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1.
Environ Manage ; 59(1): 1-9, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27826692

RESUMO

Restoration ecologists conduct both basic and applied research using a diversity of funding and collaborative models. Over the last 17 years we have assessed the effectiveness of a stream compensation project in Canada's north, where an independent university-based research program was a condition of the regulatory approval process. This resulted in a non-traditional university-government-industry partnership. Here we share seven lessons that we learned from our collective experiences with the research partnership and use the Ekati diamond mine as a case study to illustrate and support lessons learned. Our advice includes opinions on the importance of: engaging collaborators early, defining roles and responsibilities, data sharing and standardization, the use of natural streams to set restoration targets, expect setbacks and surprises, treating restoration as an opportunity to experiment, and how to define success. Many of the lessons learned are broadly applicable to those whom embark on research collaborations among industry, universities, and consulting companies within a regulatory framework and may be of particular value to collaborators in early stages of their career.


Assuntos
Ecossistema , Recuperação e Remediação Ambiental/legislação & jurisprudência , Recuperação e Remediação Ambiental/métodos , Rios , Canadá , Pesquisa Participativa Baseada na Comunidade , Comportamento Cooperativo , Regulamentação Governamental , Humanos , Indústrias , Universidades
2.
Environ Monit Assess ; 187(9): 564, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26255271

RESUMO

Defining reference conditions is central to identifying environmental effects of anthropogenic activities. Using a watershed approach, we quantified reference conditions for benthic algal communities and their relations to physico-chemical conditions in rivers in the South Nahanni River watershed, NWT, Canada, in 2008 and 2009. We also compared the ability of three descriptors that vary in terms of analytical costs to define algal community structure based on relative abundances of (i) all algal taxa, (ii) only diatom taxa, and (iii) photosynthetic pigments. Ordination analyses showed that variance in algal community structure was strongly related to gradients in environmental variables describing water physico-chemistry, stream habitats, and sub-watershed structure. Water physico-chemistry and local watershed-scale descriptors differed significantly between algal communities from sites in the Selwyn Mountain ecoregion compared to sites in the Nahanni-Hyland ecoregions. Distinct differences in algal community types between ecoregions were apparent irrespective of whether algal community structure was defined using all algal taxa, diatom taxa, or photosynthetic pigments. Two algal community types were highly predictable using environmental variables, a core consideration in the development of Reference Condition Approach (RCA) models. These results suggest that assessments of environmental impacts could be completed using RCA models for each ecoregion. We suggest that use of algal pigments, a high through-put analysis, is a promising alternative compared to more labor-intensive and costly taxonomic approaches for defining algal community structure.


Assuntos
Biota , Monitoramento Ambiental/estatística & dados numéricos , Rios/química , Rios/microbiologia , Poluentes Químicos da Água/análise , Canadá , Diatomáceas/fisiologia , Monitoramento Ambiental/métodos , Metais/análise , Modelos Biológicos , Pigmentos Biológicos/análise , Chuva , Valores de Referência , Estramenópilas/fisiologia , Temperatura , Viridiplantae/fisiologia
3.
Environ Monit Assess ; 185(9): 7895-913, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23494191

RESUMO

Assessments of stream condition using benthic algal communities have traditionally relied on taxonomy-based approaches to compare community structure at sites exposed to a stressor versus reference sites. Taxonomy-based methods are often effective, but they require high levels of training and are relatively time consuming and expensive. We examined the utility of assessing stream biological condition using algal pigments. We used gradient and control-impact study designs in 2008 and 2009 to compare the extent that algal pigments versus taxonomic descriptors of algal community structure varied along a 10.5-km stretch of the Flat River (South Nahanni River watershed, NWT, Canada) encompassing a gradient of nutrients and metals at sites upstream, adjacent to and downstream of a northern metals mine. We also calculated costs to quantify algal pigments relative to taxonomy-based methods. Multivariate analyses (ANOSIM tests, redundancy analysis) identified that pigment concentrations from benthic algal samples differed significantly (p < 0.05) between non-exposed and exposed river sites and were related to variations in water physico-chemical conditions. By contrast, community composition determined from taxonomy-based enumeration to the Order and Family levels did not differ significantly between non-exposed and exposed sites, and relations with water physico-chemical conditions were weaker and inconsistent between the study years. In-house costs to quantify algal pigments were lower than commercial rates to describe community structure using taxonomy. Thus, our data suggests that analysis of benthic algal pigments represents a viable and cost-effective bio-monitoring method for assessing anthropogenic effects on stream condition that merits further evaluation.


Assuntos
Monitoramento Ambiental/métodos , Microalgas/fisiologia , Pigmentos Biológicos/análise , Rios/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
4.
Integr Environ Assess Manag ; 13(4): 728-745, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27791328

RESUMO

Monitoring biologists continually strive to improve the effectiveness of protocols to quantify environmental and ecological effects of anthropogenic activities. We developed and applied a reference condition approach (RCA) model to assess the ability of 3 descriptors of algal community structure (algal taxonomy, diatom taxonomy, and algal pigments) to identify impairment in 2 northern rivers in the South Nahanni River Watershed, Northwest Territories, Canada. We established reference conditions by sampling 62 regional reference (i.e., minimally disturbed) sites in 2008 (n = 44) and 2009 (n = 18) and assessed the condition of 38 test sites downstream of 2 mines in 2008 (N = 20 sites) and 2009 (N = 18 sites). Patterns of impairment downstream of the 2 mines were assessed and zones of influence were identified for each algal descriptor. Results showed that the 3 RCA models using the 3 descriptors of algal community structure identified reasonably consistent assessments downstream of Prairie Creek mine with changes in algal pigments being more sensitive than the other 2 descriptors. In Flat River, however, assessment of test sites varied considerably depending on the descriptor of algal community structure. Our results suggest that benthic algal RCA models show promise as biological monitoring tools, but additional investigations are required to better understand variance in site assessments among the 3 algal community descriptors. Integr Environ Assess Manag 2017;13:728-745. © 2016 SETAC.


Assuntos
Monitoramento Ambiental/métodos , Microalgas/fisiologia , Modelos Teóricos , Poluentes Químicos da Água/análise , Canadá , Diatomáceas , Plantas , Rios/química
5.
Integr Environ Assess Manag ; 13(5): 877-891, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28383771

RESUMO

The primary goals of environmental monitoring are to indicate whether unexpected changes related to development are occurring in the physical, chemical, and biological attributes of ecosystems and to inform meaningful management intervention. Although achieving these objectives is conceptually simple, varying scientific and social challenges often result in their breakdown. Conceptualizing, designing, and operating programs that better delineate monitoring, management, and risk assessment processes supported by hypothesis-driven approaches, strong inference, and adverse outcome pathways can overcome many of the challenges. Generally, a robust monitoring program is characterized by hypothesis-driven questions associated with potential adverse outcomes and feedback loops informed by data. Specifically, key and basic features are predictions of future observations (triggers) and mechanisms to respond to success or failure of those predictions (tiers). The adaptive processes accelerate or decelerate the effort to highlight and overcome ignorance while preventing the potentially unnecessary escalation of unguided monitoring and management. The deployment of the mutually reinforcing components can allow for more meaningful and actionable monitoring programs that better associate activities with consequences. Integr Environ Assess Manag 2017;13:877-891. © 2017 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).


Assuntos
Monitoramento Ambiental/métodos , Ecossistema , Meio Ambiente , Medição de Risco
6.
Oecologia ; 100(1-2): 128-134, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28307036

RESUMO

Laboratory experiments were performed to quantify the combined effects of food abundance (low, high) and predation threat, imposed using a model fish (safe, risky) on fitness correlates (i.e. growth, time to emergence, adult body mass, fecundity, egg size) of the mayfly Baetis tricaudatus. These effects were determined by rearing larvae under different combinations of food abundance and predator threat. Fitness correlates were significantly affected by food abundance, predation threat or the interaction of these factors. High food abundance and the absence of predation threat significantly increased larval growth rates, adult body mass, fecundity, egg size, and decreased time to emergence. Long-term effects of predator threat and food abundance on fitness correlates of B. tricaudatus were compared to previously conducted short-term patch choice trials to test for concordance between short-term measures of patch choice and their potential longer-term fitness consequences. This comparison indicated that patches that were utilized the most were those that yielded the highest fitness benefits. These results suggest that behavioural costs of balancing mortality risk due to predation against food acquisition by B. tricaudatus can have strong fitness consequences.

7.
Oecologia ; 86(2): 163-169, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28313197

RESUMO

Mayfly larvae of Paraleptophlebia heteronea (McDunnough) had two antipredator responses to a nocturnal fish predator (Rhinichthys cataractae (Valenciennes)): flight into the drift and retreat into interstitial crevices. Drift rates of Paraleptophlebia abruptly increased by 30 fold when fish were actively foraging in the laboratory streams but, even before fish were removed, drift began returning to control levels because larvae settled to the substrate and moved to areas of low risk beneath stones. This drifting response was used as an immediate escape behavior which likely decreases risk of capture from predators which forage actively at night. Surprisingly, drift most often occurred before contact between predator and prey, and we suggest that in darkness this mayfly may use hydrodynamic pressure waves for predator detection, rather than chemical cues, since fish forage in an upstream direction. Although drifting may represent a cost to mayfly larvae in terms of relocation to a new foraging area with unknown food resources, the immediate mortality risk probably out-weighs the importance of staying within a profitable food patch because larvae can survive starvation for at least 2 d. In addition to drifting, mayflies retreated from upper, exposed substrate surfaces to concealed interstitial crevices immediately after a predator encounter, or subsequent to resettlement on the substrate after predator-induced drift. A latency period was associated with this response and mayflies remained in these concealed locations for at least 3 h after dace foraging ceased. Because this mayfly feeds at night and food levels are significantly lower in field refugia under stones, relative to exposed stone surfaces, predator avoidance activity may limit foraging time and, ultimately, reduce the food intake of this stream mayfly.

8.
Oecologia ; 85(3): 343-348, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28312038

RESUMO

Laboratory experiments were performed to identify the mechanisms by which three mayfly grazers, Baetis tricaudatus, Ephemerella aurivilli and Paraleptophlebia heteronea deplete algae from substrates. Field observations indicated these mayflies foraged predominantly (>70% of all individuals) within small (1-2 cm diameter), low biomass areas where algal biomass was significantly lower than the surrounding algal mat. We postulated four models of algal patch depletion based on the combined effects of a type II functional response consumptive model and four possible forms of nonconsumptive loss. These models were tested in laboratory feeding trials by examining the relative importance of consumptive and non-consumptive removal of the diatom, Navicula sp., by the three common mayfly grazers. The trials were conducted in plexiglass streams that contained substrates with one of five biomass levels (0.11, 0.24, 0.43, 0.65, 0.92 mg/cm2 dry weight) of the diatom food. After each 1 h feeding trial, consumption was measured, and the remaining algae scraped from the substrates so non-consumption and total patch depletion could be determined. Consumption by all three species followed a type II functional response; mayflies were capable of grazing diatom layers of extremely low biomass (0.11 mg/cm2) and reached an asymptotic feeding rate when diatom biomass ranged from 0.24-0.43 mg/cm2. Upper asymptotic feeding rates occurred at algal biomasses that were 20 times lower than algal biomass levels within foraging areas in the field and >50 times the overall mean algal biomass on upper stone surfaces in the Bow River. When diatom biomass was low (0.11 mg/cm2), the amount of algae ingested accounted for 27%-75% of total depletion of algal patches. Above this level, nonconsumptive, foraging-related losses increased. Thus, depletion of diatom patches was non-linear and positively related with diatom biomass due to the disproportionate increase in non-consumptive losses combined with the type II functional response consumptive model (Case 4). This disproportionate increase in non-consumptive loss may results from (i) a passive process attributable to mechanical limitations of the feeding apparatus, (ii) an active selection process during foraging or (iii) instability of the diatom material resulting in disproportionately high foraging related dislodgement. Regardless of the mechanism, our experiments indicate the importance of considering algal patch depletion by mayfly grazers as a dual product of consumptive and non-consumptive foraging processes. Furthermore, the non-linear increase in nonconsumptive loss with increased algal biomass suggests this process may be a major mechanism of algal patch depletion by mayflies when algal biomass is high.

9.
Environ Manage ; 42(6): 957-70, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18815827

RESUMO

We evaluated the cumulative effects of land use disturbance resulting from forest harvesting, and exploration and extraction of oil and gas resources on the occurrence and structure of stream fish assemblages in the Kakwa and Simonette watersheds in Alberta, Canada. Logistic regression models showed that the occurrence of numerically dominant species in both watersheds was related to two metrics defining industrial activity (i.e., percent disturbance and road density), in addition to stream wetted width, elevation, reach slope, and percent fines. Occurrences of bull trout, slimy sculpin, and white sucker were negatively related to percent disturbance and that of Arctic grayling, and mountain whitefish were positively related to percent disturbance and road density. Assessments of individual sites showed that 76% of the 74 and 46 test sites in the Kakwa and Simonette watersheds were possibly impaired or impaired. Impaired sites in the Kakwa Watershed supported lower densities of bull trout, mountain whitefish, and rainbow trout, but higher densities of Arctic grayling compared to appropriate reference sites. Impaired sites in the Simonette Watershed supported lower densities of bull trout, but higher densities of lake chub compared to reference sites. Our data suggest that current levels of land use disturbance alters the occurrence and structure of stream fish assemblages.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Peixes/crescimento & desenvolvimento , Árvores , Poluição da Água/análise , Agricultura/métodos , Alberta , Animais , Conservação dos Recursos Naturais , Meio Ambiente , Modelos Logísticos , Densidade Demográfica , Dinâmica Populacional , Truta/crescimento & desenvolvimento , Poluição da Água/efeitos adversos
10.
Environ Manage ; 42(6): 1064-76, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18839240

RESUMO

Objective assessment of habitat compensation is a central yet challenging issue for restoration ecologists. In 1997, a 3.4-km stream channel, designed to divert water around an open pit diamond mine, was excavated in the Barrenlands region of the Canadian Arctic to create productive stream habitat. We evaluated the initial success of this compensation program by comparing multiple biological attributes of the constructed stream during its first three years to those of natural reference streams in the area. The riparian zone of the constructed stream was largely devoid of vegetation throughout the period, in contrast to the densely vegetated zones of reference streams. The constructed stream also contained lower amounts of woody debris, coarse particulate organic matter (CPOM), and epilithon; had lower coverage by macrophytes and bryophytes; and processed leaf litter at a lower rate than reference streams. Species richness and densities of macroinvertebrates were consistently lower in the constructed stream compared to natural streams. This contributed to differences in macroinvertebrate assemblage structure throughout the period, although assemblages showed some convergence by year 3. The effectiveness of the constructed stream to emulate natural streams varied somewhat depending on the biological attribute being evaluated. Assessments based on individual attributes showed that minimal to moderate levels of similarity between the constructed stream and natural streams were achieved. A collective assessment of all biological and ecosystem attributes suggested that the constructed stream was not a good surrogate for natural streams during these first years. Additional time would be required before many characteristics of the constructed stream would resemble those of reference streams. Because initial efforts to improve fish habitat in the constructed stream focused on physical structures (e.g., weirs, vanes, rock, groins), ecological factors limiting fish growth were not considered and likely constrained success. We suggest that a greater focus on organic characteristics and vegetation within the stream and its riparian zone could have accelerated compensation. The addition of woody debris and CPOM, combined with planting of shrubs and herbs along the stream, should provide a source of allochthonous matter for the biotic community while large cobble and boulders should improve the physical stability of stream system, protecting its organic components.


Assuntos
Biodiversidade , Biomassa , Conservação dos Recursos Naturais/métodos , Ecossistema , Invertebrados/crescimento & desenvolvimento , Rios , Animais , Regiões Árticas , Monitoramento Ambiental , Densidade Demográfica , Dinâmica Populacional , Fatores de Tempo
11.
Environ Manage ; 29(6): 824-44, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11992174

RESUMO

The effects of livestock grazing on selected riparian and stream attributes, water chemistry, and algal biomass were investigated over a two-year period using livestock enclosures and by completing stream surveys in the Cypress Hills grassland plateau, Alberta, Canada. Livestock enclosure experiments, partially replicated in three streams, comprised four treatments: (1) early season livestock grazing (June-August), (2) late season livestock grazing (August-September), (3) all season grazing (June-September), and (4) livestock absent controls. Livestock grazing significantly decreased streambank stability, biomass of riparian vegetation, and the extent to which aquatic vegetation covered the stream channels compared with livestock-absent controls. Water quality comparisons indicated significant differences among the four livestock grazing treatments in Battle and Graburn creeks but not in Nine Mile Creek. In Graburn Creek, the concentration of total phosphorus in the all-season livestock grazing treatment was significantly higher than that in the livestock-absent control, and the early season and late season grazing treatments. Concentrations of soluble reactive phosphorus in the all-season livestock grazing treatment also exceeded that in livestock-absent control. In contrast, differences in water quality variables in the remaining 22 comparisons (i.e., 22 of the total 24 comparisons) were minor even when differences were statistically significant. Effects of livestock grazing on algal biomass were variable, and there was no consistent pattern among creeks. At the watershed scale, spatial variation in algal biomass was related (P < 0.05) with concentrations of NO(2)(-) + NO(3) (-) and soluble reactive phosphorus in two of the four study creeks. Nutrient diffusing substrata experiments showed that algal communities were either nitrogen-limited or not limited by nutrients, depending on stream and season.


Assuntos
Monitoramento Ambiental , Eutrofização , Nitrogênio/efeitos adversos , Fósforo/efeitos adversos , Poluentes da Água/efeitos adversos , Abastecimento de Água , Alberta , Ração Animal , Animais , Biomassa , Bovinos , Nitrogênio/análise , Fósforo/análise , Poaceae , Controle de Qualidade , Estações do Ano
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