Publications

Two main sources of data for species distribution models (SDMs) are site-occupancy (SO) data from planned surveys, and presence-background (PB) data from opportunistic surveys and other sources. SO surveys give high quality data about presences and absences of the species in a particular area. However, due to their high cost, they often cover a smaller area relative to PB data, and are...

Surface water from 38 streams nationwide was assessed using 14 target-organic methods (719 compounds). Designed-bioactive anthropogenic contaminants (biocides, pharmaceuticals) comprised 57% of 406 organics detected at least once. The 10 most-frequently detected anthropogenic-organics included eight pesticides (desulfinylfipronil, AMPA, chlorpyrifos, dieldrin, metolachlor, atrazine, CIAT

No abstract available.

In vitro bioassays are sensitive, effect-based tools used to quantitatively screen for chemicals with nuclear receptor activity in environmental samples. We measured in vitro estrogen (ER), androgen (AR), and glucocorticoid receptor (GR) activity, along with a broad suite of chemical analytes, in streamwater from 35 well-characterized sites (3 reference and 32 impacted) across 24 states...

Scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center collected a set of 8 sediment cores from the back-barrier environments along the northern Chandeleur Islands, Louisiana, in March 2012. The sampling efforts were part of a larger USGS study to evaluate effects on the geomorphology of the Chandeleur Islands following the construction of an...

Conservation of imperiled species is frequently challenged by insufficient knowledge of life history and environmental factors that affect various life stages. The larvae (glochidia) of most freshwater mussels in the family Unionidae are obligate ectoparasites of fishes. We described the early life history of the federally endangered Southern Kidneyshell Ptychobranchus jonesi and...

Theories linking diversity to ecosystem function have been challenged by the widespread observation of more exotic species in more diverse native communities. Few studies have addressed the underlying processes by dissecting how biotic resistance to new invaders may be shaped by the same environmental influences that determine diversity and other community properties. In grasslands with

Introduction Topographic elevation data collected with airborne light detection and ranging (lidar) can be used to analyze short- and long-term changes to beach and dune systems. Analysis of multiple lidar datasets at Dauphin Island, Alabama, revealed systematic, island-wide elevation differences on the order of 10s of centimeters (cm) that were not attributable to real-world change and...

Belize contains important habitat for Antillean manatees (Trichechus manatus manatus) and provides refuge for the highest known population density of this subspecies. As these animals face impending threats, knowledge of their dietary habits can be used to interpret resource utilization. The contents of 13 mouth, 6 digestive tract (stomach, duodenum and colon), and 124 fecal samples were

The southeastern United States is home to a diverse assemblage of snakes, but only one species, the Rough Greensnake (Opheodrys aestivus), is considered specialized for a predominantly arboreal lifestyle. Other species, such as Ratsnakes (genus Pantherophis) and Ribbonsnakes/Gartersnakes (genus Thamnophis), are widely known to climb into vegetation and trees. Some explanations given for...

We present a quantitative analysis of habitat availability in a highly regulated lowland river, comparing a restored reach with two reference reaches: an un-restored, channelized reach, and a least-altered reach. We evaluate the effects of channel modifications in terms of distributions of depth and velocity as well as distributions and availability of habitats thought to be supportive...

Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series...