What is CADDIS?
CADDIS, otherwise known as the Causal Analysis/Diagnosis Decision Information System, is an online application that uses a step-by-step guide, worksheets and examples to help scientists and engineers find, access, organize, share and use environmental information to evaluate causes of biological effects observed in aquatic systems such as streams, lakes and estuaries. It is based on U.S. EPA's Stressor Identification (SI) Guidance Document which provides a formal and rigorous process to identify stressors causing biological impairments in aquatic ecosystems, and a structure for organizing the scientific evidence supporting the conclusions. CADDIS uses the SI process, but also contains updates, clarifications and additional material developed since the SI Guidance Document was published in 2000.
Why did we call this site CADDIS?
The name CADDIS is not only an acronym, but is also the name of a group of insects called caddisflies (Trichoptera). The larva of the caddisfly (see illustration pictured at right) lives in flowing waters on the bottom surface of streams. Many species live in tubes or cases they construct from sand, pebbles, pieces of leaves and wood which are held together by an adhesive substance that the caddisfly larvae secrete. As they move about they drag the case with them, with only their front ends and legs sticking out. They eat algae, decaying plant matter and microorganisms. In turn, caddisflies are eaten by many types of fish. Caddisflies are one of the types of organisms that biologists use to monitor the health of aquatic systems. Many caddisfly species live only in high quality streams and their numbers decline as stream quality declines.
Who should use CADDIS?
The CADDIS site contains technical information (guidance, worksheets and examples) and was designed for use by scientists and engineers.
Using CADDIS the Web site
This site was designed and tested using Internet Explorer version 6.0 with a screen resolution of 800 by 600 pixels or finer. CADDIS uses pop-up windows in many places to provide supplemental information, such as additional text, enlarged images, or example worksheets. A pop-up is page or window that pops up when a link is selected. If you have problems viewing the pop-ups, please turn-off "disable pop-ups" in your browser (in Internet Explorer, use Tools: Internet Options:Privacy Tab) and be sure that JavaScript is enabled (in Internet Explorer, use Tools:Internet Options:Advanced Tab). For more information on using the site, refer to the frequently asked questions.
Printing the CADDIS Web site
CADDIS is as an on-line system enabling you to have quick access to the information you seek. Individual pages can be printed by clicking on the “Print Version” at the top of each page. You can also use our print function to print most parts of the site. The printout may be helpful as a general reference but will not provide the interactive capabilities of the Web site and excludes several tools, databases, and models. Tables and figures may be cropped or illegible. The font size and style of the printed pages may not match the web pages, and may vary from one printed section to the next. This is likely due to the differences in codes that control the font size and style for web pages versus the controls for the PDF pages.
Who developed CADDIS?
CADDIS is produced by the U.S. EPA's Causal Analysis Team. Click here for additional information on the authors, contributors, and reviewers for different parts of the Web site.
Information on U.S. EPA's biocriteria program, including the link to the Biological Assessment, Criteria and Indicators Discussion Database is available at http://www.epa.gov/waterscience/biocriteria.
