Browsing by Subject "baseline"

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    BASELINE GROUNDWATER QUALITY TESTING NEEDS IN THE EAGLE FORD SHALE REGION
    (2012-04-27) Palacios, Virginia E.
    As the pace of drilling in the Eagle Ford shale increases, so does the potential for groundwater contamination incidents. The goals of this analysis are (1) to determine whether existing baseline groundwater quality data in the Eagle Ford shale region is adequate to provide a comparison to potential future contamination from oil and gas development and (2) to define an appropriate and cost-effective list of parameters that will aid in strategic planning of baseline ground water quality testing in the Eagle Ford shale region for the same goal. First, a list of potential testing parameters is defined using case studies of proposed groundwater contamination. Second, formation water chemistry in the Eagle Ford shale region is compared to groundwater chemistry in the counties of the Eagle Ford shale region to determine which chemical indicators demonstrate potential to consistently detect contamination. Third, statistical power analysis is used as a guideline to decide whether more samples are needed for each testing parameter in each county in the Eagle Ford shale region. Next, known health effects of each testing parameter are described in order to highlight potential pollutants that should be prioritized in a sampling initiative. Finally, testing costs are reported to introduce a perspective about microeconomic choices affecting which stakeholders take responsibility for baseline groundwater quality testing. These tasks led to the findings that some of the most dangerous potential pollutants, including methane, total petroleum hydrocarbons, nitrate, volatile organic compounds, polycyclic aromatic hydrocarbons, alpha particles, beta particles, and gamma radiation, are poorly characterized in the region, if at all. Furthermore, testing these parameters is more expensive than testing less hazardous ones. Water well owners may be unable to afford the expense of testing these parameters. Therefore, a testing initiative facilitated by agencies, industry, or other organizations may be more efficient at establishing a regional baseline for these high priority, expensive tests. As such, the framework and analysis presented here can be used by groundwater managers in the Eagle Ford shale region to develop baseline sampling strategies tailored to specific counties in the region.
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    Quantifying vocal response in experimental playbacks to Risso's dolphins
    (2014-04-23) Boucher, Aimee
    In a world of constant technological development and expansion into the marine environment, the marine soundscape is constantly changing. With the addition of anthropogenic sources from naval sonar to seismic survey vessels over the past century, the deficiency of knowledge on the impact of such acoustic disturbance leaves little guidance for effective regulation of anthropogenic marine noise pollution. To help address this, the U.S. Department of Defense’s Strategic Environmental Research and Development Program (SERDP) has teamed with multiple academic and scientific institutions to research and catalog the baseline behavioral ecology across a range of odontocete species, which can then serve as a baseline for additional research. This report examines a portion of that project, conducted to assess the response of Risso’s dolphin, Grampus griseus, to natural stimuli. During an August 2013 playback study off Southern California, acoustic data were collected via digital acoustic recording tags (DTAGs) to identify the vocal response of three Risso’s dolphins, Grampus griseus. The playbacks consisted of calls from three cetacean species: Megaptera novaeangliae, Orcinus orca, and Grampus griseus. To determine whether the vocal rate measurements could be reliably quantified, a repeatability experiment was conducted. Two playback studies (O. orca and G. griseus) were conducted on one animal, while three playbacks (O. orca, G. griseus, and M. novaeangliae) were presented to two animals. Only one of the tagged animals demonstrated a noteworthy response to the O. orca exposure, with more than a 500% increase in vocalizations after the playback. Vocal rate did not vary considerably in the tag with O. orca and G. griseus playbacks and the other tag resulted in roughly zero vocalizations during pre- and post-playbacks. Based on the small sample size, it appears that G. griseus response varies in the presence of a predator – with one tag demonstrating a dramatic increase of vocal rate when exposed to O. orca calls. These results are a necessary early step in gathering baseline information on the behavioral ecology of cetaceans susceptible to anthropogenic acoustic impact. A continuation of this project and further research is necessary to fully understand how marine mammals perceive and are impacted by human expansion into the marine soundscape.