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At least 1,567 records · Page 87Linked to original sources

USGS2020

Multiple elements of soil biodiversity drive ecosystem functions across biomes

The role of soil biodiversity in regulating multiple ecosystem functions is poorly understood, limiting our ability to predict how soil biodiversity loss might affect human wellbeing and ecosystem sustainability. Here, combining a global observational study with an experimental microcosm study, we provide evidence that soil biodiversity (bacteria, fungi, protists and invertebrates) is significantly and positively associated with multiple ecosystem functions. These functions include nutrient cycling, decomposition, plant production, and reduced potential for pathogenicity and belowground biological warfare. Our findings also reveal the context dependency of such relationships and the importance of the connectedness, biodiversity and nature of the globally distributed dominant phylotypes within the soil network in maintaining multiple functions. Moreover, our results suggest that the positive association between plant diversity and multifunctionality across biomes is indirectly driven by soil biodiversity. Together, our results provide insights into the importance of soil biodiversity for maintaining soil functionality locally and across biomes, as well as providing strong support for the inclusion of soil biodiversity in conservation and management programmes.

Nature Ecology and Evolution↗

USGS2020

Estimating nitrogen removal services of eastern oyster (Crassostrea virginica) in Mobile Bay, Alabama

Eastern oysters have been acknowledged for their important contribution to human well-being by providing goods and services including nitrogen removal from water bodies. In this study, we integrated daily environmental data (2008–2016) and filtration rate model parameter uncertainty to estimate nitrogen removal from denitrification and nitrogen burial services provided by the current extent of oyster ( Crassostrea virginica ) reefs in Mobile Bay, Alabama. Oyster landing data (2008–2016) in the Bay were also used to estimate nitrogen removal through oyster harvest. A replacement cost method using an engineering solution from wastewater treatment plants was implemented to quantify the economic benefit of the nitrogen removal. The estimated total nitrogen removal services provided by oyster reefs in Mobile Bay was 34,911 ± 5,032 kg N yr −1 (mean ± 1sd), in which 22,095 ± 3,305 kg N yr −1 from denitrification, 11,047 ± 1,652 kg N yr −1 from burial of nitrogen into sediments and 1,769 ± 876 kg N yr −1 by oyster harvest. The mean economic benefit was $76,455 ± 11,020 yr −1 which was estimated as $73.2 ± 11.5 ha −1 yr −1 . This method could be used for any time period to estimate the nitrogen removal service in Mobile Bay. With proper modification of model parameters, this method could also be used elsewhere to estimate nitrogen removal services provided by oysters.

Alabama↗

USGS2023

Differential shortstopping behaviour in Whooping Cranes: Habitat or social learning?

Many migratory bird species have begun shifting their wintering grounds closer to their breeding grounds, shortening their yearly migration distance through a behavior called shortstopping. While multiple studies have investigated possible drivers, it remains unclear why only some populations adopt this behavior. We studied the differential occurrence of shortstopping in two populations of Whooping Cranes (Grus americana): a remnant population where juveniles migrate with their parents, and a reintroduced population consisting largely of captive-reared birds trained to migrate by unrelated conspecifics or by humans. Shortstopping is widespread in the reintroduced population, while the remnant population has not shown any appreciable northward movement of its overwintering sites. We examined potential drivers for this lack of shortstopping, including a lack of suitable habitat north of their current wintering area or social differences between populations. Using characteristics of winter locations used by the reintroduced population, we found that 31.4% of the remnant migration corridor was predicted to be suitable for wintering, suggesting that insufficient habitat suitability is not limiting shortstopping behaviour. However, we found evidence for behavioural differences that might explain the absence of shortstopping in the remnant population: while all juveniles of the remnant population associate with their parents during overwintering, juveniles from the reintroduced population did not associate with older conspecifics in 12 out of 25 observed wintering events, suggesting that the social transmission of winter migration behaviours might be less effective in the reintroduced population. Although social learning is generally believed to increase flexibility in migratory strategies, a strong vertical transmission of behaviour might enforce adherence to established traditions and reduce the uptake of novel behaviours such as shortstopping. We suggest that, besides habitat availability, social factors may also play a role in explaining the absence of shortstopping behaviour in some migratory bird populations.

Global Ecology and Conservation↗

USGS2014

Evidence for free-living Bacteroides in Cladophora along the shores of the Great Lakes

Bacteroides is assumed to be restricted to the alimentary canal of animals and humans and is considered to be non-viable in ambient environments. We hypothesized that Bacteroides could persist and replicate within beach-stranded Cladophora glomerata mats in southern Lake Michigan, USA. Mean Bacteroides concentration (per GenBac3 Taqman quantitative PCR assay) during summer 2012 at Jeorse Park Beach was 5.2 log calibrator cell equivalents (CCE) g -1 dry weight (dw), ranging from 3.7 to 6.7. We monitored a single beach-stranded mat for 3 wk; bacterial concentrations increased by 1.6 log CCE g -1 dw and correlated significantly with ambient temperature (p = 0.003). Clonal growth was evident, as observed by >99% nucleotide sequence similarity among clones. In in vitro studies, Bacteroides concentrations increased by 5.5 log CCE g -1 after 7 d (27°C) in fresh Cladophora collected from rocks. Partial sequencing of the 16S rRNA gene of 36 clones from the incubation experiment showed highly similar genotypes (≥97% sequence overlap). The closest enteric Bacteroides spp. from the National Center for Biotechnology Information database were only 87 to 91% similar. Genomic similarity, clonality, growth, and persistence collectively suggest that putative, free-living Bacteroides inhabit Cladophora mats of southern Lake Michigan. These findings may have important biological, medical, regulatory, microbial source tracking, and public health implications.

southern Lake Michigan↗

USGS2026

New methods provide a 300–year perspective on modern area burned in two wilderness areas of the southwest United States

Climate change, expanding human ignitions, and increased fuels from fire exclusion are driving increases in area burned and fire severity in dry conifer forests of the western United States. Increasing area burned is occurring against the backdrop of a large fire deficit caused by over a century of fire exclusion. A key land management question is whether historically frequent fire regimes can be restored. Accurate estimates of historical annual area burned (prior to circa 1900) are necessary to evaluate modern area burned (after circa 1900), but are difficult to derive, and have rarely been calibrated or validated against modern fires, leaving their accuracy uncertain. We developed new methods to use tree-ring fire scars to reconstruct historical annual area burned and compare it to modern annual area burned. We focused on two southwestern US wilderness areas—Saguaro National Park (SAGU) and the Gila Wilderness (GILA)—that have a long history of using prescribed and managed fires. The abundant modern low- and moderate-severity fires allowed us to (1) calibrate and validate the fire-scar models against mapped fires to derive the first uncertainty estimates of reconstructed annual area burned and (2) test whether active fire management can help restore annual area burned to historical levels. A multi-model ensemble consisting of 10 individual member models accurately estimated area burned of mapped modern fires with no consistent biases. Each member model had distinct strengths and assumptions that made them suitable for specific applications (e.g., the synchrony model is easily applied, and Thiessen polygons provide spatially explicit area burned estimates). The accurate reconstruction of modern area burned from relatively sparse fire-scar data at GILA suggests that dense grids may not be necessary for accurate reconstructions. Our findings reveal that despite the near absence of fire in the early 20th century, both annual and 20-year sums of area burned in recent decades are back within historical levels at GILA, and trending toward historical levels at SAGU. These results demonstrate that fire management can help restore the historically prevalent, ecologically important process of widespread, frequent, low-to-moderate-severity fire in dry conifer forests.

Arizona, New Mexico↗

USGS2023

Linear and landscape disturbances alter Mojave desert tortoise movement behavior

Introduction: Animal movements are influenced by landscape features; disturbances to the landscape can alter movements, dispersal, and ultimately connectivity among populations. Faster or longer movements adjacent to a localized disturbance or within disturbed areas could indicate reduced habitat quality whereas slower or shorter movements and reduced movements may indicate greater availability of resources. The Mojave desert tortoise ( Gopherus agassizii ) is a threatened species that is challenged by anthropogenic disturbances. Methods: We studied tortoise movements using Global Positioning System (GPS) loggers at multiple sites in the Mojave Desert of Nevada and California. Tortoises at our sites encountered localized, linear human infrastructure, including paved roads, dirt roads, and fences, as well as landscape-scale disturbances [wildfire, off highway vehicle use (OHV), livestock grazing area]. We fit two-state (moving and encamped) Hidden Markov models to GPS logger data to infer how tortoise movement behavior relates to anthropogenic and natural features. Results: We found that temporal covariates, individual-level random effects (intercepts), and sex best explained state transition probability in all sites. We compared relationships between tortoise movement and linear disturbances, which varied depending on site and context. Tortoises made longer movements within the OHV recreation area, near most dirt roads, and near a low-traffic paved road, indicating that tortoises avoid these habitat disturbances. Conversely, tortoises made shorter movements in areas of higher slope and near highways, suggesting that these features may restrict movement or provide resources that result in prolonged use (e.g., forage or drinking locations). Tortoises that encountered fences around utility-scale solar installations were more active and made longer movements near fences, indicative of pacing behavior. Discussion: These results provide insight into how different disturbances alter tortoise movement behavior and modify tortoise habitat use, providing information that can be used to manage tortoise habitat.

California, Nevada↗

USGS2018

Evaluation of biodiversity data portals based on requirement analysis

In recent years, concern about the misuse of natural resources has been increasing. It is essential to know in detail the biodiversity of an ecosystem to understand and analyze the impact of human activities on nature, as well as to promote the economic growth of a country. To achieve these goals, public and private institutions are aggregating and sharing biological data around the world by means of biodiversity data portals. The main purpose of those portals is to provide a set of tools that help users and institutions catalog, analyze, and publish raw data about different species in a manner that is open and freely available to any interested party. Normally the process of choosing the best software solution is not straightforward. This paper proposes a methodology to evaluate a collection of data portals to establish a clear and consistent selection process that analyzes a collection of requirements and research purposes. The proposed approach is based on three strategies: the use of software engineering techniques to identify the desired group of features to be available in the data portal; the application of the Kano Satisfaction Model to score each requirement according to a preset weight of importance; and the use of tree-maps to visualize the requirements based on their implementation priority, to establish a portal deployment road-map. The proposed methodology is broadly applicable to portal analyses for many communities of practice.

Ecological Informatics↗

USGS2017

Importance of the 2014 Colorado River Delta pulse flow for migratory songbirds: Insights from foraging behavior

The Lower Colorado River provides critical riparian areas in an otherwise arid region and is an important stopover site for migrating landbirds. In order to reverse ongoing habitat degradation due to drought and human-altered hydrology, a pulse flow was released from Morelos Dam in spring of 2014, which brought surface flow to dry stretches of the Colorado River in Mexico. To assess the potential effects of habitat modification resulting from the pulse flow, we used foraging behavior of spring migrants from past and current studies to assess the relative importance of different riparian habitats. We observed foraging birds in 2000 and 2014 at five riparian sites along the Lower Colorado River in Mexico to quantify prey attack rates, prey attack maneuvers, vegetation use patterns, and degree of preference for fully leafed-out or flowering plants. Prey attack rate was highest in mesquite (Prosopis spp.) in 2000 and in willow (Salix gooddingii) in 2014; correspondingly, migrants predominantly used mesquite in 2000 and willow in 2014 and showed a preference for willows in flower or fruit in 2014. Wilson’s warbler (Cardellina pusilla) used relatively more low-energy foraging maneuvers in willow than in tamarisk (Tamarix spp.) or mesquite. Those patterns in foraging behavior suggest native riparian vegetation, and especially willow, are important resources for spring migrants along the lower Colorado River. Willow is a relatively short-lived tree dependent on spring floods for dispersal and establishment and thus spring migrants are likely to benefit from controlled pulse flows.

Arizona, California↗

USGS2015

Optimizing water depth for wetland-dependent wildlife could increase wetland restoration success, water efficiency, and water security

Securing water for wetland restoration efforts will be increasingly difficult as human populations demand more water and climate change alters the hydrologic cycle. Minimizing water use at a restoration site could help justify water use to competing users, thereby increasing future water security. Moreover, optimizing water depth for focal species will increase habitat quality and the probability that the restoration is successful. We developed and validated spatial habitat models to optimize water depth within wetland restoration projects along the lower Colorado River intended to benefit California black rails ( Laterallus jamaicensis coturniculus ). We observed a 358% increase in the number of black rails detected in the year after manipulating water depth to maximize the amount of predicted black rail habitat in two wetlands. The number of black rail detections in our restoration sites was similar to those at our reference site. Implementing the optimal water depth in each wetland decreased water use while simultaneously increasing habitat suitability for the focal species. Our results also provide experimental confirmation of past descriptive accounts of black rail habitat preferences and provide explicit water depth recommendations for future wetland restoration efforts for this species of conservation concern; maintain surface water depths between saturated soil and 100 mm. Efforts to optimize water depth in restored wetlands around the world would likely increase the success of wetland restorations for the focal species while simultaneously minimizing and justifying water use.

Arizona↗

USGS2019

Nonlinearities in transmission dynamics and efficient management of vector-borne pathogens

Integrated Pest Management (IPM) is an approach to minimizing economic and environmental harm caused by pests, and Integrated Vector Management (IVM) uses similar methods to minimize pathogen transmission by vectors. The risk of acquiring a vector-borne infection is often quantified using the density of infected vectors. The relationship between vector numbers and risk of human infection is more or less linear when both vector numbers and pathogen prevalence in vectors are low, but the relationship is nonlinear when vector density and/or infection prevalence are high. Therefore, the density of infected vectors often does not accurately predict risk of human exposure to pathogens, and traditional estimates of % Control often overestimate the level of protection from infection resulting from management programs. We suggest a modified estimator, % Protection, which more accurately quantifies protection against human infection resulting from a management intervention. Cost-effectiveness of a management program is critical to protection of both public health and the environment, because the more efficiently available resources and funding are used, the fewer people get sick, and well-targeted efficient management programs minimize the need for poorly-targeted, expensive environmental interventions (e.g., broadscale pesticide applications) that tend to damage nontarget organisms and natural systems. Design of an efficient, cost-effective IVM program requires knowledge of the cost-effectiveness functions (the effectiveness of control methods at lowering vector bites and/or infection prevalence with different levels of application) of the various control methods to be applied. Alternative programs can be designed that optimize % Protection by integrating different control methods at different levels of investment, and environmental effects of these alternatives can be compared, allowing environmental considerations to be included explicitly in the decision process. IPM, IVM, and Adaptive Management share the characteristic that management decisions must be made with incomplete knowledge of the functioning of natural systems or the efficacies of interventions. IVM surveillance programs that assess the effects of individual control methods and of combinations of control methods on the numbers of vector bites and on infection prevalence in vectors, can increase knowledge of pathogen transmission dynamics and provide information to improve program effectiveness in subsequent applications.

Ecological Applications↗

USGS2014

Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem

When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis ) are an important fall food for grizzly bears ( Ursus arctos ) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles ( Dendroctonus ponderosae ) have killed many cone-producing WBP trees. We used fall (15 August–30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000–2011. We calculated Manly–Chesson (MC) indices for selectivity of WBP habitat and secure habitat (≥500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas.

Idaho, Montana, Wyoming↗

USGS2013

Amphibians and reptiles of Guyana, South America: illustrated keys, annotated species accounts, and a biogeographic synopsis

Guyana has a very distinctive herpetofauna. In this first ever detailed modern accounting, based on voucher specimens, we document the presence of 324 species of amphibians and reptiles in the country; 148 amphibians, 176 reptiles. Of these, we present species accounts for 317 species and color photographs of about 62% (Plates 1–40). At the rate that new species are being described and distributional records are being found for the first time, we suspect that at least 350 species will be documented in a few decades. The diverse herpetofauna includes 137 species of frogs and toads, 11 caecilians, 4 crocodylians, 4 amphisbaenians, 56 lizards, 97 snakes, and 15 turtles. Endemic species, which occur nowhere else in the world, comprise 15% of the herpetofauna. Most of the endemics are amphibians, comprising 27% of the amphibian fauna. Type localities (where the type specimens or scientific name-bearers of species were found) are located within Guyana for 24% of the herpetofauna, or 36% of the amphibians. This diverse fauna results from the geographic position of Guyana on the Guiana Shield and the isolated highlands or tepuis of the eastern part of the Pantepui Region, which are surrounded by lowland rainforest and savannas. Consequently, there is a mixture of local endemic species and widespread species characteristic of Amazonia and the Guianan Region. Although the size of this volume may mislead some people into thinking that a lot is known about the fauna of Guyana, the work has just begun. Many of the species are known from fewer than five individuals in scientific collections; for many the life history, distribution, ecology, and behavior remain poorly known; few resources in the country are devoted to developing such knowledge; and as far as we are aware, no other group of animals in the fauna of Guyana has been summarized in a volume such as this to document the biological resources. We briefly discuss aspects of biogeography, as reflected in samples collected at seven lowland sites (in rainforest, savanna, and mixed habitats below 500 m elevation) and three isolated highland sites (in montane forest and evergreen high-tepui forest above 1400 m elevation). Comparisons of these sites are preliminary because sampling of the local faunas remains incomplete. Nevertheless, it is certain that areas of about 2.5 km2 of lowland rainforest can support more than 130 species of amphibians and reptiles (perhaps actually more than 150), while many fewer species (fewer than 30 documented so far) occur in a comparable area of isolated highlands, where low temperatures, frequent cloudiness, and poor soils are relatively unfavorable for amphibians and reptiles. Furthermore, insufficient study has been done in upland sites of intermediate elevations, where lowland and highland faunas overlap significantly, although considerable work is being accomplished in Kaieteur National Park by other investigators. Comparisons of the faunas of the lowland and isolated highland sites showed that very few species occur in common in both the lowlands and isolated highlands; that those few are widespread lowland species that tolerate highland environments; that many endemic species (mostly amphibians) occur in the isolated highlands of the Pakaraima Mountains; and that each of the isolated highlands, lowland savannas, and lowland rainforests at these 10 sites have distinctive faunal elements. No two sites were identical in species composition. Much more work is needed to compare a variety of sites, and especially to incorporate upland sites of intermediate elevations in such comparisons. Five species of sea turtles utilize the limited areas of Atlantic coastal beaches to the northwest of Georgetown. All of these are listed by the International Union for the Conservation of Nature as being of global concern for long-term survival, mostly owing to human predation. The categories of Critically Endangered or Endangered are applied to four of the local sea turtles (80%). It is important to protect the few good nesting beaches for the sea turtles of Guyana. We have documented each of the species now known to comprise the herpetofauna of Guyana by citing specimens that exist in scientific collections, many of which were collected and identified by us and colleagues, including students of the University of Guyana (UG). We also re-identified many old museum specimens collected by others in the past (e.g., collections of William Beebe) and we used documented publications and collection records of colleagues, most of whom have been working more recently. We present dichotomous keys for identifying representatives of the species known to occur in Guyana, and we present brief annotated species accounts. The accounts provide the current scientific name, original name (with citation of the original description, which we personally examined in the literature), some outdated names used in the recent past, type specimens, type localities, general geographic distribution, examples of voucher specimens from Guyana, coloration in life (and often a color photograph), and comments pointing out interesting subjects for future research.

Proceedings of the Biological Society of Washingto↗

USGS2006

Denitrification potential in stream sediments impacted by acid mine drainage: Effects of pH, various electron donors, and iron

Acid mine drainage (AMD) contaminates thousands of kilometers of stream in the western United States. At the same time, nitrogen loading to many mountain watersheds is increasing because of atmospheric deposition of nitrate and increased human use. Relatively little is known about nitrogen cycling in acidic, heavy-metal-laden streams; however, it has been reported that one key process, denitrification, is inhibited under low pH conditions. The objective of this research was to investigate the capacity for denitrification in acidified streams. Denitrification potential was assessed in sediments from several Colorado AMD-impacted streams, ranging from pH 2.60 to 4.54, using microcosm incubations with fresh sediment. Added nitrate was immediately reduced to nitrogen gas without a lag period, indicating that denitrification enzymes were expressed and functional in these systems. First-order denitrification potential rate constants varied from 0.046 to 2.964 day −1 . The pH of the microcosm water increased between 0.23 and 1.49 pH units during denitrification. Additional microcosm studies were conducted to examine the effects of initial pH, various electron donors, and iron (added as ferrous and ferric iron). Decreasing initial pH decreased denitrification; however, increasing pH had little effect on denitrification rates. The addition of ferric and ferrous iron decreased observed denitrification potential rate constants. The addition of glucose and natural organic matter stimulated denitrification potential. The addition of hydrogen had little effect, however, and denitrification activity in the microcosms decreased after acetate addition. These results suggest that denitrification can occur in AMD streams, and if stimulated within the environment, denitrification might reduce acidity.

Microbial Ecology↗

USGS2014

Spatial distribution of loggerhead turtle ( Caretta caretta ) emergences along a highly dynamic beach in the northern Gulf of Mexico

As coastlines change due to sea level rise and an increasing human presence, understanding how species, such as marine turtles, respond to alterations in habitat is necessary for proper management and conservation. Survey data from a major nesting beach in the northern Gulf of Mexico, where a revetment was installed, was used to assess spatial distribution of loggerhead emergences. Through use of Quadrat analysis and piecewise linear regression with breakpoint, we present evidence to suggest that nest site selection in loggerheads is determined in the nearshore environment, and by characteristics such as wave height, alongshore currents, depth and patterns of erosion and accretion. Areas of relatively dense nesting were found in areas with relatively strong alongshore currents, relatively small waves, a steep offshore slope and the largest historical rates of erosion. Areas of relatively dense nesting also corresponded to areas of low nesting success. Both nesting and non-nesting emergences were clustered immediately adjacent to the revetment and at other eroding sites along the beach. These results suggest that alterations to the nearshore environment from activities such as construction of a jetty, dredging or installation of pilings, may impact sea turtle nest distribution alongshore. We also show that piecewise linear regression with breakpoint is a technique that can be used with geomorphological and oceanographic data to predict locations of nest clumping and may be useful for managers at other nesting beaches.

Florida↗

USGS1990

Long-term vegetation change at a fully protected Sonoran Desert site

To investigate desert vegetation dynamics, I undertook an open—ended study of a site that offers a combination of multiple observations through time with continuous protection from domestic livestock and other human impacts. The site is MacDougal Crater in the Sierra del Pinacate Reserve, Sonora, Mexico. Three sources of data have been used: a series of exactly matched photographs, begun in 1907; detailed permanent—plot maps, dating from 1959—1960; and an age—distribution analysis of a 170—yr—old population of Carnegiea gigantea. The crater vegetation is dominated by the woody perennials Cercidium microphyllum, Encelia farinosa, Prosopis sp., and Larrea tridentata, and the columnar cactus Carnegiea gigantea. Various populations of Larrea tridentata declined 50—90%, and Cercidium declined 60%, during the first half of this century with little or no recruitment since. Carnegiea numbers increased fourfold over the same period. A 200—fold increase in Prosopis in the playa—like crater center occurred in the early 1970s. Elsewhere on the crater floor, Encelia density increased markedly during the same period from insignificant levels in the early 1960s. Age distribution analysis for the Carnegiea population reveals three major establishment peaks during the 1790 period. Recruitment and morality records from the three sources of data are compared with regional climate records. The high mortality for some of the species was probably the result of the prolonged drought during 1936—1964. Establishment surges for some appear related to periods of unusually heavy precipitation during certain seasons. Clearly, desert communities are highly responsive to changes in the climate regime under which they grow.

Sonora↗

USGS2004

Effects of Abandoned Coal-Mine Drainage on Streamflow and Water Quality in the Mahanoy Creek Basin, Schuylkill, Columbia, and Northumberland Counties, Pennsylvania, 2001

This report assesses the contaminant loading, effects to receiving streams, and possible remedial alternatives for abandoned mine drainage (AMD) within the Mahanoy Creek Basin in east-central Pennsylvania. The Mahanoy Creek Basin encompasses an area of 157 square miles (407 square kilometers) including approximately 42 square miles (109 square kilometers) underlain by the Western Middle Anthracite Field. As a result of more than 150 years of anthracite mining in the basin, ground water, surface water, and streambed sediments have been adversely affected. Leakage from streams to underground mines and elevated concentrations (above background levels) of acidity, metals, and sulfate in the AMD from flooded underground mines and (or) unreclaimed culm (waste rock) degrade the aquatic ecosystem and impair uses of the main stem of Mahanoy Creek from its headwaters to its mouth on the Susquehanna River. Various tributaries also are affected, including North Mahanoy Creek, Waste House Run, Shenandoah Creek, Zerbe Run, and two unnamed tributaries locally called Big Mine Run and Big Run. The Little Mahanoy Creek and Schwaben Creek are the only major tributaries not affected by mining. To assess the current hydrological and chemical characteristics of the AMD and its effect on receiving streams, and to identify possible remedial alternatives, the U.S. Geological Survey (USGS) began a study in 2001, in cooperation with the Pennsylvania Department of Environmental Protection and the Schuylkill Conservation District. Aquatic ecological surveys were conducted by the USGS at five stream sites during low base-flow conditions in October 2001. Twenty species of fish were identified in Schwaben Creek near Red Cross, which drains an unmined area of 22.7 square miles (58.8 square kilometers) in the lower part of the Mahanoy Creek Basin. In contrast, 14 species of fish were identified in Mahanoy Creek near its mouth at Kneass, below Schwaben Creek. The diversity and abundance of fish species in Mahanoy Creek decreased progressively upstream from 13 species at Gowen City to only 2 species each at Ashland and Girardville. White sucker (Catostomus commersoni), a pollution-tolerant species, was present at each of the surveyed reaches. The presence of fish at Girardville was unexpected because of the poor water quality and iron-encrusted streambed at this location. Generally, macroinvertebrate diversity and abundance at these sites were diminished compared to Schwaben Creek and other tributaries draining unmined basins, consistent with the observed quality of streamwater and streambed sediment. Data on the flow rate and chemistry for 35 AMD sources and 31 stream sites throughout the Mahanoy Creek Basin were collected by the USGS during high base-flow conditions in March 2001 and low base-flow conditions in August 2001. A majority of the base-flow streamwater samples met water-quality standards for pH (6.0 to 9.0); however, few samples downstream from AMD sources met criteria for acidity less than alkalinity (net alkalinity = 20 milligrams per liter as CaCO3) and concentrations of dissolved iron (0.3 milligram per liter) and total manganese (1.0 milligram per liter). Iron, aluminum, and various trace elements including cobalt, copper, lead, nickel, and zinc, were present in many streamwater samples at concentrations at which continuous exposure can not be tolerated by aquatic organisms without an unacceptable effect. Furthermore, concentrations of sulfate, iron, manganese, aluminum, and (or) beryllium in some samples exceeded drinking-water standards. Other trace elements, including antimony, arsenic, barium, cadmium, chromium, selenium, silver, and thallium, did not exceed water-quality criteria for protection of aquatic organisms or human health. Nevertheless, when considered together, concentrations of iron, manganese, arsenic, cadmium, chromium, copper, lead, nickel, and zinc in a majority of the streambed sediment samples from Mahanoy Creek and

Scientific Investigations Report↗

USGS2019

One hundred pressing questions on the future of global fish migration science, conservation, and policy

Migration is a widespread but highly diverse component of many animal life histories. Fish migrate throughout the world's oceans, within lakes and rivers, and between the two realms, transporting matter, energy, and other species (e.g., microbes) across boundaries. Migration is therefore a process responsible for myriad ecosystem services. Many human populations depend on the presence of predictable migrations of fish for their subsistence and livelihoods. Although much research has focused on fish migration, many questions remain in our rapidly changing world. We assembled a diverse team of fundamental and applied scientists who study fish migrations in marine and freshwater environments to identify pressing unanswered questions. Our exercise revealed questions within themes related to understanding the migrating individual's internal state, navigational mechanisms, locomotor capabilities, external drivers of migration, the threats confronting migratory fish including climate change, and the role of migration. In addition, we identified key requirements for aquatic animal management, restoration, policy, and governance. Lessons revealed included the difficulties in generalizing among species and populations, and in understanding the levels of connectivity facilitated by migrating fishes. We conclude by identifying priority research needed for assuring a sustainable future for migratory fishes.

Frontiers in Ecology and Evolution↗

USGS2022

Temperature-based modeling of incubation period to protect loggerhead hatchlings on an urban beach in Northwest Florida

Sea turtle hatchlings face many natural and anthropogenic threats during their short journey to the water after emerging from nests. Reducing hatchling mortality is critical to population recovery of imperiled sea turtle species; however, protecting hatchlings is particularly challenging on beaches degraded by human development and disturbances, including artificial lighting. Managers need practical methods to reduce hatchling mortality without harming their natural behavior or development. To address this need, we describe an approach to reduce mortality of loggerhead hatchlings that relies on prediction of clutch incubation length and knowledge of hatchling emergence patterns. We developed models to predict incubation length utilizing sand temperature and nest depth data from 133 loggerhead nests laid on an urban beach in Northwest Florida from 2013 to 2020. Incubation length was predicted to within 2.2 days using mean sand temperatures measured just outside of the clutch. Predicted accuracy improved to 1.9 days using a 2-parameter model incorporating sand temperature and measured depth to the topmost eggs. Hatchlings emerged almost exclusively at night in a single large group with no evidence of asynchronous emergences. Emergence times were skewed toward the early evening, in contrast to loggerhead nests on the Florida Atlantic coast which tend to hatch near midnight. Using these prediction tools, monitoring efforts could be focused on days and times of expected emergence to enable protection of hatchlings emerging naturally from nests left in situ. The method used here, while not a substitute for recovery of degraded nesting habitat, provides a way to protect hatchlings that avoids disturbing the eggs with instruments or restraining the hatchlings with cages or screens.

Florida↗