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Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 973 records · Page 54Linked to original sources
USGS1974

Goldeye, Hiodon alosoides, in Lake Oahe: abundance, age, growth, maturity, food, and the fishery, 1963-69

Reproductive success was relatively consistent, and adequate to maintain species abundance at a nearly constant level, during 1963-69. Both abundance and growth in length increased from the lower to the upper portion of the reservoir. In most characteristics -- growth in length, length-weight relation, age at maturity, and food -- goldeye in Lake Oahe were similar to those from other Missouri River impoundments. Experimental gill nets samples all lengths (range 80-460 mm; median, 320 mm) of goldeye, bottom trawls sampled mostly small fish, (median, 215 mm) and trap nets large ones (median, 345 mm). Commercial gill nets were highly size selective (median, 375 mm); fish of ages IV-VII made up 90% of the catch. Survival rates were 57 to 52% for ages II-X. Estimated survival rates for ages V-IX declined from 44 to 35% after the inception of the commercial fishery in 1966. The peak commercial catch was 151,432 kg (1.2 kg/hectare) in 1969. Unless recruitment declines, the population can support a fishery of that magnitude.

Technical Paper↗
USGS1974

Naturally occurring vapor-liquid-solid (VLS) Whisker growth of germanium sulfide

The first naturally occurring terrestrial example of vapor-liquid-solid (VLS) growth has been observed in condensates from gases released by burning coal in culm banks. Scanning electron microscopy, X-ray diffraction, and energy dispersive analysis indicate that the crystals consist of elongated rods (≈ 100 μm) of germanium sulfide capped by bulbs depleted in germanium.

Journal of Crystal Growth↗
USGS2012

Assessment of potential additions to conventional oil and gas resources in discovered fields of the United States from reserve growth, 2012

The U.S. Geological Survey estimated volumes of technically recoverable, conventional petroleum resources that have the potential to be added to reserves from reserve growth in 70 discovered oil and gas accumulations of the United States, excluding Federal offshore areas. The mean estimated volumes are 32 billion barrels of crude oil, 291 trillion cubic feet of natural gas, and 10 billion barrels of natural gas liquids.

Fact Sheet↗
USGS2016

Scaling relation between earthquake magnitude and the departure time from P wave similar growth

We introduce a new scaling relation between earthquake magnitude ( M ) and a characteristic of initial P wave displacement. By examining Japanese K-NET data averaged in bins partitioned by M w and hypocentral distance, we demonstrate that the P wave displacement briefly displays similar growth at the onset of rupture and that the departure time ( T dp ), which is defined as the time of departure from similarity of the absolute displacement after applying a band-pass filter, correlates with the final M in a range of 4.5 ≤ M w ≤ 7. The scaling relation between M w and T dp implies that useful information on the final M can be derived while the event is still in progress because T dp occurs before the completion of rupture. We conclude that the scaling relation is important not only for earthquake early warning but also for the source physics of earthquakes.

Geophysical Research Letters↗
USGS2022

Fijian sea krait behavior relates to fine-scale environmental heterogeneity in old-growth coastal forest: The importance of integrated land–sea management for protecting amphibious animals

The importance of terrestrial coastal ecosystems for maintaining healthy coral reef ecosystems remains understudied. Sea kraits are amphibious snakes that require healthy coral reefs for foraging, but little is known about their requirements of terrestrial habitats, where they slough their skin, digest prey, and breed. Using concurrent microclimate measurements and behavior surveys, we show that a small, topographically flat atoll in Fiji with coastal forest provides many microhabitats that relate to the behaviors of Yellow Lipped Sea Kraits, Laticauda colubrina . Microclimates were significantly related to canopy cover, leaf litter depth, and distance from the high-water mark (HWM). Sea kraits were almost exclusively observed in coastal forest within 30 m of the HWM. Sloughing of skins only occurred within crevices of mature or dying trees. Resting L. colubrina were significantly more likely to occur at locations with higher mean diurnal temperatures, lower leaf litter depths, and shorter distances from the HWM. On Leleuvia, behavior of L. colubrina therefore relates to environmental heterogeneity created by old-growth coastal forests, particularly canopy cover and crevices in mature and dead tree trunks. The importance of healthy coastal habitats, both terrestrial and marine, for L. colubrina suggests it could be a good flagship species for advocating integrated land-sea management. Furthermore, our study highlights the importance of coastal forests and topographically flat atolls for biodiversity conservation. Effective conservation management of amphibious species that utilize land- and seascapes is therefore likely to require a holistic approach that incorporates connectivity among ecosystems and environmental heterogeneity at all relevant scales.

Ecology and Evolution↗
USGS2018

Integrating growth and capture–mark–recapture models reveals size‐dependent survival in an elusive species

Survival is a key vital rate for projecting the viability of wild populations. Estimating survival is difficult for many rare or elusive species because recapture rates of marked individuals are low, and the ultimate fate of individuals is unknown. Low recapture rates for many species have made it difficult to accurately estimate survival, and to evaluate the importance of individual and environmental covariates for survival. Individual covariates such as size are particularly difficult to include in capture–mark–recapture models for elusive species because the state of the individual is unknown during periods when it is not captured. Here, we integrate a von Bertalanffy growth model with a multi‐state robust‐design Cormack‐Jolly‐Seber model to test for a relationship between body size and survival in the elusive, threatened giant gartersnake, Thamnophis gigas . We take a Bayesian approach to model the size of an individual during periods when it was not captured and measured, which fully propagates uncertainty in this unobserved covariate. We found strong support for a positive relationship between snake size and annual survival, with survival increasing with size up to a peak for adult snakes, after which survival either declines slightly or plateaus for the largest individuals. Few captures of very small and very large individuals led to high uncertainty in the survival rates of these sizes. Survival of giant gartersnakes was also positively related to the amount of precipitation and the cover of emergent and floating vegetation at a site. To our knowledge, our study is the first to estimate a size–survival relationship in a snake while fully accounting for uncertainty in the size of unobserved individuals. Our results have implications for the management of this threatened species and illustrate the utility of integrating hierarchical Bayesian models to the study of survival in elusive species.

California↗
USGS2024

No evidence hunting bait increases American black bear population growth in Maine, USA

American black bear ( Ursus americanus ) populations are increasing throughout much of North America. Use of multiple harvest methods, including hunting over bait, is intended to increase harvest success rates to meet harvest and population management objectives. However, black bear population growth can be influenced by food availability, and some speculate the use of bait may inadvertently increase bear abundance through food resource supplementation. We collected hair from black bears captured from 2005–2019 and a selection of potential food items, including those used as bait from 3 study areas in Maine, USA, with different levels of human influence. We used stable isotope analysis of the black bear hair and food item samples to evaluate the contribution of different identified food groups to the diet of individual bears. We found no evidence that greater contribution of human food resources, including bait, increased the number of cubs per litter for reproductive females or that human foods comprised a greater part of the diet in years when natural food resources were less abundant. Approximately 69% of black bear harvest occurred over bait. We found the probability of reproductive-age females to be harvested increased with average representation of human foods with high carbon enrichment (including bait) in their diet, but the relationship was weak, likely because of sampling constraints. Additionally, the probability of being harvested was greater in years when natural food resources were scarce. We conclude that bait is not available on the landscape in large enough amounts or for a sufficient amount of time in Maine to substantially influence female reproduction. Our results indicate hunting over bait is an effective tool in a state that is attempting to maintain a stable bear population via harvest, and dispels conjecture that hunting over bait may increase cub production and offset the intention of harvest.

Maine↗
USGS2024

Age, growth, and trophic ecology of the Redeye Bass, an introduced invader of California rivers

Objective The Redeye Bass Micropterus coosae is a piscivore introduced into California, which has become a threat to the state's endemic freshwater fishes. It has eliminated native fishes from the middle reaches of the Cosumnes River, our study stream, which is the largest stream without a major dam on its main stem in the Sacramento–San Joaquin River drainage, central California, USA. We thoroughly documented its novel life history and ecology in California to shed light on why it has been such a successful invader despite its relatively small native range. Methods Over 4000 stable carbon and nitrogen isotope samples were utilized to refine our understanding of fish trophic position within the river food web, along with a stable isotope mixing model that accounts for uncertainty in trophic enrichment data. Result Growth was slow, with an adult size range of 9–25 cm standard length (SL), although few were larger than 15-cm SL (5–6 years old). Stable isotope analyses showed that Redeye Bass dominate the river ecosystem to the exclusion of most native fishes, occupying multiple trophic levels and microhabitats. Adults largely consumed non-native crayfish and large aquatic insects, while juveniles consumed aquatic insects, the size of prey increasing with Redeye Bass length. There was no evidence of cannibalism. Redeye Bass have effectively occupied the diverse trophic positions of at least four native fish species and have altered the trophic position of Rainbow Trout Oncorhynchus mykiss in sites where they co-occur with bass. Conclusion The introduction of Redeye Bass poses a continuing threat to native stream fishes in California and elsewhere.

Transactions of the American Fisheries Society↗
USGS2014

Hand-rearing, growth, and development of common loon ( Gavia immer ) chicks

Common loon chicks were reared in captivity in association with studies to evaluate the effects of radiotransmitter implants and to assess the ecological risk of dietary methylmercury. Here we report on hatching and rearing methods used to successfully raise chicks to 105 days of age. We experienced a 91.5% hatch rate, and 89.6% of loon chicks survived to the end of the study at 105 days. Baseline information on observed rates of fish consumption, behavioral development, and growth patterns are provided. Husbandry techniques are provided that should prove valuable to wildlife rehabilitators caring for abandoned or injured loons, and biologists contemplating methods for restoring loons to areas within their former breeding range.

Zoo Biology↗
USGS1995

Size-dependent, sex-dependent and seasonal changes in insulin-lige growth-factor-I in the loggerhead sea turtle

This study examines size-dependent, sex-dependent, and seasonal fluctuations in plasma insulin-like growth factor-I (IGF-I) concentrations in loggerhead sea turtles ( Caretta caretta ). Loggerhead turtles ( n = 158) were captured in shrimp trawler nets during a 12-month survey in Cape Canaveral Channel, Florida. Plasma samples were analyzed using a validated heterologous radioimmunoassay. Large turtles (>75 cm straight-line carapace length) had significantly higher plasma IGF-I concentrations than small turtles (⩽75 cm; P < 0.0001). Plasma IGF-I concentrations did not vary seasonally in small turtles, but large turtles had significantly higher plasma IGF-I concentrations during the spring and summer months (P < 0.005). Within the large turtles, adult males had significantly lower IGF-I concentrations than females and subadult males ( P < 0.05). These results and a review of loggerhead turtle natural history suggest that the seasonal fluctuations in plasma IGF-I of adult turtles are due to elevated IGF-I levels in reproductively active female turtles. Further research is needed to examine correlations between reproductive activities and plasma IGF-I concentrations in reptiles.

General and Comparative Endocrinology↗
USGS1998

Regulation of gill cytosolic corticosteroid receptors in juvenile Atlantic salmon: Interaction effects of growth hormone with prolactand triiodothyronine

The potential effects of growth hormone (GH), prolactin (Prl), and triiodothyronine (T 3 ) on gill Na + ,K + -ATPase activity and corticosteroid receptor (CR) concentration ( B max ) and dissociation constant ( K d ) were examined in juvenile Atlantic salmon ( Salmo salar ). Compared to controls, fish injected with GH (ovine, 5.0 μg g −1 ) had significantly greater gill Na + ,K + -ATPase activity after 7 and 14 days. Gill CR B max and K d were significantly elevated on day 7, but not day 14. T 3 also significantly increased CR B max . The effect of GH on CR B max was also additive with T 3 (5.0 μg g −1 ) treatment. There was a synergistic effect on CR B max when purified coho salmon GH (csGH, 0.1 μg g −1 ) was injected in combination with T 3 (1.6 μg g −1 ). Prl (ovine, 5.0 μg g −1 ; purified coho salmon, 0.1 μg g −1 ) did not significantly alter gill CR B max . Although Prl limited the increase in CR B max by GH, the effect was not signicant. T 3 and Prl did not have an effect on K d . GH significantly increased gill Na + ,K + -ATPase activity, T 3 administration did not have a significant effect, and Prl-treated fish had significantly lower gill Na + ,K + -ATPase activity. The results indicate that T 3 acts additively with GH, while Prl has no effect in regulating CR B max . An increase in cytosolic CR by GH and T 3 , but not Prl, may regulate gill responsiveness to cortisol and be an important mechanism in the endocrine control of physiological changes during the parr–smolt transformation.

General and Comparative Endocrinology↗
USGS2001

Effects of growth hormone and cortisol on Na+-K+-2C1-cotransporter localization and abundance the gills of Atlantic salmon

The hormones responsible for the regulation of the teleostean gill Na + –K + –2Cl − cotransporter have not been elucidated. With Western blotting and immunocytochemistry, Na + –K + –2Cl − cotransporter abundance and localization were examined in the gills of Atlantic salmon ( Salmo salar ) following 2-week treatment with growth hormone (GH; 5.0 μg · g −1 ), cortisol (50 μg · g −1 ), and both hormones in combination (GH+cortisol). GH and cortisol treatments increased gill Na + –K + –2Cl − cotransporter abundance over levels seen in controls, and both hormones together (GH+cortisol) produced a greater effect than either hormone alone. Gill Na + ,K + –ATPase activity was also elevated by all three hormone treatments. Compared to controls, Na + –K + –2Cl − cotransporter immunoreactive chloride cells on the primary filament were greater in number and size following all three treatments. Although the number of immunoreactive chloride cells on the secondary lamellae did not differ among the treatment groups, GH+cortisol increased their size. These data indicate that GH and cortisol increase gill Na + –K + –2Cl − cotransporter abundance through chloride cell proliferation and differentiation in the gills of Atlantic salmon and are likely the hormones responsible for Na + –K + –2Cl − cotransporter regulation during smolting and seawater acclimation.

Massachusetts↗
USGS1992

A petroleum discovery-rate forecast revisited-The problem of field growth

A forecast of the future rates of discovery of crude oil and natural gas for the 123,027-km2 Miocene/Pliocene trend in the Gulf of Mexico was made in 1980. This forecast was evaluated in 1988 by comparing two sets of data: (1) the actual versus the forecasted number of fields discovered, and (2) the actual versus the forecasted volumes of crude oil and natural gas discovered with the drilling of 1,820 wildcat wells along the trend between January 1, 1977, and December 31, 1985. The forecast specified that this level of drilling would result in the discovery of 217 fields containing 1.78 billion barrels of oil equivalent; however, 238 fields containing 3.57 billion barrels of oil equivalent were actually discovered. This underestimation is attributed to biases introduced by field growth and, to a lesser degree, the artificially low, pre-1970's price of natural gas that prevented many smaller gas fields from being brought into production at the time of their discovery; most of these fields contained less than 50 billion cubic feet of producible natural gas. ?? 1992 Oxford University Press.

Nonrenewable Resources↗
USGS1995

Effect of increased water depth on growth of a common perennial freshwater-intermediate marsh species in Coastal Louisiana

The response of Sagittaria lancifolia to increased water depths of 7.5 and 15 cm was examined in this field study. Water-depth treatments were achieved by digging sods containing one or two individual plants or ramets of S. lancifolia from the marsh, removing sediment from the resulting hole, and replacing the sods in their original location at the appropriate lower elevation. Plants subjected to increased water depth of 15 cm had higher mean and maximum leaf heights than disturbed control plants. Aboveground biomass was not affected by water-depth treatment; however, 15-cm treatment plants had reduced root biomass and lowered leaf tissue concentrations of Ca, Cu, Fe, Mg, and Zn. Marsh sods at 15 cm below the marsh surface had the lowest redox potential and highest interstitial water sulfide concentration, indicating that this treatment created the most stressful belowground environment. Sagittaria lancifolia plants responded to the level of stress imposed by the experimental conditions with an altered growth form of increased leaf height.

Louisiana↗
USGS1999

Natural regeneration and growth of Taxodium distichum (L.) rich. In Lake Chicot, Louisiana after 44 years of flooding

Lake Chicot, in south central Louisiana, USA, was created in 1943 by the impoundment of Chicot Bayou. Extensive establishment of woody seedlings occurred in the lake during a 1.5 year period, including the growing seasons of both 1986 and 1987, when the reservoir was drained for repair work on the dam. Study plots were established in September 1986 to document woody vegetation establishment and to provide a baseline by which to monitor survival and growth after flooding resumed. Taxodium distichum seedlings were the dominant species after one growing season, with a maximum density of 50 seedlings/m 2 , an average of about 2/m 2 , and an average height of 75 cm. The lake was reflooded at the end of 1987, bringing water depths at the study plots up to about 1.4 m. Temporary drawdowns were again conducted during the fall of 1992 and 1996. In December 1992, the site was revisited, new plots established, and saplings counted and measured. There was an average of 2.1 T. distichum stems/m 2 , and the average height was 315 cm. After the 1996 growing season, there was still an average of about 1.9 stems/m 2 , and the average height had increased to 476 cm. Preservation of T. distichum forests in relatively shallow but continuously flooded areas such as Lake Chicot may be a simple matter of draining the lake after a good seed crop and maintaining the drawdown long enough for the seedlings to grow taller than the typical growing season water level. In the case of Lake Chicot, this period was two growing seasons. This action will mimic natural, drought-related drawdowns of the lake and will allow the seedlings to establish themselves and grow tall enough to survive normal lake water levels.

Louisiana↗
USGS2016

Survival and growth of freshwater pulmonate and nonpulmonate snails in 28-day exposures to copper, ammonia, and pentachlorophenol

We performed toxicity tests with two species of pulmonate snails ( Lymnaea stagnalis and Physa gyrina ) and four taxa of nonpulmonate snails in the family Hydrobiidae ( Pyrgulopsis robusta , Taylorconcha serpenticola , Fluminicola sp., and Fontigens aldrichi ). Snails were maintained in static-renewal or recirculating culture systems with adults removed periodically to isolate cohorts of offspring for toxicity testing. This method successfully produced offspring for both species of pulmonate snails and for two hydrobiid species, P. robusta and Fluminicola sp. Toxicity tests were performed for 28 days with copper, ammonia, and pentachlorophenol in hard reconstituted water with endpoints of survival and growth. Tests were started with 1-week-old L. stagnalis , 2-week-old P. gyrina , 5- to 13-week-old P. robusta and Fluminicola sp., and older juveniles and adults of several hydrobiid species. For all three chemicals, chronic toxicity values for pulmonate snails were consistently greater than those for hydrobiid snails, and hydrobiids were among the most sensitive taxa in species sensitivity distributions for all three chemicals. These results suggest that the toxicant sensitivity of nonpulmonate snails in the family Hydrobiidae would not be adequately represented by results of toxicity testing with pulmonate snails.

Archives of Environmental Contamination and Toxico↗
USGS2012

Terrestrial and marine trophic pathways support young-of-year growth in a nearshore Arctic fish

River discharge supplies nearshore communities with a terrestrial carbon source that is often reflected in invertebrate and fish consumers. Recent studies in the Beaufort Sea have documented widespread terrestrial carbon use among invertebrates, but only limited use among nearshore fish consumers. Here, we examine the carbon source and diet of rapidly growing young-of-year Arctic cisco ( Coregonus autumnalis ) using stable isotope values (δ 13 C and δ 15 N) from muscle and diet analysis (stomach contents) during a critical and previously unsampled life stage. Stable isotope values (δ 15 N and δ 13 C) may differentiate between terrestrial and marine sources and integrate over longer time frames (weeks). Diet analysis provides species-specific information, but only from recent foraging (days). Average δ 13 C for all individuals was −25.7 ‰, with the smallest individuals possessing significantly depleted δ 13 C values indicative of a stronger reliance of terrestrial carbon sources as compared to larger individuals. Average δ 15 N for all individuals was 10.4 ‰, with little variation among individuals. As fish length increased, the proportion of offshore Calanus prey and neritic Mysis prey increased. Rapid young-of-year growth in Arctic cisco appears to use terrestrial carbon sources obtained by consuming a mixture of neritic and offshore zooplankton. Shifts in the magnitude or phenology of river discharge and the delivery of terrestrial carbon may alter the ecology of nearshore fish consumers.

Polar Biology↗
USGS2021

Identifying metabolic alterations associated with coral growth anomalies using 1H NMR metabolomics

Coral growth anomalies (GAs) are tumor-like protrusions that are detrimental to coral health, affecting both the coral skeleton and soft tissues. These lesions are increasingly found throughout the tropics and are commonly associated with high human population density, yet little is known about the molecular pathology of the disease. Here, we investigate the metabolic impacts of GAs through 1 H nuclear magnetic resonance (NMR) metabolomics in Porites compressa tissues from a site of high disease prevalence (Coconut Island, Hawaii). We putatively identified 18 metabolites (8.1% of total annotated features) through complementary 1 H and 1 H– 13 C heteronuclear single quantum correlation NMR data that increase confidence in pathway analyses and may bolster future coral metabolite annotation efforts. Extract yield was elevated in both GA and unaffected (normal tissue from a diseased colony) compared to reference (normal tissue from GA-free colony) samples, potentially indicating elevated metabolic activity in GA-impacted colonies. Relatively high variation in metabolomic profiles among coral samples of the same treatment (i.e., inter-colony variation) confounded data interpretation, however, analyses of paired GA and unaffected samples identified 73 features that differed between these respective metabolome types. These features were largely annotated as unknowns, but 1-methylnicotinamide and trigonelline were found to be elevated in GA samples, while betaine, glycine, and histamine were lower in GA samples. Pathway analyses indicate decreased choline oxidation in GA samples, making this a pathway of interest for future targeted studies. Collectively, our results provide unique insights into GA pathophysiology by showing these lesions alter both the absolute and relative metabolism of affected colonies and by identifying features (metabolites and unknowns) and metabolic pathways of interest in GA pathophysiology going forward.

Coral Reefs↗