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To support sound decision-making in environmental management, we need rigorous, defensible, and transparent synthesis of scientific evidence. The Association for the Sciences of Limnology and Oceanography and associated aquatic science societies are leaders in applying science to decision-making, and yet many environmental decisions are still at risk of having to be made without a comprehensive, well-synthesized evidence base to support them. In this article, we discuss two synergistic approaches that can help science inform decision-making: systematic review and evidence banking. Our aim is to promote the use of these approaches, and to enlist support and action from you, the aquatic science community. We propose that you can improve the use and uptake of science in decision-making by making your research more compatible with synthesis efforts by: considering risk of bias when designing your study and reporting results; reporting all relevant contextual information; analyzing your data using standard effect size approaches; and publishing your raw data. Awareness of how primary research feeds into informing policies can help you broaden the impact of your research, making it more directly relevant to decision-making and more likely to contribute to the protection of aquatic ecosystems.

Background Eutrophication of freshwater ecosystems resulting from nitrogen and phosphorus pollution is a major stressor across the globe. Despite recognition by scientists and stakeholders of the problems of nutrient pollution, rigorous synthesis of scientific evidence is still needed to inform nutrient-related management decisions, especially in streams and rivers. Nutrient stressor-response relationships are complicated by multiple interacting environmental factors, complex and indirect causal pathways involving diverse biotic assemblages and food web compartments, legacy (historic) nutrient sources such as agricultural sediments, and the naturally high spatiotemporal variability of lotic ecosystems. Determining nutrient levels at which ecosystems are affected is a critical first step for identifying, managing, and restoring aquatic resources impaired by eutrophication and maintaining currently unimpaired resources. The systematic review outlined in this protocol will compile and synthesize literature on the response of chlorophyll a to nutrients in streams, providing a state-of-the-science body of evidence to assess nutrient impacts to one of the most widely-used measures of eutrophication. This review will address two questions: “What is the response of chlorophyll a to total nitrogen and total phosphorus concentrations in lotic ecosystems?” and “How are these relationships affected by other factors?” Methods Searches for published and unpublished articles (peer-reviewed and non-peer-reviewed) will be conducted using bibliographic databases and search engines. Searches will be supplemented with bibliography searches and requests for material from the scientific and management community. Articles will be screened for relevance at the title/abstract and full text levels using pre-determined inclusion criteria; 10% (minimum 50, maximum 200) of screened papers will be examined by multiple reviewers to ensure consistent application of criteria. Study risk of bias will be evaluated using a questionnaire developed from existing frameworks and tailored to the specific study types this review will encounter. Results will be synthesized using meta-analysis of correlation coefficients, as well as narrative and tabular summaries, and will focus on the shape, direction, strength, and variability of available nutrient-chlorophyll relationships. Sensitivity analysis and meta-regression will be used to evaluate potential effects of study quality and modifying factors on nutrient-chlorophyll relationships.

Discussions and applications of the policies and practices of the U.S. Environmental Protection Agency (USEPA) in ecological risk assessment will benefit from continued clarification of the concepts of assessment endpoints and of levels of biological organization. First, assessment endpoint entities and attributes can be defined at different levels of organization. Hence, an organism-level attribute, such as growth or survival, can be applied collectively to a population-level entity such as the brook trout in a stream. Second, assessment endpoints for ecological risk assessment are often mistakenly described as ‘‘individual level,’’ which leads to the idea that such assessments are intended to protect individuals. Finally, populations play a more important role in risk assessments than is generally recognized. Organism-level attributes are used primarily for population-level assessments. In addition, the USEPA and other agencies already are basing management decisions on population or community entities and attributes such as production of fisheries, abundance of migratory bird populations, and aquatic community composition.

The United States Environmental Protection Agency (USEPA) has ongoing programs to encourage the evaluation of stream conditions based on biological indicators. Bioassessments reveal impairments but do not identify causes of impairments, a necessary step in the restoration of aquatic life. Furthermore, changes in biological condition are often caused by multiple stressors (chemical, physical, biological). To address this need, the USEPA has developed guidance to identify probable causes of biological impairments in aquatic ecosystems and to provide a structure for organizing the scientific evidence to make a credible case. The concepts and organizational structure of the process have potential applications to most ecoepi-demiological investigations.

The risk assessment framework presented in the National Research Council (NRC) Red Book played a key role in the development of ecological risk assessment (ERA). ERA frameworks have, however, developed along their own pathway and have significantly extended concepts that were introduced in the Red Book. When the U.S. Environmental Protection Agency (EPA) commissioned the Oak Ridge National Laboratory (ORNL) in 1981 to develop and apply methods for ERA, the work focused on probabilistic analysis, since that seemed to be the essence of risk. When the Red Book appeared, it suggested that the use of a logical framework to guide the process was also an important aspect of risk assessment. Therefore, the ORNL investigators developed a framework similar to the Red Book framework but more suited to ERA. When EPA initiated a project to develop an official EPA framework for ERA, the ORNL framework was presented in a colloquium intended to obtain input from scientists outside EPA. Later, the NRC sponsored a workshop...

The Big Darby Creek watershed, a highly valued ecosystem in central Ohio, USA, threatened by intensive agriculture and suburban encroachment, served as an example of how case specifics can be applied to refine and direct the planning and problem formulation stage of the U.S. Environmental Protection Agency's ecological risk assessment framework. Big Darby Creek was selected as one of five national pilot risk assessments designed to provide specific examples of how to perform an ecological risk assessment and, at the same time, to refine and improve the assessment process. The case study demonstrates how characteristics of the watershed were used to give direction to the components of establishing goals, identifying and characterizing the resource and threats to it, selecting appropriate assessment endpoints, and developing conceptual models. The hypotheses generated in the conceptual model describe expected relationships and interactions between the ecosystem at risk, identified potential stressors, and ecological effects and set the groundwork for the analysis phase that follows problem formulation.

This review assesses the state of the science on the effects of mountaintop mines and valley fills (MTM-VF) on the physicochemical characteristics of streams in the central Appalachian coalfields of West Virginia, Kentucky, Virginia and Tennessee, USA. We focus on the impacts of mountaintop removal coal mining, which involves removing all - or some portion - of the top of a mountain or ridge to expose and mine one or more coal seams. Excess overburden is disposed in constructed fills in small valleys adjacent to the mining site. MTM-VF leachate persistently increases the downstream concentrations of major ions. Conductivity is a coarse measure of these ions, which are dominated by a distinct mixture of SO(4)(2-), HCO(3)(-), Ca(2+) and Mg(2+), that reflects their source, the oxidation of pyrite to form acid followed by neutralization of the acidity by carbonate minerals within the valley fills. This results in neutral to alkaline pHs, a range at which many metals are relatively insoluble. Other compounds within coal or overburden are solubilized and occur at elevated albeit lower concentrations, including K(+), Na(+), Cl(-), Se and Mn. In terms of physical characteristics, the valley fills act like headwater aquifers, baseflows increase in streams below valley fills and water temperatures exhibit reduced seasonal variation. Peak discharges may be increased in response to intense precipitation events, because of compaction of base surfaces of the MTM-VF areas, but newer approaches to reclamation reduce this compaction and may ameliorate these peak flows. Although the sedimentation pond is intended to capture fine particles that wash downstream from the valley fill, some studies found increased fine sediments in streams downstream from valley fills. However, a proportion of these fines may be eroded from stream banks rather than the valley fills. This is probably a result of the alterations in stream flows.

Ecological risk assessment is becoming an increasingly important tool for ranking, assessing, reducing, and managing environmental risks. To pro- vide Agency-wide guidance in this area in the U.S., EPA's Risk Assessment Forum has begun a multi-year guidelines development program. The first step in this program was the publication of the report “Framework for Ecological Risk Assessment” which describes the principles, concepts, terminology, and structure of ecological risk assessments.

Ecological risk assessments evaluate the likelihood of adverse ecological effects caused by stressors related to human activities such as draining of wetlands or release of chemicals. The term stressor is used to describe any chemical, physical, or biological entity that can induce adverse effects on ecological components (i.e., individuals, populations, communities, or ecosystems). In this review article, a historical perspective on ecological risk assessment activities at the U.S. Environmental Protection Agency (EPA) is followed by a discussion of the EPA's “Framework Report,” which describes the basic elements for conducting an ecological risk assessment. The “Framework Report” is neither a procedural guide nor a regulatory requirement within the EPA. Rather, it is intended to foster a consistent approach to ecological risk assessments within the Agency, identify key issues, and define terminology.

Responsible care and management of Earth's resources requires scientific support, but the pool of underused research is growing rapidly. Environmental science research studies describe associations between variables (e.g. statistical relationships between stressors and responses). We propose open-access and online sharing of such associations. This concept differs from various efforts around the world to promote sharing of primary research data, but holds similar goals of improved use of existing knowledge. The initiative is made possible by recent developments in information technology and evolving online culture (e.g. crowdsourcing and citizen science). We have begun to connect existing projects that catalog and store associations, thereby moving toward a single virtual repository. Researchers and decision makers may share and re-use associations for myriad purposes, including: increasing efficiency and timeliness of systematic reviews, environmental assessments and meta-analyses, identifying knowledge gaps and research opportunities, providing evolved metrics of research impact, and demonstrating connections between research and environmental improvement.