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MacDonald D.D.,MacDonald Environmental science Ltd. | Moore D.R.J.,Intrinsik Environmental Sciences Inc. | Ingersoll C.G.,Columbia Environmental Research Center | Smorong D.E.,MacDonald Environmental science Ltd. | And 6 more authors.
Archives of Environmental Contamination and Toxicology | Year: 2011

A remedial investigation/feasibility study (RI/FS) of the Calcasieu Estuary cooperative site was initiated in 1998. This site, which is located in the southwestern portion of Louisiana in the vicinity of Lake Charles, includes the portion of the estuary from the saltwater barrier on the Calcasieu River to Moss Lake. As part of the RI/FS, a baseline ecological risk assessment (BERA) was conducted to assess the risks to aquatic organisms and aquatic-dependent wildlife exposed to environmental contaminants. The purpose of the BERA was to determine if adverse effects on ecological receptors are occurring in the estuary; to evaluate the nature, severity, and areal extent of any such effects; and to identify the substances that are causing or substantially contributing to effects on ecological receptors. This article describes the environmental setting and site history, identifies the chemicals of potential concern, presents the exposure scenarios and conceptual model for the site, and summarizes the assessment and measurement endpoints that were used in the investigation. Two additional articles in this series describe the results of an evaluation of effects-based sediment-quality guidelines as well as an assessment of risks to benthic invertebrates associated with exposure to contaminated sediment. © 2011 Springer Science+Business Media, LLC.


Hughes R.M.,Oregon State University | Amezcua F.,National Autonomous University of Mexico | Chambers D.M.,Center for Science in Public Participation | Daniel W.M.,Michigan State University | And 8 more authors.
Fisheries | Year: 2016

Following a four-year period of writing, member comment, and multiple revisions, the AFS Position Paper and Policy on Mining and Fossil Fuel Extraction was approved unanimously by the membership at the Society's annual business meeting August 19, 2015, in Portland, Oregon. The entire document can be read at fisheries.org/policy_statements; a brief summary follows. © 2016, American Fisheries Society.


Cott P.A.,Natural Resources Canada | Schein A.,MacDonald Environmental science Ltd. | Hanna B.W.,Wilfrid Laurier University | Johnston T.A.,Laurentian University | And 2 more authors.
Environmental Reviews | Year: 2015

Canada's Northwest Territories (NWT) is currently the focus of significant exploration and development activity. In particular, increased global demand for oil and gas resources has resulted in an escalation in the search for hydrocarbon deposits. Canada's north is a landscape defined by water where large numbers of pristine water bodies still exist in remote areas. Northern development activities conducted in these areas will affect these sensitive aquatic ecosystems that support important fish and fish habitat. Fishes in low productivity northern systems grow slowly and mature late, making them particularly sensitive to environmental perturbations. The fishery resources of the NWT are an integral component of our northern ecosystems, and are of significant economic and cultural importance to northern people. By necessity, linear developments constructed in the NWT, such as roads, seismic lines, and pipelines, intersect lakes, rivers, and streams. This paper discusses linear development activities and their impacts on northern fishes, with a focus on oil and gas developments. Once a target area is identified, the development of northern oil and gas reserves typically follows a predictable sequence of events: (i) construction of temporary access roads into the exploration area to conduct seismic surveys to delineate reserves; (ii) exploration well(s) are drilled to assess the potential of the deposit; (iii) if the deposit is of economic interest, then production wells are developed and gathering systems constructed, often coupled with additional transportation infrastructure; (iv) a pipeline is then built to move the hydrocarbons southward to processing facilities; and (v) after the reserve is depleted, closure of all associated infrastructure is conducted and the site is remediated. The main stressors from these activities that may impact fish and aquatic ecosystems include sediment transport to water bodies, noise and pressure impacts from the use of explosives, water withdrawal, obstructions to flow and fish passage, removal of in-stream structure and riparian vegetation, enhanced access and fisheries exploitation, and contaminant spills. These stressors can adversely affect fish directly (e.g., through direct toxicity associated with exposure to elevated contaminants) or indirectly (e.g., through habitat degradation). Such impacts on fish can vary in severity, and on temporal and spatial scales, depending on the nature and extent of the disturbance. These activities can have cumulative impacts and can be exacerbated by natural or indirect stressors, such as a changing climate or forest fires. Appropriate baseline monitoring needs to be conducted, prior to development, to allow for appropriate mitigation to be employed and sound and responsible resource management decisions to be made within an adaptive management framework. © 2015 Published by NRC Research Press.


PubMed | MacDonald Environmental science Ltd.
Type: Journal Article | Journal: Ecotoxicology (London, England) | Year: 2013

: The weight-of-evidence approach to the development of sediment quality guidelines (SQGs) was modified to support the derivation of biological effects-based SQGs for Florida coastal waters. Numerical SQGs were derived for 34 substances, including nine trace metals, 13 individual polycyclic aromatic hydrocarbons (PAHs), three groups of PAHs, total polychlorinated biphenyls (PCBs), seven pesticides and one phthalate ester. For each substance, a threshold effects level (TEL) and a probable effects level (PEL) was calculated. These two values defined three ranges of chemical concentrations, including those that were (1) rarely, (2) occasionally or (3) frequently associated with adverse effects. The SQGs were then evaluated to determine their degree of agreement with other guidelines (an indicator of comparability) and the percent incidence of adverse effects within each concentration range (an indicator of reliability). The guidelines also were used to classify (using a dichotomous system: toxic, with one or more exceedances of the PELs or non-toxic, with no exceedances of the TELs) sediment samples collected from various locations in Florida and the Gulf of Mexico. The accuracy of these predictions was then evaluated using the results of the biological tests that were performed on the same sediment samples. The resultant SQGs were demonstrated to provide practical, reliable and predictive tools for assessing sediment quality in Florida and elsewhere in the southeastern portion of the United States.


PubMed | MacDonald Environmental science Ltd.
Type: Journal Article | Journal: Archives of environmental contamination and toxicology | Year: 2011

A remedial investigation/feasibility study (RI/FS) of the Calcasieu Estuary cooperative site was initiated in 1998. This site, which is located in the southwestern portion of Louisiana in the vicinity of Lake Charles, includes the portion of the estuary from the saltwater barrier on the Calcasieu River to Moss Lake. As part of the RI/FS, a baseline ecological risk assessment (BERA) was conducted to assess the risks to aquatic organisms and aquatic-dependent wildlife exposed to environmental contaminants. The purpose of the BERA was to determine if adverse effects on ecological receptors are occurring in the estuary; to evaluate the nature, severity, and areal extent of any such effects; and to identify the substances that are causing or substantially contributing to effects on ecological receptors. This article describes the environmental setting and site history, identifies the chemicals of potential concern, presents the exposure scenarios and conceptual model for the site, and summarizes the assessment and measurement endpoints that were used in the investigation. Two additional articles in this series describe the results of an evaluation of effects-based sediment-quality guidelines as well as an assessment of risks to benthic invertebrates associated with exposure to contaminated sediment.

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