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CADDIS Volume 1: Stressor Identification

The Step-by-Step Guide Introduction

CADDIS provides a pragmatic guide for determining the causes of detrimental changes and undesirable biological conditions observed in aquatic systems. The causal analysis process presented here is derived from the Stressor Identification Guidance Document published jointly by the Office of Water and the Office of Research and Development of the U.S. EPA. The basic approach remains the same, but several changes were made to make the process more accessible.

Using the Step-by-Step Guide

The Step-by-Step Guide organizes the Stressor Identification process into five steps. Each step can be accessed using the navigation menu on the left, through the site map, or by clicking on the links at the bottom of the page. Each step has three tabs: an overview; an in-depth look into the step (with right-hand navigation boxes to provides quick links to additional details for Steps 3 through 5); and a review of results and next steps. In Step 5, the in-depth material is covered in two tabs (weighing the evidence and comparing the evidence) to make it easier to follow. Throughout the site, supplemental information and example worksheets can be viewed in "pop-up" boxes. The site map or left-hand navigation bar can always get you back where you started if you get lost in the site.

If you are a new user, we recommend that you start by reading the Guide Overview which provides a summary of the entire process; then read the Fundamentals of Causal Analysis to get a summary of the principles and methodology underlying CADDIS; then go through each step in order.

If you are already familiar with the process and fundamentals, the Step-by-Step Guide provides detailed technical guidance with examples and advice. You may find it helpful to review the types of evidence, or to skip directly to the parts of the site you find most useful or needed. Here are some short cuts to our most-used pages:

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