five native fish, two native shrimp, and a few native snails. The native fish and crustaceans of Hawaii's freshwater systems are all amphidromous (adult lives are spent in streams, and larval periods as marine or estuarine zooplankton). During the 20th century, land-use patterns on Oahu reflected increases in population and decreases in large-scale agricultural operations over time. The last two remaining sugarcane plantations on Oahu closed in the mid-1990's, and much of the land that once was used for sugarcane now is urbanized or used for diversified agriculture. Although two large pineapple plantations continue to operate in central Oahu, some of the land previously used for pineapple cultivation has been urbanized. Natural and human-related factors control surface- and ground-water quality and the distribution and abundance of aquatic biota on Oahu. Natural factors that may affect water quality include geology, soils, vegetation, rainfall, ocean-water quality, and air quality. Human-related factors associated with urban and agricultural land uses also may affect water quality. Ground-water withdrawals may cause saltwater intrusion. Pesticides and fertilizers that were used in agricultural or urban areas have been detected in surface and ground water on Oahu. In addition, other organic compounds associated with urban uses of chemicals have been detected in surface and ground water on Oahu. The effects of urbanization and agricultural practices on instream and riparian areas in conjunction with a proliferation of nonnative fish and crustaceans have resulted in a paucity of native freshwater macrofauna on Oahu. A variety of pesticides, nutrients, and metals are associated with urban and agricultural land uses, and these constituents can affect the fish and invertebrates that live in the streams.

Water-Resources Investigations Report↗
USGS1985

Fishery survey and related limnological conditions of Williams Lake, Hubbard County, Minnesota

Bluegill ( Lepomis macrochirus ), pumpkinseed sunfish ( Lepomis gibbosus ), largemouth bass ( Micropterus salmoides ), yellow perch ( Perca flavescens ) rock bass ( Amploplites rupestris ), black crappie ( Pomozis nigromaculatus ), and northern pike ( Esox lucius ) were found in Williams Lake, Hubbard County, Minnesota, during a fishery survey of the lake in late August 1982. The most abundant fish were the bluegills. These fish live in the large littoral zone of the lake; this zone underlies 55% of the surface area of the lake. The most ubiquitous benthic invertebrate in the littoral zone ( amphipods ) and the most abundant benthic invertebrate ( chironomid larvae ) were major food sources for the bluegill. Other organisms found in the stomach contents of fish collected in this survey were zooplankton, gastropods, Diptera larvae, odonates, terrestrial insects, and other fish. Daphnia were the only zooplankters of a diverse plankton community that were found in stomach contents. The abundance of fish other than bluegill was typical for a system in which northern pike is the major predator.

Minnesota↗
USGS1986

Benthic invertebrate population characteristics as affected by water quality in coal-bearing regions of Tennessee

Benthic invertebrate and water quality data collected during previous U.S. Geological Survey studies to provide background hydrologic information on streams draining Tennessee coal reserves, were evaluated to identify possible relations between stream biota and water quality. Linear regressions produced low correlation coefficients relating the number of taxa/sample, total number of organisms/sample, sample diversity, and percentage composition of selected orders of invertebrates, with average water quality parameter values available at sampling stations (r is < 0.62 at p=0.05). Analyses of these data by linear regressions explained little of the variability in benthic invertebrate samples primarily because the distributions of benthic organisms along environmental gradients are nonlinear. Variability in substrate characteristics in the study area and seasonal insect emergence patterns also complicated interpretation of these data. However, analysis of variance tests did indicate significant trends towards reduced number of taxa, number of organisms, and sample diversity at stations with relatively poor water quality conditions. Decreasing percentage composition of Ephemeroptera was generally accompanied by an increase in percent Diptera at stations with higher water quality constituent concentrations and acidic pH (> than 0.6 units). These trends indicate significant differences in benthic communities at sites with evidence of more severe land use impacts. Additional data on benthic invertebrates, water quality, and physical habitat conditions, along with analyses of data using multivariate statistical methods are needed to define ecological relations between specific groups of invertebrates and environmental conditions.

Tennessee↗
USGS1988

Physical, chemical, and biological characteristics of the Boise River from Veterans Memorial Parkway, Boise to Star, Idaho, October 1987 to March 1988

Physical, chemical, and biological characteristics of the Boise River were examined from October 1987 to March 1988 to determine whether trace elements in effluents from two Boise wastewater treatment facilities were detrimental to aquatic communities. Cadmium, chromium, hexavalent chromium, cyanide, lead, nickel, and silver concentrations in the Boise River were less than or near analytical detection levels and were less than chronic toxicity criteria when detectable. Arsenic, copper, and zinc were detected in concentrations less than chronic toxicity criteria. Concentrations of trace elements in bottom material generally were small and could not be attributed to effluents from wastewater treatment facilities. From October to December 1987, mean density of benthic invertebrates colonizing artificial substrates was from 6,100 individuals/substrate downstream from the West Boise wastewater treatment facility to 14,000 individuals per substrate downstream from the Lander Street wastewater treatment facility. From January to March 1988 , mean density of benthic invertebrates colonizing artificial substrates was from 7,100 individuals per substrate downstream from the West Boise facility to 10,000 individuals per substrate near Star. Insect communities upstream and downstream from the wastewater treatment facilities were strongly associated, and coeffients of community loss indicated that effluents had benign enriching effects. Distribution of mayflies indicates that trace-element concentrations in effluents did not adversely affect intolerant organisms in the Boise River. Condition factor of whitefish was significantly increased downstream from the Lander Street wastewater treatment facility and was significantly decreased downstream from the West Boise wastewater treatment facility.

Idaho↗
USGS1989

Effects of land use on the water quality and biota of three streams in the Piedmont province of North Carolina

Three small streams in North Carolina 's northern Piedmont were studied to compare the effects of land use in their watersheds on water quality characteristics and aquatic biota. Devil 's Cradle Creek (agricultural watershed) had more than two times the sediment yield of Smith Creek (forested watershed) (0.34 tons/acre compared to 0.13 tons/acre), and Marsh Creek (urban watershed) had more than four times the yield of Smith Creek (0.59 tons/acre). Concentrations of nutrients were consistently highest in Devil 's Craddle Creek. Concentrations of total copper, iron, and lead in samples from each of the three streams at times exceeded State water quality standards as did concentrations of total zinc in samples from both Smith and Marsh Creeks. Successively lower aquatic invertebrate taxa richness was found in the forested, the agricultural, and the urban watershed streams. Invertebrate biota in Smith Creek was dominated by insects, such as Ephemeroptera, that are intolerant to stress from pollution, whereas Devil 's Cradle Creek was dominated by the more tolerant Diptera, and Marsh Creek was dominated by the most pollution-tolerant group, the Oligochaeta. Fish communities in the forested and agricultural watershed streams were characterized by more species and more individuals of each species, relative to a limited community in urban Marsh Creek. Three independent variables closely linked to land use--suspended-sediment yield, suspended-sediment load, and total lead concentrations in stream water--are inversely associated with the biological communities of the streams.

North Carolina↗
USGS1993

Surface-water hydrology and quality, and macroinvertebrate and smallmouth bass populations in four stream basins in southwestern Wisconsin, 1987-90

Data on streamflow, water quality, and macroinvertebrate and smallmouth bass (microptercus dolomieni) populations were collected from July 1987 through September 1990, in four streams in southwestern Wisconsin to determine the effect of surface-water hydrology and quality on populations of macroinvertebrates and smallmouth bass. The study was a joint project of the U.S. Geological Survey and the Wisconsin Department of Natural Resources. Drought conditions greatly affected streamflows in southwestern Wisconsin throughout much of the period of study. Precipitation in all four basins in 1988 and 1989 was 9.91 to12.41 inches less than 1951-80 normal precipitation of 32.88 inches. The lowest annual mean discharge was recorded in water year 1988 at all of the streamflow- gaging stations except at Rattlesnake Creek, where annual mean discharge was lowest in water year 1990. Overland-flow runoff during the reproductive period of smallmouth bass (mid-May to mid-July) was 0.02 inch in 1988 at the Sinsinawa River and Rattlesnake Creek. Overland-flow runoff in the Little Platte River and the Livingston Branch of the Pecatonica River also was low in 1988 (0.03 inch and 0.04 inch, respectively) during the reproductive period of smallmouth bass. The trend of low overland-flow runoff continued in 1989; in water year 1990, however, overland-flow runoff during the reproductive period of smallmouth bass was 1.38 inches at Livingston Branch of the Pecatonica River and 0.22 inch at Rattlesnake Creek. Turbidity ranged from 1.5 nephelometric turbidity units at Rattlesnake Creek to 3,700 nephelometric turbidity units at the Sinsinawa River. Suspended-solid concentrations ranged from 2 milligrams per liter at Rattlesnake Creek to a maximum 24,300 milligrams per liter at the Livingston Branch of the Pecatonica River. The high turbidities and suspended-solid concentrations, which occurred during storms, did not last for long periods of time and are not thought to have been harmful to the biota of the rivers. Un-ionized ammonia concentrations exceeded the State of Wisconsin, Department of Natural Resources' standard of 0.04 milligram per liter for warmwater streams at all four of the streams. The maximum concentration of un-ionized ammonia measured was 0.10 milligram per liter at Rattlesnake Creek and there was no discernible effects on smallmouth bass or macroinvertebrates. Dissolved-oxygen concentrations at all four study streams occasionally decreased to below or near the concentration of 1 milligram per liter considered necessary to sustain life of smallmouth bass. Two fish kills were documented as the result of low dissolved-oxygen concentrations. All of these episodes of low dissolved-oxygen concentrations occurred during or just after rainstorms and subsequent increasing streamflows. Samples of water-sediment mixture and bottom material were analyzed for pesticides commonly used in the basins. Samples from all of the stations had concentrations of herbicides that exceeded the analytical reporting limit. Water-sediment samples at the Sinsinawa River had the highest herbicide concentration. The concentration of metolachlor was the highest of the herbicides-- 110 micrograms per liter; concentrations of atrazine and cyanazine were next highest at 97 and 84 micrograms per liter, respectively. All of the water-sediment mixture samples had insecticide concentrations below the analytical reporting limit, with the exception of carbofuran. One water-sediment mixture sample collected at the Little Platte River had a carbofuran concentration of 0.44 microgram per liter. No pesticides were detected in the bottom-material samples collected at the four study streams. Richness of macroinvertebrate taxa did not differ substantially among the four streams during the study, but the abundances of several taxa differed significantly among streams. Livingston Branch of the Pecatonica River had comparatively few midges but many caddisflies, whereas Rattlesnake Creek had many non-insect taxa and relatively few caddisflies. The Little Platte River had consistently high numbers of caddisflies, mayflies, and riffle beetles. Macroinvertebrate-community composition, as measured by Bray-Curtis dissimilarity coefficients, varied considerably over time within and among the streams. The macroinvertebrate community composition of the Little Platte River changed very little during the winter of 1987-88 as compared to the other streams, but the community composition of the Livingston Branch of the Pecatonica River changed substantially. The communities of Rattlesnake Creek and Livingston Branch of the Pecatonica River became more similar to the community of the Little Platte River from fall 1987 through fall 1988, whereas the community in the Sinsinawa River remained distinct. Water quality, as estimated by biotic-index values, generally was better in the Little Platte River than in the other streams from fall 1987 through fall 1988. However, water quality appeared to have deteriorated (biotic-index values increased) in the Little Platte River during the winter of 1988-89. Water quality in the Livingston Branch of the Pecatonica River also deteriorated during the same period. The drought of 1988-89 and accompanying decrease in frequency of storms contributed to an uncharacteristically stable environment for macroinvertebrate development in most streams. Total taxa richness increased in three of the four streams. Total taxa richness did not increase in the Little Platte River, possibly because of moderate flooding that occurred prior to the spring 1989 sampling period or, more likely, because of changes in dissolved-oxygen concentrations. Although dissolved-oxygen concentrations were fairly similar in all streams, dissolved-oxygen concentrations were lower in 1989 in the Little Platte River than in other streams. The observed increase in biotic-index values in the Little Platte River during the spring of 1989 supports a decline in water quality. Smallmouth bass reproduction was related to precipitation and streamflow during the critical mid-May to mid-July reproductive period. Reproductive success was good (38-297 Age 0 smallmouth bass per acre) in 1988 and 1989 and poor (0-3 Age 0 smallmouth bass per acre) in 1987 and 1990. This pattern corresponded with total precipitation of less than 7 inches in May and June in 1988 and 1989 and greater than 7 inches in 1989 and 1990. In years when runoff exceeded 0.10 inch, only three or fewer Age 0 (smallmouth bass less than 1 year old) smallmouth bass per acre were caught in late summer to fall sampling surveys. In contrast, when overland runoff was less than 0.10 inch, 32 to 297 Age 0 smallmouth bass per acre were found in late summer or fall. The numbers of Age 0 smallmouth bass per acre were significantly different from each other at the 1 -percent probability level (p=0.0001). Smallmouth bass reproductive success indicated that smallmouth bass in these streams were extremely vulnerable to the amount of runoff during the early stage of their life. Low concentrations of dissolved oxygen constituted the most detrimental water-quality problem affecting smallmouth bass populations. Dissolved-oxygen concentrations were occasionally less than 3 milligrams per liter, a dissolved-oxygen concentration that may be detrimental to early-life stages of smallmouth bass in the streams; however, smallmouth bass were apparently able to withstand these low dissolved-oxygen concentrations and seem to have survived in some situations when dissolved-oxygen concentration decreased to1 milligram per liter.

Wisconsin↗
USGS1993

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Humboldt Wildlife Management Area, Churchill and Pershing Counties, Nevada, 1990-91

A reconnaissance investigation was begun in 1990 to determine whether the quality of irrigation drainage in and near the Humboldt Wildlife Management Area, Nevada, has caused or has the potential to cause harmful effects on human health, fish, and wildlife or to impair beneficial uses of water. Samples of surface and ground water, bottom sediment, and biota collected from sites upstream and downstream from the Lovelock agricultural area were analyzed for potentially toxic trace elements. Also analyzed were radioactive substances, major dissolved constitu- ents, and nutrients in water, as well as pesticide residues in bottom sediment and biota. In samples from areas affected by irrigation drainage, the following constituents equaled or exceeded baseline concentrations or recommended standards for protection of aquatic life or propagation of wildlife--in water: arsenic, boron, dissolved solids, mercury, molybdenum, selenium, sodium, and un-ionized ammonia; in bottom sediment; arsenic and uranium; and in biota; arsenic, boron, and selenium. Selenium appears to be biomagnified in the Humboldt Sink wetlands. Biological effects observed during the reconnaissance included reduced insect diversity in sites receiving irrigation drainage and acute toxicity of drain water and sediment to test organisms. The current drought and upstream consumption of water for irrigation have reduced water deliveries to the wetlands and caused habitat degradation at Humboldt Wildlife Management Area. During this investigation. Humboldt and Toulon Lakes evaporated to dryness because of the reduced water deliveries.

Water-Resources Investigations Report↗
USGS1995

Selected chemical characteristics and acute toxicity of urban stormwater, streamflow, and bed material, Maricopa County, Arizona

The chemistry and toxicity of urban stormwater, streamflow, and bed material in the Phoenix, Arizona, area were characterized to determine if urban stormwater could degrade the quality of streams. Toxic phases of stormwater (oil and grease, suspended solids, dissolved metals, and dissolved organics) were identified to aid water-quality managers minimize the sources of toxicants. Acute aquatic toxicity tests were done using the water flea Ceriodaphnia dubia and fathead minnows (Pimaphales promelas), and acute sediment toxicity tests were done using the amphipod Hyalella azteca. Statistical analyses also were used to determine the effect of urbanization on the quality of water and bed material and to identify toxic constituents. Statistical analyses indicated that urban stormwater could degrade the quality of streamflow with oil and grease, pesticides, dissolved trace metals, and ammonia, and that ammonia, lead, cadmium, and zinc are released by urban activities and accumulate in bed material. Ammonia may be from fertilizers, fecal matter, and other sources. Lead probably is from vehicles that use leaded gasoline. Cadmium and zinc could be from paniculate metal in oil, brake pads, and other sources. Samples of the initial runoff from urban drainage basins appeared to be more toxic than flowweighted composite samples, and stormwater was more harmful to fathead minnows than to Ceriodaphnia dubia. Streamflow samples from the Salt River were not toxic to either species, which indicates that urban stormwater could degrade the quality of the Salt River. The enhanced mortality rate of fathead minnows exposed to urban stormwater from most urban drainage basins indicated that the toxicants were more detrimental to fish than to insects and could be present in stormwater throughout the Phoenix area. The most toxic stormwater samples were collected from the drainage basins with residential and commercial land use, and the toxicity probably was due to surfactants and (or) other constituents leached from asphalt and resealant Results of toxicity identification evaluations indicated that the toxicity of stormwater mostly was due to organic constituents; dissolved zinc and copper also appeared to contribute to stormwater toxicity. Statistical comparisons of chemical data to toxicity data indicated that organophosphate pesticides were not the toxic constituents, and the toxicity generally was due to organic constituents that were not analyzed. The most toxic bed-material samples were collected from a drainage basin with undeveloped land use. In these bed-material samples, mortality rates were significantly higher than in samples from ephemeral channels. Comparisons between the toxicity of bed-material samples from undeveloped and urban drainage basins and between urban drainage basins and ephemeral channels showed no significant difference. In urban drainage basins, bed-material samples collected from areas where stormwater accumulates appeared to be more toxic than samples collected from areas where stormwater does not accumulate. For bed-material samples from the undeveloped drainage basin, mortality rates strongly correlated with recoverable concentrations of zinc and moderately correlated with recoverable concentrations of copper. The high mortality rate probably was due to naturally occurring trace metals. For bed-material samples from urban drainage basins, mortality rates significantly correlated with recoverable concentrations of cadmium and zinc, which resulted from urban activities. The bioavailability of trace metals in bed material appeared to be controlled by the adsorption properties of organic carbon, iron, and manganese. Organochlorine pesticides were detected in most bed-material samples; however, mortality rates were poorly correlated with pesticide concentrations.

Arizona↗
USGS1995

Characteristics, transport, and yield of sediment in Juday Creek, St. Joseph County, Indiana, 1993-94

Juday Creek is a tributary of the St. Joseph River in St. Joseph County, north-central Indiana. The creek has been identified as one of the few streams in the State that can support a naturally reproducing brown trout population. A recent study of benthic invertebrates shows a decline in the production rate of insect species and suggests that this decline may be caused by increased sedimen- tation. This report presents the results of a study of the sediment conditions in Juday Creek from April 1993 through June 1994. Measurements of streamflow, suspended sediment, and bedload were made at six sampling sites during three storms and a period of low flow. A total of 11 samples were collected during storms, and 1 sample was collected during low flow at each site. Bed-material samples were collected at the six sites. Sediment cores were collected from the delta of an instream pond and at a sediment trap near the mouth of the stream. Scour and fill at the six sites were monitored by means of scour chains and surveyed cross sections. The instream pond was surveyed twice, and the volume weight of the sediment was determined to estimate the yield of sediment for the upper reach of Juday Creek. Particle-size distributions indicate that the bed material is predominantly sand and gravel and that very little of the bed material is silt or finer (less than 0.062 millimeter). Analysis of sediment cores showed that most of the sediment deposited in the sediment trap and instream pond was sand. Sediment sampling during a period of low flow detected only minimal concentrations of suspended sediment; the maximum concentration was 6 milligrams per liter, equivalent to a daily load of 0.32 ton. Bedload ranged from 5.2 to 76.7 grams per cross- channel sampling, equivalent to 0.11 to 1.70 tons per day. Sediment sampling during the storms indicates that bedload discharge is the primary mode of sediment transport. Suspended-sediment concentration ranged from 4 to 67 milligrams per liter; the median was 17 milligrams per liter. Bedload ranged from 3.4 to 862 grams per cross- channel sampling; the median was 109 grams. Only 15 percent of the samples were less than 50 grams. Scour chains and surveyed cross sections documented some scour and fill at most of the sites.Scour and fill tended to balance out; after a 1-year period, the net change in the streambed altitude was minimal. Some infilling was the net result at most of the sites. Surveys of the instream pond determined that the volume of sediment delivered to the pond from April 1993 to April 1994 was approximately 26,500 cubic feet. The average volume weight of the sediment was determined to be 102 pounds per cubic foot. The sediment yield for the upper reach of Juday Creek from April 1993 to April 1994 was estimated to be 48 tons per square mile.

Indiana↗
USGS1997

Distribution of fish, benthic invertebrate, and algal communities in relation to physical and chemical conditions, Yakima River basin, Washington, 1990

Biological investigations were conducted in the Yakima River Basin, Washington, in conjunction with a pilot study for the U.S. Geological Survey's National Water-Quality Assessment Program. Ecological surveys were conducted at 25 sites in 1990 to (1) assess water-quality conditions based on fish, benthic invertebrate, and algal communities; (2) determine the hydrologic, habitat, and chemical factors that affect the distributions of these organisms; and (3) relate physical and chemical conditions to water quality. Results of these investigations showed that land uses and other associated human activities influenced the biological characteristics of streams and rivers and overall water-quality conditions. Fish communities of headwater streams in the Cascades and Eastern Cascades ecoregions of the Yakima River Basin were primarily composed of salmonids and sculpins, with cyprinids dominating in the rest of the basin. The most common of the 33 fish taxa collected were speckled dace, rainbow trout, and Paiute sculpin. The highest number of taxa (193) was found among the inverte- brates. Insects, particularly sensitive forms such as mayflies, stoneflies, and caddisflies (EPT--Ephemeroptera, Plecoptera, and Trichoptera fauna), formed the majority of the invertebrate communities of the Cascades and Eastern Cascades ecoregions. Diatoms dominated algal communities throughout the basin; 134 algal taxa were found on submerged rocks, but other stream microhabitats were not sampled as part of the study. Sensitive red algae and diatoms were predominant in the Cascades and Eastern Cascades ecoregions, whereas the abundance of eutrophic diatoms and green algae was large in the Columbia Basin ecoregion of the Yakima River Basin. Ordination of physical, chemical, and biological site characteristics indicated that elevation was the dominant factor accounting for the distribution of biota in the Yakima River Basin; agricultural intensity and stream size were of secondary importance. Ordination identified three site groups and three community types. Site groups consisted of (1) small streams of the Cascades and Eastern Cascades ecoregions, (2) small streams of the Columbia Basin ecoregions, and (3) large rivers of the Cascades and Columbia Basin ecoregions. The small streams of the Columbia Basin could be further subdivided into two groups--one where agricultural intensity was low and one where agricultural intensity was moderate to high. Dividing the basin into these three groups removed much of the influence of elevation and facilitated the analysis of land-use effects. Community types identified by ordination were (1) high elevation, cold-water communities associated with low agricultural intensity; (2) lower elevation, warm-water communities associated with low agricultural intensity, and (3) lower elevation, warm-water communities associated with moderate to high agricultural intensity. Multimetric community condition indices indicated that sites in the Cascades and Eastern Cascades site group were largely unimpaired. In contrast, all but two sites in the Columbia Basin site group were impaired, some severely. Agriculture (nutrients and pesticides) was the primary factor responsible for this impairment, and all impaired sites were characterized by multiple indicators of impairment. Three sites (Granger Drain, Moxee Drain, and Spring Creek) had high levels of impairment. Sites in the large-river site group were moderately to severely impaired downstream from the city of Yakima. High levels of impairment at large-river sites corresponded with high levels of pesticides in fish tissues and the occurrence of external anomalies.

Washington↗
USGS2001

Gore Creek watershed, Colorado — Assessment of historical and current water quantity, water quality, and aquatic ecology, 1968–98

The historical and current (1998) water-quantity, water-quality, and aquatic-ecology conditions in the Gore Creek watershed are described as part of a study by the U.S. Geological Survey, done in cooperation with the Town of Vail, the Eagle River Water and Sanitation District, and the Upper Eagle Regional Water Authority. Interpretation of the available water-quantity, water-quality, and aquatic-ecology data collected by various agencies since 1968 showed that background geology and land use in the watershed influence the water quality and stream biota. Surface-water nutrient concentrations generally increased as water moved downstream through the Town of Vail, but concentrations at the mouth of Gore Creek were typical when compared with national data for urban/undeveloped sites. Nitrate concentrations in Gore Creek were highest just downstream from a wastewater-treatment plant discharge, but concentrations decreased at sites farther downstream because of dilution and nitrogen uptake by algae. Recent total phosphorus concentrations were somewhat elevated when compared to the U.S. Environmental Protection Agency recommended level of 0.10 milligram per liter for control of eutrophication in flowing water. However, total phosphorus concentrations at the mouth of Gore Creek were relatively low when compared to a national study of phosphorus in urban land-use areas. Historically, suspended sediment associated with construction of Interstate 70 in the early 1970's has been of primary concern; however, recent data indicate that streambed aggradation of sediment originating from Interstate 70 traction sanding currently is a greater concern. About 4,000 tons of coarse sand and fine gravel is washed into Black Gore Creek each year following application of traction materials to Interstate 70 during adverse winter driving conditions. Suspended-sediment concentrations were low in Black Gore Creek; however, bedload-transport rates of as much as 4 tons per day have been measured. Water samples were collected during spring and fall of 1997 from five alluvial monitoring wells located throughout the Town of Vail. Nutrient concentrations generally were low in the alluvial monitoring wells. Specific-conductance values ranged from 265 to 557 microsiemens per centimeter at 25 degrees Celsius. Concentrations of radon in monitoring-well samples exceeded the 300-picocuries-per-liter U.S. Environmental Protection Agency proposed maximum contaminant level (which has been suspended pending further review). Low levels of bacteria and methylene blue active substances indicate there is little or no wastewater contamination of shallow ground water in the vicinity of the monitoring wells and one of the municipal water-supply wells. Ground-water ages in the alluvial aquifer ranged from about 2 to about 50 years old. These ages indicate that changes in land-management practices may not have an effect on ground-water quality for many years. Differences in macroinvertebrate-community structure were found among sites in Gore Creek by evaluating changes in relative abundance, total abundance, and dominant functional feeding groups of the major macroinvertebrate groups. Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies), and Coleoptera (beetles) exhibited relatively low tolerance to water-quality degradation when compared with Diptera (midges) and non-insects (sludge worms). More than 80 percent of the macroinvertebrate community at sites located farthest upstream was composed of mayflies, stoneflies, and caddisflies, indicating favorable water-quality and habitat conditions. The relative percentages of midges and sludge worms greatly increased in the downstream reaches of Gore Creek, which drain relatively larger areas of urban and recreation land uses, indicating the occurrence of nutrient and organic enrichment in Gore Creek. The macroinvertebrate community in Black Gore Creek indicated adverse effects from sediment deposition. Macroinvertebrate abundance was considerably reduced at the two sites where streambed sediment was more prevalent; however, differences in abundance also may have been related to differences in habitat and availability of food resources. The lower 4 miles of Gore Creek, downstream from Red Sandstone Creek, have been designated a Gold Medal fishery in recognition of the high recreational value of the abundant brown trout community. Gore Creek contained twice as many trout as a reference site with similar habitat characteristics in Rocky Mountain National Park. Moderate increases in nutrient concentrations above background conditions have increased the growth and abundance potential for aquatic life in Gore Creek, while at the same time, esthetic and water-quality conditions have remained favorable. The spatial distribution of nitrate concentrations was consistent with the observed spatial distribution of algal biomass and macroinvertebrate-community characteristics. Algal biomass was limited by available resources (sunlight and nutrients) in the upstream reaches of Gore Creek and limited by macroinvertebrate grazing and water-quality conditions in the downstream reaches. The fish community has benefited from enhanced biological production in the downstream reach of Gore Creek. Increases in algal biomass and macroinvertebrate abundance, in response to higher nutrient concentrations, provide ample food resources necessary to support the abundant fish community. Trace-element data for surface water, ground water, streambed sediment, fish tissue, and macroinvertebrate tissue indicate that concentrations are generally low in the Gore Creek watershed. In streambed-sediment samples, cadmium, copper, and zinc concentrations were below background levels reported for the Upper Colorado River Basin in Colorado. Concentrations of cadmium, copper, iron, and silver in surface water have occasionally exceeded stream standards in the past, but recent surface-water data indicate these trace elements currently are not of concern. Manganese concentrations commonly exceeded the 50-microgram-per-liter stream standard in Black Gore Creek. Elevated manganese concentrations were primarily attributable to the sedimentary geology of the area. Concentrations of organic constituents are low in the Gore Creek watershed. Pesticides were detected infrequently and at low concentrations in surface-water, ground-water, bed-sediment, and whole-body fish-tissue samples. Volatile organic compounds also were detected at low concentrations in surface- and ground-water samples.

Colorado↗
USGS1999

Surface-water-quality assessment of the Yakima River basin in Washington: Spatial and temporal distribution of trace elements in water, sediment, and aquatic biota, 1987-91

The report describes the distribution of trace elements in sediment, water, and aquatic biota in the Yakima River basin, Washington. Trace elements were determined from streambed sediment, suspended sediment, filtered and unfiltered water samples, aquatic insects, clams, fish livers, and fish fillets between 1987 and 1991. The distribution of trace elements in these media was related to local geology and anthropogenic sources. Additionally, annual and instantaneous loads were estimated for trace elements associated with suspended sediment and trace elements in filtered water samples. Trace elements also were screened against U.S. Environmental Protection Agency guidelines established for the protection of human health and aquatic life.

Washington↗
USGS2015

Ultraviolet vision may be widespread in bats

Insectivorous bats are well known for their abilities to find and pursue flying insect prey at close range using echolocation, but they also rely heavily on vision. For example, at night bats use vision to orient across landscapes, avoid large obstacles, and locate roosts. Although lacking sharp visual acuity, the eyes of bats evolved to function at very low levels of illumination. Recent evidence based on genetics, immunohistochemistry, and laboratory behavioral trials indicated that many bats can see ultraviolet light (UV), at least at illumination levels similar to or brighter than those before twilight. Despite this growing evidence for potentially widespread UV vision in bats, the prevalence of UV vision among bats remains unknown and has not been studied outside of the laboratory. We used a Y-maze to test whether wild-caught bats could see reflected UV light and whether such UV vision functions at the dim lighting conditions typically experienced by night-flying bats. Seven insectivorous species of bats, representing five genera and three families, showed a statistically significant &lsquo;escape-toward-the-light&rsquo; behavior when placed in the Y-maze. Our results provide compelling evidence of widespread dim-light UV vision in bats.

Arizona, Colorado↗
USGS2011

Collection of mammal manure and other Debris by nesting Burrowing Owls

Burrowing Owls ( Athene cunicularia ) routinely collect and scatter dry manure of mammals around their nesting burrows. Recent studies have suggested this behavior attracts insect prey to the nesting burrow. However, some Burrowing Owls do not use manure, but instead, collect and scatter other materials (e.g., grass, moss, paper, plastic) around their nesting burrow in a similar fashion. Use of these materials seemingly contradicts the prey-attraction hypothesis. Using observational and experimental methods, we tested whether Burrowing Owls preferred manure to other materials commonly found at nesting burrows in eastern Washington. We found a wide variety of materials at nests, but grass and manure were the most common materials. The amount of manure present at nests was negatively correlated with the amount of other materials, and with the distance to the nearest source of manure. Burrowing Owls showed no preference between horse manure and grass divots at experimental supply stations that we placed near nesting burrows. They did prefer these two materials to carpet pieces and aluminum foil (both materials that are often found at Burrowing Owl nests). Our results did not support the premise that Burrowing Owls specifically seek out manure when lining their nesting burrows. The unusual behavior of collecting and scattering mammal manure and other debris at Burrowing Owl nests may serve functions other than (or in addition to) prey attraction and alternative hypotheses need further testing before the function of this behavior is certain.

Journal of Raptor Research↗
USGS2020

Toward improving pollinator habitat: Reconstructing prairies with high forb diversity

Reconstructed prairies can provide habitat for pollinating insects, an important ecosystem service. To optimize reconstructions for pollinators, goals may include enhancing flowering plant cover and richness and increasing bloom availability early and late in the growing season. Resistance to invasive exotic species must also be a goal in any reconstruction, but it is unclear how increasing forb richness and dominance may affect susceptibility to invasion. We compared planted forb richness and cover, cover of planted grasses, and persistence of exotic species 10 y post-planting of reconstructions with 58 species (extra-high richness), 34 species (high), 20 species (medium), and 10 species (low) planted at the same time in the same fields, and using the same methods and overall seeding rate at Neal Smith National Wildlife Refuge in Iowa, USA. Planted forb richness and cover were higher and planted warm-season, but not cool-season, grass cover was lower in the extra-high richness plots. Mean Coefficient of Conservatism was higher and there was less cover of exotic forbs in the extra-high richness plots. Cover of exotic cool-season grasses was greater in the extra-high richness plots than in the lower-richness plots and this trend was still increasing at the last sample date. Our results are encouraging in that we increased cover of pollinator-friendly habitat, but invasive grasses are a concern as they may reduce forb cover and opportunities for ground-nesting bees in the long term.

Iowa↗
USGS2006

Canada thistle biological control agents on two South Dakota wildlife refuges

We monitored populations of Canada thistle biocontrol agents Cassida rubiginosa, Ceutorhynchus litura, Larinus (= Hadroplantus) planus, Urophora cardui, Orellia (= Terellia) ruficauda, and Rhinocyllus conicus on Canada thistle (Cirsium arvense) at two national wildlife refuges in South Dakota from 1999 through 2003. C. litura, U. cardui, O. ruficauda, and R. conicus were present on both refuges. Agent populations were low except for C. litura, which was present in up to 90% of stems in some plots. C. litura infestation did not reduce thistle flowering, stem length, or over-winter survival. There was no change in thistle stem numbers over the study period and no difference in stem numbers in areas of high C. litura populations compared to areas of low C. litura populations. Our results suggest that insect biological control agents are inadequate for reduction of Canada thistle in southern South Dakota.

Natural Areas Journal↗
USGS2020

Evidence for a growing population of eastern migratory monarch butterflies is currently insufficient

The eastern migratory population of monarch butterflies has experienced a multi-decadal decline, but a recent increase in abundance (to 6.05 ha in winter 2018) has led some observers to question whether the population has reversed its long-standing decline and embarked on a trajectory of increasing abundance. We examined this possibility through changepoint analyses, first assessing whether a change in trajectory existed and whether that change was sufficient to alter our estimated risk for the population. We found evidence of a change in trajectory in 2014, but insufficient statistical support for a significantly increasing population since that time (β = 0.285, 95% CI = -0.127, 0.697). If the population estimate for winter 2019 is ≥4.0 ha, we will then be able to credibly assert the population has been increasing since 2014. However, given estimated levels of time series variability, presumed habitat capacity and no recent change in status or trend, there was a 13.5% probability of observing a population estimate as large or larger than was reported for winter 2018. Despite insufficient evidence for an increasing population, near-term risk of quasi-extinction by 2023 has declined (mean risk declining from 43% to 20%) because of higher abundance estimates since 2014. Our analyses highlight the incredible difficulty in drawing robust conclusions from annual changes in abundance over a short time series, especially for an insect that commonly exhibits considerable year-to-year variation. Thus, we urge caution when drawing conclusions regarding species status and trends for any species for which limited data are available.

Frontiers in Ecology and Evolution↗