Publications

Pressure transducers (sensors) are accurate, reliable, and cost-effective tools to measure and record the magnitude, extent, and timing of hurricane storm surge. Sensors record storm-surge peaks more accurately and reliably than do high-water marks. Data collected by sensors may be used in storm-surge models to estimate when, where, and to what degree stormsurge flooding will occur...

Over the past century, seagrass habitats from the bays of Texas to the gulf shores of Florida have decreased. Seagrass beds, which are highly dependent on water quality and clarity for survival, are home to a multitude of aquatic plants and animals and a source of economic activity through commercial and recreational fishing and ecotourism. The U.S. Environmental Protection Agency’s Gulf...

Aim The long-term stability of coastal ecosystems such as mangroves and salt marshes depends upon the maintenance of soil elevations within the intertidal habitat as sea level changes. We examined the rates and processes of peat formation by mangroves of the Caribbean Region to better understand biological controls on habitat stability. Location Mangrove-dominated islands on the...

In 2001, the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey began a series of studies on the transport of anthropogenic and natural contaminants (TANC) to public-supply wells. The main goal of the TANC program was to better understand the source, transport, and receptor factors that control contaminant movement to public-supply wells in representative...

The U.S. Geological Survey, in cooperation with the Texas Water Development Board, used surface geophysical methods at the Texas A&M University Brazos River Hydrologic Field Research Site near College Station, Texas, in a pilot study, to characterize the hydrostratigraphic properties of the Brazos River alluvium aquifer and determine the effectiveness of the methods to aid in generating...

Hurricane Katrina caused extreme changes to the barrier islands of the central Gulf of Mexico coast. Dauphin Island, Ala., migrated landward and stranded the remains of its oceanfront row homes in the sea. Chandeleur Islands, La., were completely stripped of their sand, leaving only marshy outcrops in the storm's wake.

Microbially catalyzed cleavage of the imadazole ring of caffeine was observed in stream sediments collected upstream and downstream of municipal wastewater treatment plants (WWTP) in three geographically separate stream systems. Microbial demethylation of the N-methyl component of cotinine and its metabolic precursor, nicotine, also was observed in these sediments. These findings...

Hyperammonemia, arising from variety of disorders, leads to severe neurological dysfunction. The mechanisms of ammonia toxicity in brain are not completely understood. This study investigated the effects of ammonia on monoaminergic systems in brains of fathead minnows (Pimephales promelas). Fish serve as a good model system to investigate hyperammonemic effects on brain function since no...

The western burrowing owl (Athene cunicularia hypugaea) is threatened in Mexico, endangered in Canada, and declining in most of the western United States. Most previous research has focused on burrowing owl breeding biology, and little is known about its winter ecology. We determined characteristics of roost sites used by western burrowing owls in southern Texas during winter. Data on 46...

The genetically unique population of muskellunge Esox masquinongy inhabiting Shoepack Lake in Voyageurs National Park, Minnesota, is potentially at risk for loss of genetic variability and long-term viability. Shoepack Lake has been subject to dramatic surface area changes from the construction of an outlet dam by beavers Castor canadensis and its subsequent failure. We simulated the...

The occurrence of hurricane landfalls on the United States may be related to alternating intervals of persistent above-average and below-average surface temperature of the North Atlantic Ocean. The cycle of temperature variations, known as the Atlantic Multidecadal Oscillation (AMO), has been identified by study of records based on thermometer readings that go back to the late 1800s...

Sturgeon use benthic habitats in and adjacent to main channels where environmental conditions can include bedload sediment transport and high near-bed flow velocities. Bed velocity measurements obtained with acoustic Doppler instruments provide a means to assess the concentration and velocity of sediment moving near the streambed, and are thus indicative of the bedload sediment transport...