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At least 37 records · Page 2Linked to original sources

USGS2016

Hemidactylus parvimaculatus (Sri Lankan spotted house gecko)

USA: LOUISIANA: St. Tammany Parish: private property ca. 4 km S of Abita Springs, E of State Hwy 59, and N of Interstate 12 (30.44000°N, 90.02000°W; WGS 84). 18 August 2013. Brad M. Glorioso. Verified by David Heckard. Florida Museum of Natural History (UF 176422, photo voucher). New parish record. This species was first reported in the Americas in the vicinity of Audubon Zoo in New Orleans, Louisiana (Heckard et al. 2013. IRCF Reptiles & Amphibians 20:192–196). This is the third report of this species in Louisiana (Heckard et al. 2013, op. cit.; Borgardt 2015. Herpetol. Rev. 46:217), and is now documented from Orleans, Jefferson, and St. Tammany parishes in southeast Louisiana. The individual was located at night, ca. 10 m from a dwelling on the forest floor amid a downed picket fence, which was resting atop a thick layer of pine needles. There are H. turcicus at the property, but this individual was recognized as unusual, and many photos were taken before releasing the animal. It was not until much later that it was determined to be H. parvimaculatus. The origin of this individual is unknown, as the owners of this 1.62-ha property are elderly and do not keep any pets. Subsequent casual searches have not turned up any new individuals. I thank David Heckard for his help with identification and discussion of this species in Louisiana.

Herpetological Review↗

USGS1990

Hurricane impacts on the coastal environment

In terms of insured losses, Hurricane Andrew is the most severe catastrophe in the Nation's history. Prior to the arrival of Andrew, the U.S. Geological Survey (USGS), in cooperation with the Louisiana Geological Survey (LGS), acquired an extensive body of information and data on the behavior and long-term erosion of Louisiana barrier islands. As a result, we have a clear understanding of pre-storm conditions in this area; Andrew provided an opportunity to learn in detail the impact of a very large storm on Louisiana coastal environment.

Fact Sheet↗

USGS2018

Molecular and morphological data reveal non-monophyly and speciation in imperiled freshwater mussels (Anodontoides and Strophitus)

Accurate taxonomic placement is vital to conservation efforts considering many intrinsic biological characteristics of understudied species are inferred from closely related taxa. The rayed creekshell, Anodontoides radiatus (Conrad, 1834), exists in the Gulf of Mexico drainages from western Florida to Louisiana and has been petitioned for listing under the Endangered Species Act. We set out to resolve the evolutionary history of A. radiatus, primarily generic placement and species boundaries, using phylogenetic, morphometric, and geographic information. Our molecular matrix contained 3 loci: cytochrome c oxidase subunit I, NADH dehydrogenase subunit I, and the nuclear-encoded ribosomal internal transcribed spacer I. We employed maximum likelihood and Bayesian inference to estimate a phylogeny and test the monophyly of Anodontoides and Strophitus. We implemented two coalescent-based species delimitation models to test seven species models and evaluate species boundaries within A. radiatus. Concomitant to molecular data, we also employed linear morphometrics and geographic information to further evaluate species boundaries. Molecular and morphological evidence supports the inclusion of A. radiatus in the genus Strophitus, and we resurrect the binomial Strophitus radiatus to reflect their shared common ancestry. We also found strong support for polyphyly in Strophitus and advocate the resurrection of the genus Pseudodontoideus to represent ‘Strophitus’ connasaugaensis and ‘Strophitus’ subvexus. Strophitus radiatus exists in six well-supported clades that were distinguished as evolutionary independent lineages using Bayesian inference, maximum likelihood, and coalescent-based species delimitation models. Our integrative approach found evidence for as many as 4 evolutionary divergent clades within S. radiatus. Therefore, we formally describe two new species from the S. radiatus species complex (Strophitus williamsi and Strophitus pascagoulaensis) and recognize the potential for a third putative species (Strophitus sp. cf. pascagoulaensis). Our findings aid stakeholders in establishing conservation and management strategies for the members of Anodontoides, Strophitus, and Pseudodontoideus.

Alabama, Florida, Louisiana, Mississippi↗

USGS2022

Storeria occipitomaculata (Red-bellied Snake)

STORERIA OCCIPITOMACULATA (Red-bellied Snake). USA: LOUISIANA: St. Mary Parish: Bayou Teche National Wildlife Refuge (29.69425N, 91.46701W; WGS 84). 18 August 2022. William C. Carroll and Aidan G. Phillips. Verified by Coleman M. Sheehy III. Florida Museum of Natural History, University of Florida (UF 193423; photo voucher). Adult photographed in leaf litter in a wet bottomland hardwood forest with a mixed composition of hardwood trees and Dwarf Palmetto (Sabal minor). New parish record (Dundee and Rossman 1989. The Amphibians and Reptiles of Louisiana. Louisiana State University Press, Baton Rouge, Louisiana. 300 pp.). The snake was found 68.5 km to the east-southeast from the nearest other documented specimen in Vermilion Parish (UF 177730; Muse et al. 2016. Herpetol. Rev. 47:266). This record is the second documentation of S. occipitomaculata in a coastal Louisiana parish (Muse et al. 2016, op. cit.). These two recent findings challenge our previous understanding that this species is absent from coastal parishes (Boundy and Carr 2017. Amphibians & Reptiles of Louisiana: An Identification and Reference Guide. Louisiana State University Press, Baton Rouge, Louisiana. 282 pp.). Storeria occipitomaculata is fossorial and can be difficult to locate, but these two recent records suggest additional populations may yet be discovered where suitable forested habitat exists along the coast.

Louisiana↗

USGS2019

Hemidactylus parvimaculatus (Sri Lankan spotted house gecko)

USA: LOUISIANA: PLAQUEMINES PARISH: 0.15 km S of the intersection of LA-23 and Jump road, Venice (29.266630°N, 89.35570°W; WGS 84). 2 May 2019. V. C. Montross and W. McGighan. Verified by Aaron M. Bauer. Florida Museum of Natural History (UF 189238; photo voucher). New parish record. On 2 May 2019, three Hemidactylus parvimaculatus were observed after lifting an abandoned door left on the side of Jump Basin Road. An adult specimen was photographed. This record extends the known distribution of this species in Louisiana south of all previously recorded parishes and is 105 km SW of the species’ first recorded location in the state at Audubon Zoo, Orleans Parish (Heckard et al. 2013. IRCF Reptil. Amphib. 20:192–196). Four additional parishes in southeastern Louisiana have since been added to its known distribution including Jefferson (Borgardt 2015. Herpetol. Rev. 46:217), St. Tammany (Glorioso 2016. Herpetol. Rev. 47:81), St. John (Borgardt 2016. Herpetol. Rev. 47:258), and Tangipahoa (Erdman 2017. Herpetol. Rev. 48:125), as well as Chambers and Orange counties in east Texas (Davis and LaDuc 2019. Herpetol. Rev. 50:102).

Louisiana↗

USGS2015

Geologic framework for the assessment of undiscovered oil and gas resources in sandstone reservoirs of the Upper Jurassic-Lower Cretaceous Cotton Valley Group, U.S. Gulf of Mexico region

The U.S. Geological Survey (USGS) is assessing the undiscovered oil and gas resources in sandstone reservoirs of the Upper Jurassic–Lower Cretaceous Cotton Valley Group in onshore areas and State waters of the U.S. Gulf of Mexico region. The assessment is based on geologic elements of a total petroleum system. Four assessment units (AUs) are defined based on characterization of hydrocarbon source and reservoir rocks, seals, traps, and the geohistory of the hydrocarbon products. Strata in each AU share similar stratigraphic, structural, and hydrocarbon-charge histories. The Cotton Valley Group extends in the subsurface from southern Texas to the Florida Panhandle in an arcuate belt that crosses northern Louisiana, the southern part of Arkansas, and southern Mississippi and Alabama. Three of the AUs are quantitatively assessed for undiscovered volumes of hydrocarbons in conventional accumulations. The Cotton Valley Updip Oil AU includes areas between the maximum updip limit of the Cotton Valley Group and a curved belt of regional faults (included in the Peripheral Fault System AU). Hydrocarbon charge to this AU remains uncertain. The Peripheral Fault System Oil and Gas AU includes the Mexia, Talco, State Line, South Arkansas, Pickens, Gilbertown, and other fault segments, which trapped early oil that migrated from source rocks within the Smackover Formation. Hydrocarbons in the Downdip Oil and Gas AU are primarily associated with low-amplitude salt-related features in the East Texas, North Louisiana, and Mississippi salt basins. The Tight Sandstone Gas AU contains gas-charged sandstones previously referred to collectively as “massive.” Their reservoir properties are consistent with the USGS’s definition of continuous reservoirs, and their resources, therefore, are assessed using a separate methodology. Optimal coincidence of low-permeability sandstone, gas-mature source rocks, and complex structures of the regional Sabine feature encouraged development of a general “sweet spot” area in eastern Texas.

Conference Paper↗

USGS2012

A catalog of Louisiana's nesting seabird colonies

Summarizing his colonial nesting waterbird survey experiences along the northern coast of the Gulf of Mexico in a paper presented to the Colonial Waterbird Group of the Waterbird Society (Portnoy 1978), bird biologist John W. Portnoy stated, “This huge concentration of nesting waterbirds, restricted almost entirely to the wetlands and estuaries of southern Louisiana, is unmatched in all of North America; for example, a 1975 inventory of wading birds along the Atlantic Coast from Maine to Florida [Custer and Osborn, in press], tallied 250,000 breeding [waterbirds] of 14 species, in contrast with the 650,000 birds of 15 species just from Sabine Pass to Mobile Bay.” The “650,000 birds” to which Portnoy referred, were tallied by him in a 1976 survey of coastal Louisiana, Mississippi, and Alabama (see below, under “Major Surveys” section). According to the National Atlas of Coastal Waterbird Colonies in the Contiguous United States: 1976-82 (Spendelow and Patton 1988), the percentages of the total U.S. populations of Laughing Gull (11%), Forster's Tern (52%), Royal Tern (16%), Sandwich Tern (77%), and Black Skimmer (44%) which annually nest in Louisiana are significant – perhaps crucially so in the cases of Forster's Tern, Sandwich Tern, and Black Skimmer. Nearly three decades after Spendelow and Patton's determinations above, coastal Louisiana still stands out as the major center of colonial wading bird and seabird nesting in all of the United States. Within those three intervening decades, however, the collective habitats which comprise Louisiana's now fragile coastal zone have taken major hits from commercial/residential, oil & gas, and other industrial development, primarily in the form of coastal erosion exacerbated by these and other factors (Portnoy 1978, Spendelow and Patton 1988, Martin and Lester 1990, Green, et al. 2006). Moreover, during this same period, both geologic subsidence rates (Tornqvist et al. 2008) and mean sea-level (Tornqvist et al. 2002) have increased, along with significant tropical storm activity; all of which have combined to impact available marsh, barrier island, beach, and dredge spoil nesting habitat for waterbirds, especially seabirds, throughout the coastal zone of Louisiana. The primary objective of this publication is to detail those coastal Louisiana colonial seabird nesting sites for which we have reasonably accurate data, in a tabular, site-by-site format. All major survey (1976-2008) data of site-by-site seabird species counts, as well as several smaller data sets, referred to in the site history tables as “miscellaneous observations” obtained during the May-June seabird breeding period, are included. It is our hope that these data will provide a dependable foundation from which future colonial seabird nesting surveys might be planned and carried out, as well as showcase the importance of coastal Louisiana's seabird rookeries, and contribute to their conservation.

Louisiana↗

USGS1970

Aspects of oil and gas operations on federal and Indian lands of interest to engineers

It is always enjoyable to attend any meeting of the Society of Petroleum Engineers. I am happy to have this opportunity to speak to you because I believe that petroleum engineers can benefit from a better understanding of the Mineral Leasing Act and the regulations that implement the act insofar as these affect or influence your work. The regulations that implement the leasing act are commonly known as the Oil and Gas Operating Regulations. These regulations are officially described as Part 221 of Title 30 of the Code of Federal Regulations. They are printed in a small green booklet which most printed in a small green booklet which most of you have probably seen at one time or other. The requirements of the operating regulations, as specifically set forth in the booklet, or as determined by policy judgments in our various offices, can affect some aspects of your work. I think it would be appropriate first to discuss the two types of lands, Federal lands and Indian lands, which are subject to the Oil and Gas Operating Regulations. Federal lands generally are classified in two categories, acquired land and public domain lands. Acquired lands are lands to which the Federal Government obtained title by purchase, exchange, condemnation, or private gift. These lands are scattered private gift. These lands are scattered throughout the United States and total about 54 million acres, or about 7.5 percent of the area classified as public percent of the area classified as public lands. The public domain lands are lands to which the United States has held title since their original acquisition. There are public lands in 30 states, but the large bulk of the lands are located in Alaska and the Western States. You may recall from your history courses some of the purchases and treaties by which the United States obtained most of the lands now described as public domain lands. The Louisiana Purchase in 1803 included among the Western States most of Montana, eastern and central Wyoming, northeast Colorado, and the northern part of Texas. This treaty also included a large part of the area now generally referred to as The "Midwest". The annexation of Texas occurred in 1845 and it is somewhat surprising to realize that this included, among other lands, a strip of land through western Colorado and a rectangular shaped piece of land in Wyoming, south of Rawlins piece of land in Wyoming, south of Rawlins The acquisition of the Oregon Territory in 1846 brought into the Union parts of western Wyoming and Montana as well as what is now Idaho, Oregon, and Washington.

Colorado, Idaho, Montana, North Dakota, South Dako↗

USGS2013

Detection of salt marsh vegetation stress and recovery after the Deepwater Horizon Oil Spill in Barataria Bay, Gulf of Mexico using AVIRIS data

The British Petroleum Deepwater Horizon Oil Spill in the Gulf of Mexico was the biggest oil spill in US history. To assess the impact of the oil spill on the saltmarsh plant community, we examined Advanced Visible Infrared Imaging Spectrometer (AVIRIS) data flown over Barataria Bay, Louisiana in September 2010 and August 2011. Oil contamination was mapped using oil absorption features in pixel spectra and used to examine impact of oil along the oiled shorelines. Results showed that vegetation stress was restricted to the tidal zone extending 14 m inland from the shoreline in September 2010. Four indexes of plant stress and three indexes of canopy water content all consistently showed that stress was highest in pixels next to the shoreline and decreased with increasing distance from the shoreline. Index values along the oiled shoreline were significantly lower than those along the oil-free shoreline. Regression of index values with respect to distance from oil showed that in 2011, index values were no longer correlated with proximity to oil suggesting that the marsh was on its way to recovery. Change detection between the two dates showed that areas denuded of vegetation after the oil impact experienced varying degrees of re-vegetation in the following year. This recovery was poorest in the first three pixels adjacent to the shoreline. This study illustrates the usefulness of high spatial resolution airborne imaging spectroscopy to map actual locations where oil from the spill reached the shore and then to assess its impacts on the plant community. We demonstrate that post-oiling trends in terms of plant health and mortality could be detected and monitored, including recovery of these saltmarsh meadows one year after the oil spill.

Louisiana↗

USGS2023

Site occupancy of focal shorebird species at Whiskey Island and Caminada Headland, Louisiana 2012–2020

Coastal restoration through island construction and augmentation is an increasingly common management method in the northern Gulf of Mexico, but evaluating the impacts to shorebird species is difficult. Shorebirds are mostly migratory and many aspects of their life history, including reproduction in some species, occur in other places. In addition, counts or observations of shorebirds made at any given time represent only a portion of the population and that proportion may change with site conditions such as time of day and weather. Dynamic occupancy models can account for imperfect detection and produce estimates of the proportion of area occupied over time as a way to track trends in bird utilization over time. In this chapter we report on occupancy trends for five focal shorebird species from Caminada Headland and Whiskey Island: American Oystercatcher ( Haematopus palliatus ), Piping Plover ( Charadrius melodus ), Red Knot ( Calidris canutus ), Snowy Plover ( Charadrius nivosus ), and Wilson’s Plover ( Charadrius wilsonia ). We examined up to nine years of surveys at the two sites to model long-term trends in occupancy rates from a period spanning before, during, and after restoration. Our objective was to determine if there was change in occupancy over time (trend) during the restoration period. Field sampling was conducted as described in Chapter 1 for the five focal species in this chapter. To create spatial units for occupancy analysis we used a grid of 53 unique cells at Caminada Headland and 26 unique cells at Whiskey Island. All observations of the species were located into spatial units using GIS and presence of each species in each cell was determined for each visit within a sampling season. Sampling seasons were defined for species as the period of time where they were most likely to be using the study area, and corresponded with wintering (August–May), breeding (April–August), or staging (March–October). We did not include covariates for initial occupancy or colonization and site survival because these were small sites with homogenous habitat. We did account for time of year within a season by treating survey date as a covariate of detection probability and allowed it to vary throughout the season. We tested for a trend in occupancy over time by determining if the estimated slope through the series of annual occupancy estimates was significantly different from 0. We conducted 153 total surveys at Caminada Headland from 11 January 2013 to 5 June 2019, and 213 total surveys at Whiskey Island from 7 August 2012 to 19 August 2020. The number of surveys per year varied by species and site and range from 6–23 per species annually at Caminada Headland and 11–28 per species annually at Whiskey Island. Occupancy trends were able to be assessed for all species at both sites, with the exception of the American Oystercatcher, which were only observed in sufficient numbers to estimate occupancy at Whiskey Island. We found a significant positive trend in occupancy from 0.325 to 0.741 for American Oystercatcher at Whiskey Island. There was no significant trend in Piping Plover occupancy at Caminada Headland where occupancy was consistently high (0.910 to 0.947). At Whiskey Island, Piping Plover occupancy estimates increased from 0.574 to 0.908 during the study period which was a significant increase. At Caminada Headland and Whiskey Island Red Knot occupancy varied from 0.482 to 0.891 and 0.350 to 0.742, respectively, but showed no significant trend over the study period. Snowy Plover occupancy at Caminada Headland increased significantly from 0.295 to 0.785 over the study period. Snowy Plover occupancy also increased significantly at Whiskey Island from 0.442 to 0.906. Wilson’s Plover occupancy declined slightly during the study period from 0.946 to 0.935 at Caminada Headland, and from 0.858 to 0.736 at Whiskey Island, but the decline was not significant at either site. We found no evidence that occupancy declined significantly for any of the species during the period prior to, during, and after restoration. We did find a significant increasing trend in occupancy for Snowy Plover at Caminada Headland and a significant increasing trend for American Oystercatcher, Piping Plover, and Snowy Plover at Whiskey Island. Our modeling results indicate that sampling such as this is sufficient for occupancy modeling and can provide a robust metric for comparison over time or among sites. In future research we plan to investigate the sample size needed to detect a trend. We are currently conducting a power analysis to determine the minimum amount of sampling necessary to have power to detect a trend based on the detection probabilities from this study.

Report↗

USGS2012

Variation in reproductive life history traits between two populations of Blackbanded Darters (Percina nigrofasciata)

We examined the life history of Blackbanded Darters (Percina nigrofasciata) from two streams in the Choctawhatchee River drainage, Florida, over a three-year study period. Blackbanded Darters from Turkey Creek were longer than fish from Ten Mile Creek; however, size-adjusted clutch and egg sizes were similar between populations. Larger females produced larger clutches, whereas egg size did not vary with female body size. Seasonally, clutch sizes were greater in May than in August. When contrasted with previous studies of Blackbanded Darters in Alabama and Louisiana, the reproductive season of Blackbanded Darters in Florida was unusually long, ceasing for only a few months in late fall. The reproductive season was longer in Turkey Creek than in Ten Mile Creek. Differences in thermal regime among streams may explain differences in life history traits among local and distant populations of Blackbanded Darters. This research, alone and in combination with previous studies of this species, emphasizes two main points. First, it reaffirms that life history studies based on a single locality or conducted at a single point in time may fail to capture the full range of variation in life history traits. Second, it highlights the extensive phenotypic variation found in species with broad geographic ranges. Such species lend themselves to comparative and experimental research on patterns and causes of life history variation.

Copeia↗

USGS2016

Inference of population structure and demographic history in Taxodium distichum , a coniferous tree in North America, based on amplicon sequence analysis

PREMISE OF THE STUDY: Studies of natural genetic variation can elucidate the genetic basis of phenotypic variation and the past population structure of species. Our study species, Taxodium distichum , is a unique conifer that inhabits the flood plains and swamps of North America. Morphological and ecological differences in two varieties, T. distichum var. distichum (bald cypress) and T. distichum var. imbricarium (pond cypress), are well known, but little is known about the level of genetic differentiation between the varieties and the demographic history of local populations. METHODS: We analyzed nucleotide polymorphisms at 47 nuclear loci from 96 individuals collected from the Mississippi River Alluvial Valley (MRAV), and Gulf Coastal populations in Texas, Louisiana, and Florida using high-throughput DNA sequencing. Standard population genetic statistics were calculated, and demographic parameters were estimated using a composite-likelihood approach. KEY RESULTS: Taxodium distichum in North America can be divided into at least three genetic groups, bald cypress in the MRAV and Texas, bald cypress in Florida, and pond cypress in Florida. The levels of genetic differentiation among the groups were low but significant. Several loci showed the signatures of positive selection, which might be responsible for local adaptation or varietal differentiation. CONCLUSIONS: Bald cypress was genetically differentiated into two geographical groups, and the boundary was located between the MRAV and Florida. This differentiation could be explained by population expansion from east to west. Despite the overlap of the two varieties’ ranges, they were genetically differentiated in Florida. The estimated demographic parameters suggested that pond cypress split from bald cypress during the late Miocene.

American Journal of Botany↗

USGS1941

Attwater's prairie-chicken-its life history and management

Attwater's prairie chicken, a characteristic bird of the Texas coastal prairie, is closely related to the now extinct heath-hen of northeastern North America. Once abundant in an area extending from the coastal tall-grass prairies of southwestern Louisiana and Texas west and south to near Port Isabel, it has decreased in numbers as man has exploited its habitat, until now it is threatened with the same fate as that of the heath-hen. Important factors limiting the numbers of the bird include excessive or persistent rainfall during the nesting season, heavy grazing, excessive pasture burning, agricultural operations, and overshooting. Management will usually involve protection from excessive killing, improvement of food and cover, and control of predators and of the kill by hunters. Responsibility for this rests with the landowner. Optimum prairie chicken range apparently consists of well-drained grassland, with some weeds or shrubs, the cover varying in density from light to heavy; and with surface water available in summer; diversification within the grassland type is essential. In the absence of ample refuges for the species, probably all other favorable factors together will fail to save Attwater's prairie chicken from extinction. This number continues the series of the North American Fauna issued by the Bureau of Biological Survey, of the United States Department of Agriculture, prior to its transfer and consolidation with the Bureau of Fisheries on June 30, 1940, to form the Fish and Wildlife Service, in the Department of the Interior.

North American Fauna↗

USGS2022

Long-term assessments are critical to determining persistence and shoreline protection from oyster reef nature-based coastal defenses

Nature-based coastal defense using bivalve reefs provides a potentially self-sustaining approach for regions facing high coastal land loss, relative sea level rise and increasing frequency and intensity of storms. Success of such nature-based coastal defense depends on the reef-building species' life history, habitat requirements, and ability to thrive through short-term and longer-term environmental variation, yet few projects have reported on outcomes beyond the first few years. In coastal Louisiana, USA, Crassostrea virginica (oyster) is an ecosystem engineer, creating self-sustaining, vertically accreting reefs that also provide ecosystem services. Here, we examine the short (< 3 years) and medium (> 10 years) term outcomes of experimental reefs constructed in 2009 for nature-based coastal defense in a Louisiana, USA estuarine lake. Oyster reef density, demography, along with adjacent salt marsh, and shoreline movement were compared at six fringing shoreline reefs and paired reference sites over the first three years post-construction (2009–2011), and a decade later (2019–2020). Oyster density measured in 2019–2020 (< 60 ind m −2 ) was less than 10% of density measured during 2009–2011 (> 1000 ind m −2 ). This density difference largely reflected a lack of new recruits and small oysters (< 75 mm shell height) in later samples, with adult oyster densities similar between 2011, 2019 and 2020. Lack of smaller oysters in recent sampling likely reflected the impact of multiple extended low salinity events in this region in recent years, including the record-breaking low salinity in 2019. No differences in shoreline characteristics were detected in marsh vegetation, soil properties or nutrient concentrations between reef and reference sites during early and later years. Similarly, shoreline erosion at both reef and reference sites immediately post-construction, and 10 years later, was high (~1 m y −1 ) indicating a lack of shoreline protection from these reefs. These findings highlight the need to consider both current and future conditions, including the effect of extreme years, when implementing nature-based coastal defense. On the other hand, the persistence of reproductive-sized oysters on the reef 10 years post creation, indicate reef resilience and potential for reef development and shoreline benefits, should better site conditions return in future years. Determining restoration success within variable and dynamic environments requires frequent monitoring which is required to understand responses to short and longer-term environmental variation.

Louisiana↗

USGS2016

Osteopilus septentrionalis (Cuban treefrog)

USA: LOUISIANA: St. Tammany Parish: on private property on Allen Road in Slidell (ca. 30.262°N, 89.741°W; WGS 84). 2 April 2013. Aaron Steece. Verified by Hardin Waddle. Florida Museum of Natural History (UF 177727, photo voucher). New parish record. This adult was found ca. 2 m high on a branch at the edge of a wooded area behind a house. It was photographed and released, as the species identity and significance was unknown. The origin of this individual is unknown. The homeowner stated that he bought nursery plants often, but checked them thoroughly as he put them indoors. Since this initial finding, the homeowner learned more about Cuban Treefrogs and searched for them on many occasions at this location for two years, but detected no additional Cuban Treefrogs.

Louisiana↗

USGS2016

Fishes in paleochannels of the Lower Mississippi River alluvial valley: A national treasure

Fluvial geomorphology of the alluvial valley of the Lower Mississippi River reveals a fascinating history. A prominent occupant of the valley was the Ohio River, estimated to have flowed 25,000 years ago over western Tennessee and Mississippi to join the Mississippi River north of Baton Rouge, Louisiana, 750–800 km south of the present confluence. Over time, shifts in the Mississippi and Ohio rivers toward their contemporary positions have left a legacy of abandoned paleochannels supportive of unique fish assemblages. Relative to channels abandoned in the last 500 years, paleochannels exhibit harsher environmental conditions characteristic of hypereutrophic lakes and support tolerant fish assemblages. Considering their ecological, geological, and historical importance, coupled with their primordial scenery, the hundreds of paleochannels in the valley represent a national treasure. Altogether, these waterscapes are endangered by human activities and would benefit from the conservation attention afforded to our national parks and wildlife refuges.

Lower Mississippi River valley↗

USGS2014

The potential for sea-level-rise-induced barrier island loss: Insights from the Chandeleur Islands, Louisiana, USA

As sea level rises and hurricanes become more intense, barrier islands around the world become increasingly vulnerable to conversion from self-sustaining migrating landforms to submerging or subaqueous sand bodies. To explore the mechanism by which such state changes occur and to assess the factors leading to island disintegration, we develop a suite of numerical simulations for the Chandeleur Islands in Louisiana, U.S.A., which appear to be on the verge of this transition. Our results suggest that the Chandeleurs are likely poised to change state, leading to their demise, within decades depending on future storm history. Contributing factors include high rates of relative sea level rise, limited sediment supply, muddy substrate, current island position relative to former Mississippi River distributary channels, and the effects of changes in island morphology on sediment transport pathways. Although deltaic barrier islands are most sensitive to disintegration because of their muddy substrate, the importance of relative sea level rise rate in determining the timing of threshold crossing suggests that the conceptual models for deltaic barrier island formation and disintegration may apply more broadly in the future.

Louisiana, Mississippi↗

USGS2014

Screening native botanicals for bioactivity: an interdisciplinary approach

Objective: Plant-based therapies have been used in medicine throughout recorded history. Information about the therapeutic properties of plants often can be found in local cultures as folk medicine is communicated from one generation to the next. The aim of this study was to identify native Louisiana plants from Creole folk medicine as a potential source of therapeutic compounds for the treatment of insulin resistance, type 2 diabetes, and related disorders. Methods: We used an interdisciplinary approach combining expertise in disciplines ranging from cultural anthropology and botany to biochemistry and endocrinology to screen native southwest Louisiana plants. Translation of accounts of Creole folk medicine yielded a list of plants with documented use in treating a variety of conditions, including inflammation. These plants were collected, vouchered, and catalogued before extraction of soluble components. Extracts were analyzed for bioactivity in regulating inflammatory responses in macrophages or fatty acid–induced insulin resistance in C2C12 skeletal muscle cells. Results: Several extracts altered gene expression of inflammatory markers in macrophages. Multiplex analysis of kinase activation in insulin-signaling pathways in skeletal muscle also identified a subset of extracts that alter insulin-stimulated protein kinase B phosphorylation in the presence of fatty-acid–induced insulin resistance. Conclusion: An interdisciplinary approach to screening botanical sources of therapeutic agents can be successfully applied to identify native plants used in folk medicine as potential sources of therapeutic agents in treating insulin resistance in skeletal muscle or inflammatory processes associated with obesity-related insulin resistance.

Louisiana↗