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Fauteux D.,University of Quebec | Lupien G.,Ministere du Developpement Durable de lEnvironnement | Fabianek F.,Laval University | Gagnon J.,University of Quebec | And 2 more authors.
Canadian Field-Naturalist

Skulls are often used to identify small mammals, and most identification keys to small mammals have been developed on the assumption that whole skulls will be available. however, the skulls of small mammals are seldom found intact in predator pellets or nests, and the bones of several individuals are often scattered and mixed, making counting impossible without the use of a specific cranial part. In addition, only a few keys include all the species found in the eastern provinces of Canada. Mandibles readily resist degradation by the gastric acids of both avian and mammalian predators and are often found intact in food caches of mustelids and in bat hibernacula. We therefore designed an illustrated dichotomous key to small mammals (mean mass <5 kg) of eastern Canada based on diagnostic mandible characters (including the teeth and one dentary bone). We identified and confirmed diagnostic characters to distinguish 55 species from the orders lagomorpha, rodentia, Soricomorpha, Carnivora, and Chiroptera. these diagnostic characters are based on a review of the literature and were confirmed by measurements performed on both museum and trapped specimens. In order to facilitate identification, photographic illustrations are provided for each couplet of the key. the ability to identify small mammals using their mandibles will reduce the number of skull components needed and has proven to be a useful tool in the study of the diet of predators. this key may also be helpful in identifying bats in the genera Myotis, Perimyotis, and Eptesicus, which are presently affected by the spread of white-nose syndrome (caused by Pseudogymnoascus destructans) throughout the eastern part of Canada. Source

Tremblay T.,UQAM | Hunter J.,Geological Survey of Canada | Lamontagne C.,Ministere du Developpement Durable de lEnvironnement | Nastev M.,Geological Survey of Canada
Canadian Water Resources Journal

A high-resolution seismic reflection survey was carried out in the Chateauguay River watershed in Quebec, Canada. The seismic profiles extend across a buried valley filled with till and marine clays with the objective of defining the spatial extent of stratified materials associated with the buried portion of the Mercier esker. The acquired knowledge provides insight into the various sedimentary processes of importance for groundwater management at the Mercier esker site, the largest contaminated site in Quebec. Notably, the discontinuity of the till layer underneath the Mercier esker is an important flow path for contamination. Following the initial field tests, four seismic lines ranging from 800 to 2100 m in length were chosen. At all four sites, the depth to bedrock was greater than 20 m and saturated marine clays were present at the surface. High frequency reflection signals provided excellent vertical resolution, allowing precise reconstruction of the underground stratigraphic details. Locally, in the absence of borehole logs, it was difficult to assess the exact nature of the high-velocity sediments (till or gravel) found in humps observed in the seismic survey. In regard to the success of the stratigraphic section where borehole logs are available, it is recommended that a refined grid of seismic lines be surveyed close to the contaminated area. © 2010 Canadian Water Resources Association. Source

This regional hydrogeological study of the Chateauguay River watershed was undertaken during a four-year period, between 2003 and 2007, and required the involvement of several multidisciplinary groups. The rationale for the study was the lack of knowledge on the state of the groundwater resource, which hindered management efforts in the watershed. The project objective was to define the major aquifer units and the quality and quantity of the groundwater resources. The applied methodology consisted of compiling existing data and generating a digital database, acquiring new eld data, and updating geological maps, followed by determining the hydrodynamic and hydrogeochemical processes, and assessing the sustainability The regional aquifer units are comprised of sedimentary bedrock formations and occasional coarse fluvioglacial sediments. The nature and thickness of the surficial deposits defines the hydrogeological settings and flow regimes. © 2010 Canadian Water Resources Association. Source

Giroux I.,Ministere du Developpement Durable de lEnvironnement | Roy N.,Ministere du Developpement Durable de lEnvironnement | Lamontagne C.,Ministere du Developpement Durable de lEnvironnement
Canadian Water Resources Journal

The occurrence of pesticides in groundwater of the Chateauguay River watershed was investigated. The Chateauguay River is an important tributary of the St. Lawrence River. In this exploratory project, conducted between August and October 2005, water samples were collected from 57 rural domestic wells. Among them, 15 were located near apple orchards, 22 near vegetables production centres, and 20 near corn or soybean fields. In the Chateauguay River watershed, each type of crop is related to a specific hydrogeologic setting. Apple orchards are grown in sandy and gravelly soils in areas of moderate topography. Vegetables are grown in organic-rich soils, whereas corn and soybean are grown mainly in the clay-rich soils of the St. Lawrence plain. Low concentrations of pesticides were detected in 13 of the 57 wells sampled (23%); seven in clay soils near corn and soybean crops, and six in organic soils near vegetables crops. Surprisingly, no pesticides were detected in the wells situated in the most vulnerable zones near apple orchards. Detected pesticides include the herbicides atrazine, metolachlor, linuron, diuron, and metribuzin; the insecticides chlorpyrifos and diazinon; and the fungicide chlorothalonil. Concentrations for all pesticides detected in the wells are below drinking water guidelines. © 2010 Canadian Water Resources Association. Source

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