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Publications

Read publications and other informational products to learn more about USGS science occurring in the Mississippi Basin.

Filter Total Items: 5565

A decade of insights into grassland ecosystem responses to global environmental change A decade of insights into grassland ecosystem responses to global environmental change

Earth’s biodiversity and carbon uptake by plants, or primary productivity, are intricately interlinked, underlie many essential ecosystem processes, and depend on the interplay among environmental factors, many of which are being changed by human activities. While ecological theory generalizes across taxa and environments, most empirical tests of factors controlling diversity and...
Authors
Elizabeth T. Borer, James B. Grace, W. Stanley Harpole, Andrew S. MacDougall, Eric W. Seabloom

Manatee grazing impacts on a mixed species seagrass bed Manatee grazing impacts on a mixed species seagrass bed

The endangered manatee Trichechus manatus is one of few large grazers in seagrass systems. To assess the long-term impacts of repeated grazing on seagrasses, we selected a study site within Kennedy Space Center in the northern Banana River, Brevard County, Florida, that was typically grazed by large numbers of manatees in spring. Two 13x13 m manatee exclosures and 2 paired open plots of...
Authors
Lynn W. Lefebvre, Jane A. Provancha, Daniel H. Slone, W. Judson Kenworthy

Demersal fish assemblages on seamounts and other rugged features in the northeastern Caribbean Demersal fish assemblages on seamounts and other rugged features in the northeastern Caribbean

Recent investigations of demersal fish communities in deepwater (>50 m) habitats have considerably increased our knowledge of the factors that influence the assemblage structure of fishes across mesophotic to deep-sea depths. While different habitat types influence deepwater fish distribution, whether different types of rugged seafloor features provide functionally equivalent habitat for...
Authors
Andrea M. Quattrini, Amanda W.J. Demopoulos, Randal Singer, Adela Roa-Varon, Jason D. Chaytor

Numerical modeling of the effects of Hurricane Sandy and potential future hurricanes on spatial patterns of salt marsh morphology in Jamaica Bay, New York City Numerical modeling of the effects of Hurricane Sandy and potential future hurricanes on spatial patterns of salt marsh morphology in Jamaica Bay, New York City

The salt marshes of Jamaica Bay, managed by the New York City Department of Parks & Recreation and the Gateway National Recreation Area of the National Park Service, serve as a recreational outlet for New York City residents, mitigate flooding, and provide habitat for critical wildlife species. Hurricanes and extra-tropical storms have been recognized as one of the critical drivers of...
Authors
Hongqing Wang, Q. Chen, Kelin Hu, Gregg A. Snedden, Ellen K. Hartig, Brady R. Couvillion, Cody L. Johnson, Philip M. Orton

Conservation genetics of American crocodile, Crocodylus acutus, populations in Pacific Costa Rica Conservation genetics of American crocodile, Crocodylus acutus, populations in Pacific Costa Rica

Maintaining genetic diversity is crucial for the survival and management of threatened and endangered species. In this study, we analyzed genetic diversity and population genetic structure at neutral loci in American crocodiles, Crocodylus acutus, from several areas (Parque Nacional Marino Las Baulas, Parque Nacional Santa Rosa, Parque Nacional Palo Verde, Rio Tarcoles, and Osa...
Authors
Laurie A. Mauger, Elizabeth Velez, Michael S. Cherkiss, Matthew L. Brien, Frank J. Mazzotti, James R. Spotila

Acute sensitivity of a broad range of freshwater mussels to chemicals with different modes of toxic action Acute sensitivity of a broad range of freshwater mussels to chemicals with different modes of toxic action

Freshwater mussels, one of the most imperiled groups of animals in the world, are generally underrepresented in toxicity databases used for the development of ambient water quality criteria and other environmental guidance values. Acute 96-h toxicity tests were conducted to evaluate the sensitivity of 5 species of juvenile mussels from 2 families and 4 tribes to 10 chemicals (ammonia...
Authors
Ning Wang, Chris D. Ivey, Christopher G. Ingersoll, William G. Brumbaugh, David Alvarez, Edward J. Hammer, Candice R. Bauer, Tom Augspurger, Sandy Raimondo, M.Christopher Barnhart

Relationships between salinity and short-term soil carbon accumulation rates form marsh types across a landscape in the Mississippi River Delta Relationships between salinity and short-term soil carbon accumulation rates form marsh types across a landscape in the Mississippi River Delta

Salinity alterations will likely change the plant and environmental characteristics in coastal marshes thereby influencing soil carbon accumulation rates. Coastal Louisiana marshes have been historically classified as fresh, intermediate, brackish, or saline based on resident plant community and position along a salinity gradient. Short-term total carbon accumulation rates were assessed...
Authors
Melissa M. Baustian, Camille L. Stagg, Carey L. Perry, Leland C Moss, Tim J. B. Carruthers, Mead Allison

Expert elicitation, uncertainty, and the value of information in controlling invasive species Expert elicitation, uncertainty, and the value of information in controlling invasive species

We illustrate the utility of expert elicitation, explicit recognition of uncertainty, and the value of information for directing management and research efforts for invasive species, using tegu lizards (Salvator merianae) in southern Florida as a case study. We posited a post-birth pulse, matrix model in which four age classes of tegus are recognized: hatchlings, 1 year-old, 2 year-olds...
Authors
Fred A. Johnson, Brian J. Smith, Mathieu Bonneau, Julien Martin, Christina Romagosa, Frank J. Mazzotti, J. Hardin Waddle, Robert Reed, Jennifer Kettevrlin Eckles, Laurie J. Vitt

Predicting the impacts of Mississippi River diversions and sea-level rise on spatial patterns of eastern oyster growth rate and production Predicting the impacts of Mississippi River diversions and sea-level rise on spatial patterns of eastern oyster growth rate and production

There remains much debate regarding the perceived tradeoffs of using freshwater and sediment diversions for coastal restoration in terms of balancing the need for wetland restoration versus preserving eastern oyster (Crassostrea virginica) production. Further complicating the issue, climate change-induced sea-level rise (SLR) and land subsidence are also expected to affect estuarine...
Authors
Hongqing Wang, Q. Chen, Megan La Peyre, Kelin Hu, Jerome F. La Peyre

Chronic toxicity of azoxystrobin to freshwater amphipods, midges, cladocerans, and mussels in water-only exposures Chronic toxicity of azoxystrobin to freshwater amphipods, midges, cladocerans, and mussels in water-only exposures

Understanding the effects of fungicides on nontarget organisms at realistic concentrations and exposure durations is vital for determining potential impacts on aquatic ecosystems. Environmental concentrations of the fungicide azoxystrobin have been reported up to 4.6 μg/L in the United States and 30 μg/L in Europe. The objective of the present study was to evaluate the chronic toxicity...
Authors
James L. Kunz, Christopher G. Ingersoll, Kelly L. Smalling, Adria Elskus, Kathryn Kuivila

Operational shoreline mapping with high spatial resolution radar and geographic processing Operational shoreline mapping with high spatial resolution radar and geographic processing

A comprehensive mapping technology was developed utilizing standard image processing and available GIS procedures to automate shoreline identification and mapping from 2 m synthetic aperture radar (SAR) HH amplitude data. The development used four NASA Uninhabited Aerial Vehicle SAR (UAVSAR) data collections between summer 2009 and 2012 and a fall 2012 collection of wetlands dominantly...
Authors
Amina Rangoonwala, Cathleen E Jones, Zhaohui Chi, Elijah W. Ramsey

Toxicity of chromium (VI) to two mussels and an amphipod in water-only exposures with or without a co-stressor of elevated temperature, zinc, or nitrate Toxicity of chromium (VI) to two mussels and an amphipod in water-only exposures with or without a co-stressor of elevated temperature, zinc, or nitrate

The objectives of the present study were to develop methods for propagating western pearlshell (Margaritifera falcata) for laboratory toxicity testing and evaluate acute and chronic toxicity of chromium VI [Cr(VI)] to the pearlshell and a commonly tested mussel (fatmucket, Lampsilis siliquoidea at 20 °C or in association with a co-stressor of elevated temperature (27 °C), zinc (50 µg Zn...
Authors
Ning Wang, James L. Kunz, Chris D. Ivey, Christopher G. Ingersoll, M. Christopher Barnhart, Elizabeth A. Glidewell
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