A stressor (or agent—an alternative term often used) is defined as any chemical (e.g., toxics or nutrients), physical entity (e.g., dams, fishing nets, or suspended sediments), or biological entity (e.g., non-native or genetically engineered organisms) that can induce an adverse response. The term “stressor” is used broadly to encompass entities that cause primary effects, and those primary effects can cause secondary (i.e., indirect) effects (U.S. EPA, 1998). This tool set is presented as four modules:

• Stressors in ERA

Chemical

See information and tools related to chemical stressors

 

Biological

See information and tools related to biological stressors

 

Physical

See information and tools related to physical stressors