Biologically Important Areas | Ocean Noise Strategy

Biologically Important Areas


Overview of BIA 1

Biologically Important Areas (BIAs) identify areas and times within which cetacean species or populations are known to concentrate for specific behaviors, or be range-limited, and provide additional context within which to examine potential interactions between cetaceans and human activities. Specific to anthropogenic sound and marine mammals, there is compelling evidence indicating that a variety of contextual factors, including behavioral state and life stage, can influence the probability, nature, and extent of a marine mammal's response to noise. The BIAs provide some of this important contextual information for cetaceans and can augment the cetacean density, distribution, and occurrence data typically used in marine mammal impact assessments. BIAs are compilations of the best available science and have no inherent or direct regulatory power. They have been used by NOAA, other federal agencies, and the public to support planning and marine mammal impact assessments, and to inform the development of conservation measures for cetaceans.

Explore the Biologically Important Areas Map

Definition of a Biologically Important Area

Regional experts were asked to compile the best available information from scientific literature, unpublished data, and expert knowledge to identify areas shoreward of the U.S. Exclusive Economic Zone (EEZ) that are biologically important to cetacean species (or populations), either seasonally or year-round. For each identified BIA, Van Parijs et al. (2015) presents a written summary with an associated map and metadata table that details the type and quantity of information used to define the Important Area, providing a transparent method for evaluating the Important Area designation.

BIA types


Additional information about the initial Review Process, as well as important caveats that should be considered in the use of BIAs, may be found HERE.

2021 Updates to the BIAs (BIA 2)!

NOAA, with the support of the U.S. Navy, has convened a working group of regional cetacean experts who have begun updating and revising the BIAs identified in Van Parijs et al. (2015), identifying the full extent of any BIAs that overlap U.S. waters and adding new BIAs where appropriate. The use of a new BIA scoring and labeling system will improve the utility and interpretability of the BIAs by designating an overall Importance Score for each BIA that considers: 1) the intensity and characteristics underlying an area’s identification as a BIA; and 2) the quantity, quality, and type of information, and associated uncertainties, upon which the BIA delineation depends. Each BIA will also include an indicator of boundary uncertainty and spatiotemporal variability (dynamic, ephemeral, or static). Finalization of the updated website and database is scheduled December 2021.