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Full-Text Articles in Natural Resources Management and Policy
Prey Depletion By Odonate Larvae: Combining Evidence From Multiple Field Experiments, Clay L. Pierce, Dan M. Johnson, Thomas H. Martin, Charles N. Watson, Robert E. Bohanan, Philip H. Crowley
Prey Depletion By Odonate Larvae: Combining Evidence From Multiple Field Experiments, Clay L. Pierce, Dan M. Johnson, Thomas H. Martin, Charles N. Watson, Robert E. Bohanan, Philip H. Crowley
Clay L. Pierce
In this paper we re-analyze previously published data regarding the response of several prey populations to manipulation of predaceous larval dragonfly (Insecta: Odonata) densities in four separate field enclosure experiments. Using a computer-intensive "rerandomization" approach to testing hypotheses, we show that the individual experiments were not sufficiently powerful to consistently reject false null hypotheses. Combining the data from three comparable experiments, we can enhance the power associated with such tests. Three prey categories (Trichoptera, Oligochaeta, and large Cladocera), constituting less than one-third of the typical odonate diet, were found to be consistently depleted in enclosures with odonate larvae; but the …
Fish Acute Toxicity Syndromes And Their Use In The Qsar Approach To Hazard Assessment, Steven P. Bradbury, James M. Mckim, Gerald J. Niemi
Fish Acute Toxicity Syndromes And Their Use In The Qsar Approach To Hazard Assessment, Steven P. Bradbury, James M. Mckim, Gerald J. Niemi
Steven P. Bradbury
Implementation of the Toxic Substances Control Act of 1977 creates the need to reliably establish testing priorities because laboratory resources are limited and the number of industrial chemicals requiring evaluation is overwhelming. The use of quantitative structure activity relationship (QSAR) models as rapid and predictive screening tools to select more potentially hazardous chemicals for in-depth laboratory evaluation has been proposed. Further implementation and refinement of quantitative structure-toxicity relationships in aquatic toxicology and hazard assessment requires the development of a "mode-of-action" database. With such a database, a qualitative structure-activity relationship can be formulated to assign the proper mode of action, and …
Physiological Response Of Rainbow Trout (Salmo Gairdneri) To Acute Fenvalerate Lntoxication, Steven P. Bradbury, James M. Mckim, Joel R. Coats
Physiological Response Of Rainbow Trout (Salmo Gairdneri) To Acute Fenvalerate Lntoxication, Steven P. Bradbury, James M. Mckim, Joel R. Coats
Steven P. Bradbury
The physiological responses of rainbow trout (Salmo gairdneri) to fenvalerate intoxication during aqueous exposure were examined to provide information about the pyrethroid mode of action in fish. Trout (n = 4) were exposed to 412 ± 50 μg/liter fenvalerate and died in 10.9 ± 1.5 hr. Brain, liver, and carcass fenvalerate concentrations associated with mortality were 0.16 ± 0.05, 3.62 ± 0.57, and 0.25 ± 0.05 mg/kg, respectively. Visible signs of intoxication included elevated cough rate, tremors, and seizures. Histopathological examination of gill tissue showed damage consistent with irritation. An evaluation of respiratory-cardiovascular and blood chemistry responses indicated an elevated …
Estimating The Value Of Water Quality Improvements In A Recreational Demand Framework, Nancy E. Bockstael, Catherine Kling, W. Michael Hanemann
Estimating The Value Of Water Quality Improvements In A Recreational Demand Framework, Nancy E. Bockstael, Catherine Kling, W. Michael Hanemann
Catherine Kling
With the advent of Executive Order 12291, policymakers involved in water quality regulation are increasingly interested in assessing the benefits of their programs. Several methods for valuing water quality improvements using recreational demand models have been developed by economists, most of which depend on observing recreationists visiting an array of sites with varying water quality and costs of access. In this paper, three general types of models are described: systems of demands, discrete choice models, and the hedonic travel cost approach; the latter two models are demonstrated using a common data set on water quality and swimming behavior in the …