What are impacts to designated Critical Habitat referred to as?

Impacts to designated Critical Habitat are referred to as "Adverse modifications." This term is used within the context of the Endangered Species Act (ESA) to denote negative changes that affect the designated habitat of a threatened or endangered species. Such modifications can hinder the conservation of the species and impede recovery efforts.

The concept of adverse modifications encompasses various factors, including habitat loss, degradation, and other disturbances that make the environment less suitable for the species. Identifying these adverse modifications is critical for ensuring the long-term viability of endangered species and their habitats, as well as guiding conservation measures and assessments by federal agencies.

In contrast, the other terms listed refer to different concepts within environmental and regulatory frameworks. Reasonable and prudent measures are typically recommendations made to minimize impacts during project implementation. A FONSI (Finding of No Significant Impact) is a determination that a project will not have a significant effect on the environment, allowing it to proceed without a full Environmental Impact Statement. Adverse impacts generally describe negative effects but do not specifically address the context of critical habitat under the ESA.