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At least 19 recordsLinked to original sources
USGS2000

Surface water quality of the major drainage basins of Big Thicket National Preserve

Surface water quality was monitored at 19 stations (2-4 week intervals) in six drainage basins of Big Thicket National Preserve of east Texas between 1996 and 1999. The parameters monitored were temperature, dissolved oxygen, pH, conductivity, current speed, light attenuation, chlorophyll a and concentrations of ammonium, ortho-phosphate, nitrate and nitrite. The best water quality (low nutrients and chlorophyll a; no hypoxia) was found in the Big Sandy Creek, Turkey Creek and Village Creek systems. Water quality in the Neches River was also generally good except for instances of moderate algal blooms. The Pine Island Bayou system, however, typically showed poor water quality. Very low current velocities and high concentrations of nutrients promoted massive spring plankton blooms (chlorophyll a in excess of 100 μg L-1) and subsequent hypoxia/anoxia (dissolved oxygen less than 5 mg L-1). In this system, hypoxia occurred as early as April and as late as December.

Texas↗
USGS2006

Ectoparasites of Burrowing Owls (Athene cunicularia hypugaea) wintering in southern Texas

Fifteen Western Burrowing Owls (Athene cunicularia hypugaea) were captured over two winters (2001-2003) in southern Texas and examined for ectoparasites. Four of the 15 owls (27%) harbored feather lice, and the maximum number of lice found on any individual was ??? three. Two species of feather lice were found: Colpocephalum pectinatum occurred on three of the owls, and Strigiphilus speotyti was found on four owls. No fleas or other ectoparasites were found on any of the Burrowing Owls. The low diversity and numbers of ectoparasites suggest that ectoparasites are not threatening the health of wintering Burrowing Owls in southern Texas.

Texas Journal of Science↗
USGS2010

A comparison of litter production in young and old baldcypress (Taxodium distichum L.) stands at Caddo Lake, Texas

Aboveground primary productivity for cypress forests was assessed from measurements of litter production in two age groups and in two hydrological regimes (standing water and free-flowing). Caddo Lake, located in northeast Texas on the Texas-Louisiana border, offered a unique study site since it is dominated by extensive stands composed entirely of Taxodium distichum (L.) Rich, (baldcypress) in different age groups. Young stands (approximately 100 years old) are found along the shoreline and on shallow flooded islands. Old stands (-150 to 300 years old) are found in deeper water where they were continuously flooded. Litter production over three years from October 1998 to September 2001 was measured. Litter consisting of leaves, twigs, bark, reproductive parts, and Tillandsia usneoides (L.) L. (Spanish moss) was collected monthly using 0.5 m 2 floating traps. Tree diameters were measured within 200 m 2 circular plots in each stand. The young stands supported densities greater than 2,000 stems/ha and a mean stand basal area of 72.3 m 2 /ha, whereas old stands supported lower densities of about 500 stems/ha but with a similar mean stand basal area of 73.3 m 2 /ha. There was a significant difference between old and young stands for overall yearly litter production, averaging about 670 g/m 2 /yr in the young stands and 460 g/m 2 /yr in the old stands. Leaves and twigs were significantly greater in the young stands, while reproductive parts were higher in old stands. Litter collections between years or hydrological regimes were not significantly different.

Texas↗
USGS2011

Effects of herbivory and flooding on reforestation of baldcypress ( Taxodium distichum [L.]) saplings planted in Caddo Lake, Texas

The effects of herbivory and flooding were examined on survival and growth of planted baldcypress ( Taxodium distichum (L.) Rich.) saplings at three sites in Caddo Lake, TX, over a 4-yr period. There were two flood regimes (shallow periodic and deep continuous), where half of the saplings in each flood regime were protected by tree shelters to prevent herbivory. By the end of the first year, over 80% of saplings survived with half of saplings classified as healthy. By the end of the fourth year, only half of the saplings were alive and one-third were healthy. At all three sites, the combination of no protection and continuous flooding resulted in a significant number of missing saplings. Likewise, most unprotected saplings in periodic flooding were missing by the end of the study. Saplings clipped by herbivores showed about 50% chance of recovery, but many of the sprouts were of poor quality. Protected saplings in tree shelters achieved significantly greater survival and height growth.

Louisiana, Texas↗
USGS2011

Water quality and amphibian health in the Big Bend region of the Rio Grande Basin

Male and female Rio Grande leopard frogs (Rana berlandieri) were collected in May 2005 from the main stem and tributaries of the Rio Grande in the Big Bend region of Texas. Frogs were examined for (1) incidence of testicular ovarian follicles in males; (2) thyroid epithelial cell height, a potential index of exposure to thyroid-disrupting contaminants; and (3) incidence of liver melanomacrophage aggregates, a general index of exposure to contaminants. Standard parameters of surface water quality and concentrations of selected elements, including heavy metals, were determined at each frog collection site. Heavy metals also were measured in whole-frog composite extracts. Water cadmium concentrations in most sites and chloride concentrations in the main stem exceeded federal criteria for freshwater aquatic life. Mercury was detected in frogs from the two collection sites in Terlingua Creek. There was a seventeen percent incidence of testicular ovarian follicles in male frogs. Mean thyroid epithelial cell height was greater in frogs from one of the Terlingua Creek sites (Terlingua Abajo). No differences were observed in the incidence of hepatic macrophage aggregates among sites. In conclusion, although potential cause-effect relationships between indices of habitat quality and amphibian health could not be established, the results of this study raise concerns about the general quality of the aquatic habitat and the potential long-term consequences to the aquatic biota of the Big Bend region. The presence of ovarian follicles in male frogs is noteworthy but further study is necessary to determine whether this phenomenon is natural or anthropogenically induced.

Texas Journal of Science↗
USGS2011

Gas shale/oil shale

The production of natural gas from shales continues to increase in North America, and shale gas exploration is on the rise in other parts of the world since the previous report by this committee was published by American Association of Petroleum Geologists, Energy Minerals Division (2009). For the United States, the volume of proved reserves of natural gas increased 11% from 2008 to 2009, the increase driven largely by shale gas development (Energy Information Administration 2010c). Furthermore, shales have increasingly become targets of exploration for oil and condensate as well as gas, which has served to greatly expand their significance as ‘‘unconventional’’ petroleum reservoirs. This report provides information about specific shales across North America and Europe from which gas (biogenic or thermogenic), oil, or natural gas liquids are produced or is actively being explored. The intent is to reflect the recently expanded mission of the Energy Minerals Division (EMD) Gas Shales Committee to serve as a single point of access to technical information on shales regardless of the type of hydrocarbon produced from them. The contents of this report were drawn largely from contributions by numerous members of the EMD Gas Shales Advisory Committee, with much of the data being available from public websites such as state or provincial geological surveys or other public institutions. Shales from which gas or oil is being produced in the United States are listed in alphabetical order by shale name. Information for Canada is presented by province, whereas for Europe, it is presented by country.

Natural Resources Research↗
USGS2016

Combining citizen science species distribution models and stable isotopes reveals migratory connectivity in the secretive Virginia rail

Stable hydrogen isotope (δD) methods for tracking animal movement are widely used yet often produce low resolution assignments. Incorporating prior knowledge of abundance, distribution or movement patterns can ameliorate this limitation, but data are lacking for most species. We demonstrate how observations reported by citizen scientists can be used to develop robust estimates of species distributions and to constrain δD assignments. We developed a Bayesian framework to refine isotopic estimates of migrant animal origins conditional on species distribution models constructed from citizen scientist observations. To illustrate this approach, we analysed the migratory connectivity of the Virginia rail Rallus limicola , a secretive and declining migratory game bird in North America. Citizen science observations enabled both estimation of sampling bias and construction of bias-corrected species distribution models. Conditioning δD assignments on these species distribution models yielded comparably high-resolution assignments. Most Virginia rails wintering across five Gulf Coast sites spent the previous summer near the Great Lakes, although a considerable minority originated from the Chesapeake Bay watershed or Prairie Pothole region of North Dakota. Conversely, the majority of migrating Virginia rails from a site in the Great Lakes most likely spent the previous winter on the Gulf Coast between Texas and Louisiana. Synthesis and applications . In this analysis, Virginia rail migratory connectivity does not fully correspond to the administrative flyways used to manage migratory birds. This example demonstrates that with the increasing availability of citizen science data to create species distribution models, our framework can produce high-resolution estimates of migratory connectivity for many animals, including cryptic species. Empirical evidence of links between seasonal habitats will help enable effective habitat management, hunting quotas and population monitoring and also highlight critical knowledge gaps.

Journal of Applied Ecology↗
USGS2021

U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative—2018 annual report

The Wyoming Landscape Conservation Initiative (WLCI) was established in 2007 as a collaborative interagency partnership to develop and implement science-based conservation actions. During the past 11 years, partners from U.S. Geological Survey (USGS), State and Federal land management agencies, universities, and the public have collaborated to implement a long-term (more than 10 years) science-based program that assesses and enhances the quality and quantity of wildlife habitats in the southwest Wyoming region while facilitating responsible development. The USGS WLCI Science Team completes scientific research and develops tools that inform and support WLCI partner planning, decision making, and on-the-ground management actions. In fiscal year 2018, the USGS initiated 3 new projects and continued efforts on 21 ongoing science and web-development projects. The first new project was initiated to support Secretarial Order 3362 which calls on the USGS to assist Western States in mapping big-game migration corridors and developing new mapping tools. During 2018, the USGS hosted a workshop in Laramie, Wyoming, which included more than 70 State and Federal wildlife experts from Colorado, New Mexico, Texas, and Wyoming. Most of the mapping and migration tool curricula used in the workshop were derived from prior WLCI studies and mapping efforts of big-game migration movement in habitats undergoing large-scale energy development. The second new project was in response for WLCI partners to better understand sedimentation and hydrogeomorphic processes in a cold-desert headwater and the third new project was designed to improve our approach for people to access, manage, and analyze WLCI data and WLCI resource information. The USGS published 18 products (including peer-reviewed journal articles, USGS series publications, and data releases) and provided more than a dozen professional oral and poster presentations at scientific meetings and numerous informal presentations to WLCI partners at meetings and workshops. This report summarizes the objectives and status of each project and highlights the USGS 2018 accomplishments and products.

Wyoming↗
USGS2025

Impact of a place-based role-playing exercise on student sense of classroom community and science identity in a hydrology class

Fostering a sense of classroom community in earth science classes supports students’ sense of belonging within the classroom and the broader scientific community, helping them build a sense of identity as a geoscientist. This study examines the effects of incorporating a 2-week, collaborative role-playing activity on sense of classroom community and science identity in an introductory hydrology class. Students assumed roles of residents, medical center representatives, government employees, and environmental activists to learn about flooding through a community-centered lens, focusing on a flood event in Harris County, Texas during Tropical Storm Allison. Pre-post-surveys were given immediately before and after the learning module to evaluate classroom community, science identity using Likert scales, and hydrologist identity using a pictorial scale. Qualitative analysis of a short-answer question in which students defined “hydrologist” provided context for quantitative identity data. Post-survey data on classroom community shows an increase in mean agreement as compared to the pre-survey. This increase was statistically significant for four classroom community statements. Paired science identity data show small effect size and no significant change, but pictorial identity as a hydrologist shows significant growth. Social aspects of the role-playing activity did not significantly alter student’s already high science identity but altered their conceptions of the social implications of hydrology and increased identity as hydrologists. The significant increase in classroom community has important implications for using role-playing as an active learning strategy to enhance student learning experience by creating a positive classroom climate and connecting hydrology concepts to community needs.

Journal of Geoscience Education↗
USGS2020

The use of support vectors from support vector machines for hydrometeorologic monitoring network analyses

Hydrometeorologic monitoring networks are ubiquitous in contemporary earth-system science. Network stakeholders often inquire about the importance of sites and their locations when discussing funding and monitoring design. Support vector machines (SVMs) can be useful by their assigning each monitoring site as either a support or nonsupport vector. A potentiometric surface was created from synthetic data and 800 random observation locations (sites) as an analog to a groundwater-level network. Using generalized additive models for potentiometric surface prediction, simulations show that a subsample of support vectors from the 800 sites will out perform random samples of sample size equaling the support vector count. Support vector percentages from simulation quantify the recurrence that SVMs assign each site as a support vector, and these percentages in turn measure site importance. An example application of support vector percentages identifies important monitoring sites needed to regionalize the 0.1 annual exceedance probability peak streamflow. The results indicate that 152 of 283 streamgages with support vector percentages equalling 100 percent have not operated since about 2000 and generally have much smaller drainage areas than the greater streamgage network in Texas. The drainage area disparity is an indication of historical imbalance in peak streamflow data acquisition from various stream sizes in Texas.

Texas↗
USGS2022

Flow–recruitment relationships for Shoal Chub and implications for managing environmental flows

Objective Regulation of river flow regimes by dams and diversions impacts aquatic biota and ecosystems globally. However, our understanding of the ecological consequences of flow alteration and ecological benefits of flow restoration lags behind our ability to manipulate flows, and there is a need for broader development of flow–ecology relationships. Approaches for establishing flow–ecology relationships have recently shifted away from state-based methods that analyze snapshots of ecological conditions and towards rate-based methods focused on mechanisms that link hydrology with dynamics of important ecological components and processes. Methods We used a rate-based approach to validate environmental flow standards developed for the lower Brazos River, Texas, by analyzing the relationship between flow regime components and recruitment strength of imperiled Shoal Chub Macrhybopsis hyostoma , a fluvial specialist and pelagic-broadcast-spawning fish. We collected 254 age-0 Shoal Chub (9–40 mm total length), extracted their otoliths to estimate age in days, and used a generalized additive model to regress the number of captured recruits that hatched on a calendar date against flow regime metrics, such as pulse magnitude, flow rate of change, and pulse timing in relation to environmental flow standards proposed by a science advisory committee (Brazos Basin and Bay Area Expert Science Team). Result The model revealed that flow magnitude, rate of change, and timing were all significant predictors that collectively explained 60% of variation in the recruitment strength index. Hindcasting for 1919–2020 showed a general reduction in recruitment strength following commencement of flow regulation in the lower Brazos River and revealed that high recruitment correlated with years in which most or all proposed flow tiers were attained, whereas low recruitment correlated with years when less than half of the targeted tiers were attained. Conclusion Our work represents an effective validation method for environmental flow recommendations and reveals specific flow regimes that benefit an imperiled fish species.

New Mexico, Texas↗