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At least 1,621 records · Page 90Linked to original sources

Wetlands serve as natural sources for improvement of stream ecosystem health in regions affected by acid deposition

For over 40 years, acid deposition has been recognized as a serious international environmental problem, but efforts to restore acidified streams and biota have had limited success. The need to better understand the effects of different sources of acidity on streams has become more pressing with the recent increases in surface water organic acids, or 'brownification' associated with climate change and decreased inorganic acid deposition. Here, we carried out a large scale multi-seasonal investigation in the Adirondacks, one of the most acid-impacted regions in the United States, to assess how acid stream producers respond to local and watershed influences and whether these influences can be used in acidification remediation. We explored the pathways of wetland control on aluminum chemistry and diatom taxonomic and functional composition. We demonstrate that streams with larger watershed wetlands have higher organic content, lower concentrations of acidic anions, and lower ratios of inorganic to organic monomeric aluminum, all beneficial for diatom biodiversity and guilds producing high biomass. Although brownification has been viewed as a form of pollution, our results indicate that it may be a stimulating force for biofilm producers with potentially positive consequences for higher trophic levels. Our research also reveals that the mechanism of watershed control of local stream diatom biodiversity through wetland export of organic matter is universal in running waters, operating not only in hard streams, as previously reported, but also in acid streams. Our findings that the negative impacts of acid deposition on Adirondack stream chemistry and biota can be mitigated by wetlands have important implications for biodiversity conservation and stream ecosystem management. Future acidification research should focus on the potential for wetlands to improve stream ecosystem health in acid-impacted regions and their direct use in stream restoration, for example, through stream rechanneling or wetland construction in appropriate hydrologic settings.

Global Change Biology↗

Water quality in the Trinity River basin, Texas, 1992-95

Water quality in the Trinity River basin was studied during 1992-95 as part of the USGS National Water-Quality Assessment (NAWQA) Program. Studies included chemical sampling of streams, streambed sediments, biota, and ground water; measuring distributions of biological communities in streams; and measuring physical characteristics of streams that affect biological habitat. The sampling design, in general, relates water-quality conditions to causative human and natural environmental factors. The occurrence of pesticides, for example, is related to land use. Trends are mixed, with a substantial improvement in the diversity of fish species downstream from Dallas and large decreases in regulated contaminants such as DDT; but increases in unregulated contaminants such as polychlorinated biphenyls.

Texas↗

Areas Susceptible to Irrigation-Induced Selenium Contamination of Water and Biota in the Western United States

The U.S. Department of the Interior (DOI) studied contamination induced by irrigation drainage in 26 areas of the Western United States during 1986-95. Comprehensive compilation, synthesis, and evaluation of the data resulting from these studies were initiated by DOI in 1992. Soils and ground water in irrigated areas of the West can contain high concentrations of selenium because of (1) residual selenium from the soil's parent rock beneath irrigated land; (2) selenium derived from rocks in mountains upland from irrigated land by erosion and transport along local drainages, and (3) selenium brought into the area in surface water imported for irrigation. Application of irrigation water to seleniferous soils can dissolve and mobilize selenium and create hydraulic gradients that cause the discharge of seleniferous ground water into irrigation drains. Given a source of selenium, the magnitude of selenium contamination in drainage-affected aquatic ecosystems is strongly related to the aridity of the area and the presence of terminal lakes and ponds. Marine sedimentary rocks and deposits of Late Cretaceous or Tertiary age are generally seleniferous in the Western United States. Depending on their origin and history, some Tertiary continental sedimentary deposits also are seleniferous. Irrigation of areas associated with these rocks and deposits can result in concentrations of selenium in water that exceed criteria for the protection of freshwater aquatic life. Geologic and climatic data for the Western United States were evaluated and incorporated into a geographic information system (GIS) to produce a map identifying areas susceptible to irrigation-induced selenium contamination. Land is considered susceptible where a geologic source of selenium is in or near the area and where the evaporation rate is more than 2.5 times the precipitation rate. In the Western United States, about 160,000 square miles of land, which includes about 4,100 square miles (2.6 million acres) of land irrigated for agriculture, has been identified as being susceptible. Biological data were used to evaluate the reliability of the map. In 12 of DOl's 26 study areas, concentrations of selenium measured in bird eggs were elevated sufficiently to significantly reduce hatchability of the eggs. The GIS map identifies 9 of those 12 areas. Deformed bird embryos having classic symptoms of selenium toxicosis were found in four of the study areas, and the map identifies all four as susceptible to irrigation-induced selenium contamination.

Circular↗

National water-quality assessment program : the Albemarle- Pamlico drainage

In 1991, the U.S. Geological Survey (USGS) began to implement a full-scale National Water-Quality Assessment (NAWQA) program. Long-term goals of the NAWQA program are to describe the status and trends in the quality of a large, representative part of the Nation's surface- and ground-water resources and to provide a sound, scientific understanding of the primary natural and human factors affecting the quality of these resources. In meeting these goals, the program will produce a wealth of water quality information that will be useful to policy makers and managers at the national, State, and local levels. Study-unit investigations constitute a major component of the NAWQA program, forming the principal building blocks on which national-level assessment activities are based. The 60 study-unit investigations that make up the program are hydrologic systems that include parts of most major river basins and aquifer systems. These study units cover areas of 1,200 to more than 65,000 square miles and incorporate about 60 to 70 percent of the Nation's water use and population served by public water supply. In 1991, the Albemarle-Pamlico drainage was among the first 20 NAWQA study units selected for study under the full-scale implementation plan. The Albemarle-Pamlico drainage study will examine the physical, chemical, and biological aspects of water quality issues in a coordinated investigation of surface water and ground water in the Albemarle-Pamlico drainage basin. The quantity and quality of discharge from the Albemarle-Pamlico drainage basin contribute to some water quality problems in the biologically sensitive waters of Albemarle and Pamlico Sounds. A retrospective analysis of existing water quality data will precede a 3-year period of intensive data-collection and analysis activities. The data resulting from this study and the improved understanding of important processes and issues in the upstream part of the study unit will enhance understanding of the quality of water in Albemarle-Pamlico Sounds, the second largest estuarine system in the United States.

Open-File Report↗

San Diego Multiple Species Conservation Program (MSCP) Rare Plant Monitoring Review and Revision

Introduction The San Diego Multiple Species Conservation Program (MSCP) was developed for the conservation of plants and animals in the south part of San Diego County, under the California Natural Community Conservation Planning Act of 1991 (California Department of Fish and Game) and the Federal Endangered Species Act of 1973, as amended (16 U.S. Code 1531-1544.) The Program is on the leading edge of conservation, as it seeks to both guide development and conserve at-risk species with the oversight of both State and Federal agencies. Lands were identified for inclusion in the MSCP based on their value as habitat for at-risk plants or plant communities (Natural Community Conservation Planning, 2005). Since its inception in the mid-1990s the Program has protected over 100,000 acres, involving 15 jurisdictions and the U.S. Fish and Wildlife Service (USFWS) and California Department of Fish and Game (CDFG) in the conservation of 87 taxa. Surveys for covered species have been conducted, and management and monitoring have been implemented at some high priority sites. Each jurisdiction or agency manages and monitors their conservation areas independently, while collaborating regionally for long-term protection. The San Diego MSCP is on the forefront of conservation, in one of the most rapidly growing urban areas of the country. The planning effort that developed the MSCP was state-of-the-art, using expert knowledge, spatial habitat modeling, and principles of preserve design to identify and prioritize areas for protection. Land acquisition and protection are ahead of schedule for most jurisdictions. Surveys have verified the locations of many rare plant populations known from earlier collections, and they provide general information on population size and health useful for further conservation planning. Management plans have been written or are in development for most MSCP parcels under jurisdictional control. Several agencies are developing databases for implementation and management tracking. In many ways this program is at the cutting edge of regional conservation, testing concepts, developing techniques, and demonstrating conservation effectiveness in new and uncharted ways. Periodic program review is crucial to the continued success of the program, as it moves from a phase of planning and acquisition to one of management and monitoring. Ecological monitoring is the key to assessing the success of the protection and management implemented at each individual reserve and for the MSCP as a whole. The ultimate goal of the Program is conservation of at-risk taxa and their habitats, as well as underlying ecological processes that contribute to sustainability of the ecosystem. Monitoring guidelines and timetables were developed by Ogden Environmental and Energy Services Co., Inc. (1996), and reviewed by Conservation Biology Institute (2001). The Program is in transition now, from the initial stage of land protection to one of land management and monitoring to determine population responses to management regimes. Several agencies have already invested substantial effort in status and trend monitoring, while others are developing their monitoring plans. Management is ongoing at several sites. With both management and monitoring, collaboration and coordination among jurisdictions can be especially fruitful in conserving resources and maximizing success.

Scientific Investigations Report↗

Monitoring ecosystem quality and function in arid settings of the Mojave Desert

Monitoring ecosystem quality and function in the Mojave Desert is both a requirement of state and Federal government agencies and a means for determining potential long-term changes induced by climatic fluctuations and land use. Because it is not feasible to measure every attribute and process in the desert ecosystem, the choice of what to measure and where to measure it is the most important starting point of any monitoring program. In the Mojave Desert, ecosystem function is strongly influenced by both abiotic and biotic factors, and an understanding of the temporal and spatial variability induced by climate and landform development is needed to determine where site-specific measurements should be made. We review a wide variety of techniques for sampling, assessing, and measuring climatic variables, desert soils, biological soil crusts, annual and perennial vegetation, reptiles, and small mammals. The complete array of ecosystem attributes and processes that we describe are unlikely to be measured or monitored at any given location, but the array of possibilities allows for the development of specific monitoring protocols, which can be tailored to suit the needs of land-management agencies.

Scientific Investigations Report↗

Hydrology, water quality, and biological characteristics of Levittown Lake, Toa Baja, Puerto Rico, April 2010–June 2011

Levittown Lake is a 30-hectare, brackish waterbody located in the municipality of Toa Baja, on the northern coast of Puerto Rico. The lake is a small, man-made feature formed by draining the marshland over which the Levittown community was built. Levittown Lake has an average depth of about 5 meters and a water level at/near mean sea level. Tidal oscillations within the lake were minimal during the study, about 10 centimeters regardless of ocean tides, and the daily flushing rate of the lake was about 2 percent of its entire water volume. Hydrologic, water-quality, and biological data were collected in Levittown Lake and adjacent areas (specifically, the inlet/outlet channel and Caño El Hato drainage canal) between April 2010 and June 2011 (1) to establish baseline conditions and determine the water quality of the lake on the basis of preestablished standards and (2) for contrast with other, more healthy coastal lagoons. The study provides a baseline for an assessment of the potential of Levittown Lake to function as a coastal lagoon. Water-quality properties measured onsite (temperature, pH, dissolved oxygen concentration, specific conductance, salinity, and water transparency) varied diurnally and seasonally. In general, water-quality properties were in compliance with current regulatory Class SB standards established by the Puerto Rico Environmental Quality Board, except for some dissolved oxygen concentration and pH measurements. Some dissolved oxygen concentration measurements at the water surface and all dissolved oxygen concentration measurements at the lake bottom were lower than the values recommended by the Puerto Rico Environmental Quality Board. The pH of the water at the lake surface ranged from 7.3 to 9.1, with the upper value exceeding the recommended pH values. Nutrient concentrations were below the current regulatory standards of less than 5 milligrams per liter (mg/L) for total nitrogen and 1 mg/L for total phosphorus. The measured concentrations of chlorophyll a varied throughout the year of sampling and indicate that eutrophic conditions predominate in Levittown Lake. The phytoplankton yielded an average net productivity of 0.5 milligram of oxygen per liter per hour, as determined by light and dark bottle primary productivity studies conducted on a monthly basis and measured in the early morning hours. Because these measurements were restricted to the morning hours, a qualification of the representativeness of the results to the full diurnal cycle is necessary. The measured hourly respiration rate averaged 0.39 milligram of oxygen per liter. Diel studies were planned in the lake to assess dissolved oxygen concentration diurnal curves and ultimately to compute the community net primary productivity, respiration, and gross productivity. Conditions during the diel studies were later determined to be unsuitable, limiting the assessment of community metabolism. Another biological indicator evaluated during the study was the phytoplankton biomass, and results indicated that phytoplankton biomass measured at the Levittown Lake ranged from 6.0 to 112.5 mg/L. Fecal indicator bacteria concentrations ranged from 10 to 1,540,000 colonies per 100 milliliters of water. Concentrations generally were greatest in and near the Caño El Hato drainage canal and, during the study, exceeded current regulatory standards established for Puerto Rico.

Puerto Rico↗

Sulfate reduction in ground water of southeastern Montana

Ground water in southeastern Montana was investigated to determine if sulfide production was bacterially mediated. Sulfate—reducing bacteria were detected in 25 of 26 ground—water samples in numbers ranging from 2.0 x 10 1 to greater than 2.4 x 10 4 bacteria per 100 milliliters. Stable sulfur isotope fractionation studies indicate a biological role in sulfate reduction. However, sulfate—reducing activity as determined by use of a radioactive sulfur isotope was observed in only 1 of 16 samples. Bacterial dissimilatory sulfate reduction is postulated to be responsible for a major part of the sulfide produced in these ground waters. These bacteria are most likely active in the adsorbed state, possibly in subsurface microzones where environmental conditions are conducive to sulfate reduction.

Montana↗

Interlaboratory comparison of three sediment bioaccumulation tests

Standard bioaccumulation tests are commonly conducted using Macoma nasuta (clam), and Alitta virens (polychaete) for marine tests, and Lumbriculus variegatus (an oligochaete) for freshwater tests. Because the interlaboratory variability associated with these tests is unknown, four experienced laboratories conducted standard 28-day bioaccumulation tests with the above species using sediments contaminated with polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Chemical analysis of tissue samples was performed by a single laboratory. The intralaboratory variance among replicates was relatively low for PCB tissue concentrations, with coefficients of variation (CVs) ranging from 9% to 28% for all laboratories and species, with the exception of one laboratory reporting higher variability for L . variegatus (CV = 51%). Intralaboratory variance for PCB tissue concentrations was higher than interlaboratory variance for A. virens and L . variegatus , and the magnitude of difference (MOD) for laboratory means ranged from 1.4 to 2.0 across species. Intralaboratory variability was also low for lipid content, and lipid normalization of PCB and PAH body residues generally had little impact on variability. In addition to variability across bioassay laboratories, analytical variability was evaluated by different laboratories measuring the concentration of PCBs and total lipids in a subsample of tissue homogenate of sediment-exposed test organisms. Variability associated with tissue analysis was higher than bioassay laboratory variability only in tests with L . variegatus . Statistical differences between samples may be observed due to the low intralaboratory variability; however, the biological significance of these differences may be limited because the MOD is low. Considering the MOD when comparing bioaccumulation across treatments accounts for uncertainty related to inherent variability of the test in the interpretation of statistically significant results.

Massachusetts↗

Status of three-dimensional geological mapping and modeling activities in the U.S. Geological Survey

The U.S. Geological Survey (USGS), created in 1879, is the national geological survey for the United States and the sole science agency within its cabinet-level bureau, the Department of the Interior. The USGS has a broad mission, including: serving the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect quality of life. USGS scientific activities are organized around major topics, or Mission Areas, aligned with distinct science themes; three-dimensional (3-D) modelling typically supports research and project work within a specific Mission Area. The vastness, diversity, and complexity of the geological landscape of the United States has resulted in the creation of 3-D geological framework models that are local or regional in scale; a National-scale 3-D model is only beginning to evolve. This paper summarizes 3-D geological modeling at the USGS and does not discuss 3-D modeling that is conducted by other Federal agencies, state geological surveys, academia, or industry within the U.S. This paper updates and expands upon a similar status report of USGS 3-D modeling activities of Jacobsen et al. (2011).

Report↗

Viability of piping plover Charadrius melodus metapopulations

The metapopulation viability analysis package, VORTEX , was used to examine viability and recovery objectives for piping plovers Charadrius melodus , an endangered shorebird that breeds in three distinct regions of North America. Baseline models indicate that while Atlantic Coast populations, under current management practices, are at little risk of near-term extinction, Great Plains and Great Lakes populations require 36% higher mean fecundity for a significant probability of persisting for the next 100 years. Metapopulation structure (i.e. the delineation of populations within the metapopulation) and interpopulation dispersal rates had varying effects on model results; however, spatially-structured metapopulations exhibited lower viability than that reported for single-population models. The models were most sensitive to variation in survivorship; hence, additional mortality data will improve their accuracy. With this information, such models become useful tools in identifying successful management objectives; and sensitivity analyses, even in the absence of some data, may indicate which options are likely to be most effective. Metapopulation viability models are best suited for developing conservation strategies for achieving recovery objectives based on maintaining an externally derived, target population size and structure.

Biological Conservation↗

Water quality in southern Florida: Florida, 1996-98

Major influences and findings for water quality and biology in southern Florida, including the Everglades, are described and illustrated. Samples were collected to determine total phosphorus, dissolved organic carbon, pesticides, mercury, nitrate, volatile organic carbon compounds, and radon-222. Water-management, agricultural, and land-use practices are discussed. Sixty-three species of fish in 26 families were collected; 43 native species, 10 exotic or nonnative species, and 10 species of marine fish that periodically inhabit canals and rivers were identified.

Florida↗

U.S. Geological Survey climate and land use change science strategy—A framework for understanding and responding to global change

Executive Summary The U.S. Geological Survey (USGS), a nonregulatory Federal science agency with national scope and responsibilities, is uniquely positioned to serve the Nation’s needs in understanding and responding to global change, including changes in climate, water availability, sea level, land use and land cover, ecosystems, and global biogeochemical cycles. Global change is among the most challenging and formidable issues confronting our Nation and society. Scientists agree that global environmental changes during this century will have far-reaching societal implications (Intergovernmental Panel on Climate Change, 2007; U.S. Global Change Research Program, 2009). In the face of these challenges, the Nation can benefit greatly by using natural science information in decisionmaking. Since the passage of the U.S. Global Change Research Act of 1990, the USGS has made substantial scientific contributions to understanding the interactive living and nonliving components of the Earth system. USGS natural science activities have led to fundamental advances in observing and understanding climate and land-cover change and the effects these changes have on ecosystems, natural-resource availability, and societal sustainability. Most of these major advances were pursued in partnership with other organizations within and outside the Department of the Interior. The inherent value of partnerships with other U.S. Global Change Research Program agencies and natural-resource managers is emphasized in all aspects of the planning and implementation of this Science Strategy for the coming decade. Over the next 10 years, the USGS will make substantial contributions to understanding how Earth systems interact, respond to, and cause global change. The USGS will work with science partners, decisionmakers, and resource managers at local to international levels (including Native American tribes) to improve understanding of past and present change; develop relevant forecasts; and identify those lands, resources, and communities most vulnerable to global change processes. Science will play an essential role in helping communities and land and resource managers understand local to global implications, anticipate effects, prepare for changes, and reduce the risks associated with decisionmaking in a changing environment. USGS partners and stakeholders will benefit from the data, predictive models, and decision-support products and services resulting from the implementation of this strategy. This Science Strategy recognizes core USGS strengths that are applied to key societal problems. It establishes seven goals for USGS global change science and strategic actions that may be implemented in the short term (1–5 years) and the longer term (5–10 years) to improve our understanding of the following areas of inquiry: Rates, causes, and impacts of past global changes; The global carbon cycle; Biogeochemical cycles and their coupled interactions; Land-use and land-cover change rates, causes, and consequences; Droughts, floods, and water availability under changing land-use and climatic conditions; Coastal response to sea-level rise, climatic change, and human development; and Biological responses to global change. In addition to the seven thematic goals, we address the central role of monitoring in accordance with the USGS Science Strategy recommendation that global change research should rely on existing “…decades of observational data and long-term records to interpret consequences of climate variability and change to the Nation’s biological populations, ecosystems, and land and water resources” (U.S. Geological Survey, 2007, p. 19). We also briefly describe specific needs and opportunities for coordinating USGS global change science among USGS Mission Areas and address the need for a comprehensive and sustained communications strategy.

Circular↗

Belowground dynamics in mangrove ecosystems

Mangrove ecosystems are tropical/subtropical communities of primarily tree species that grow in the intertidal zone. These tidal communities are important coastal ecosystems that are valued for a variety of ecological and societal goods and services (fig. 1). Mangrove wetlands are important filters of materials moving between the land and sea, trapping sediment, nutrients, and pollutants in runoff from uplands and preventing their direct introduction into sensitive marine ecosystems such as seagrass beds and coral reefs. Mangroves serve as nursery grounds and refuge for a variety of organisms and are consequently vital to the biological productivity of coastal waters. Furthermore, because mangroves are highly resilient to disturbances such as hurricanes, they represent a self-sustaining, protective barrier for human populations living in the coastal zone. Mangrove ecosystems also contribute to shoreline stabilization through consolidation of unstable mineral sediments and peat formation. In order to help conserve mangrove ecoystems, scientists with the United States Geological Survey (USGS) at the National Wetlands Research Center are working to more fully understand the dynamics that impact these vital ecosystems.

Fact Sheet↗

Limnological studies of the major streams in Chester County, Pennsylvania

The major streams in Chester County, Pennsylvania were studied to determine their environmental state, and to relate this condition to land- use patterns. A biological numerical rating system on a scale of 1 to 10 was developed to classify stream conditions. One indicates extremely toxic conditions and 10 balanced biological conditions. The majority of the streams studied had ratings between 4 and 8, indicating they were experiencing varying degrees of enrichment and/or sediment deposition. The streams with high numerical ratings were generally found in rural and agricultural areas. Streams with low numerical rating were found mostly in areas near waste treatment facilities or industry. Large changes in the numerical rating of a stream were related to changes in land-use patterns. Relationships were developed between dissolved solids concentrations and the biological numerical ratings of the streams. Streams with ratings from 6 to 10 had dissolved solids concentrations of approximately 100 mg/L. At ratings of 5 to 1, the dissolved solids concentrations increased progressively from 122 to 310 mg/L. Chemical data for the streams were related to the dominant orders of benthic invertebrates. The stoneflies were found to be the most sensitive to high levels of chemical constituents. The trueflies, mayflies, and caddis flies showed a wide tolerance to various chemical constituents.

Pennsylvania↗

Assessment of ecological conditions and potential effects of water produced from coalbed natural gas development on biological communities in streams of the Powder River structural basin, Wyoming and Montana, 2005-08

Ongoing development of coalbed natural gas in the Powder River structural basin in Wyoming and Montana led to formation of an interagency task group to address concerns about the effects of the resulting production water on biological communities in streams of the area. The interagency task group developed a monitoring plan and conducted sampling of macroinvertebrate, algal, and fish communities at 47 sites during 2005-08 to document current ecological conditions and determine existing and potential effects of water produced from coalbed natural gas development on biological communities. Macroinvertebrate, algal, and fish community composition varied between drainage basins, among sites within drainage basins, and by year. Macroinvertebrate communities of the main-stem Tongue River were characterized by higher taxa richness and higher abundance of Ephemeroptera, for example, compared to macroinvertebrate communities in plains tributaries of the Tongue River and the main-stem Powder River. Fish communities of the Tongue River were characterized by higher taxa richness and abundance of introduced species compared to the Powder River where native species were dominant. Macroinvertebrate community metric values from sites in the middle reach of the main-stem Powder River, from below Willow Creek to below Crazy Woman Creek, differed from metric values in the upper and lower reaches of the Powder River. Metrics indicative of communitywide differences included measures of taxa richness, relative abundance, feeding mode, and tolerance. Some of the variation in the macroinvertebrate communities could be explained by variation in environmental variables, including physical (turbidity, embeddedness, bed substrate size, and streamflow) and chemical (alkalinity and specific conductance) variables. Of these environmental variables, alkalinity was the best indicator of coalbed natural gas development because of the sodiumbicarbonate signature of the production water. Algal samples from the main-stem Powder River generally confirmed the pattern observed in the macroinvertebrate communities. Algal communities at sites in the middle reach of the Powder River commonly were characterized by dominance by a single taxon and by low biovolume of algae compared to other sites. In contrast to the macroinvertebrate and algal communities, species richness of fish communities was highest in the middle reach of the Powder River. Although a few significant differences in fish metrics were determined along the main-stem Powder River, the differences did not correspond to the pattern observed for the macroinvertebrate and algae communities. Differences in biological communities were noted between years, potentially due to the effects of drought. Macroinvertebrate community metrics, such as Diptera taxa richness, were significantly different in the severe drought year of 2006 from metric values in 2005 and 2007-08. Waterquality data collected during the study indicated that, with few exceptions, water-quality constituents generally did not exceed State or Federal acute and chronic criteria for the protection of aquatic life.

Scientific Investigations Report↗

Chapter A6. Section 6.1. Temperature

Accurate temperature measurements are required for accurate determinations of important environmental parameters such as pH, specific electrical conductance, and dissolved oxygen, and to the determination of chemical reaction rates and equilibria, biological activity, and physical fluid properties. This section of the National Field Manual (NFM) describes U.S. Geological Survey (USGS) guidance and protocols for measurement of temperature in air, ground water, and surface water and calibration of the equipment used. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters will be announced on the USGS Home Page on the World Wide Web under 'New Publications of the U.S. Geological Survey.'

Techniques of Water-Resources Investigations↗

Barred owl research needs and prioritization in California

Barred owls (Strix varia) have reached high densities within the range of the northern spotted owl (S. occidentalis caurina) and are rapidly increasing in number within the range of the California spotted owl (S. o. occidentalis). Encroaching populations of barred owls pose a significant competitive threat to the viability of both spotted owl subspecies in California. In response, the Director of the California Department of Fish and Wildlife (CDFW) convened the California Barred Owl Science Team (BOST) to identify and address the threat posed by barred owls to spotted owls in California. BOST is composed of subject matter scientists with a goal to provide objective scientific review and recommendations to CDFW to promote the recovery and conservation of spotted owls in California. In this document, BOST identifies, describes, and prioritizes key research needs for barred owls that have the potential to benefit the conservation of spotted owls in California. Key research needs were identified from multiple in-person and remote meetings of BOST, with considerable input from attending representatives from state and federal natural resource agencies. BOST and liaisons recognize that periodic updates of this document will likely be required as more is learned about the ecology of barred owls in California and research needs and priorities evolve. Research that BOST deemed the most likely to provide a rigorous scientific basis for reducing barred owl populations included experimental removals, along with ecological studies expected to generate information that would provide avenues for the effective management of barred owls. Other high priority research needs include research using biological samples obtained during experimental removals to better understand the ecology of barred owls and the threats they pose to spotted owls and associated wildlife. We conclude the document with a discussion of how projects are related to the State Wildlife Action Plan. In Appendix I, we discuss considerations for maximizing the success of proposed removal experiments and ecological research on barred owls.

Report↗