Ecosystems Research Division

A series of fact sheets describe some of the research being conducted at the Ecosystems Research Division. More information can be obtained by following the links provided or contacts listed in the fact sheets.

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Behavior of biological, chemical and physical agents in the natural and human-influenced environment

• Watershed Health Assessment Tools Investigating Fisheries (What If). The Canaan Valley Institute (CVI, a nonprofit outreach organization) and the U.S. Environmental Protection Agency, Ecosystems Research Division (ERD), Athens, Georgia, are collaborating on adding to the existing GIS/modeling tools (Landscape Analyst, Highlands Profiler, REVA web tool) to address aquatic ecosystem management and restoration. What If is the software toolset developed for desktop computers and includes the relational database, all supporting statistical and simulation modeling tools and help system functions and documentation for a consistent assessment package. What If Fact Sheet (pdf, 2 pp., 118 KB)
• Chiral Chemistry: The Ultimate in Pollutant Speciation We ordinarily think that the diagram of a molecule's structure shows everything about the way the atoms connect to make a specific chemical with defined properties. With some molecules, a careful look at their three-dimensional structure offers a surprise -- there are two ways to connect the molecules. The objective of our research is to determine the environmental occurrences, fate and effects of selected chiral pesticides and organic pollutants. Mirror Images: Chiral Chemistry (PDF, 2 pp., 320 KB)
• Impervious Cover -Paving Paradise Nonpoint source pollution is pollution from diffuse sources such as urban/suburban areas and farmlands; this is now recognized as the primary threat to water quality in the United States. As urban and suburban development increases, the amount of land covered with impervious surfaces -- areas where infiltration of water into the underlying soil is prevented -- also increases. Impervious Cover - Paving Paradise (PDF, 2 pp., 120 KB)
• Microbial Indicators What do microbes tell us about the health of aquatic ecosystems? One of the most important components of global change over the next three or four decades will be land use/cover change in watersheds and basins including a range of freshwater, estuarine and coastal ecosystems in the United States. These changes, which are mostly driven by human activities, will likely interact with other changes, such as climate change, to alter aquatic ecosystem functioning and structure. Microbial Indicators What do microbes tell us about the health of aquatic ecosystems? (PDF, 2 pp., 110 KB)

Assessing impacts of chemicals and stressors in the environment through simulation models

• ERD's Computational Toxicology Research Program The ORD CompTox Research Initiative defines the "toxicity process"as: (1) formation of a chemical stressor, (2) the environmental concentration of the stressor, (3) the level of exposure of the stressor to a vulnerable organism, (4) the effective dose inside the organism, (5) a biological event triggered by the stressor, and finally, (6) a toxic effect. The objective of ORD's CompTox Research Initiative is to improve linkages across this continuum, resulting in improved approaches for prioritizing chemicals for subsequent screening and testing, and better methods for quantitative risk assessment. The overall success of the initiative is dependent on the development and coupling of new computational quantitative structure activity relationships (e.g., QSARs) and "omic"(i.e., genomic, proteomic and metabonomic) tools. This computational approach will significantly reduce EPA's dependence on animal testing to obtain chemical-specific toxicity data.ERD's Computational Toxicology Research Program (PDF, 2 pp., 47 KB)
• Visual Beach Pathogen Modeling: Clean and Safe Water The problem is pathogens (bacteria, viruses, and protozoa) in teh waters at public beaches. These pathogens can cause illness in exposed humans, ranging in severity. EPA is developing a new model to estimate the position and concentration of contaminated water to help develop accurate public announcements of beach status. Visual Beach: Pathogen Modeling (PDF, 2 pp., 158 KB)
• Multimedia Modeling: The Future of Exposure and Risk Assessment A multimedia assessment model can be described as being like a bookcase for storing, accessing, and processing large volumes of information that can be used to solve problems. Creating a multimedia environmental assessment model requires the cooperation of scientists and engineers from many disciplines. Multi-Agency Cooperative Modeling (PDF, 2 pp., 401 KB)
• Computer Models for Environmental Fate of Chemical Pollutants: SPARC In light of recent trends in environmental regulatory strategies, the U.S. EPA will have to rely more heavily on predictive models when performing the increasingly complex exposure and risk assessments. These new models require huge arrays of input data, and many of the required inputs are neither available in the published literature nor easily measured. The SPARC model will provide much of this data. Computer Models for Environmental Fate of Chemicals: SPARC (PDF, 2 pp., 712 KB)
• BASS: Bioaccumulation and Aquatic System Simulator The Bioaccumulation and Aquatic System Simulator (BASS) is a computer model that simulates the population and bioaccumulation dynamics of age-structured fish communities. Although BASS was specifically developed to simulate the bioaccumulation of chemical pollutants within a community or ecosystem context, it can also simulate population and community dynamics of fish assemblages that are exposed to a variety of non-chemical stressors such as altered thermal regimes associated with hydrological alterations or industrial activities, commercial or sports fisheries, and introductions of non-native or exotic fish species. BASS: Bioaccumulation and Aquatic System Simulator (PDF Format) (PDF, 2 pp., 58 KB)

Responsible use of chemicals and remediation of contaminated sites

• Pesticide Exposure: Responsible and Safe Pesticide Use Pesticides are important for keeping American agriculture productive, free from pest infestations and desease, and economically viable. Many pesticides are also toxic to wildlife and consumers, so EPA and industry work together to write careful instructions for their safe and responsible use. Pesticide Exposure: Responsible and Safe Pesticide Use (PDF, 2 pp., 264 KB)
• On-line Site Assessment Calculators The U.S. Environmental Protection Agency has developed a suite of on-line calculators for assessing transport of environmental contaminants in the subsurface. OnSite on-line calculators for Subsurface Contaminant Transport Site Assessment (PDF, 2 pp., 259 KB) More Information...