Essential Fish Habitat (EFH) is broadly defined by the Magnuson-Stevens Fishery Conservation and Management Act (MSA), to include "those waters and substrate necessary to fish for spawning, breeding, feeding, or growth to maturity". Waters include aquatic areas and their associated physical, chemical, and biological properties that are used by fish and may include historic areas; substrate includes sediment, hard bottom, structures underlying the waters, and associated biological communities; necessary means the habitat required to support a sustainable fishery and the managed species' contribution to a healthy ecosystem; and "spawning, breeding, feeding, or growth to maturity" covers a species' full life cycle.
The MSA requires all Federal agencies to consult with the National Marine Fisheries Service (NMFS) on all actions, or proposed actions, permitted, funded, or undertaken by the [federal] agency, that may adversely affect designated EFH. For the state of Washington, EFH has been designated for 3 species of pacific salmon, 83 species of groundfish, and 5 coastal pelagic species.
A Biological Evaluation (BE), prepared to assess the impacts of a project on listed threatened or endangered species, should include an assessment of potential impacts to designated EFH in the project area. It is recommend that the information in the EFH assessment portion of the BE be referenced from other portions of the BE as much as possible in order to minimize duplication of effort. For example, project description, parts of the effects analysis and several of the conservation measures may be appropriate to "reference" in the EFH assessment. If it is determined the project will adversely affect EFH, the Corps will coordinate with NMFS in conjunction with the ESA consultation process.
For more information and guidance on EFH, including assessments, templates, and a list of designated EFH for your area, please see the National Marine Fisheries Service's EFH website at https://www.fisheries.noaa.gov/national/habitat-conservation/essential-fish-habitat#more-information.