Basking Ecology of the Yellow-Blotched Sawback (Graptemys flavimaculata), an Imperiled Turtle Species of the Pascagoula River System, Mississippi, United States

2011 ◽  
Vol 10 (2) ◽  
pp. 188-197 ◽  
Author(s):  
Will Selman ◽  
Carl P. Qualls
Keyword(s):  
United States ◽  
River System ◽  
Turtle Species ◽  
Pascagoula River

Mitigating Impacts of Natural Hazards on Fishery Ecosystems

2008 ◽  
Keyword(s):  
United States ◽  
Hurricane Katrina ◽  
River System ◽  
Oxygen Depletion ◽  
Large River ◽  
Fish Kills ◽  
Subsistence Fisheries ◽  
Inland Fisheries ◽  
Stock Assessments ◽  
Fisheries Restoration

<em>Abstract</em>.—Extensive fish kills, primarily from dissolved oxygen depletion, were reported in rivers and associated backwaters throughout southern Mississippi following Hurricane Katrina. Of particular concern were fisheries associated with the Pascagoula River, the last physically unmodified large river system in the contiguous United States. Posthurricane stock assessments were conducted in 2006 to ascertain appropriate fisheries restoration actions for this internationally recognized natural resource. Emphasis focused on fishes that traditionally supported recreational, artisanal, and subsistence fisheries, primarily sunfish (Centrarchidae) and catfish (Ictaluridae). These fisheries were considered some of the more productive inland fisheries in the state prior to the storm.

International trade—WTO—quantitative restrictions—environmental protection—endangered species—U.S. import ban on shrimp

1999 ◽  
Vol 93 (2) ◽  
pp. 507-514 ◽  
Author(s):  
Bernard H. Oxman ◽  
Gregory Shaffer
Keyword(s):  
United States ◽  
International Trade ◽  
Endangered Species ◽  
Dispute Settlement ◽  
The United States ◽  
Turtle Species ◽  
Wild Fauna ◽  
Appellate Body ◽  
Wto Dispute Settlement ◽  
Gatt 1994

United States—Import Prohibition of Certain Shrimp and Shrimp Products.World Trade Organization, Appellate Body, October 12, 1998.In May 1996, the United States effectively prohibited imports of shrimp and shrimp products from all countries that do not require commercial shrimp trawlers to use turtle-excluder devices (TEDs) to permit endangered species of sea turtles to escape from trawling nets to avoid drowning. In January 1997, India, Malaysia, Pakistan and Thailand requested that the WTO Dispute Settlement Body establish a panel to determine whether this import ban, among other things, violates the prohibition on quantitative restrictions in Article XI of GATT (1994). The United States maintained that its import ban was permitted under the exceptions set forth in paragraphs (b) and (g) of GATT Article XX. Four turtle species that migrate in and out of waters subject to the complaining parties’ jurisdiction are listed as endangered under the Convention on International Trade in Endangered Species of Wild Fauna and Flora and are covered by the relevant U.S. regulation.

scholarly journals A constraint on post–6 Ma timing of western Grand Canyon (Arizona, USA) incision removed: Local derivation indicated by ca. 5.4 Ma fluvial deposits below Shivwits Plateau basalts north of Grand Canyon

Geosphere ◽  
2021 ◽  
Author(s):  
A.T. Steelquist ◽  
G.E. Hilley ◽  
I. Lucchitta ◽  
R.A. Young
Keyword(s):  
United States ◽  
Detrital Zircon ◽  
Colorado River ◽  
Landscape Evolution ◽  
Colorado Plateau ◽  
Grand Canyon ◽  
River System ◽  
Fluvial Deposits ◽  
Western Colorado ◽  
Rule Out

The timing of integration of the Colorado River system is central to understanding the landscape evolution of much of the southwestern United States. However, the time at which the Colorado River started incising the westernmost Grand Canyon (Arizona) is still an unsettled question, with conflicting interpretations of both geologic and thermochronologic data from western Grand Canyon. Fluvial gravels on the Shivwits Plateau, north of the canyon, have been reported to contain clasts derived from south of the modern canyon, suggesting the absence of western Grand Canyon at the time of their deposition. In this study, we reassess these deposits using modern geochronologic measurements to determine the age of the deposits and the presence or absence of clasts from south of the Grand Canyon. We could not identify southerly derived clasts, so cannot rule out the existence of a major topographic barrier such as Grand Canyon prior to the age of deposition of the gravels. 40Ar/39Ar analysis of a basalt clast entrained in the upper deposit (in combination with prior data) supports a maximum age of deposition of ca. 5.4 Ma, limiting deposition to post-Miocene, a period from which very few diagnostic and dated fluvial deposits remain in the western Colorado Plateau. Analysis of detrital zircon composition of the sand matrix supports interpretation of the deposit as being locally derived and not part of a major throughgoing river. We suggest that the published constraint of &lt;6 Ma timing of Grand Canyon incision may be removed, given that no clasts that must be sourced from south of Grand Canyon were found in the only known outcrop of gravels under the Shivwits Plateau basalts at Grassy Mountain north of Grand Canyon.

scholarly journals Salmonella genomics and population analyses reveal high inter- and intra- serovar diversity in freshwater

2021 ◽  
Author(s):  
Abigail M. Deaven ◽  
Christina M. Ferreira ◽  
Elizabeth A. Reed ◽  
Jeremy R. Chen See ◽  
Nora A. Lee ◽  
...  
Keyword(s):  
United States ◽  
River Basin ◽  
River Discharge ◽  
River System ◽  
The United States ◽  
Population Diversity ◽  
Foodborne Illness ◽  
Culture Methods ◽  
Susquehanna River ◽  
Susquehanna River Basin

Freshwater can support the survival of the enteric pathogen Salmonella, though temporal Salmonella diversity in a large watershed has not been assessed. At 28 locations within the Susquehanna River basin, 10-liter samples were assessed in spring and summer over two years. Salmonella prevalence was 49%, and increased river discharge was the main driver of Salmonella presence. The amplicon-based sequencing tool, CRISPR-SeroSeq, was used to determine serovar population diversity and detected 25 different Salmonella serovars, including up to ten serovars from a single water sample. On average there were three serovars per sample, and 80% of Salmonella-positive samples contained more than one serovar. Serovars Give, Typhimurium, Thompson, and Infantis were identified throughout the watershed and over multiple collections. Seasonal differences were evident: serovar Give was abundant in the spring, while serovar Infantis was more frequently identified in the summer. Eight of the ten serovars most commonly associated with human illness were detected in this study. Crucially, six of these serovars often existed in the background, where they were masked by a more abundant serovar(s) in a sample. Serovars Enteritidis and Typhimurium, especially, were masked in 71% and 78% of samples where they were detected, respectively. Whole genome sequencing-based phylogeny demonstrated that strains within the same serovar collected throughout the watershed were also very diverse. The Susquehanna River basin is the largest system where Salmonella prevalence and serovar diversity has been temporally and spatially investigated and this study reveals an extraordinary level of inter- and intra-serovar diversity. Importance Salmonella is a leading cause of bacterial foodborne illness in the United States, and outbreaks linked to fresh produce are increasing. Understanding Salmonella ecology in freshwater is of importance, especially where irrigation practices or recreational use occur. As the third largest river in the United States east of the Mississippi, the Susquehanna River is the largest freshwater contributor to the Chesapeake Bay, and the largest river system where Salmonella diversity has been studied. Rainfall, and subsequent high river discharge rates were the greatest indicator of Salmonella presence in the Susquehanna and its tributaries. Several Salmonella serovars were identified, including eight commonly associated with foodborne illness. Many clinically important serovars were present at a low frequency within individual samples so could not be detected by conventional culture methods. The technologies employed here reveal an average of three serovars in a 10-liter sample of water, and up to 10 serovars in a single sample.

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