Risk Analysis

Cover image for Vol. 36 Issue 5

Edited By: L. Anthony Cox, Jr.

Impact Factor: 2.502

ISI Journal Citation Reports © Ranking: 2014: 5/46 (Social Sciences Mathematical Methods); 9/99 (Mathematics Interdisciplinary Applications)

Online ISSN: 1539-6924

Special Issue: Ecological Risk Assessment

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Special Issue: Ecological Risk Assessment in Risk Analysis

Editor: Wayne G. Landis

This virtual issue presents 25 of the key papers on ecological risk assessment to appear in Risk Analysis since its founding. In the early part of the 1980s, the field of ecological risk assessment had not yet been recognized as a unique discipline. The US Environmental Protection Agency framework or guidance about ecological risk had not been developed. Initial growth of the field started in the 1990s, and by the early 21st century, risk assessments about non-indigenous species and conservation biology began to appear. Currently, Risk Analysis still publishes papers on contaminants in the ecological environment, but risk assessment for other kinds of ecological stressors constitute among the leading papers of the journal.

The next sections represent my evaluation of all the ecological risk assessment papers in the journal. Picking 25 papers for this virtual issue was a challenge. My criteria were simple. Identify papers that were: (1) important markers in the development of ecological risk assessment and (2) illustrate a broad range of topics in ecological risk analysis. I hope you enjoy reading through these articles and thinking about their implications, I enjoyed the exercise of going through all our papers and thinking about this selection.

1980s and 1990s: The Beginnings of Ecological Risk Assessment

2000-Present: The Broadening of Ecological Risk Assessment

Nonindigenous Species and Conservation

Risk Communication

Contaminated Sites and Chemicals

What’s Next?: The Future of Ecological Risk Assessment

1980s and 1990s: The Beginnings of Ecological Risk Assessment

Several of the key topics in the field of ecological risk assessment were presented during the journal’s first decade.

The first paper in Risk Analysis that is recognizable as an ecological risk assessment was by Stewart and Leschine (1986) and examined risks due to oil spills. This paper appeared three years before the Exxon Valdez Oil spill and remains an interesting read.

I found climate change as a risk assessment topic as far back as the 1980s. Lave and Vickland (1989) examined the impacts of sea level rise and other effects on a number of cultures.

The 1980s and 1990s were dominated by papers dealing with contaminated sites and the development of probabilistic tools for calculating risk. There were three notable exceptions. The introduction of species into new environments has been a topic we covered. For example, Meindert de Jong (1992) published the first risk assessment for the introduction of a biological control organism into the environment. Harris et al followed this up in 1999; biological introductions were viewed as an important research subject.

Burgman et al (1999) introduced the use of ecological risk assessment in the analysis of conservation practices for threatened and endangered species. This area of research becomes one of the key topic areas of the journal.

Suter et al (1995) tackled one of the thorniest issues in risk assessment, how to combine human health assessment and ecological assessment. Seventeen years later it is still not clear how to integrate these approaches.

Risk perception and communications for ecological risk assessments emerged as an area of study. McDaniels et al (1995) started the literature in the journal that specifically deals with the perception of risk as calculated in ecological risk assessments.

Judgment and analysis in oil spill risk assessment
Stewart T, Leschine T.
1986; 6(3):305-315.

Adjusting to greenhouse effects: The demise of traditional cultures and the cost to the USA
Lave L, Vickland KH.
1989; 9(3):283-291.

Risk assessment for the application of biological control of a forest weed by a common plant pathogenic fungus
de Jong M.
1992; 12(4):465-466.

An approach for balancing health and ecological risks at hazardous waste sites
Suter II G, Cornaby B, Hadden C, Hull R, Stack M, Zafran F.
1995; 15(2):221-231.

Uncertainty in comparative risk analysis for threatened Australian plant species
Burgman M, Keith D, Walshe T.
1999; 19(4):585-598.

Characterizing perception of ecological risk
McDaniels T, Axelrod L, Slovic P.
1995; 15(5):575-588.

2000-Present: The Broadening of Ecological Risk Assessment

A major trend in Risk Analysis has been the expanding of risk assessment beyond its use for chemicals and contaminated sites. One of the draws of the Society for Risk Analysis and the journal to me has been the breadth of subject areas that are welcomed in the journal. Ecological risk assessment in many other journals seems focused on contaminants, but Risk Analysis has welcomed other applications of the science.

Nonindigenous Species and Conservation

Mark C. Anderson of New Mexico State University was the coordinating editor for a series of papers in 2004 that established the journal as a venue for the risk assessment of non-indigenous or invasive species. Four of the papers from this series are presented in the list. These are key papers setting some of the important parameters for conducting risk assessments in this area. Anderson et al (2004) summarized the broad findings of the papers published in this issue. Marvier et al (2004) discussed the interactions between habitat, disturbance and fragmentation in setting the risk for invasion. With (2004) furthers the discussion, stressing the importance of the structure of the landscape in setting probabilities of invasion.

Stepien et al (2005) demonstrated that the invasive fish in the Great Lakes were likely from multiple invasions. In calculating risk for non-indigenous species, this is an important result. Multiple invasions occurred, at least in this case. Deines et al (2005) created a patch dynamic incorporating the invasion by a non-indigenous species, competition and contamination. The dynamics of a beachhead effect were described in this paper. Notably, both Deines and Chen were undergraduates at the time.

Yemshanov and Koch (Yemshanov et al 2009, Koch et al 2009) produced two of the most complete risk assessment papers dealing with pest invasions. These papers incorporated both the stochastic and spatial nature of the invasion process. These helped set the standard for the risk analysis of non-indigenous species. Also appearing during the same timeframe, Cook et al (2009) discussed the regulatory and response framework for the management of biosecurity. This paper represents the breadth of the journal, dealing with both the science of invasion and the regulation-management.

In February of 2010, an entire issue of Risk Analysis was dedicated to ecological risk assessment and a number of papers in this special issue are from that series. Burgman et al (2010) discussed the use of Bayes nets in an invasive species risk assessment. This is one of the first papers to discuss the use of Bayes nets in this application. Walshe and Burgman (2010) presented a framework for managing invasive species, so the theoretical and practical were both presented for non-indigenous species. Landis and Bryant (2010) used a weight of evidence approach and used the framework of an age structured probabilistic population model to examine the various causes of the decline of Pacific herring in Puget Sound.

Risk analysis for invasive species: General framework and research needs
Andersen MC, Adams H, Hope B, Powell M.
2004; 24(4):893–900.

Habitat destruction, fragmentation, and disturbance promote invasion by habitat generalists in a multispecies metapopulation
Marvier M, Kareiva P, Neubert MG.
2004; 24(4):869–878.

Assessing the risk of invasive spread in fragmented landscapes
With KA.
2004; 24(4):803–815.

Spatial risk assessment across large landscapes with varied land use: Lessons from a conservation assessment of military lands
Andersen MC, Thompson B, Boykin K.
2004; 24(5):1231–1242.

Genetic diversity of invasive species in the Great Lakes versus their Eurasian source populations: Insights for risk analysis
Stepien CA, Brown JE, Neilson ME, Tumeo MA.
2005; 25(4):1043–1060.

Modeling the risks of nonindigenous species introductions using a patch-dynamics approach incorporating contaminant effects as a disturbance
Deines AM, Chen VC, Landis WG.
2005; 25(6):1637–1651.

Mapping invasive species risks with stochastic models: A cross-border United States-Canada application for Sirex noctilio Fabricius
Yemshanov D, Koch FH, McKenney DW, Downing MC, Sapio F.
2009; 29(6):868–884.

Evaluating critical uncertainty thresholds in a spatial model of forest pest invasion risk
Koch FH, Yemshanov D, McKenney DW, Smith WD.
2009; 29(9):1227–1241.

Adaptive approaches to biosecurity governance
Cook DC, Liu S, Murphy B, Lonsdale WM.
2010; 30(9):1303–1314.

Reconciling uncertain costs and benefits in Bayes nets for invasive species management
Burgman MA, Wintle BA, Thompson CA, Moilanen A, Runge MC, Ben-Haim Y.
2010; 30(2):277–284.

A framework for assessing and managing risks posed by emerging diseases
Walshe T, Burgman M.
2010; 30(2):236–249.

Using weight of evidence characterization and modeling to investigate the cause of the changes in Pacific Herring (Clupea pallasi) population dynamics in Puget Sound and at Cherry Point, Washington
Landis WG, Bryant PT.
2010; 30(2):183–202.

Risk Communication

Risk communication for ecological risk assessment has also been part of the dialog in Risk Analysis. Slimak and Dietz (2006) wrote one of the earliest pieces dealing specifically with ecological risk assessment. Mozumder et al (2009) pointed to the difficulties of communicating risk, even one as apparent as wildfire, to the public. Risk communication is one of the most challenging aspects of the field of risk analysis.

Personal values, beliefs, and ecological risk perception
Slimak MW, Dietz T.
2006; 26(6):1689–1705.

Provision of a wildfire risk map: Informing residents in the wildland urban interface
Mozumder P, Helton R, Berrens RP.
2009; 29(11)1588–1600.

Contaminated Sites and Chemicals

This final segment takes the special issue to the roots of risk analysis. The Society for Risk Analysis was created in part as a response to contaminated site cleanup after the passage of Superfund. Contaminant issues are still an important part of the dialog in the journal.

Bengtsson and Törneman (2009) apply spatial analysis to the risk assessment of PAHs. Although spatially explicit assessments have been part of conservation and non-indigenous risk assessments, they are not as often applied to contaminated sites. This is a nice example of such an application.

Banks et al (2010) and Mebane (2010) are two more papers from the February 2010 dedicated ecological risk assessment volume. Banks et al sets as a criterion that life history strategy is critical when extrapolating toxicity data from species to species. The toxicity has population scale effects that are necessary to take into account, although to date this is rarely done. Mebane (2010) investigates the ecological relevance of species sensitivity distributions for predicting sensitivity. This is one of the few papers that are explicit about the population and community scales in using the species sensitivity distribution in risk analysis.

Linkov et al (2011) detailed the use of multicriteria decision analysis and its application to a weight of evidence approach. It has become apparent that often weight of analysis is so qualitative that a variety of outcomes can be realized from very similar sets of data. Linkov et al demonstrated that multicriteria decision analysis adds rigor to the application of weight of evidence approaches.

Gibbs (2011) calls for testing risk predictions in the most recent article included in this special issue. I learned a while ago that generating hypotheses, generating predictions and then testing those predictions were required for science. One of the criticisms I often hear of risk analysis is that it is a technique and not science. Gibbs points out that testing risk predictions should be part of the risk analysis process.

A spatial approach to environmental risk assessment of PAH contamination
Bengtsson G, Törneman N.
2009; 29(1):48–61.

The use of surrogate species in risk assessment: Using life history data to safeguard against false negatives
Banks JE, Ackleh AS, Stark JD.
2010; 30(2):175–182.

Relevance of risk predictions derived from a chronic species sensitivity distribution with cadmium to aquatic populations and ecosystems
Mebane CA.
2010; 30(2):203–223.

Use of multicriteria decision analysis to support weight of evidence evaluation
Linkov I, Welle P, Loney D, Tkachuk A, Canis L, Kim JB, Bridges T.
2011; 31(8):1211–1225.

Ecological risk assessment, prediction, and assessing risk predictions
Gibbs M.
2011; 31(11):1784–1788.

What’s Next?: The Future of Ecological Risk Assessment

So after covering 32 years of ecological risk assessment in the pages of Risk Analysis, it is perhaps time to look to the future. I will not pretend to see out another 32 years. Most of the analyses that I conduct in my research were not really possible until the late 1990s and early 2000s. My horizon is then somewhat shorter, the next 5 to 10 years or the introduction of the iPad 7.

The first section describes a critical current and future priority, the confirmation of risk hypotheses. It is about time to see papers in Risk Analysis that demonstrate that ecological risk assessment provides predictions that can be confirmed. The final section contains my predictions of the future trends in the subjects in Risk Analysis.

Future Priority-Testing of Risk Assessment Hypotheses

An ecological risk assessment is a probabilistic prediction of a current situation or future event. Therefore the prediction should be testable or at least certain segments of the assessment confirmable. Yet in my survey of the publications in Risk Analysis I do not find a specific publication where the goal of the study was to confirm an ecological risk assessment prediction. Here are several examples of how confirmation can be accomplished. I am sure that the risk assessment community can come up with other suggestions.

Sampling and analysis of a site after a risk assessment to confirm the risk prediction. This method seems so obvious but seems not to be a common occurrence, judging by the list of publications. In fact, a risk assessment should probably be initiated as a first step before extensive sampling is conducted to make the entire process more efficient and oriented towards the testing of a risk-based hypothesis. Part of the risk assessment prediction can be the patterns of risk in a landscape. The measurements could include changes in community structure, productivity, water quality, invasion by nonindigenous species or other endpoints. Given the probabilistic nature of risk assessment the hypothesis will be a pattern of distributions.

Use risk assessment to predict the outcome of a management strategy and then conduct follow on studies to confirm the hypothesis. Part of the management strategy should include the types of studies that make this process possible.

Changes in age structure or other features of a population (genetic diversity, patch dynamics) can be predicted and then tested by field observation. In some cases historic catch data may be used to see if current status and trends can be successfully predicted.

Biomarkers may be expressed or genes activated upon exposure to specific toxicants or other stressors. The use of these tools can confirm exposure pathways and at least part of the cause-effect pathway.

Conduct a laboratory or outdoor controlled study where the risk assessment process is used to generate predictions regarding outcomes, and then design those controlled studies to specifically test those predictions. While it is unlikely that the scale of a watershed or regional scale risk assessment could be matched in this manner, components of these types of assessment could be examined in detail.

Use historical data to predict current conditions. For many sites historic data on contamination, the status of endpoints, the rate of colonization of invasives, for example, exists. Use this information to estimate risk and see how it matches to current conditions.

An added benefit to the field is that having the risk assessments subject to confirmation should force the process to become more specific in its calculation of effects. In fact, why not make every risk assessment have a list of confirmable features that can be tested? It will be interesting to see if the field of ecological risk assessment can meet this challenge.

Future Topics in Risk Analysis

In Risk Analysis, the subjects of ecological risk analysis have been very broad and now regularly include non-indigenous species, natural resource management and disease. These are topics far removed from the contaminated site issues that used to dominate the field. In the future I expect that these non-contaminant subjects will increase and even dominate the field. As global climate change causes landscapes to become altered, these issues will be universal and the management issues profound.

Climate change is a profound driver of environmental alteration. At a recent conference at Wingspread Wisconsin,1 global climate change was recognized as profoundly impacting ecological risk assessment. Many of the assumptions such as baseline conditions, consistency of fate and transport rates, exposure, and biomagnification and toxic response will not hold. As climate changes so will the ranges of current species and non-indigenous species. Depending upon the endpoint or ecosystem service, the influence of climate change may produce negative or even positive changes. I expect this new field to be one of the growing areas in the ecological risk assessment literature.

Related to climate change is the issue of energy extraction, production and transportation. Processes such as fracking (hydraulic fracturing) are being extensively discussed and should be examined using risk analysis. Extracting energy using deep water drilling and transportation of the crude or refined product will continue and should continue as a topic for the journal. There is no reason that this topic should be only fossil fuels. Solar, wind and hydroelectric energy are also fair game for such an in-depth analysis.

A trend in the past has been the development of more sophisticated methods of conducting risk analysis. Multiple criteria decision-making will likely see an expansion. Application of Bayesian networks and influence diagrams is expanding and I hope that we see more of that in the pages of our journal.

The use of age-structured population models will become a more common way of addressing population-scale impacts. The realization that populations often occur as patches within a heterogeneous environment is becoming a paradigm in the invasive species literature. Now it needs to spread to the contaminant related investigations.

I see the end of the risk quotient as a means of estimating risk. That has essentially happened already if our recently published papers are a harbinger. Given the complexity of ecological systems and their dynamic nature, reducing a decision to a simple ratio now seems to me as an act of desperation.

Final Thoughts

Perhaps the most amusing part of this exercise is when the future ecological risk assessment editor of Risk Analysis looks at this list in ten years and compares it to the papers published in the last decade. I am looking forward to reading their analysis and predictions.

1 The influence of global climate change on the scientific foundations and applications of environmental toxicology and chemistry. A Society of Environmental Toxicology and Chemistry Pellston Conference held at the Wingspread Conference Center, Racine, Wisconsin, July 16-21.