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With the push for energy independence and fuels that emit fewer greenhouse gases, domestically produced natural gas has been growing in popularity. But alongside this growth have come concerns that hydraulic fracturing (“fracking”), a procedure used in the extraction of natural gas and oil, may pollute ground and surface waters. Responding to increasing public pressure for federal action and a call by the U.S. House of Representatives Appropriations Conference Committee, the U.S. Environmental Protection Agency (EPA) announced 18 March 2010 it will conduct a comprehensive study to investigate the potential adverse effects of fracking on water quality and public health
Classifying Stream Reaches in Hawaii based on Ecological Potential Besides influences of human landscape factors on stream organisms, many “natural” landscape factors also affect distributions and abundances of species found in different stream habitats. To account for those influences, we used an analytical approach to create groupings of perennial stream reaches with similar natural landscape characteristics that were found to be influential to distributions of nine native stream taxa including fish, shrimp, and snails (Table 2). This approach, referred to as classification, is driven by relationships between natural landscape factors and stream organisms and does not account for influences of anthropogenic factors....
Tags: 2015, Hawaii, Method
The cumulative disturbance index for estuaries included information from each of the variables investigated, combining information on land use, river flow, pollution, and eutrophication. Although these represent many of the major sources of disturbance to estuary habitats, data on some habitat stressors was not available for analysis and will likely cause instances where condition is overestimated. The reader should keep this limitation in mind when examining the information in this assessment. Similarly, information on localized disturbance or mitigation is not available on a national scale and could not be included. Therefore, the results of this assessment represent conservative estimates of the relative level...
Identifying Disturbances to Fish Habitat Multi-stressor models were used to identify the most important disturbance factors for Gulf estuaries. For each species, the significant stressors identified in the screening models, along with the event-level variables (temperature, salinity, distance to shore) were combined using a backward selection process to develop a final model for each individual fish species. Backward selection eliminates variables in a stepwise fashion based on statistical significance, until only highly significant (95% confidence level) predictors are left in the model. Once final model configurations for each species were complete, they were used to measure anthropogenic disturbance levels...
With the push for energy independence and fuels that emit fewer greenhouse gases, domestically produced natural gas has been growing in popularity. But alongside this growth have come concerns that hydraulic fracturing (“fracking”), a procedure used in the extraction of natural gas and oil, may pollute ground and surface waters. Responding to increasing public pressure for federal action and a call by the U.S. House of Representatives Appropriations Conference Committee, the U.S. Environmental Protection Agency (EPA) announced 18 March 2010 it will conduct a comprehensive study to investigate the potential adverse effects of fracking on water quality and public health
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Assembling Predictor Data Predictor data variables include both anthropogenic stressors and natural variables that can affect the susceptibility of estuaries to pollutants and other stressors. Predictors for this assessment were measured at two different scales in space and time: “event-level” and “estuary-level”. Event-level data were recorded at the specific times and locations of individual fish trawls and include variables like water temperature, salinity, and location (i.e. distance to shore). Estuary-level data refers to values averaged at the estuary level. Estuary-level variables include a range of anthropogenic stressors (e.g. nutrient loadings, toxic releases, land use, and population characteristics),...
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Integrating Data into the Spatial Framework This assessment investigated the effects of anthropogenic stressors on 220 estuaries in the conterminous U.S. The nested spatial framework, identical to the one used in 2010, was used to assemble and analyze spatial habitat data. The framework defined four units (see Figure 7) to analyze human effects on estuaries: Estuaries: Range from relatively small river mouths (e.g. Carmel River Mouth) to large bays (e.g. San Antonio Bay), and also include some very large and complex estuary systems (e.g. Chesapeake Bay) as well as deep inland seas (e.g. Puget Sound). Estuaries are delineated as distinct units except for very large systems with many tidal tributaries, which are...