©2002 CRC Press LLC Ecological Risk Assessment in Coastal and Estuarine Environments Michael C. Newman, Robert C. Hale, and Morris H. Roberts, Jr. CONTENTS 13.1 Introduction 13.2 Chapter Contributions to Coastal and Estuarine Risk Assessment 13.3 Conclusion References 13.1 INTRODUCTION Hearing the rising tide, I think how it is pressing also against other shores I know … — Rachel Carson 1 When Rachel Carson published Silent Spring , 2 she had already established her reputation by authoring two popular books, Under the Sea Wind 3 and The Edge of the Sea . 1 This being the case, it is puzzling that Silent Spring , a book literally changing how we view our relationship with our environment, contained so little material about marine pollution. Such inconsistencies about marine environments were commonplace at that time. At the same time that the last two books were published, the first author spent many indolent hours as a child on a particular Long Island Sound beach, alternately watching for dolphins on the horizon and, at the sand’s edge, watching rats scurrying between the riprap in search of edible garbage. Much more effort was spent scanning for surfacing dolphins than watching the rats compete for garbage. Tar balls and rusty aerosol cans were as plentiful in the drift zone as were skate egg cases and strings of whelk eggs. At one end of the beach was a picturesque New England lighthouse silhouetted against plumes of smoke rising above the Bridgeport city dump. Coastal pollution was as obvious as that in nearby streams, lakes, and lands, but, for the coastal and estuarine habitats, the eye 13 ©2002 CRC Press LLC was drawn more to attractive, not degraded, seaside features. The tide of contami- nation was similarly rising in other coastal environs but was viewed only peripherally. We focused on the aesthetic and recreational pleasures of the coast. Although much less apparent today, remnants of this tendency to ignore the evidence of degradation exist in our activities. What are the roots of this incongruity? A review of current U.S. environmental legislation 4,5 indicates that a lack of legal mandates was not the reason. Ample legislation included the overarching National Environmental Protection Act (1969); Marine Mammal Protection Act (1972); Coastal Zone Management Act (1972); Clean Water Act (1972); Federal Water Pollution Control Act (1977); Marine Pro- tection Research and Sanctuaries Act (1972), especially Chapter 27 and amendments in the Ocean Dumping Ban (1988); the Comprehensive Environmental Response, Compensation and Liability Act (1980) as amended by the Superfund Amendments and Reauthorization Act (1986), which established a risk assessment context; the Organotin Antifouling Paint Control Act (1988); the Ocean Dumping Ban (1988); and the Oil Pollution Act (1990). The need was equally obvious and legislative initiatives were nearly as timely for stewardship for marine as for freshwater and land resources. Full consideration of coastal and estuarine pollution was delayed by cultural biases. There were contrasting romantic and pragmatic delusions about the oceans that delayed action as incisive as that made for freshwater and land stewardship. Deeply embedded attitudes and complex use patterns regarding marine resources made marine regulation more difficult. For example, conse- quences of complex, traditional use patterns coupled with efficient modern fishing gear are manifest in the current worldwide decline of marine fisheries. 6 In contrast to a complex of mores surrounding land ownership and obligations associated with terrestrial landscapes, tradition associated with coastal resources emerged more from the concept of the commons. Laissez-faire mores for com- mons use resulted in a higher risk of degradation with coastal resources compared with terrestrial resources. Perhaps more importantly, our culture has consistently portrayed the ocean as larger than humankind, a relationship reflected in innumerable literary works. Humans might be overpowered by the seas, but not vice versa. This sense that the ocean was too vast to be adversely impacted delayed rejection of “the solution to pollution is dilution” paradigm for marine systems. One piece of evidence for this mind-set was the relatively late passage of the Ocean Dumping Ban (1988) amend- ment to the Marine Protection Research and Sanctuaries Act (1972). Despite an initial delay, the capacity of coastal and estuarine environments to absorb the cumulative loading of contaminants is now the focus of much insightful research and effective action. Key aspects of marine pollution are being synthe- sized; for example, see Reference 7. An entire issue of the leading journal, Environmental Toxicology and Chemistry (Vol. 20, No. 1, 2001) was recently devoted to toxicant chemistry, effect, and risk assessment in marine and coastal systems. (However, only one article in the journal issue addressed risk assessment.) In the lead editorial, Scott 8 emphasized the importance of studying contaminants in coastal systems: ©2002 CRC Press LLC … [The coastal] zone represents 8% of the planet’s surface but is the source of 26% of the world’s primary productivity. More than 76% of all commercially and recre- ationally important fish and shellfish species are estuarine-dependent. Only recently have these coastal areas been recognized as resource bases of national significance and also among the nation’s most highly stressed natural systems. … Historically, the focus of environmental toxicology and risk assessment has been on rivers and lakes. The available dilution in near-coastal areas was thought to mitigate adverse effects of anthropogenic contaminants. However, this perception has changed because of constantly increasing population densities and scientific evidence of envi- ronmental degradation. Approximately 44% of U.S. estuaries, assessed in 1998 for environmental quality, were impaired. The complexity of attitudes, uses, and stressors impinging on coastal and estu- arine systems is now being confronted directly and fully. A recent issue of Limnology and Oceanography (Vol. 44, No. 3, 1999) was dedicated to multiple stressors in freshwater and marine ecosystems. Marine ecosystems discussed in that issue range widely from southeastern U.S. estuaries and bays, northeastern U.S. harbors, and coral reefs (Florida Keys reef system and Great Barrier Reef). Integrated coastal planning and assessment activities are becoming more prominent (e.g., References 9 and 10), including those for acutely endangered systems such as coral reefs (e.g., References 11 and 12). Despite recent progress, implementation of the ecological risk assessment par- adigm to coastal and estuarine ecosystems still lags behind that for freshwater and terrestrial systems. As an example, the excellent treatments of ecological risk assess- ment written by Suter and colleagues 13,14 provide limited coverage of assessments of coastal and estuarine systems. The U.S. EPA Guidelines for Ecological Risk Assessment 15 requires considerable augmentation prior to optimal use for coastal and estuarine systems. Enrichment of the ecological risk assessment paradigm is the next crucial step in eliminating the differences in effective environmental stewardship for marine, freshwater, and terrestrial environments. The chapters contained in this edited book were developed with that goal in mind. 13.2 CHAPTER CONTRIBUTIONS TO COASTAL AND ESTUARINE RISK ASSESSMENT In this brief summary chapter, the preceding chapters will be placed into the context of the current ecological risk assessment paradigm (see Chapter 1). The framework for discussion will be Figure 1.1 (reproduced here) from Chapter 1 in which the steps of ecological risk assessments are diagrammed. The intent of Chapter 1 was to provide a context for ecological risk assessment in estuarine and coastal regions, to describe major sources of information applicable to risk assessments in these environments, and to highlight areas needing special attention during assessments in marine systems. Strong and dynamic gradients, e.g., salinity and hydraulic flow, dominate the ecology and chemistry of these systems, and their influence must be considered in estuarine risk assessments more than in ©2002 CRC Press LLC other environments. By their nature, coastal and estuarine environments are transition zones within landscapes. Risk assessments must fully consider relevant landscape features, e.g., the contaminant loadings in river discharge into an estuary or the land use around the estuary proper. Further, as is the case for all ecotones, crucial features The ecological risk assessment paradigm as presented by the U.S. EPA (see Chapter 1 for further detail). ©2002 CRC Press LLC of coastal environments cannot be captured solely by envisioning them as ecosystems existing between adjacent ecosystems. The ecotone framework may be equally, or more, important than the ecosystem context underpinning problem formulation in most ecological risk assessments. Currently, several general methods are applied for identifying hazards in coastal and estuarine systems, and these methods generate important information applicable to risk assessments. Methods currently include water quality criteria generation, sediment quality guidelines, and toxics characterization methods. While the criteria and guidelines have utility for management, the tools of probabilistic risk assessment can improve our ability to protect marine and other environmental resources. The European, or more specifically European Union (EU), context for coastal and estuarine risk assessments was explored in Chapter 2. Consequently, this chapter covered all aspects of the risk assessment paradigm diagrammed in the figure, but from a European perspective. After outlining the political institutions of the EU, the authors discussed how environmental legislation is promulgated, a process distinct from that in the United States. Under existing and developing legislation, both prospective and retrospective risk assessment are primary tools used in the management of hazardous chemicals. In both cases, the focus is the hazard quotient approach, although probabilistic risk assessment approaches are being evaluated for incorporation into future directives. At present, difficulties arising from incomplete information regarding existing and new chemicals are acknowledged as the reason for delay in actual management of many chemicals even when impacts of their use are apparent. In the EU, no action is taken to regulate a material until the risk assessment is complete. Many people conclude from the resulting conundrum that the EU should apply the controversial Precautionary Principle, that is, to take regulatory action to prevent present or possible impacts while the risk assessment proceeds. Reflecting the theme discussed in the introduction to this chapter, the predom- inant freshwater focus was acknowledged for risk assessment and discussed in the context of using the more abundant data for freshwater species to predict conse- quences to saltwater species. The EU approach to saltwater assessments is described in detail, including current shortcomings. The use of freshwater species data to predict risks to saltwater species is a significant shortcoming that applies not only to the EU but also to the United States (see Chapter 1). To change the current practice effectively will require substantially more data for marine species. The authors of Chapter 3 addressed emerging contaminants of concern and provided examples of several classes. They discussed chemicals underemphasized in current research, legislation, and risk assessments and those that may elicit inadequately studied effects, such as endocrine disruption discussed in Chapter 8. Their treatment here contributes directly to the “problem formulation” and “exposure analysis” components of the risk assessment paradigm (see the figure). Emphasis was on assuring that these important contaminants are more fully considered in assessments of multiple stressors in freshwater, estuarine, and coastal environments. Emerging toxicants are those recently introduced in significant amounts, those historically ignored in environmental regulation and risk assessment, and those being applied now in new ways that require more careful scrutiny. Some priority pollutants ©2002 CRC Press LLC such as polychlorinated biphenyls (PCBs) are considered here as well because new knowledge has changed the context for considering their potential effects. Other emergent toxicants included brominated fire retardants, natural and synthetic estro- gens, alkylphenol polyethoxylates and related compounds, pharmaceutical agents, antimicrobial agents, and chemicals in personal care products. As one studies emerging toxicants, one is struck by the complexity of chemical mixtures that exist in various environments. Chemical mixtures may have synergistic or antagonistic effects that are inadequately considered in risk assessment because of our poor understanding of interactions. This observation calls into question the traditional chemical-by-chemical evaluation of environmental risk, also discussed in Chapters 1 and 2. Biosolids, sewage sludge destined for land application, are another interesting example of a complex stressor. Current regulation of these in the United States is based on incomplete risk assessments that consider only a subset of the contaminants present. For example, the nonylphenols and brominated diphenyl ethers, although present in biosolids in milligram per kilogram quantities, are not considered. Different objectives in assessing resulting risks in the EU vs. the United States also produce different conclusions. In the former, a “do no harm” approach is taken toward contaminant accumulation in receiving soils and effects on soil organisms. In the United States, the maximum allowable toxicant concentration (MATC) for the protection of humans and livestock is the end point of concern. This may relate to differing views of the environment with the perception in the United States that resources are less limited, akin to our attitude toward the oceans expressed earlier in this chapter. Chapter 4 discussed the causal assessment at the center of every risk assessment. It described inherent errors that emerge in informal methods used to generate pre- liminary and definitive statements of cause and effect. Qualitative methods of assign- ing causality were demonstrated with the example of notionally polycyclic aromatic hydrocarbon (PAH)-induced hepatic cancers in fish from contaminated coastal envi- ronments. The chapter then provided details of a formal, Bayesian approach that minimizes the likelihood of a mistake in the assessment of causality. An example was provided of quantitatively estimating the likelihood of a fish kill given the presence of Pfiesteria piscicida or a related complex of marine dinoflagellates. This chapter contributes especially to the problem formulation and risk characterization stages of the risk assessment paradigm, but also to all the other components that depend on identifying causal linkages between toxicants and effects. Three chapters addressed key issues relevant to the “analysis phase” of the risk assessment paradigm. Each chapter focused on a specific group of chemicals in the context of speciation, bioavailability, and effects. Chapter 5 provided details for both bioavailability and effects essential to the analysis phase of risk assessment for organic compounds present in the marine environment. Bioavailability from water, sediment, and food was discussed, including models for quantifying uptake. Mechanisms of xenobiotic metabolism and elimination were described. Considerable discussion was devoted to the mech- anisms of contaminant transformation to readily excreted metabolites and the adverse consequences occurring if a metabolite is more toxic or carcinogenic than the parent compound. ©2002 CRC Press LLC Chapter 6 emphasized bioavailability and bioaccumulation of metals, especially those of ionic mercury and methylmercury. It contributed directly to exposure anal- ysis (see the figure). The role of food chain transfer of metals from water to the target organism was discussed specifically as it pertains to mercury, but the author also discussed the role of this route for other metals. The author included a brief discussion of how dissolved organic material, particulate organic material, and acid volatile sulfides affect availability and uptake from water and sediment. The discus- sion reviewed environmental speciation of metals and the role that speciation plays in bioaccumulation and trophic transfer. Chapter 7 expanded considerably on the theme of metal exposure and effects to estuarine and coastal organisms. The theme of chemical speciation and its relationship to accumulation of metals was extended in this chapter to a consid- eration of how one uses this information in risk assessment to meet regulatory requirements. This included discussion of applying equilibrium models such as the Dynamic Multipathway Bioaccumulation Model (DYMBAM) to incorporate dissolved and dietary sources of metals into predictions of bioaccumulation. This chapter addressed many exposure and effects characterization issues of the analysis phase of a risk assessment. As discussed briefly in Chapter 3, the role of xenobiotics as endocrine-dis- rupting agents is becoming a major area of effects research for marine organisms. Chapter 8 dealt primarily with the ecological effects aspects of the analysis phase of the risk assessment paradigm for endocrine-disrupting agents, an increasingly important class of xenobiotics. The authors first summarized information about modes of action and effects in marine fish and invertebrates. Many modes of action and effects that were discussed for endocrine disruption extended discussions in previous chapters that focused on biotransformation and clearance of chemicals from tissues (Chapter 5) and emergent contaminants (Chapter 3). The authors then extended the review to describe methods for generating a coherent risk assessment strategy for endocrine disruptors with particular reference to marine organisms. This is a new application of the risk assessment paradigm that is likely to bring significant new issues to the discussion. The focused assessment of risk to marine mammals was the topic of Chapter 9. This chapter raised the issue of how to describe exposure (a major element in the analysis phase of the risk assessments process) for cetaceans, pinnipeds, and mus- telids. Most of these charismatic animals are not amenable to laboratory experimen- tation and legal issues often preclude controlled experimental exposures. Much discussion focused on determining toxicity reference values (TRVs) for persistent organochlorine (POC) compounds. The ultimate intent was to determine exposure dose to animals that cannot be readily sampled or subjected to experimental expo- sure. The authors then reviewed literature related to effects on marine mammals, noting that most studies were hampered by the sample size and life mode of these species. Finally, data from New Zealand marine mammals were used as a case study for a risk assessment. This risk analysis employed a hazard quotient approach that used the exposure and effects parameters as estimated by the methods described earlier in the chapter. The chapter thus addressed problem formulation and risk characterization in addition to effects and exposure assessments, resulting in a ©2002 CRC Press LLC general risk assessment for marine mammals exposed to POC compounds. However, end points of concern other than those elicited by dioxin-like chemicals may be important, e.g., the endocrine-disrupting agents discussed in Chapter 8. The remaining chapters shifted focus from effects at the suborganismal and individual levels to those at higher levels of biological organization. These three chapters looked to a more comprehensive risk analysis addressing populations, incorporating analyses of spatial and temporal heterogeneity. Chapter 10 presented a matrix model for predicting demographic consequences of chronic exposure to a pollutant. Data for a New Bedford Harbor (Massachusetts) fish population ( Fundulus heteroclitus ) chronically exposed to PCBs were used as a case study for model application. Interestingly, demographic projections from toxicological evaluations of fish naive to PCBs predicted poor population status. This prediction contrasted with the apparent robustness of the New Bedford Harbor population. Compensatory shifts including those related to life history and physio- logical adjustments were described that lead to increased potential for evolutionary effects. The authors suggested that a paucity of demographic data for the well-studied fish used in the case study contributed to the difficulty in deriving a retrospective model that accurately predicted the condition of the population. The authors pro- posed research at additional sites subject to different types of stressors to evaluate further the applicability of the model and to seek improvements in its use. The disparity between prediction and real populations raised the issue of dealing with risk assessment in a multigenerational context to account for adaptation of resident populations to the gradual introduction of contaminants that occurred historically. Chapter 11 considered population-based risk assessment in a complex land- scape. As mentioned above, such a landscape context can be essential in adequately defining risk to coastal and estuarine species. Although the modeled heron popu- lation described was lacustrine, the approach taken for this common coastal species is directly applicable to landscapes encompassing marine features and pollution. In this study, heron exposure to mercury was through their diet. A set of well- known models for uptake by various routes was integrated with demographic analysis. A metapopulation context for this analysis was developed using a Geo- graphical Information System (GIS) analysis of habitat and then applied to pre- dicting population consequences of exposure. Risk was estimated and placed into the context of different metapopulation scenarios including the presence of sig- nificant migration to compensate for excess mortality or depressed reproductive success. Important features of this population-level study were its spatially and demographically explicit structure. There was a similar landscape context for Chapter 12 that included an explicit recognition of the ultimate use of any risk assessment, i.e., risk management to reduce risk as suggested in Chapters 1 and 2. The potential or known incremental chemical risks for a highly modified urban estuary were emphasized in this chapter. The authors discussed the implications that apply to any implementation of risk management; one must understand that the human activities producing environmen- tal risk, especially in urban areas, are an unchangeable and persistent feature of the landscape that must be addressed in any risk assessment. This issue was alluded to in several earlier chapters. ©2002 CRC Press LLC The analysis stage of risk assessment was developed in a context described by the authors as an “ecological coincidence analysis.” This approach is one that assumes cause-and-effect relationships rather than attempting to demonstrate them. The distribution of stressors was compared to that of receptors to determine the extent of co-occurrence. Ecological coincidence was the central theme in their analysis and was based on the notion that there can be no effect if there is no co- occurrence. To demonstrate this principle, the authors used three U.S. examples including the Passaic River estuary in New Jersey, the Fox River lacustuary of Lake Michigan (Wisconsin), and the New York Harbor. Here, coincidence in both time and space was essential to the analysis. The ultimate result of such analyses was an estimate of time-dependent and site-specific dose for the exposure analysis. In the examples, specific estuarine considerations are included such as restriction of avian foraging on tidal flats to periods of low tide. Thus, differential exposure in time is not only a matter of historical (an issue raised in Chapter 10) and seasonal differences in spatial distribution of a receptor, but also differences on tidal scales. In the analysis, the potential for behaviorally mediated reduction in exposure was discussed. As in the preceding chapter, GIS methodologies played an important role in the analysis phase of the risk assessment process. Although the importance of stressor and receptor coincidence in time and space is not new, the use of the concept as a central element in specific estuarine landscape risk assessments brought the implications of the concept into sharper focus. 13.3 CONCLUSION The intent in developing this book was to accelerate the application of ecological risk assessment in coastal and estuarine systems. Despite the need for such assess- ments, the development of methods applicable to these systems has lagged behind those for freshwater and terrestrial systems. Coastal and estuarine environments have features unique or extreme relative to other environments; therefore, this special attention to risk assessment in these habitats is necessary. These tend to be environments with high risk of adverse impacts stemming from increasing and complex uses by humans. Assessment is particularly difficult due to the inherent complexity of these landscape features and the complex of human activities occur- ring within them. Each chapter provides information about or examples of applying the current ecological risk assessment paradigm to these unique and vulnerable environ- ments. Collectively, the authors suggest future directions that assessors can and should pursue. The authors in this book did not address risks to certain, highly valued habitats such as coral reefs or areas of low human population density such as coastal agricultural areas. Also, little attention was been given to the effects of contaminants on primary producers except relative to toxicant entry into the food chain. In this book, attention to estuarine or marine communities was limited. As we look to the future, these and other issues not included here must be given careful consideration in problem formulation, analysis, and, ultimately, risk characterization. Our risk assessments are never definitive, and the benefits of our risk management are always ©2002 CRC Press LLC uncertain without consideration of the full diversity of biological organization and stressor exposure. This may lend additional support for the Precautionary Principle, already gaining acceptance in the EU (Chapter 2). As we have learned in recent decades, the old paradigm is flawed that the sea exceeds our ability to decimate it. Even as we hasten to develop and implement new paradigms for environmental management to benefit the oceans, our industrial society is changing the environment without adequate attention to the preservation of vital resources. For our children and grandchildren to also enjoy indolent moments along estu- arine and coastal shores, either appropriate risk-based paradigms for reasoned action must be formulated or we must apply precautionary measures. It is our hope that the contents of this book will help in some small but meaningful way to convey the need for solutions to the problems emerging from our use of the coastal resource. REFERENCES 1. Carson, R., The Edge of the Sea , Houghton Mifflin, Boston, 1955. 2. Carson, R., Silent Spring , Houghton Mifflin, Boston, 1962. 3. Carson, R., Under the Sea Wind , Oxford University Press, New York, 1941. 4. Rand, G.M. and Carriger, J.F., U.S. environmental law statutes in coastal zone pro- tection, Environ. Toxicol. Chem., 20, 115, 2001. 5. WEST Group, Federal Environmental Laws , 2000 Edition, WEST Group, Eagan, MN. 6. Sissenwine, M.P., Marine fisheries at a critical juncture, Fisheries , 18, 6, 1993. 7. Kennish, M.J., Practical Handbook of Estuarine and Marine Pollution , CRC Press, Boca Raton, FL, 1997. 8. Scott, G., Marine and estuarine toxicology and chemistry, Environ. Toxicol. Chem., 20, 3, 2001. 9. Rodríguez, G.R., Breddia, C.A., and Pérez-Martell, E., Eds ., Environmental Coastal Regions III , WIT Press, Boston, 2000. 10. Pernetta, J. and Elder, D., Cross-sectoral, Integrated Coastal Area Planning (CICAP): Guidelines and Principles for Coastal Area Development , IUCN (International Union for Conservation of Nature and Natural Resources), Gland, Switzerland, 1993. 11. Anonymous, Reefs at Risk , IUCN (International Union for Conservation of Nature and Natural Resources), Gland, Switzerland, 1993. 12. Gustavson, K., Huber, R.M., and Ruitenbeek, J., Eds., Integrated Coastal Zone Management of Coral Reefs: Decision Support Modeling , The International Bank for Restoration and Development/The World Bank, Washington, D.C., 2000. 13. Suter, G.W., Jr., Ecological Risk Assessment , CRC Press/Lewis Publishers, Boca Raton, FL, 1993. 14. Suter, G.W., Jr., Efroymson, R.A., Sample, B.E., and Jones, D.S., Eds ., Ecological Risk Assessment of Contaminated Sites , Lewis Publishers, Boca Raton, FL, 2000. 15. U.S. EPA, Guidelines for Ecological Risk Assessment, U.S. EPA/630/R-95/002F, April 1998, Final, U.S. Environmental Protection Agency, Washington, D.C. . historically. Chapter 11 considered population-based risk assessment in a complex land- scape. As mentioned above, such a landscape context can be essential in adequately defining risk to coastal and estuarine. Ecological Risk Assessment in Coastal and Estuarine Environments Michael C. Newman, Robert C. Hale, and Morris H. Roberts, Jr. CONTENTS 13. 1 Introduction 13. 2 Chapter Contributions to Coastal. freshwater, and terrestrial environments. The chapters contained in this edited book were developed with that goal in mind. 13. 2 CHAPTER CONTRIBUTIONS TO COASTAL AND ESTUARINE RISK ASSESSMENT