Monique G. Dubé

Cumulative effect assessment in Canada: a regional framework for aquatic ecosystems

Abstract Sustainable development of the aquatic environment depends upon routine and defensible cumulative effects assessment (CEA). CEA is the process of predicting the consequences of development relative to an assessment of existing environmental quality. Theoretically, it provides an on-going mechanism to evaluate if levels of development exceed the environments assimilative capacity; i.e., its ability to sustain itself. In practice, the link between CEA and sustainable development has not been realized because CEA concepts and methods have developed along two dichotomous tracks. One track views CEA as an extension of the environmental assessment (EA) process for project developments. Under this track, stressor-based (S-B) methods have been developed where the emphasis is on local, project-related stressors, their link with aquatic indicators, and the potential for environmental effects through stressor-indicator interactions. S-B methods focus on the proposed development and prediction of project-related effects. They lack a mechanism to quantify existing aquatic quality especially at scales broader than an isolated development. This limitation results in the prediction of potential effects relative to a poorly defined baseline state. The other track views CEA as a broader, regional assessment tool where effects-based (E-B) methods specialize in quantification of existing aquatic effects over broad spatial scales. However, the predictive capabilities of E-B methods are limited because they are retrospective, i.e., the stressor causing the effect is identified after the effect has been measured. When used in isolation, S-B and E-B methods do not address CEA in the context necessary for sustainable development. However, if the strengths of these approaches were integrated into a holistic framework for CEA, an operational mechanism would exist to better monitor and assess sustainable development of our aquatic resources. This paper reviews the existing conceptual basis of CEA in Canada including existing methodologies, limitations and strengths. A conceptual framework for integrating project-based and regional-based CEA is presented.

Integration of Effects-Based and Stressor-Based Approaches into a Holistic Framework for Cumulative Effects Assessment in Aquatic Ecosystems

As the density of development increases, there is a growing need to address the cumulative effects of project developments on the environment. In Canada this need has been recognized in legislation whereby new project developments that require an environmental assessment under the Canadian Environmental Assessment Act are required to address the cumulative effects of proposed project activities relative to the existing environmental condition. Unfortunately, existing stressor-based and effects-based approaches to environmental assessment do not adequately address cumulative effects as defined under the Act when used in isolation. However, elements from each approach can be conceptually incorporated into a holistic cumulative effects assessment framework. Key framework components include: (1) an effects-based assessment to determine existing accumulated environmental state, (2) a stressor-based assessment to predict potential impacts of new development relative to the existing environmental state, (3) post-development monitoring to assess the accuracy of impact predictions and to provide an avenue for adaptive management, and (4) decision-making frameworks to link scientific information to public opinion and managerial action. The key advantage of this framework is that it provides a more holistic, systematic approach for incorporation of ecological information into a scientific and management framework for cumulative effects assessment.

A Proposed Framework for Investigation of Cause for Environmental Effects Monitoring

Environmental Effects Monitoring (EEM) programs in Canada have been developed for the pulp and paper and metal mining industries, and require a cyclical evaluation of the receiving environment to determine whether effects exist when the facilities are in compliance with existing regulations. Identifying the cause of environmental effects is a specific, identified stage in this monitoring program, but as yet there has not been a synthesis of what is meant by “identification of cause”. We propose a multitiered guidance framework for the identification of the cause of environmental effects after they have been detected, confirmed, and their extent and magnitude documented. As part of point source confirmation, the framework includes levels to define whether there is an effect, whether it is related to the effluent discharge facility, and whether response patterns in the receiver are characteristic of a particular stressor type. The next tier involves investigating individual process wastes within the facility to determine the components that are contributing to effects caused by exposure to the final effluent. The last three tiers of the framework relate to characterizing the chemical classes involved in the effect and, ultimately, to identifying the specific chemicals associated with the responses. Although there is increasing knowledge of specific causes of environmental effects gained as one progresses through the levels of investigation, there is a concomitant increase in effort and costs required. Stakeholder input is critical in determining the depth of the investigation as well as how to proceed once the environmental effects information is available.

Using artificial streams to assess the effects of metal-mining effluent on the life cycle of the freshwater midge (Chironomus tentans) in situ.

In 2002, we developed an in situ life-cycle bioassay with Chironomus tentans in artificial streams to evaluate the effects of a complex metal mine effluent under ambient environmental conditions. The bioassay was tested in the field using effluent from the Copper Cliff Waste Water Treatment Plant at INCO (Sudbury, ON, Canada). Chironomus tentans were exposed throughout the life cycle to 45% Copper Cliff effluent, which is the average effluent concentration measured in Junction Creek (ON, Canada), the natural receiving environment. Chironomus tentans in the effluent treatment exhibited reduced survival (p = 0.001), reduced total emergence (p = 0.001), increased time-to-emergence (p = 0.001), and reduced hatching success (p = 0.001) relative to animals in the reference water treatment. Chironomus tentans in the effluent treatment were not significantly different from the reference in terms of growth, sex ratio, number of egg cases/female, and number of eggs/egg case. This research showed how a life-cycle bioassay could be used in situ to assess metal mine effluent effects on a benthic invertebrate.

Utility of mobile, field-based artificial streams for assessing effects of pulp mill effluents on fish in the Canadian environmental effects monitoring (EEM) program

Although the utility of artificial streams(mesocosms) as research tools for assessingeffects of contaminants on aquatic biota hasbeen recognized, their use in regulatoryprograms has been limited. We conducted threestudies to examine the utility of using mobile,field-based artificial streams to assess theeffects of pulp and paper effluents on fish asrequired in the Canadian Environmental EffectsMonitoring (EEM) program. When evaluatedagainst criteria of environmental relevance,interpretability, scientific defensibility, andcost-effectiveness, mesocosms satisfied allcriteria. Measured endpoints on fish survival,energy use (growth, gonad size) and energystorage (liver size, condition) were relevantto the detection and quantification of effluenteffects on fish. Response patterns were similarto those reported in the literature for fieldsurveys showing reduced gonad size andincreased liver size in adult mummichog (Fundulus heteroclitus) and decreased growth ofjuveniles. The flexibility of the systems tomeasure effects in multiple, replicatedtreatments under controlled effluent exposureand ambient conditions of water quality,temperature and photoperiod provided data thatcould not be obtained at these sites usingfield assessment approaches. The repeatabilityof using the same mobile, mesocosm system ofuniform design and operation at different millsites and for different receiving environmentswas unique and contributed to consistentscientific evaluation and interpretation. Thesestudies demonstrated that mesocosms producedgood quality data that fit within the requiredregulatory context of the Canadian EEM program.

Comparison of a partial life‐cycle bioassay in artificial streams to a standard beaker bioassay to assess effects of metal mine effluent on Chironomus tentans

A novel, partial life-cycle bioassay using Chironomus tentans in artificial streams was developed for evaluating the effects of metal mine effluent. The utility of this bioassay was compared to an existing beaker life-cycle bioassay under laboratory conditions. Chironomus tentans larvae were exposed to 45% (v/v) treated metal mine effluent from day 11 through hatching of the second generation. Response patterns were consistent between the two bioassays for hatching success and time to emergence but inconsistent for other endpoints. Significant effects of effluent were obtained for growth, survival, number of adults emerged, and number of eggs per egg case in the artificial stream bioassay but not in the beaker bioassay. Conversely, significant effects on sex ratio and number of egg cases per female were observed in the beaker bioassay but not in the artificial stream bioassay. These differences are believed to be a consequence of the number of organisms per replicate used in each bioassay, which results in a difference in statistical power. As a result, higher coefficients of variation and effects sizes were observed in the beaker bioassay relative to the artificial stream bioassay for almost all endpoints. These results provide evidence that the bioassay in artificial streams can be an effective tool for evaluating the effects of metal mine effluent on life-cycle endpoints in C. tentans.

Assessing large spatial scale landscape change effects on water quality and quantity response in the lower Athabasca River basin.

Increased land use intensity has been shown to adversely affect aquatic ecosystems. Multiple landscape stressors interact over space and time, producing cumulative effects. Cumulative Effects Assessment (CEA) is the process of evaluating the impact a development project may have on the ecological surroundings, but several challenges exist that make current approaches to cumulative effects assessment ineffective. The main objective of this study was to compare results of different methods used to link landscape stressors with stream responses in a highly developed watershed, where past work has shown that the river has experienced significant water quality and quantity changes to improve approaches to CEA. The study site was the lower reaches of the Athabasca River, Canada that have been subjected to a diverse range of intense anthropogenic developments since the late 1960s. Linkages between landscape change and river response were evaluated using correlation analyses, stepwise, multiple regression, and regression trees. Notable landscape changes include increased industrial development and forest cut-blocks, made evident from satellite imagery and supporting ancillary data sets. Simple regression analyses showed water use was closely associated with total phosphorus (TP) and Na(+) concentrations, as well as specific conductance. The regression trees for total organic carbon (TOC), TP, and Na(+) showed that the landscape variables that appear as the first characteristic were the same variables that showed significant relations for their respective simple regression models. Simple, stepwise, and multiple regressions in conjunction with regression trees were useful in this study for capturing the strongest associations between landscape stressors and river response variables. The results highlight the need for improved scaling methods and monitoring strategies crucial to managing cumulative effects to river systems.

Accumulated state of the Yukon River watershed: Part I critical review of literature

A consistent methodology for assessing the accumulating effects of natural and manmade change on riverine systems has not been developed for a whole host of reasons including a lack of data, disagreement over core elements to consider, and complexity. Accumulated state assessments of aquatic systems is an integral component of watershed cumulative effects assessment. The Yukon River is the largest free flowing river in the world and is the fourth largest drainage basin in North America, draining 855,000 km(2) in Canada and the United States. Because of its remote location, it is considered pristine but little is known about its cumulative state. This review identified 7 hot spot areas in the Yukon River Basin including Lake Laberge, Yukon River at Dawson City, the Charley and Yukon River confluence, Porcupine and Yukon River confluence, Yukon River at the Dalton Highway Bridge, Tolovana River near Tolovana, and Tanana River at Fairbanks. Climate change, natural stressors, and anthropogenic stresses have resulted in accumulating changes including measurable levels of contaminants in surface waters and fish tissues, fish and human disease, changes in surface hydrology, as well as shifts in biogeochemical loads. This article is the first integrated accumulated state assessment for the Yukon River basin based on a literature review. It is the first part of a 2-part series. The second article (Dubé et al. 2013a, this issue) is a quantitative accumulated state assessment of the Yukon River Basin where hot spots and hot moments are assessed outside of a normal range of variability.

Accumulated state assessment of the Yukon River watershed: Part II quantitative effects‐based analysis integrating western science and traditional ecological knowledge

This article is the second in a 2-part series assessing the accumulated state of the transboundary Yukon River (YR) basin in northern Canada and the United States. The determination of accumulated state based on available long-term (LT) discharge and water quality data is the first step in watershed cumulative effect assessment in the absence of sufficient biological monitoring data. Long-term trends in water quantity and quality were determined and a benchmark against which to measure change was defined for 5 major reaches along the YR for nitrate, total and dissolved organic carbon (TOC and DOC, respectively), total phosphate (TP), orthophosphate, pH, and specific conductivity. Deviations from the reference condition were identified as hot moments in time, nested within a reach. Significant increasing LT trends in discharge were found on the Canadian portion of the YR. There were significant LT decreases in nitrate, TOC, and TP at the Headwater reach, and significant increases in nitrate and specific conductivity at the Lower reach. Deviations from reference condition were found in all water quality variables but most notably during the ice-free period of the YR (May-Sept) and in the Lower reach. The greatest magnitudes of outliers were found during the spring freshet. This study also incorporated traditional ecological knowledge (TEK) into its assessment of accumulated state. In the summer of 2007 the YR Inter Tribal Watershed Council organized a team of people to paddle down the length of the YR as part of a Healing Journey, where both Western Science and TEK paradigms were used. Water quality data were continuously collected and stories were shared between the team and communities along the YR. Healing Journey data were compared to the LT reference conditions and showed the summer of 2007 was abnormal compared to the LT water quality. This study showed the importance of establishing a reference condition by reach and season for key indicators of water health to measure change, and the importance of placing synoptic surveys into context of LT accumulated state assessments.

Assessing the sublethal effects of in‐river concentrations of parameters contributing to cumulative effects in the athabasca river basin using a fathead minnow bioassay

The Athabasca River basin, located in Alberta, Canada, covers 157, 000u2009km(2) and holds significant cultural and economic importance. Recent research assessed changes in several water quality and quantity parameters that have changed both spatially (along the river continuum) and temporally (pre-development and present day) in the Athabasca River Basin. In particular, parameters such as salinity and dissolved sulphate have changed significantly across the Athabasca River mainstem over the past five decades. Further laboratory testing has linked concentrations of these parameters to changes in fathead minnow reproduction. Research is required to determine whether these changes observed in the laboratory can be applied to actual in-river conditions. The objectives of the present study were to twofold: assess changes in fathead minnow response metrics (i.e., condition, liver and gonad size, egg production, and gill histology) associated with increasing concentrations of salinity and dissolved sulphate and determine whether sublethal effect thresholds established in laboratory experiments correspond to actual in-river concentrations using water from the mouth and headwaters of the Athabasca River. Three dose-response experiments (NaCl, SO4, and water sampled from the mouth of the Athabasca River) were conducted at Jasper National Park, Alberta, Canada. Significant increases in mean eggs per female per day occurred at the 50% treatment for the mouth experiment and thresholds previously developed in the laboratory were verified.