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Ecological Exposure Research



An ecosystem is all the living organisms in an area, along with their environment. A river ecosystem, for example, includes all the birds, fish, bugs, algae and bacteria living in that river, as well as the rocks, sand, soil, and water in that river.

EPA scientists look at both ecosystem functions and ecosystem exposures. Ecosystem functions research is designed to better understand what ecosystems do, how useful they are, and how we can protect the valuable functions they perform, such as providing clean air and clean water. Ecosystem exposures research uses new technology to better determine the extent that ecosystems have been exposed to stress, such as pollution from chemicals and other contaminants. Together, these two types of ecosystems research provide the knowledge needed to better manage and protect our nation's ecosystems.

Research in Action

Detecting and Monitoring Aquatic Invasive Species
EPA ecological exposure scientists are developing new DNA-based tools for the early detection and monitoring of aquatic invasive species. These tools will help prevent future invasions and the spread of existing exotic species. The spread of invasive species in our nation’s waters has costly economic and ecological impacts. The exchange of ballast water from the hulls of ships is one of the ways that these invasive species are introduced.

Classification of Functional Process Zones in Large Rivers
EPA's ecological exposure scientists are developing tools to rapidly classify river segments based upon their hydrology and geology to help identify areas of river systems that are best candidates for cleanup efforts. Each river is unique, and comparing areas of two different rivers often will not provide useful information. By classifying river segments into "Functional Process Zones" that categorize stream sections by how they work in the overall system, EPA's scientists are helping states and local governments identify the best areas to devote river cleanup funds and efforts.

Molecular Indicators (Exposure Biomarkers in Aquatic Organisms)
EPA scientists have found that plant and animal cells can change in very specific ways when they are exposed to chemicals and other pollutants To measure these changes, EPA researchers have developed biomarker-based methods that allow them to screen for molecular-level changes in aquatic organisms. These methods provide information about the concentrations of chemicals in aquatic ecosystems and the impact that chemicals may have on organisms that live there.

Relative Risk of Pharmaceuticals in Wastewater
EPA scientists are surveying 50 of the nation’s largest municipal wastewater treatment plants and analyzing the samples to determine how much of 48 different pharmaceutical ingredients make their way from our medicine cabinets to our rivers and streams. Using this information, EPA ecologists will be able to better understand potential exposures to these pharmaceuticals, and develop new tools to help manage that risk.

Headwater Streams
Ecological exposure researchers with EPA are developing ways to identify, assess, and maintain headwater streams where stream networks begin. The health of headwater streams is important to the quality of water downstream. EPA ecological exposure scientists have developed tools for assessing the quality and permanence of headwater streams to provide guidance for regional, tribal and state agencies in protecting these precious resources.

Development of DNA barcoding
EPA ecologists are using unique DNA "barcodes" of certain aquatic species to develop faster, cheaper methods for assessing the health of streams and lakes. Traditionally, researchers have had to collect specimens of aquatic species and analyze them in a laboratory — a process that can be time-consuming, expensive, and labor-intensive. By finding short, identifying DNA sequences — or "barcodes" — EPA’s scientists are able to quickly and inexpensively identify the kinds of organisms present in lakes and rivers, making it easier to assess the overall health of these ecosystems.

Other Projects

Wetlands - Understanding the Provisioning of Ecosystem Services
EPA is conducting research that will help scientists identify and understand the services provided by wetlands. These complex ecosystems not only are homes for countless animal and plant species, they also help keep rivers and streams free of contamination by trapping agricultural runoff from nearby fields. This information will help EPA scientists develop new, sustainable ways to maintain the water quality of our rivers.

Innovative Physical, Chemical and Biological Tools to Assess Sediment Remediation Performance
EPA scientists are studying rivers where new techniques are being used to help decrease sedimentation. When a river or stream has too much sediment, water quality downstream can suffer. EPA’s ecologists are evaluating sedimentation reduction techniques to learn how effective they are, and what impact, if any, they have on the physical, chemical, and biological health of rivers.

Ecosystems Goods and Services Production Function Library
Ecologists in EPA are using a new way to look at ecosystems to create a tool that will help illustrate the benefits we derive from ecosystems and how human activity can affect those benefits. Many of the goods and services on which our health and economic well-being depend — clean air and clean water, for example — are produced, in whole or in part, by the ecosystems around us. EPA's researchers are collecting existing information on ecosystem functions into the Ecosystems Production Function Library, or EPF-L. The library will allow researchers from across the country to examine the goods an ecosystem produces, the level of demand for those goods, and how human activities could reduce or increase an ecosystem’s production of that good. This in turn will help scientists develop conservation tools specifically tailored to maximize the goods and services produced by a particular ecosystem.

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