EPA Updates Online Application for Determining Causes of Ecological Impairment
On Oct. 4, EPA announced the update of an online application that
helps scientists and engineers find, access, organize and share
information to evaluate causes of biological impairment in aquatic
The "Causal Analysis/Diagnosis Decision Information System -- 2007"
(CADDIS) Web site was developed by EPA's National Center for
Environmental Assessment (NCEA) in response to strong demand within the
agency and from stakeholders seeking a defensible method for
determining causes of ecological impairment. CADDIS guides users
through EPA's Stressor Identification process, with interactive tools,
methods and worksheets.
Thousands of water bodies in the United States have been reported to
have an "unknown" cause of impairment. To formulate appropriate
management actions for impaired water bodies, it is critical to
identify the causes of biological impairment, such as excess fine
sediments, nutrients or toxic substances. Effective causal analyses
call for knowledge of the mechanisms, symptoms and stressor-response
relationships for various stressors.
The first version of CADDIS was released in 2006. The update includes the following changes:
- The addition of eight modules, each describing a common
stressor or candidate cause of biological impairment. The stressor
modules include metals, sediments, nutrients, dissolved oxygen,
temperature alteration and unspecified toxic chemicals.
- An interactive Flash-based conceptual model diagram for phosphorus, a common stressor.