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111.
Samples of breast muscle from 32 species of waterfowl collected from 123 sites across Canada were analyzed for chlorobenzenes (CBz), chlordane-related compounds (CHL), hexachlorocyclohexanes (HCH), DDT, mirex, dieldrin, PCBs and mercury. ΣDDT, ΣCBz and ΣPCB were the compounds most frequently found above trace levels. ΣHCH and ΣMirex were detected the least often. Mercury was detected in all of the mergansers, over 50% of dabbling, bay and sea ducks, and in less than 2% of the geese analysed. The highest levels of contaminants were generally found in birds feeding at higher trophic levels such as sea ducks and mergansers. With the exception of a few samples of mergansers and long-tailed ducks from eastern Canada, which contained ΣPCB concentrations of 1.0–2.4 mg kg−1, ΣPCB levels were less than 1 mg kg−1 wet weight. Only one merganser from eastern Canada had a ΣDDT concentration (2.6 mg kg−1 ww) which was greater than 1 mg kg−1 ww. The highest ΣCHL (0.10 mg kg−1 ww) was also found in mergansers from eastern Canada. Levels of total mercury in breast muscle were either low (< 1 mg kg−1 ww) or below detection limits with the exception of a few samples of mergansers from eastern Canada which contained mercury concentrations of 1.0–1.5 mg kg−1 ww. Health Canada determined that the organochlorine and mercury levels found in samples of breast muscle of ducks and geese analysed in this study did not pose a health hazard to human consumers and therefore these waterfowl were safe to eat. 相似文献
112.
The Sudbury region in Canada is known for the mining and smelting of high-sulphide ores containing nickel, copper, iron and precious metals. Although reports provide information of metal levels in soil and plants, knowledge of genetic effects on plants growing in contaminated areas is limited. The main objective of this study was to characterise the level of genetic diversity in Pinus banksiana and Pinus resinosa populations from the Sudbury (Ontario) region using microsatellite markers. Soil samples were analysed for concentrations of metals. High levels of metal contents in soil were observed within short distances of the smelter compared with control sites. The level of genetic diversity was very low for P. resinosa populations and moderate for P. banksiana samples. Observed heterozygosity was fivefold higher in P. banksiana populations than P. resinosa populations studied. Overall, 17 and 24% of the total genetic diversity were attributed to differences among populations for P. banksiana and P. resinosa, respectively. In general, the inbreeding was significantly higher in P. resinosa populations than P. banksiana populations and gene flows were relatively low in both species. No significant trend of the levels of genetic diversity for metal contaminated and uncontaminated sites was found. 相似文献
113.
Old-growth forests have declined significantly across the world. Decisions related to old growth are often mired in challenges
of value diversity, conflict, data gaps, and resource pressures. This article describes old-growth values of citizens and
groups in Nova Scotia, Canada, for integration in sustainable forest management (SFM) decision-making. The study is based
on data from 76 research subjects who participated in nine field trips to forest stands. Research subjects were drawn from
Aboriginal groups, environmental organizations, forestry professionals, and rural and urban publics. Diaries, group discussions,
and rating sheets were used to elicit information during the field trips. Findings show that different elicitation techniques
can influence the articulation of intensity with which some values are held. In addition, certain values are more often associated
with old-growth than with other forest-age classes. Some values associated with old-growth are considered more important than
others, and some silvicultural treatments are perceived to compromise old-growth values more than others. Demographic characteristics,
such as constituency group, gender, and age, are shown to influence value priorities. Ideas on how to incorporate old-growth
values into SFM decision-making are highlighted. 相似文献
114.
Neal Michelutti Huijun Liu Lynda E. Kimpe Mark Mallory Marianne S.V. Douglas 《Environmental pollution (Barking, Essex : 1987)》2009,157(10):2769-2775
Polychlorinated biphenyls (PCBs) were measured in sediment cores from ponds located near a large seabird colony at Cape Vera, Devon Island, Arctic Canada. Surface sediment PCB concentrations were ∼5× greater in seabird-affected sites relative to a nearby control pond and were correlated with independent indicators of seabird activity including, sedimentary δ15N and lakewater chlorophyll a and cadmium concentrations. PCB fluxes were amongst the highest recorded from the High Arctic, ranging from 290 to 2400 ng m−2 yr−1. Despite a widespread ban of PCBs in the mid-1970s, PCB accumulation rates in our cores increased, with the highest values recorded in the most recent sediments. Possible mechanisms for the recent PCB increases include a vertical flux step driven by seabird-delivered nutrients and/or delayed loading of PCBs from the catchment into the ponds. The high PCB levels recorded in the seabird-affected sites suggest that seabird colonies are exposing coastal ecosystems to elevated levels of contaminants. 相似文献
115.
Kakali Mukhopadhyay Xi Chen Paul Thomassin 《International Journal of Green Energy》2017,14(4):400-415
The Government of Canada has committed that Canada’s total greenhouse gas (GHG) emissions be reduced by 17% from 2005 levels by 2020. The new Renewable Fuels Regulations required 2% renewable content in diesel fuel and heating distillate oil and 5% for gasoline. This represents approximately 2.1 billion liters of ethanol and 600 million liters of biodiesel requirement per year, which would reduce GHG emissions by more than four million tones. Canada is expected to consume more fuel ethanol compared to its production capacity. The above mandates as well as the gap in consumption and production of biofuel will have enormous impact on the Canadian economy. In this backdrop, an input–output model of the Canadian economy is developed to estimate the macroeconomic impact of the ethanol and biodiesel production in Canada. The impacts on sectoral prices have also been calculated. Simulation exercises have been attempted to reach the mandates using modified Leontief model. Results show that agriculture sector is affected because of feedstock use in the biofuel sector. Mining and manufacturing industries also show a considerable impact. In addition, the impact on commodity prices cannot be ignored. Finally, to meet the target of Copenhagen commitment, the nation needs to revise the blending capacity of ethanol and biodiesel. 相似文献
116.
This article presents a methodological framework for strategic environmental assessment (SEA) application. The overall objective
is to demonstrate SEA as a systematic and structured policy, plan, and program (PPP) decision support tool. In order to accomplish
this objective, a stakeholder-based SEA application to greenhouse gas (GHG) mitigation policy options in Canadian agriculture
is presented. Using a mail-out impact assessment exercise, agricultural producers and nonproducers from across the Canadian
prairie region were asked to evaluate five competing GHG mitigation options against 13 valued environmental components (VECs).
Data were analyzed using multi-criteria and exploratory analytical techniques. The results suggest considerable variation
in perceived impacts and GHG mitigation policy preferences, suggesting that a blanket policy approach to GHG mitigation will
create gainers and losers based on soil type and associate cropping and on-farm management practices. It is possible to identify
a series of regional greenhouse gas mitigation programs that are robust, socially meaningful, and operationally relevant to
both agricultural producers and policy decision makers. The assessment demonstrates the ability of SEA to address, in an operational
sense, environmental problems that are characterized by conflicting interests and competing objectives and alternatives. A
structured and systematic SEA methodology provides the necessary decision support framework for the consideration of impacts,
and allows for PPPs to be assessed based on a much broader set of properties, objectives, criteria, and constraints whereas
maintaining rigor and accountability in the assessment process. 相似文献
117.
We consider the extent to which the Mackenzie Valley Resource Management Act (MVRMA) provides an opportunity for deliberative democracy to emerge within the context of resource management in Canada's North. The focus is on the extent to which the tenets of deliberative democracy are exercised in the environmental assessment (EA) of the Snap Lake diamonds project. Data collection included semi-structured interviews with assessment participants, and a review of documentation surrounding the EA process, and the case study. Results combined four principles of deliberative democracy: generality, autonomy, power neutrality, and ideal role taking. The EA conducted under the MVRMA can serve as a deliberative process, as illustrated by opportunities for dialogue, access to different perspectives, and learning outcomes. However, many of these positive results occurred through nonmandated technical sessions. The absence of participant funding also limits the deliberative potential of the MVRMA. 相似文献
118.
加拿大森林可持续管理标准和指标评介 总被引:1,自引:0,他引:1
介绍了加拿大森林可持续管理标准和指标的产生过程 ,详细介绍了该标准和指标的特点和其中的 6个标准、若干个要素、指标等 ,结合我国的实际分析了该标准和指标对我国可持续森林管理的启示和借鉴作用。 相似文献
119.
Fish habitat loss has been prevalent over the last century in Canada. To prevent further erosion of the resource base and
ensure sustainable development, Fisheries and Oceans Canada enacted the habitat provisions of the Fisheries Act in 1976. In 1986, this was articulated by a policy that a “harmful alteration, disruption, or destruction to fish habitat”
(HADD) cannot occur unless authorised with legally binding compensatory habitat to offset the HADD. Despite Canada’s progressive
conservation policies, the effectiveness of compensation habitat in replicating ecosystem function has never been tested on
a national scale. The effectiveness of habitat compensation projects in achieving no net loss of habitat productivity (NNL)
was evaluated at 16 sites across Canada. Periphyton biomass, invertebrate density, fish biomass, and riparian vegetation density
were used as indicators of habitat productivity. Approximately 63% of projects resulted in net losses in habitat productivity.
These projects were characterised by mean compensation ratios (area gain:area loss) of 0.7:1. Twenty-five percent of projects
achieved NNL and 12% of projects achieved a net gain in habitat productivity. These projects were characterised by mean ratios
of 1.1:1 and 4.8:1, respectively. We demonstrated that artificially increasing ratios to 2:1 was not sufficient to achieve
NNL for all projects. The ability to replicate ecosystem function is clearly limited. Improvements in both compensation science
and institutional approaches are recommended to achieve Canada’s conservation goal. 相似文献
120.
Disaster researchers have long analysed disruption to affected residents' ontological security, often represented by routines and familiar landmarks. Surprisingly little of this work, though, assesses who is most likely to experience feelings of disruption. Using a representative set of survey data, complemented by follow-up interview data from 40 residents affected by the Southern Alberta Flood of June 2013, this paper explores how demographic characteristics, such as gender and place attachment, impact on residents' sense of disruption and loss. The findings indicate that women and people with stronger emotional and social ties to their neighbourhoods are most likely to experience disrupted ontological security; home flooding and evacuation orders are also significant predictors. The qualitative interview data reveal that many participants felt unsettled and disrupted by myriad factors, such as ongoing construction, which prevented them from establishing a ‘new normal’. The paper concludes by discussing the implications of these findings for policymakers and service providers. 相似文献