What is a sensitive aquatic site?

A sensitive aquatic site refers to environments that are particularly vulnerable to pesticide exposure and its potential adverse effects. In this context, identification of such sites is critical for the protection of aquatic ecosystems and the organisms that inhabit them.

The correct answer focuses on irrigation or drainage ditches, which can be especially sensitive due to their connections to larger water bodies and ecosystems. These ditches can serve as conduits for pesticide runoff, leading to contamination of larger water bodies and harming aquatic life. Given their structure and function, these areas have a direct path for pollutants to enter and affect both the water quality and the organisms, making them sensitive to pesticide application and runoff, particularly when dormant insecticides are involved.

In contrast, while bodies of water used for fishing and recreation may seem vulnerable, they might not specifically denote sensitivity in the same way as operational irrigation systems. Heavy restrictions on locations where pesticides are applied are typically informed by sensitivity, but the definition is broader than just those restrictions. Areas designated for breeding aquatic species do indicate some level of ecological sensitivity, yet they do not encompass the operational nuances of irrigation and drainage systems that make them critical points for pesticide risk assessment.