Regional ecological risk assessment using a relative risk model: A case study of the Darwin Harbour,Darwin, Australia

There are many proposed and ongoing commercial, industrial, and residential developments within the Darwin Harbour catchment in Northern Australia, to accommodate the projected population growth over the next 20 years. Hence, it is necessary to ensure the balance between these developments and ecosystem conservation. We evaluated ecological risk for the Darwin Harbour using a relative risk model (RRM). The catchment was divided into 22 risk regions based on small catchment boundaries and their homogeneity. Through the RRM, we ranked and summed the stressors and habitats within regions. The interaction between stressors and habitats were modeled through exposure and effect filters. The ecological assessment endpoints were maintenance of the mangrove health and the maintenance of water quality. The risk regions—Myrmidon Creek, Blackmore River, Bleesers Creek, and Elizabeth River—showed the highest total relative risk for ecological assets. These risk regions had a high percentage cover of industrial, commercial, and residential areas; diffuse entry points; and climate change effects. Creek A, Sandy Creek, West Arm, and Pioneer Creek were the risk regions with lowest total relative risk scores. The RRM is a robust application that is suitable for a large geographic area where multiple stressors are of concern.     

Regional Ecological Risk Assessment of a Near Shore Marine Environment: Cherry Point,WA

We conducted a regional ecological risk assessment for a near shore marine environment in northwestern Washington State using the Relative Risk Model. The objectives of this study were threefold: (1) to analyze cumulative impacts from multiple sources of chemical and non-chemical stressors in the near shore region and upland watersheds of Cherry Point (2) to determine the utility of Monte Carlo type uncertainty analysis in a rank-based regional risk assessment and (3) to investigate the effects of model habitat characterization on risk estimates. We used geographic information systems to compile and compare spatial data to determine ranks for sub-regions within the study area. By quantitatively combining ranks with exposure and effects filters, we estimated total relative risk between sub-regions and relative contributions of stressors. Finally, we used Monte Carlo analysis and an alternative ranking scheme to evaluate the effects of model and parameter uncertainty on risk predictions. The regional risk assessment results suggest the major contributors of risk are vessel traffic, upland urban and agricultural land use and shoreline recreational activities. This assessment demonstrated the applicability of regional risk assessment to marine near shore regions and the benefit of Monte Carlo analysis in describing uncertainty in a Relative Risk Model regional risk assessment.     

A Regional Multiple Stressor Risk Assessment of the Codorus Creek Watershed Applying the Relative Risk Model

The relative risk model (RRM) used in Port Valdez, AK, and in Oregon's Willamette/McKenzie Watershed was applied to the Codorus Creek Watershed in south central Pennsylvania. The assessment evaluated the relative risk model for its applicability for ranking ecological risks within the Codorus Creek Watershed. The Codorus Creek Watershed approach included ranking stressors and habitats for regions within the watershed. Geographical Information Systems were vital in compiling and comparing stressor and habitat spatial data from regions in the watershed. The risk of ecological impacts to degrade assessment endpoints were calculated and ranked by quantitatively determining the interactions of the stressors and habitats as defined in the conceptual site model. Uncertainty assessment was conducted and the impact upon the relative ranks and risk conclusions evaluated. To determine regional risks, risk management information was gathered identifying areas to be protected, areas of high stress, and areas where additional information is needed. The results supported the applicability of the RRM and suggested areas and stressors for restoration efforts in the Codorus Creek Watershed. Two critical sets of conclusions were drawn from the assessment. First, in the Codorus Creek Watershed, the most significant stressor is agriculture land use, the most significantly impacted endpoint is water quality, and the most vulnerable habitats are those for macroinvertebrates and warm-water fish. Second, this risk assessment demonstrates the feasibility of using the RRM for assessing risk from multiple stressors on habitats with multiple assessment endpoints in an eastern watershed.     

A Regional Ecological Risk Assessment of the Kaipara Harbour,New Zealand,Using a Relative Risk Model

A regional ecological risk assessment was conducted for the Kaipara Harbour catchment in New Zealand. The Relative Risk Model was used to prioritize management of the sources of stress and habitats of concern in the basin. Semi-structured interviews with 25 representative stakeholders were conducted to obtain the resource-users’ perspectives and to identify the regional stressor sources and receptor habitat data for the model. For this risk analysis we divided the catchment into nine ecological districts. Mixed-methodological approaches including content analysis, geospatial analysis, and source documentation were used to categorize source and habitat rankings, based on the relative abundance of each in the nine ecological districts. Risk characterization revealed that fishing pressure and tidal energy pose the largest sources of perceived risk to the catchment; shellfish and Maui dolphin habitats are the receptors estimated to be at greatest risk; and the Kaipara and Rodney ecological districts are the sub-regions estimated with the greatest combined risk. A Monte Carlo analysis confirmed the source inputs and revealed greater uncertainty than the estimated habitat input results. The results of this assessment can be used by policy-makers, conservation groups, and municipalities to inform the future management efforts in the harbor and catchment.     

Risk assessment of land ecology on a regional scale: Application of the relative risk model to the mining city of Daye,China

The ecological risk assessment of land ecosystems plays a vital role in land environment protection and management in China. To identify the ecological impairment in land ecosystems, risk assessment of regional land ecology was conducted in Daye, a traditional mining city in Central China, using the relative risk model (RRM). The study area was divided into six sub-regions; and the sources, stressors, habitats, and end points of the impairment were identified. A conceptual model was built to represent the ecological interactions among risk components. Results showed the following: (1) The traditional iron–coal mining sub-region and the mineral processing sub-region exhibited high risk. (2) Mining was the largest risk source, followed by solid waste piling and urbanization. (3) Disappearance of habitats was the greatest risk stressor, followed by the accumulation of pollutants and heavy metals. (4) Among the eight identified habitats, the lake habitat was the most likely to be affected. (5) Health threats, soil contamination, and landscape aesthetic dysfunctions appeared to be the end points under the largest risk pressure. Finally, Monte Carlo analysis was used to evaluate the effects of uncertainty on risk model predictions. Our assessment model was proven to be generally valid for regional land ecology risk assessment.     

Using the Ecological Risk Index Based on Combined Watershed and Administrative Boundaries to Assess Human Disturbances on River Ecosystems

Efforts at the restoration of river ecosystems are needed not only in local habitats but are also important in terrestrial regions. Large-scale assessment of human activities can be useful in integrated watershed management. In this study, we modified the Ecological Risk Index (ERI) by considering the spatial distribution of human activities in China's Haihe River Basin (HRB). The stressor factors of human activities included population, impervious surface, cattle, agricultural land use, industry, fertilizers, pesticides, water conservation facilities, and roads. A total of 423 assessment units in the HRB were created by combining watershed and administrative boundaries to analyze the spatial distribution of human activities. Two index options, the ERI (including all stressors) and the ERI-D (excluding reservoirs and sluices), were examined for different management objectives. All the stressors and both ecological risk indices (ERI and ERI-D) were ranked in four levels: low, moderate, high, and very high. Our study demonstrated that the ERI and ERI-D can provide an overview of the spatial pattern of human stressors related to river ecosystems across a large geographic region. The approach developed in this study is useful for prioritizing management actions in targeted areas.     

A Regional Multiple-Stressor Rank-Based Ecological Risk Assessment for the Fjord of Port Valdez,Alaska

We conducted an ecological risk assessment of the marine environment of Port Valdez, a fjord in south-central Alaska. Because the assessment was regional rather than site-specific and contained a large number of different stressors in a variety of environments, we required a nontraditional method to estimate risks. We created a Relative Risk Model to rank and sum individual risks numerically within each subarea, from each source, and to each habitat. Application of this model involved division of Port Valdez into 11 subareas containing specific ecological and anthropogenic structures and activities. Within each subarea, the stressor sources were analyzed to estimate exposure of receptors within habitats leading to effects relevant to the chosen assessment endpoints. The subareas were analyzed and compared to form a Port-wide perspective of ecological risk. Available chemical concentrations from sediment and mussels collected from the Port were compared to various toxicological benchmarks as a partial confirmation of the risk analysis. An estimation of the risk of polycyclic aromatic hydrocarbons (PAHs) to marine invertebrates indicated low risk. The municipal boat harbor had the highest estimate, which reflected our relative risk rankings. The Relative Risk Model approach appears robust and has potential for use in situations where multiple stressors are of concern and for assessments covering broad geographic areas. In the Port Valdez assessment the approach provided relative risk rankings for chemical and physical stressors from various sources. But data were available for confirmation of risk estimates only for the chemical stressors. The rankings are relative, and extrapolation beyond the scenario in which they were developed is not warranted. Uncertainty is large, and the numerical scores collapse a multidimensional space into a single value. Use of just the numerical score out of context is more valid than with other indexes. The value of the approach lies in the relative rankings and the accounting of the components of the relative risk score.     

生态风险评价研究进展

20多年来,生态风险评价研究经历了从环境风险到生态风险到区域生态风险评价的发展历程,风险源由单一风险源扩展到多风险源,风险受体由单一受体发展到多受体,评价范围由局地扩展到区域景观水平.区域生态风险评价就是大尺度上研究复杂环境背景下包含多风险源、多风险受体的综合风险研究.目前,区域生态风险评价的理论框架已经搭建起来,统计方法多采用相对评价法.区域生态风险评价未来的发展方向为继续加强实验和野外调查,进一步减小不确定性,逐步解决尺度推移问题.区域生态风险评价必须与经济、社会、文化相结合,才能充分发挥它在管理决策中的作用.     

Planning Transboundary Ecological Risk Assessments at Military Installations

Ecological risk assessments at military installations that are performed to support natural resources management objectives rely on information from the surrounding region. Stressors such as noise, ozone, and ozone precursors cross installation boundaries, and effects of urbanization and highway development are regional in scale. Ecological populations are not limited to one side of the installation boundary. Therefore, a framework for transboundary ecological risk assessment at military installations is under development. This article summarizes the problem formulation stage. Components include: (1) regional management goals such as installation Integrated Natural Resources Management Plans and land acquisition, (2) involvement of multiple stressors, and (3) large-scale assessment endpoint entities. Challenges of selecting measures of exposure include: quantifying exposure to aggregate stressors, describing land cover consistently in the region, describing rates of land-cover transition, scaling local measurements to a region, and aggregating or isolating exposures from within and outside of the installation. Measures of effect that are important to transboundary or regional ecological risk assessments at military installations are those that represent: effects at a distance from the stressor, large-scale effects, effects of habitat change or fragmentation, spatial extrapolations of localized effects, and integrated effects of multiple stressors. These factors are reflected in conceptual models.     

2022年冬奥会崇礼赛区多重压力下生态风险评价

冬奥会这类重大体育赛事对举办城市的经济转型、城市功能升级、竞争力提升等方面具有助推效应,而其带来的生态影响也不容小觑。近年随着赛事规模的不断扩大和户外场馆的建设,冬奥会导致的生态风险愈加突出。然而,对于规模大、历时长的冬奥会复杂生态风险目前还缺乏定量评价方法。研究旨在探讨一种区域生态风险评价方法,即相对风险模型,并基于地理信息系统（GIS）定量评价冬奥会赛前准备阶段多重压力下的生态风险。选择2022年冬奥会崇礼赛区为案例区,构建压力-生境-终点三大要素组成的相对风险模型,将整个崇礼划为6个风险分区,辨识了冬奥会赛前阶段包括各种人类生产、建设活动和自然因素的11类压力（威胁）、6类生境和4个评价终点,并确定了压力和生境的分级标准。压力分级评价结果显示,道路和交通活动的得分最高,得分最低的是火灾。生境相对等级评价表明,河流栖息地的得分最高,得分最低的是湿地与景区滑雪场。从不同生态终点得分看,生物多样性的风险最高,娱乐休闲风险最低。总体区域风险评价表明,VI区四台嘴乡冬奥场馆核心区的风险得分最高,而风险最低的为III区,包括石嘴子乡和驿马图乡。最后,对相对风险评价的不确定性进行分析,并讨论其优缺点。总之,尽管存在不确定性,相对方法模型仍被认为是评估和优先考虑多个资产的多重压力风险的稳健方法,也是决策者确定管理行动优先级的有用筛选工具。研究证明了相对风险模型方法评估2022年冬奥会主办地风险的可行性,研究结果明确了崇礼区恢复工作的重点区域和压力,对冬奥会的可持续管理和地方发展具有重要参考价值。     

A Procedure for Ecological Tiered Assessment of Risks (PETAR)

Several procedures for Ecological Risk Assessment (ERA) have been suggested. The use of these existing procedures often relies on availability of existing data and/or on large resources for acquisition of new ones. This paper presents a three-tiered procedure for retrospective evaluation of risks adapted to limited resources and scarce background information of relevance for risk assessments, such as in developing countries. The tiers require successively more detailed investigations. The approach assures that resources available for site-specific investigations are directed towards well-formulated questions raised during previous stages of the assessment. The first tier, the preliminary assessment, is a qualitative evaluation of existing information on anthropogenic stressors, sources of stressors and expected ecological effects. The second tier is a regional risk assessment; a semi-quantitative evaluation of ecological risks, over large geographical areas, which results in a ranking of sources and stressors having the greatest potential for ecological impact and ranking of subareas inside the study area more likely to be impacted. The final tier is a site-specific and quantitative risk assessment, at a smaller scale and requiring more resources, that incorporates methodologies for establishing causality between exposure to multiple stressors and effects on specific endpoints of ecological and societal relevance.     

Regional Risk Assessment of a Brazilian Rain Forest Reserve

The objective of this study was to identify subareas inside and near an Atlantic Rain Forest reserve, the Parque Estadual Turístico do Alto Ribeira (PETAR), most likely to be affected by land use in the vicinity of the area. In addition, the study aimed to compare risks per stressor source (agriculture, human settlements and mining) to both epigean (surface) and hypogean (subterranean) aquatic fauna. The methodological approach included the relative vulnerability of endpoints to the stressors (pesticides, metals, nutrients, and particles) and ranking of stressor sources and habitats (epigean and hypogean streams) based on their relative distribution in 14 subareas within the catchment areas of the main rivers that cross PETAR: Pilões, Betari and Iporanga. Four subareas presented high risk for both epigean and hypogean fauna. Three of those areas were located inside the Betari catchment area, where most of the settlements and abandoned lead mines are located. The fourth area was situated in the headwaters of the Pilões River, where agricultural activities are intense. Agriculture and human settlements were the activities most likely to cause impacts on aquatic ecosystems. Uses of risk assessment results include management of the PETAR and communication to stakeholders by the Park Administration.     

区域生态风险评价的关键问题与展望

区域生态风险评价具有多风险因子、多风险受体、多评价终点、强调不确定性因素以及空间异质性的特点,它与传统的生态风险评价在风险源、胁迫因子和评价尺度上具有明显区别。尝试建立了一个基于陆地生态系统的区域生态风险评价框架,同时针对目前区域生态风险评价的研究现状,指出不确定性分析、尺度外推难、评价指标不统一、评价标准不统一、风险因子筛选及优先排序、区域内污染物复合、水生过渡到陆生生态系统风险评价、特殊的人为因素等是目前区域生态风险评价存在的关键问题及难点所在,并提出解决这些问题可能所需的工具、手段和理论方法突破。最后指出区域生态风险观测与数据采集加工、区域生态风险指标体系的统一与整合、区域生态风险评价方法论、区域生态风险的空间分布特征与表达以及区域生态风险评价反馈与管理机制5个方面是区域生态风险评价未来的研究重点。     

A Pilot Application of Regional Scale Risk Assessment to the Forestry Management of the Upper Grande Ronde Watershed,Oregon

An issue in forestry management has been the integration of a variety of different information into a threat analysis or risk assessment. In this instance, regional scale risk assessment was applied to the Upper Grande Ronde watershed in eastern Oregon to examine the potential of risk assessment for use in the management of broad landscapes. The site was a focus of study for the U.S. Forest Service through the Interior Northwest Landscape Analysis System (INLAS) project. In the study, a range of stressors, habitats, and endpoints were identified from previous studies in the watershed, and endpoints were determined from meeting with the primary stakeholder, the U.S. Forest Service. These endpoints were focused around the historic range of variability (HRV) defined for the area. The relative risk model (RRM) incorporating a Monte Carlo analysis was used as the analysis tool. The risk model output showed the HRV fire regime was the endpoint most at risk. The results of this analysis were compared to the Wallowa-Whitman National Forest prioritization of watershed restoration analysis. The RRM demonstrated similar results but with a better accounting for uncertainty. From this trial the RRM has proven to be a potential management tool for forestry management.     

区域生态风险评价——以呼和浩特市区为例

区域生态风险具有大尺度、多因素、多风险受体的特点,难以直接定量;从生态风险的定义出发,构建景观破碎度和面积加权生态价值指数评价区域生态风险,并以ArcGIS和Fragstats软件为研究平台,通过空间采样和插值方法得到区域生态风险的空间分布规律。以2006年Spot卫星遥感数据解译的呼和浩特市区土地利用图为例,研究结果表明生态风险值范围在0.04-0.26之间,空间梯度差异明显,风险较高区域为东北部的大青山山区以及西南角的平原农业区,北部风险驱动力主要来自土壤侵蚀、地下水源地水位下降、水质恶化以及林地的退化;南部则是快速工业化导致林地、草地、特别是耕地景观转换为居民与工矿用地景观。案例研究结果表明所建方法直观、简便,可定量描述区域景观生态风险的相对大小和空间分布规律。     

The Apache Longbow–Hellfire Missile Test at Yuma Proving Ground: Introduction and Problem Formulation for a Multiple Stressor Risk Assessment

An ecological risk assessment was conducted at Yuma Proving Ground, Arizona, as a demonstration of the Military Ecological Risk Assessment Framework (MERAF). The focus of the assessment was a testing program at the Cibola Range, which involved an Apache Longbow helicopter firing Hellfire missiles at moving targets, that is, M60-A1 tanks. The problem formulation for the assessment included conceptual models for three component activities of the test, helicopter overflight, missile firing, and tracked vehicle movement, and two ecological endpoint entities, woody desert wash communities and desert mule deer (Odocoileus hemionus crooki) populations. An activity-specific risk assessment framework was available to provide guidance for assessing risks associated with aircraft overflights. Key environmental features of the assessment area include barren desert pavement and tree-lined desert washes. The primary stressors associated with helicopter overflights were sound and the view of the aircraft. The primary stressor associated with Hellfire missile firing was sound. The principal stressor associated with tracked vehicle movement was soil disturbance, and a resulting, secondary stressor was hydrological change. Water loss to desert washes and wash vegetation was expected to result from increased ponding, infiltration, and/or evaporation associated with disturbances to desert pavement. A plan for estimating integrated risks from the three military activities was included in the problem formulation.     

Ten Years of the Relative Risk Model and Regional Scale Ecological Risk Assessment

It has been 10 years since the publication of the relative risk model (RRM) for regional scale ecological risk assessment. The approach has since been used successfully for a variety of freshwater, marine, and terrestrial environments in North America, South America, and Australia. During this period the types of stressors have been expanded to include more than contaminants. Invasive species, habitat loss, stream alteration and blockage, temperature, change in land use, and climate have been incorporated into the assessments. Major developments in the RRM have included the extensive use of geographical information systems, uncertainty analysis using Monte Carlo techniques, and its application to retrospective assessments to determine causation. The future uses of the RRM include assessments for forestry and conservation management, an increasing use in invasive species evaluation, and in sustainability. Developments in risk communication, the use of Bayesian approaches, and in uncertainty analyses are on the horizon.     

Conceptual Model Development for Invasive Species and a Regional Risk Assessment Case Study: The European Green Crab,Carcinus maenas,at Cherry Point,Washington, USA

The goal of this article was to generate a method of regional scale ecological risk assessment using an adaptation Relative Risk Model (RRM). As a case study we performed a quantitative, regional risk assessment of an invasive species, the European green crab (Carcinus maenas) at Cherry Point, Washington, USA. The conceptual model was modified from the RRM and incorporates the structure of the hierarchical patch dynamic paradigm. The ranks and filters were integrated to determine the relative contribution of each source of C. maenas to risk as well as the risk to selected biological endpoints, habitats and sub-regions for two source scenarios: (1) current conditions (2004) and (2) future conditions during an El Nino year. The results suggest that the habitat and endpoint with the greatest risk are the eelgrass habitat and the juvenile Dungeness crab, respectively. The Cherry Point subregion was identified as the area having the most risk in the first source scenario, while the Lummi Bay sub-region is most at risk during an El Nino event. The risk of impacts is substantially higher for all endpoints, habitats and sub-regions when El Nino–driven current dispersal is considered. The methodology applied in this case study can be modified and applied to determine the risk of introduction and impacts of other invasive species to the Strait of Georgia, Puget Sound, and other coastal areas.     

Assessment of the biological health of the Brantas River, East Java, Indonesia using the Australian River Assessment System (AUSRIVAS) methodology

This study aimed to evaluate the applicability of the Australian River Assessment System (AUSRIVAS) bioassessment methodology to assess the biological health of streams in the upper-middle Brantas River catchment, East Java, Indonesia. A total of 84 `minimally disturbed' reference sites were selected and sampled for macroinvertebrates in riffle habitats. Sampling of macroinvertebrates and identification to family level was conducted by local biologists following intensive training, and under supervision. A quality control protocol was introduced to ensure the data were reliable and reproducible. A suite of `potential predictor' and `monitoring' environmental variables were also measured at each site. The macroinvertebrate data were used to develop a predictive AUSRIVAS model for the upper-middle Brantas river, and the model was then used to assess the `health' of 15 test sites in the catchment. Bioassessment outputs – Observed (O)/Expected (E) ratios – were found to be broadly related to measures of physical disturbance from land use and riparian degradation. Through the process of local reference site selection and sampling, model development, validation and subsequent use, the Australian AUSRIVAS rapid bioassessment method was assessed as being highly applicable to the upper-middle catchment sections of Indonesian river systems.     

A Bayesian Approach to Landscape Ecological Risk Assessment Applied to the Upper Grande Ronde Watershed,Oregon

We present a Bayesian network model based on the ecological risk assessment framework to evaluate potential impacts to habitats and resources resulting from wildfire, grazing, forest management activities, and insect outbreaks in a forested landscape in northeastern Oregon. The Bayesian network structure consisted of three tiers of nodes: landscape disturbances, habitats, and the ecological resources or endpoints of interest to land managers. Nodes at each tier were linked to lower nodes if ecological and spatial relationships existed between them. All parameters had four potential discrete states: zero, low, medium, and high. Our model reliably predicted probable risk to habitats and endpoints from natural and anthropogenic disturbances. The disturbances most likely to transform habitats and effect ecological resources were forest management and wildfire. Of the six habitats, moist forest (characterized by Douglas fir and grand fir) was found to be at greatest risk of ecological impacts. The management endpoint with the highest likelihood of impact was historical range of variability (HRV) for salmon habitat, followed by recreation (hunting native ungulates) and HRV wildfire. We found that the Bayesian approach to ecological risk assessment was a useful method to assess potential impacts to ecological resources resulting from forest management and natural disturbances.