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At least 937 records · Page 52Linked to original sources
USGS1990

Coal in sub-Saharan-African countries undergoing desertification

Coal has been reported in 11 of the 16 sub-Saharan countries discussed in this appraisal: Mauritania, Senegal, Mali, Niger, Benin, Nigeria, Cameroon, Central African Republic, Sudan, Ethiopia, and Somalia. No coal occurrences have been reported in Gambia, Togo, Burkina, Chad, and Djibouti but coal may be present within these countries because neighboring countries do contain coal-bearing rocks. Most of these countries are undergoing desertification or will in the near future. Wood, directly or in the form of charcoal, constitutes two-thirds of the fuel used in Africa. Destruction of forest and shrub lands for fuel is occurring at an increasing rate because of desertification and increasing energy demands. The decline in biological productivity, coupled with concentration of population in areas where water is available and crops may be grown, leads to increasing shortages of wood for fuel. Part of the present and future energy needs of the sub-Saharan region could be met by use of indigenous coal and peat. Nine sedimentary basins, completely or partially within the sub-Saharan region, have the potential of either coal and/or peat deposits of economic value: 1- Senegal Basin, 2- Taoudeni Basin and Gao Trough, 3- Niger Basin, 4- Chad Basin, 5- Chari Basin, 6- Benue Trough (Depression), 7- Sudan Trough, 8- Plateau and Rift Belt, and 9- Somali Basin. Niger and Nigeria are the only countries in sub-Saharan Africa in which coal is presently being mined as a fuel source for powerplants and domestic use. Peat occurs in the deltas, lower river, and interdunal basin areas of Senegal, Mauritania, and Sudan. Peat can be used as an alternate fuel source and is currently being tested as a soil amendment in the agricultural sector.

Journal of African Earth Sciences↗
USGS2014

Mountain landscapes offer few opportunities for high-elevation tree species migration

Climate change is anticipated to alter plant species distributions. Regional context, notably the spatial complexity of climatic gradients, may influence species migration potential. While high-elevation species may benefit from steep climate gradients in mountain regions, their persistence may be threatened by limited suitable habitat as land area decreases with elevation. To untangle these apparently contradictory predictions for mountainous regions, we evaluated the climatic suitability of four coniferous forest tree species of the western United States based on species distribution modeling (SDM) and examined changes in climatically suitable areas under predicted climate change. We used forest structural information relating to tree species dominance, productivity, and demography from an extensive forest inventory system to assess the strength of inferences made with a SDM approach. We found that tree species dominance, productivity, and recruitment were highest where climatic suitability (i.e., probability of species occurrence under certain climate conditions) was high, supporting the use of predicted climatic suitability in examining species risk to climate change. By predicting changes in climatic suitability over the next century, we found that climatic suitability will likely decline, both in areas currently occupied by each tree species and in nearby unoccupied areas to which species might migrate in the future. These trends were most dramatic for high elevation species. Climatic changes predicted over the next century will dramatically reduce climatically suitable areas for high-elevation tree species while a lower elevation species, Pinus ponderosa, will be well positioned to shift upslope across the region. Reductions in suitable area for high-elevation species imply that even unlimited migration would be insufficient to offset predicted habitat loss, underscoring the vulnerability of these high-elevation species to climatic changes.

Arizona;California;Colorado;Idaho;Kansas;Montana;N↗
USGS2009

A new species of Platyrrhinus (Chiroptera: Phyllostomidae) from western Colombia and Ecuador, with emended diagnoses of P. aquilus, P. dorsalis, and P. umbratus

The Neotropical bat genus Platyrrhinus (Chiroptera: Phyllostomidae: Stenodermatinae) currently comprises 15 species. Our morphological and morphometric analysis of large and medium-sized Platyrrhinus revealed a distinctive Undescribed species from western South America. We also recognize P. aquilus (Handley & Ferris 1972) and P. umbratus (Lyon 1902) as valid species. We describe P. nitelinea sp. nov. from western Colombia and Ecuador and provide emended diagnoses along with descriptions of P. aquilus, P.. dorsalis, and P. umbratus. Phylogenetic analysis of Platyrrhinus based on morphological characters indicates that P. aquilus is closely related to P. aurarius and P. nigellus, P. umbratus to P. chocoensis, and P. nitelinea to P. vittatus.

Proceedings of the Biological Society of Washingto↗
USGS2022

Coupling process-based and empirical models to assess management options to meet conservation goals

Conservation lands face a mounting threat of ecosystem transformation and the loss of biodiversity from the invasion of fire-prone perennial and annual grasses. Managers must make difficult decisions to find efficient ways to expend limited resources to manage large and complex landscapes amidst substantial uncertainty regarding effective treatment strategies, climates, and invader-induced novel processes. We developed a state-and-transition simulation model coupled with a fire behavior model to study impacts to native biodiversity and fire regimes in a national park invaded by a perennial grass. We evaluated resources required to meet management objectives, and how to spatially allocate available resources efficiently and effectively. Management strategies and ecological scenarios strongly influenced the ability to minimize potential impacts; the inclusion of a new management strategy, aerial precision spot spraying targeting low cover levels in remote regions, was needed to supplement current treatments that can only target large, dense patches. Adding this new treatment method may be enough to conserve the desert ecosystem from small scale transformation through invasive competition and from broad functional transformations through invasive-induced fire regime changes. Spot spraying may also be highly beneficial if wetter monsoonal conditions create faster growth rates, decreasing the ability to contain the invasion even with unlimited management resources. Given current annual budgets for control, and the new treatment option, invasion control and preservation of native biodiversity may be possible regardless of spatial prioritization. Coupled empirical and process-based models efficiently simulated the effects of management activities, quantifying potential management costs and ecological impacts, while considering a wide range of possible future uncertainties associated with climate, spread rates, and wildfires lacking historical precedent. These techniques could be applied to other situations to evaluate the feasibility of conservation goals and to determine actions that would be most efficient and effective in meeting those goals.

Arizona↗
USGS2006

Characters and phylogenetic relationships of nectar-feeding bats, with descriptions of new Lonchophylla from western South America (Mammalia: Chiroptera: Phyllostomidae: Lonchophyllini)

The Neotropical Lonchophyllini (Chiropter: Phyllostomidae) currently comprise four genera and thirteen species of nectar-feeding bats. These species often are separated into larger-bodied (eight species) and smaller-bodied (five species) forms to aid in identification. Our morphological and morphometrical analyses of the smaller Lonchophyllini revealed the existence of two distinctive, previously undescribed species of bats of the genus Lonchophylla from western South America. We describe a new form from Amazonian Peru as Lonchophylla pattoni and one from western Colombia as Lonchophylla cadenai. Phyllogenetic analysis of the Lonchophyllini based primarily on morphological characters indicates that these two new species are closely related to Lonchophylla thomasi.

Proceedings of the Biological Society of Washingto↗
USGS2013

U.S. Geological Survey natural hazards science strategy— Promoting the safety, security, and economic well-being of the Nation

Executive Summary The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research—founded on detailed observations and improved understanding of the responsible physical processes—can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events. To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science. In October 2010, the Natural Hazards Science Strategy Planning Team (H–SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory and nonstatutory roles regarding floods, earthquakes, tsunamis, landslides, coastal erosion, volcanic eruptions, wildfires, and magnetic storms—the hazards considered in this plan. There are numerous other hazards of societal importance that are considered either only peripherally or not at all in this Strategy because they are either in another of the USGS strategic science plans (such as drought) or not in the overall mission of the USGS (such as tornados).

Circular↗
USGS2012

Natural hazards science strategy

The mission of the U.S. Geological Survey (USGS) in natural hazards is to develop and apply hazard science to help protect the safety, security, and economic well-being of the Nation. The costs and consequences of natural hazards can be enormous, and each year more people and infrastructure are at risk. USGS scientific research—founded on detailed observations and improved understanding of the responsible physical processes—can help to understand and reduce natural hazard risks and to make and effectively communicate reliable statements about hazard characteristics, such as frequency, magnitude, extent, onset, consequences, and where possible, the time of future events. To accomplish its broad hazard mission, the USGS maintains an expert workforce of scientists and technicians in the earth sciences, hydrology, biology, geography, social and behavioral sciences, and other fields, and engages cooperatively with numerous agencies, research institutions, and organizations in the public and private sectors, across the Nation and around the world. The scientific expertise required to accomplish the USGS mission in natural hazards includes a wide range of disciplines that this report refers to, in aggregate, as hazard science. In October 2010, the Natural Hazards Science Strategy Planning Team (H–SSPT) was charged with developing a long-term (10-year) Science Strategy for the USGS mission in natural hazards. This report fulfills that charge, with a document hereinafter referred to as the Strategy, to provide scientific observations, analyses, and research that are critical for the Nation to become more resilient to natural hazards. Science provides the information that decisionmakers need to determine whether risk management activities are worthwhile. Moreover, as the agency with the perspective of geologic time, the USGS is uniquely positioned to extend the collective experience of society to prepare for events outside current memory. The USGS has critical statutory and nonstatutory roles regarding floods, earthquakes, tsunamis, landslides, coastal erosion, volcanic eruptions, wildfires, and magnetic storms—the hazards considered in this plan. There are numerous other hazards of societal importance that are considered either only peripherally or not at all in this Strategy because they are either in another of the USGS strategic science plans (such as drought) or not in the overall mission of the USGS (such as tornados).

Open-File Report↗
USGS2023

Contemporary distribution of non-native Chinook salmon (Oncorhynchus tshawytscha) in South America

Chinook salmon represent one of the most successful salmonid introductions in South America, and today multiple naturalized populations exist across Patagonia. Here, we present an updated regional distribution of Chinook salmon that includes new records of occurrences collected between 2006 and 2022. We found a significant range expansion in terms of occurrences for adult (18 new basins; 2,854,108 km 2 ) and adult spawners or juvenile (12 new basins; 53,262 km 2 ) salmon extending both to the north and south of the previously known colonized range in South America. This range expansion (38% of the area considering only occurrences indicating reproduction via adult spawners or juvenile salmon) included major basins draining to both the Pacific Ocean and Atlantic Ocean coasts of the continent. Adult Chinook salmon are currently reported from 48 large basins (33.62°–54.97° S) covering a total drainage area of 3,047,197 km 2 . The observed expansion we document here has been likely driven by the dispersal of straying adults from historically naturalized populations. Our findings provide evidence that the invasion of Chinook salmon in South America is ongoing and updated information relevant to the management of this invasive and socio-ecologically important fish.

Biological Invasions↗
USGS2004

The distribution of seabirds and pinnipeds in Marguerite Bay and their relationship to physical features during austral winter 2001

The distribution of seabirds and pinnipeds and their relationship to physical oceanographic variables were investigated as part of the US Southern Ocean Global Ocean Ecosystem Dynamics field program along a study grid centered around Marguerite Bay on the west Antarctic Peninsula during late fall (April-May) and winter (July-August), 2001. Sea-ice conditions during the cruises provided an opportunity to compare the relationship among physical oceanographic variables and species distributions before and after the development of pack ice. During the fall cruise before pack ice development, both sea-ice-affiliated species and open-water-affiliated were observed in the area. The most common ice-affiliated species observed at this time were snow petrel (Pagodroma nivea, 0.7 individuals km-2) and Antarctic petrel (Thalassoica antarctica, 0.2 individuals km-2) and the most common open-water-affiliated species were blue petrel (Halobaena caerulea, 0.4 individuals km-2), cape petrel (Daption capense, 0.2 individuals km-2), and southern fulmar (Fulmarus glacialoides, 0.1 individuals km-2). In addition, Antarctic fur seals (Arctocephalus gazella, 0.1 individuals km-2) and crabeater seals (Lobodon carcinophagus, 0.4 individuals km-2) were observed in low numbers. Akaike's information criterion was used to assess competing models that predicted predator distributions based on physical oceanographic variables proposed to structure predator distribution in previous research. These analyses indicated that predator distributions were primarily associated with water-mass structure and variability in bottom depth during the fall cruise. Crabeater seal, snow petrel, Antarctic petrel, and southern fulmar had higher densities in Inner Shelf Water, particularly near Alexander Island where a coastal current was present. Blue petrel, kelp gull (Larus dominicanus), and southern giant petrel (Macronectes giganteus) were positively associated with variability in bottom depth in April-May, suggesting that hydrographic processes influenced by bathymetry may have been important in structuring bird distributions. After the development of pack ice, during July and August, only sea-ice-affiliated species, including snow petrel (1.0 individuals km-2), Antarctic petrel (0.1 individuals km-2), Ade??lie penguin (Pygoscelis adeliae, 0.4 individuals km-2), and crabeater seal (0.3 individuals km-2), were observed. Seabirds were primarily associated with sea-ice characteristics (e.g. sea-ice concentration, sea-ice type) rather than the water-column environment later in the winter. Results from this study suggest that the timing and extent of sea-ice development in the fall may influence over-winter predation by seabirds and pinnipeds on zooplankton and fish on the western Antarctic Peninsula. Delays in sea-ice development may allow seabirds and pinnipeds access to biologically important areas such as the Inner Shelf Water for a longer period of time thereby increasing predation on zooplankton and fish. ?? 2004 Elsevier Ltd. All rights reserved.

Deep-Sea Research Part II: Topical Studies in Ocea↗
USGS2023

Genetic diversity and IUCN Red List status

The International Union for Conservation of Nature (IUCN) Red List is an important and widely used tool for conservation assessment. The IUCN uses information about a species’ range, population size, habitat quality and fragmentation levels, and trends in abundance to assess extinction risk. Genetic diversity is not considered, although it affects extinction risk. Declining populations are more strongly affected by genetic drift and higher rates of inbreeding, which can reduce the efficiency of selection, lead to fitness declines, and hinder species’ capacities to adapt to environmental change. Given the importance of conserving genetic diversity, attempts have been made to find relationships between red-list status and genetic diversity. Yet, there is still no consensus on whether genetic diversity is captured by the current IUCN Red List categories in a way that is informative for conservation. To assess the predictive power of correlations between genetic diversity and IUCN Red List status in vertebrates, we synthesized previous work and reanalyzed data sets based on 3 types of genetic data: mitochondrial DNA, microsatellites, and whole genomes. Consistent with previous work, species with higher extinction risk status tended to have lower genetic diversity for all marker types, but these relationships were weak and varied across taxa. Regardless of marker type, genetic diversity did not accurately identify threatened species for any taxonomic group. Our results indicate that red-list status is not a useful metric for informing species-specific decisions about the protection of genetic diversity and that genetic data cannot be used to identify threat status in the absence of demographic data. Thus, there is a need to develop and assess metrics specifically designed to assess genetic diversity and inform conservation policy, including policies recently adopted by the UN's Convention on Biological Diversity Kunming-Montreal Global Biodiversity Framework.

Conservation Biology↗
USGS2015

Genetic signatures of historical dispersal of fish threatened by biological invasions: the case of galaxiids in South America

Aim The ecological effects of biological invasions are well documented, but little is known about the effects of invaders on the genetic structure of native species. We examined the phylogeography, genetic variation and population structuring of two galaxiid fishes, Aplochiton zebra and A. taeniatus , threatened by non-native salmonids, and whose conservation is complicated by misidentification and limited knowledge of their genetic diversity. Location Chile and the Falkland Islands. Methods We combined microsatellite and mitochondrial DNA (16S rDNA and COI) markers to compare genetic diversity, effective population size and gene flow of Aplochiton spp. populations differentially affected by salmonid presence. Results We identified two 16S rDNA haplotypes among A. zebra – one dominant in coastal populations and another dominant in inland populations. Populations living on the island of Chiloé displayed a mixture of coastal and inland haplotypes, as well as high microsatellite diversity, as one would expect if the island had been a refugium during the Last Glacial Maximum, or a contact zone among populations. Microsatellite data revealed strong population structuring, indicative of current isolation patterns, and a negative correlation between the genetic diversity of A. zebra and the relative abundance of invasive salmonids. Main conclusions Our study indicates that population structuring of A. zebra reflects the influence of historical patterns of migration, but also the current levels of reduced gene flow among watersheds. Invasive salmonids, known to compete with and prey on native galaxiids, may have had negative impacts on the genetic diversity of Aplochiton spp. The low genetic variation found in some populations, coupled with potential biases in abundance estimates due to species misidentification, highlight the urgent need for more research into the conservation status of the two species of Aplochiton .

Journal of Biogeography↗
USGS2017

Water, Energy, and Biogeochemical Model (WEBMOD), user’s manual, version 1

The Water, Energy, and Biogeochemical Model (WEBMOD) uses the framework of the U.S. Geological Survey (USGS) Modular Modeling System to simulate fluxes of water and solutes through watersheds. WEBMOD divides watersheds into model response units (MRU) where fluxes and reactions are simulated for the following eight hillslope reservoir types: canopy; snowpack; ponding on impervious surfaces; O-horizon; two reservoirs in the unsaturated zone, which represent preferential flow and matrix flow; and two reservoirs in the saturated zone, which also represent preferential flow and matrix flow. The reservoir representing ponding on impervious surfaces, currently not functional (2016), will be implemented once the model is applied to urban areas. MRUs discharge to one or more stream reservoirs that flow to the outlet of the watershed. Hydrologic fluxes in the watershed are simulated by modules derived from the USGS Precipitation Runoff Modeling System; the National Weather Service Hydro-17 snow model; and a topography-driven hydrologic model (TOPMODEL). Modifications to the standard TOPMODEL include the addition of heterogeneous vertical infiltration rates; irrigation; lateral and vertical preferential flows through the unsaturated zone; pipe flow draining the saturated zone; gains and losses to regional aquifer systems; and the option to simulate baseflow discharge by using an exponential, parabolic, or linear decrease in transmissivity. PHREEQC, an aqueous geochemical model, is incorporated to simulate chemical reactions as waters evaporate, mix, and react within the various reservoirs of the model. The reactions that can be specified for a reservoir include equilibrium reactions among water; minerals; surfaces; exchangers; and kinetic reactions such as kinetic mineral dissolution or precipitation, biologically mediated reactions, and radioactive decay. WEBMOD also simulates variations in the concentrations of the stable isotopes deuterium and oxygen-18 as a result of varying inputs, mixing, and evaporation. This manual describes the WEBMOD input and output files, along with the algorithms and procedures used to simulate the hydrology and water quality in a watershed. Examples are presented that demonstrate hydrologic processes, weathering reactions, and isotopic evolution in an alpine watershed and the effect of irrigation on water flows and salinity in an intensively farmed agricultural area.

Techniques and Methods↗
USGS2018

Managing forest habitat for conservation-reliant species in a changing climate: The case of the endangered Kirtland’s Warbler

Conservation and recovery of species of concern necessitates evaluating forest habitat conditions under changing climate conditions, especially in the early stages of the delisting process. Managers must weigh implications of near-term habitat management activities within the context of changing environmental conditions and a species’ biological traits that may influence their vulnerability to changing conditions. Here we applied established population-habitat relationships based on decades of monitoring and research-management collaborations for the Kirtland’s Warbler ( Setophaga kirtlandii ) to project potential impacts of changing environmental conditions to breeding habitat distribution, quantity, and quality in the near future. Kirtland’s warblers are habitat-specialists that nest exclusively within dense jack pine ( Pinus banksiana ) forests between ca. 5–20 years of age. Using Random Forests to predict changes in distribution and growth rate of jack pine under future scenarios, results indicate the projected distribution of jack pine will contract considerably (ca. 75%) throughout the Lake States region, U.S.A. in response to projected environmental conditions in 2099 under RCP 4.5 and 8.5 climate scenarios regardless of climate model. Reduced suitability for jack pine regeneration across the Lake States may constrain management options, especially for creating high stem-density plantations nesting habitat. However, conditions remain suitable for jack pine regeneration within their historical and current core breeding range in northern Lower Michigan and several satellite breeding areas. Projected changes in jack pine growth rates varied within the core breeding area, but altered growth rates did not greatly alter the duration that habitat remained suitable for nesting by the Kirtland’s Warblers. These findings contribute to Kirtland’s Warbler conservation by informing habitat spatial planning of plantation management to provide a constant supply of nesting habitat based on the spatial variability of potential loss or gain of lands environmentally suitable for regenerating jack pine in the long-term.

Michigan, Wisconsin↗
USGS2008

Avian movements and wetland connectivity in landscape conservation

The current conservation crisis calls for research and management to be carried out on a long-term, multi-species basis at large spatial scales. Unfortunately, scientists, managers, and agencies often are stymied in their effort to conduct these large-scale studies because of a lack of appropriate technology, methodology, and funding. This issue is of particular concern in wetland conservation, for which the standard landscape approach may include consideration of a large tract of land but fail to incorporate the suite of wetland sites frequently used by highly mobile organisms such as waterbirds (e.g., shorebirds, wading birds, waterfowl). Typically, these species have population dynamics that require use of multiple wetlands, but this aspect of their life history has often been ignored in planning for their conservation. We outline theoretical, empirical, modeling, and planning problems associated with this issue and suggest solutions to some current obstacles. These solutions represent a tradeoff between typical in-depth single-species studies and more generic multi-species studies. They include studying within- and among-season movements of waterbirds on a spatial scale appropriate to both widely dispersing and more stationary species; multi-species censuses at multiple sites; further development and use of technology such as satellite transmitters and population-specific molecular markers; development of spatially explicit population models that consider within-season movements of waterbirds; and recognition from funding agencies that landscape-level issues cannot adequately be addressed without support for these types of studies.

Conservation Biology↗
USGS1993

Options for water-level control in developed wetlands

Wetland habitats in the United States currently are lost at a rate of 260,000 acres/year (105,218 ha/year). Consequently, water birds concentrate in fewer and smaller areas. Such concentrations may deplete food supplies and influence behavior, physiology, and survival. Continued losses increase the importance of sound management of the remaining wetlands because water birds depend on them. Human activities modified the natural hydrology of most remaining wetlands in the conterminous United States, and such hydrologic alterations frequently reduce wetland productivity. The restoration of original wetland functions and productivity often requires the development of water distribution and discharge systems to emulate natural hydrologic regimes. Construction of levees and correct placement of control structures and water-delivery and water-discharge systems are necessary to (1) create soil and water conditions for the germination of desirable plants, (2) control nuisance vegetation, (3) promote the production of invertebrates, and (4) make foods available for wildlife that depends of wetlands (Leaflets 13.2.1 and 13.4.6). This paper provides basic guidelines for the design of wetlands that benefit wildlife. If biological considerations are not incorporated into such designs, the capability of managing wetlands for water birds is reduced and costs often are greater. Although we address the development of palustrine wetlands in migration and wintering areas, many of the discussed principles are applicable to the development of other wetland types and in other locations.

Book chapter↗
USGS2026

21st-century mangrove expansion along the southeastern United States

Warming winter temperatures are driving range expansion of tropical, cold-sensitive mangroves into temperate ecosystems. Along the Atlantic coast of North America, the mangrove range limit is particularly sensitive to climate variability and historical data demonstrate that the mangrove-salt marsh ecotone on this coast has shifted recurrently during recent centuries. However, a comprehensive understanding of how this mangrove-salt marsh ecotone may shift in the future remains lacking. Here, we combine ensemble forecasting of mangrove distribution for the next century with high-resolution oceanographic dispersal simulations, phenological observations, and historical hurricane data to project future mangrove-salt marsh dynamics at the rapidly changing range limit in northeastern Florida (USA). We show that warming winter temperatures will drive continued poleward expansion of mangroves along North America's Atlantic coast, potentially reaching South Carolina by 2100. With ongoing climate change, suitable mangrove habitat is projected to expand beyond the current range limit, and dispersal simulations suggest successful colonization of these sites from established mangrove populations. Additionally, patterns in hurricane directionality and intensity and field reports of propagule presence reveal that these high-energy events may significantly contribute to future mangrove range expansion by facilitating long-distance, storm-driven propagule dispersal. The encroachment of mangroves in salt marsh-dominated latitudes is expected to substantially modify wetland ecosystem function and structure, emphasizing how the identification of newly colonizable habitat can inform conservation strategies and site-specific decisions on mangrove management.

Florida, Georgia, North Carolina, South Carolina↗
USGS2017

Status of scientific knowledge, recovery progress, and future research directions for the Gulf Sturgeon, Acipenser oxyrinchus desotoi Vladykov, 1955

The Gulf Sturgeon, Acipenser oxyrinchus desotoi , is an anadromous species of Acipenseridae and native to North America. It currently inhabits and spawns in the upper reaches of seven natal rivers along the northern coast of the Gulf of Mexico from the Suwannee River, Florida, to the Pearl River, Louisiana, during spring to autumn. Next to the Alligator Gar (Atractosteus spatula) , the Gulf Sturgeon is currently the largest fish species occurring in U.S. Gulf Coast rivers, attaining a length of 2.35 m and weights exceeding 135 kg, but historically attained a substantially larger size. Historically, the spawning populations existed in additional rivers from which the species has been wholly or nearly extirpated, such as the Mobile and Ochlockonee rivers, and possibly the Rio Grande River. Most Gulf Sturgeon populations were decimated by unrestricted commercial fishing between 1895–1910. Subsequently most populations remained unrecovered or extirpated due to continued harvest until the 1970s–1980s, and the construction of dams blocking access to ancestral upriver spawning grounds. Late 20th Century harvest bans and net bans enacted by the several Gulf Coast states have stabilized several populations and enabled the Suwannee River population to rebound substantially and naturally. Hatchery supplementation has not been necessary in this regard to date. Sturgeon are resilient and adaptable fishes with a geological history of 150 million years. Research undertaken since the 1970s has addressed many aspects of Gulf Sturgeon life history, reproduction, migration, population biology, habitat requirements, and other aspects of species biology. However, many knowledge gaps remain, prominently including the life history of early developmental stages in the first year of life. Natural population recovery is evident for the Suwannee River population, but seems promising as well for at least four other populations. The Pascagoula and Pearl River populations face a challenging future due a combination of natural and anthropogenic factors. These two populations, and perhaps the Escambia River population, are particularly vulnerable to periodic mass mortality due to major stochastic events including hurricanes, flooding, hypoxia, and toxic spills. The present manuscript provides a comprehensive synthesis of knowledge regarding the Gulf Sturgeon at the organismal and population levels, identifying knowledge gaps as priorities for future research. Topics not treated in the present synthesis include morphology, internal biology, physiology, and endocrinology. Topics only briefly treated include parasites and diseases, contaminants, and sturgeon aquaculture.

Journal of Applied Ichthyology↗
USGS2009

Effects of highway construction on stream water quality and macroinvertebrate condition in a mid-Atlantic highlands watershed, USA

Refining best management practices (BMPs) for future highway construction depends on a comprehensive understanding of environmental impacts from current construction methods. Based on a before-after-control impact (BACI) experimental design, long-term stream monitoring (1997–2006) was conducted at upstream (as control, n = 3) and downstream (as impact, n = 6) sites in the Lost River watershed of the Mid-Atlantic Highlands region, West Virginia. Monitoring data were analyzed to assess impacts of during and after highway construction on 15 water quality parameters and macroinvertebrate condition using the West Virginia stream condition index (WVSCI). Principal components analysis (PCA) identified regional primary water quality variances, and paired t tests and time series analysis detected seven highway construction-impacted water quality parameters which were mainly associated with the second principal component. In particular, impacts on turbidity, total suspended solids, and total iron during construction, impacts on chloride and sulfate during and after construction, and impacts on acidity and nitrate after construction were observed at the downstream sites. The construction had statistically significant impacts on macroinvertebrate index scores (i.e., WVSCI) after construction, but did not change the overall good biological condition. Implementing BMPs that address those construction-impacted water quality parameters can be an effective mitigation strategy for future highway construction in this highlands region.

West Virginia↗