Which of the following best describes the term "non-target aquatic species"?

The term "non-target aquatic species" specifically refers to species that may be impacted by treatment but are not the primary focus of the pest control measures. In the context of aquatic pest control, herbicides and other treatments are usually applied to manage specific invasive or unwanted species. However, these treatments can unintentionally affect other aquatic organisms that were not meant to be controlled. This distinction is crucial for understanding the ecological implications of pest control methods, as protecting non-target species is essential to maintaining biodiversity and ecosystem health in treated areas.

The other choices do not accurately capture the essence of non-target species. Species that thrive in treated areas are typically those that can withstand or exploit the changes brought on by treatment, while those intentionally treated are part of the control process. Species established after treatment may indicate a shift in the ecosystem, but they don't reflect the unintended consequences of pest control methods. Therefore, the most accurate definition aligns with the concept of species affected by the treatment, even though they were not the target of the control efforts.