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Similar to many freshwater ecosystems, the Laurentian Great Lakes of North America have undergone numerous anthropogenic stressors resulting in considerable loss of biodiversity and habitat. Among Great Lakes fishes, the coregonine sub-family has endured the most extensive declines, including extinction of several species (Coregonus johannae, C. alpenae, and C. kiyi orientalis) and at least 10 instances of local extirpations of other species (C. nigripinnis, C. reighardi, C. zenithicus, C. hoyi, and C. artedi) across all 5 lakes, much of which occurred prior to the 1960s owing to overfishing, interactions with non-indigenous species, and habitat loss. Despite these declines, no federal-, provincial-, or state-mandated actions were ever implemented to conserve coregonine diversity, potentially because so much of the coregonine declines occurred prior to the enactment of federal conservation legislation. Possible explanations for inaction since enactment of that legislation include insufficient data on biological vulnerability or threats, unresolved taxonomy, and limited support from the fishery management agencies and their stakeholders prior to the 2000s. In recent decades, however, several fishery management agencies have undertaken efforts to re-introduce coregonine diversity. These efforts helped lead to development of a science-based framework to restore coregonines that was universally endorsed by fishery managers representing eight U.S. states, four U.S. tribal organizations, and the province of ON, Canada, in May 2018. The basin-wide framework is based on principles of conservation biology and adaptive management. We describe details of its key steps, including planning, restoring, and evaluating, while also describing recent implementation efforts to develop methods, improve available resources, and enhance coordination across the basin. Although our paper describes a regional effort to restore native coregonines, our adaptive-management approach could be used by other multi-agency stakeholders seeking to conserve or restore native fishes. [ABSTRACT FROM AUTHOR]

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Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper reviews the re-emergence of delays as a source of concern at the Canada-US border. We reassess their economic impacts in light of new economic research and conduct model-based numerical simulations to estimate the regional composition of trade impacts and welfare costs within Canada. We find ample reason for concern about the re-emergence of these delays, as the economic consequences are likely to be particularly acute for Ontario and Quebec. Our findings have significant public policy relevance to Canada at both national and regional levels given the current renewed interests in border protection issues. [ABSTRACT FROM AUTHOR]

Background/aim: Therapy programmes aim to provide services that are family-centred and address the specific needs of children. The Canadian Occupational Performance Measure (COPM) and the Perceived Efficacy and Goal Setting system (PEGS) are two measures that are available to assist in determining therapy priorities for children and their parents; however, the use of these measures has not been documented for children who have sustained a stroke. This project aimed to describe the functional concerns identified by children and their parents following paediatric stroke. Methodology: A cross-sectional design was used. A total of 26 children were recruited from a paediatric stroke outpatient clinic, and functional concerns were identified using either the COPM or the PEGS. Results: Children and their parents identified similar issues. Of the 26 participants, 23 (88.5%) reported ongoing functional concerns at three months or more following stroke, whereas three participants did not identify any ongoing functional concerns. Functional concerns were grouped into categories of self-care, productivity and leisure as outlined in the Canadian Model of Occupational Performance. Concerns were identified across all functional domains by both children and their parents. Conclusions: The COPM and PEGS provided useful information about functional issues that are important to children and their parents following paediatric stroke. Use of these client-centred measures provides an opportunity to better understand the impact of paediatric stroke on children's functional abilities, and allows greater scope for service provision and planning for this group of children. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the genetic aspects of 15-acetyldeoxynivalenol (15-ADON) chemotypes of Fusarium graminearum fungal population in Canada. The study employs restriction length fragment polymorphism, in which 206 monoconidial isolates of F. graminearum's chemotype were selected for genetic analysis based on their mycotoxin. Results reveal a genetic homogeneity among the F. graminearum population which suggests the chemotypes' geographic population expansion in Canada.

The article investigates the welfare impact of border delays in trade due to post September 11, 2001 security concerns. A computable general equilibrium model of regional trade for Canada was used, modeling both private costs related with increased security and public costs of administering and enforcing the border. Results suggest welfare costs of relatively modest border delays are quite high, which raises the possibility that the damage resulting from even more widespread border delays could be quite extensive in a trade-dependent country like Canada.

The endangered population of sockeye salmon in Cultus Lake, British Columbia, Canada, migrates through commercial fishing areas along with other, much more abundant sockeye salmon populations, but it is not feasible to selectively harvest only the latter, abundant populations. This situation creates controversial trade-offs between recovery actions and economic revenue. We conducted a Bayesian decision analysis to evaluate options for recovery of Cultus Lake sockeye salmon. We used a stochastic population model that included 2 sources of uncertainty that are often omitted from such analyses: structural uncertainty in the magnitude of a potential Allee effect and implementation uncertainty (the deviation between targets and actual outcomes of management actions). Numerous state-dependent, time-independent management actions meet recovery objectives. These actions prescribe limitations on commercial harvest rates as a function of abundance of Cultus Lake sockeye salmon. We also quantified how much reduction in economic value of commercial harvests of the more abundant sockeye salmon populations would be expected for a given increase in the probability of recovery of the Cultus population. Such results illustrate how Bayesian decision analysis can rank options for dealing with conservation risks and can help inform trade-off discussions among decision makers and among groups that have competing objectives. [ABSTRACT FROM AUTHOR]

This paper outlines some arguments shout the role of transportation costs in determining the welfare consequences of trade restrictions. The analysis uses a computable general equilibrium (CGE) model and presents the relevant features for trade analysis. The model has two alternative spatial formulations. In the first, all production and trade occur at one point, while in the second the regions are separated by distance. The calculated effects of a unilateral tariff increase are compared using the CGE model with the "point" and "distance" formulation. While the presence of transportation costs is crucial to some sectoral trade and production results, most welfare results are relatively insensitive to the spatial structure of the model. [ABSTRACT FROM AUTHOR]

A theoretical analysis of "optimal" (Nash equilibrium) tariff rates is presented. A numerical general equilibrium model is then used to find Nash equilibrium tariff rates for the United States and Canada. The Nash equilibrium tariffs are small relative to partial equilibrium estimates: 18 percent for the United States and 6 percent for Canada. The United States is essentially indifferent between the Nash equilibrium and free trade, while Canada is better off at the latter by $4 billion. Empirical results support theoretical predictions that the optimal tariff is smaller when the country is smaller, there are scale economies and free entry, and capital is internationally mobile. [ABSTRACT FROM AUTHOR]

We examined spatial patterns of covariation in indices of survival rate (residuals from the best-fit stock- recruitment curve) across four decades among 43 wild pink salmon (Oncorhynchus gorbuscha) stocks from 14 geographical regions in Washington, British Columbia, and Alaska. We found strong evidence of positive covariation among stocks within each region and between certain adjacent regions (e.g., correlations from 0.3 to 0.7) but no evidence of covariation between stocks ofdistant regions (e.g., separated by 1000 km or more). This suggests that important environmental processes affecting temporal variation in survival rates of pink salmon from spawners to recruits operate at regional spatial scales rather than at the larger ocean basin scale. Based on limited fry abundance data, we found that this covariation in spawner-to-recruit survival rates may be strongly influenced by marine processes. [ABSTRACT FROM AUTHOR]

Climate change, fishing, and aquaculture have affected and will continue to influence Canadian marine biodiversity, albeit at different spatial scales. The Arctic is notably affected by reduced quality and quantity of sea ice caused by global warming, and by concomitant and forecasted changes in ocean productivity, species ecology, and human activity. The Atlantic has been especially impacted by severe overfishing and human-induced alterations to food webs. Climate change, fishing, and aquaculture have all affected, to varying degrees, biodiversity on Canada's Pacific coast. Past and projected trends in key biodiversity stressors reveal marked change. Oceanographic trends include increasing surface water temperatures, reduced salinity, increased acidity, and, in some areas, reduced oxygen. Reductions in Canada's fishery catches (those in 2009 were half those of the late 1980s), followed by reductions in fishing pressure, are associated with dramatic changes in the species composition of commercial catches in the Atlantic (formerly groundfish, now predominantly invertebrates and pelagic fish) and the Pacific (formerly salmon, now predominantly groundfish). Aquaculture, dominated by the farming of Atlantic salmon, grew rapidly from the early 1980s until 2002 and has since stabilized. Climate change is forecast to affect marine biodiversity by shifting species distributions, changing species community composition, decoupling the timing of species' resource requirements and resource availability, and reducing habitat quality. Harvest-related reductions in fish abundance, many by 80% or more, coupled with fishing-induced changes to food webs, are impairing the capacity of species to recover or even persist. Open-sea aquaculture net pens affect biodiversity by ( i) habitat alteration resulting from organic wastes, chemical inputs, and use of nonnative species; ( ii) exchange of pathogens between farmed and wild species; and ( iii) interbreeding between wild fish and farmed escapees. Physical and biological changes in the oceans, along with direct anthropogenic impacts, are modifying Canadian marine biodiversity with implications for food security and the social and economic well-being of coastal communities. To assess the consequences of changes in biodiversity for Canada's oceans and society, it is necessary to understand the current state of marine biodiversity and how it might be affected by projected changes in climate and human uses. [ABSTRACT FROM AUTHOR]

Canada has made numerous international and national commitments to sustain marine biodiversity. International commitments include the implementation of ecosystem-based management, the establishment a network of marine protected areas, and the restoration of commercially exploited fish stocks. However, the international commitments tend to be quite general in nature with the precise governance implications of key principles, such as precaution and the ecosystem approach, being open to interpretation, thus leaving considerable room for discretion in implementation. Consequently, a plethora of soft law documents has emerged to provide more specific guidance to decision-makers and progressively develop international law and policy. Nationally, Canada has embraced a long list of commitments that are supportive of sustaining marine biodiversity through legislation and numerous policy-related documents. Nonetheless, Canada has left many of these commitments unfulfilled or inadequately fulfilled, such as ( i) the development of integrated management plans for coastal and marine waters, ( ii) the implementation of the precautionary approach for Canada's fisheries, and ( iii) the establishment of recovery strategies and identification of critical habitat for species at risk. Although the goal of effective protection of marine biodiversity in Canada appears to be guided by international and national commitments, there remains a clear need to fully implement, operationalize, and strengthen these commitments as articulated in the Oceans Act, fisheries management-related policies, the Species at Risk Act, and others. [ABSTRACT FROM AUTHOR]

Analyses of genetic diversity, trichothecene genotype composition, and population structure were conducted using 4086 Fusarium graminearum isolates collected from wheat in eight Canadian provinces over a three year period between 2005 and 2007. The results revealed substantial regional differences in Fusarium head blight pathogen composition and temporal population dynamics. The 3ADON trichothecene type consistently predominated in Maritime provinces (91%) over the sampled years, and increased significantly (P<0.05) between 2005 and 2007 in western Canada, accounting for 66% of the isolates in Manitoba by the end of the sampling period. In contrast, 3ADON frequency was lower (22%, P<0.001) in the eastern Canadian provinces of Ontario and Québec and did not change significantly between 2005 and 2007, resulting in two distinct longitudinal clines in 3ADON frequency across Canada. Overall, genetic structure was correlated with toxin type, as the endemic population (NA1) was dominated by 15ADON isolates (86%), whereas a second population (NA2) consisted largely of 3ADON isolates (88%). However, the percentage of isolates with trichothecene genotypes that were not predictive of their genetic population assignment (recombinant genotypes) increased from 10% in 2005 to 17% in 2007, indicating that trichothecene type became an increasingly unreliable marker of population identity over time. In addition, there were substantial regional differences in the composition of recombinant genotypes. In western and maritime provinces, NA2 isolates with 15ADON genotypes were significantly more common than NA1 isolates with 3ADON genotypes (P<0.001), and the reverse was true in the eastern provinces of Québec and Ontario. Temporal trends in recombinant genotype composition also varied regionally, as the percentage of 15ADON isolates with NA2 genetic backgrounds increased approximately three fold in western and Maritime provinces, while the opposite trends were observed in Québec and Ontario. The results indicate that F. graminearum population dynamics in Canada have been influenced by a complex adaptive landscape comprising different regional selective pressures, and do not reflect a simple model of dispersal and integration following the introduction of a novel pathogen population. In addition, we identified F. graminearum strains that produce the recently discovered A-trichothecene mycotoxin (NX-2) for the first time in Canada, representing a significant expansion of the known range of NX-2 producing strains in North America., (Published by Elsevier Inc.)

Analysis of Fusarium head blight (FHB) pathogen diversity revealed that 3ADON producing Fusarium graminearum are prevalent in North America and identified significant population structure associated with trichothecene chemotype differences (F(ST)>0.285; P<0.001). In addition, we identified a trichothecene chemotype cline in Canada and documented a recent and significant shift in FHB pathogen composition by demonstrating that the 3ADON chemotype frequency in western Canada increased more than 14-fold between 1998 and 2004. On average, isolates from 3ADON populations produced significantly (P<0.05) more trichothecene and had significantly (P<0.005) higher fecundity and growth rates than isolates from the 15ADON population. These results indicate that selection is driving the rapid spread of an introduced pathogen population that is more toxigenic and potentially more vigorous. The discovery of this previously unrecognized pathogen diversity has significant implications for food safety and cereal production in North America.

Genetic diversity within populations of Fusarium pseudograminearum isolated from wheat grains from the Canadian provinces of Alberta and Saskatchewan was investigated. Three restriction enzymes (EcoRI, HaeIII, and PstI) were used to carry out restriction analysis of the nuclear ribosomal DNA (nrDNA) intergenic spacer region (IGS region) and eight primers were used to generate inter-simple sequence-repeat (ISSR) molecular markers. Our study indicated substantially high genetic diversity within these two populations, but low genetic differentiation and frequent gene flow among populations. The IGS data showed no genetic distinction between the two Alberta populations and only minor genetic differentiation between the Saskatchewan and Alberta populations. Analysis of molecular variance indicated that most genetic variability resulted from differences among isolates within populations. Multilocus linkage disequilibrium analysis suggested a panmictic population genetic structure and the occurrence of significant recombination in F. pseudograminearum. Regular gene flow and random mating between isolates from different populations could result in novel genotypes with both improved pathological and biological traits.