Biologically Important Areas II for cetaceans within U.S. and adjacent waters - Updates and the application of a new scoring system

Abstract

Building on earlier work identifying Biologically Important Areas (BIAs) for cetaceans in U.S. waters (BIA I), we describe the methodology and structured expert elicitation principles used in the “BIA II” effort to update existing BIAs, identify and delineate new BIAs, and score BIAs for 25 cetacean species, stocks, or populations in seven U.S. regions. BIAs represent areas and times in which cetaceans are known to concentrate for activities related to reproduction, feeding, and migration, as well as known ranges of small and resident populations. In this BIA II effort, regional cetacean experts identified the full extent of any BIAs in or adjacent to U.S. waters, based on scientific research, Indigenous knowledge, local knowledge, and community science. The new BIA scoring and labeling system improves the utility and interpretability of the BIAs by designating an overall Importance Score that considers both (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 and scoring depend. Each BIA is also scored for boundary uncertainty and spatiotemporal variability (dynamic, ephemeral, or static). BIAs are region-, species-, and time-specific, and may be hierarchically structured where detailed information is available to support different scores across a BIA. BIAs are compilations of the best available science and have no inherent regulatory authority. BIAs may be used by international, federal, state, local, or Tribal entities and the public to support planning and marine mammal impact assessments, and to inform the development of conservation and mitigation measures, where appropriate under existing authorities. Information provided online for each BIA includes: (1) a BIA map; (2) BIA scores and label; (3) a metadata table detailing the data, assumptions, and logic used to delineate, score, and label the BIA; and (4) a list of references used in the assessment. Regional manuscripts present maps and scores for the BIAs, by region, and narratives summarizing the rationale and information upon which several representative BIAs are based. We conclude with a comparison of BIA II to similar international efforts and recommendations for improving future BIA assessments.

Biologically Important Areas II for cetaceans within U.S. and adjacent waters - West Coast Region

“…BIAs for all seven regions around the U.S. were delineated and scored using an overall approach detailed in Harrison et al (2023). Given the differences in available data and the species being included, we outline here some of the region-specific approaches used to evaluate BIAs along the U.S. West Coast and provide additional details and relevant caveats in the Supplementary Materials (Supplementary File A, Section S1).…”

“…There have been a number of documented threats to cetaceans in this region, including ship strikes (Berman-Kowalewski et al, 2010;Redfern et al, 2013;Rockwood et al, 2017), entanglements (NOAA, 2023;Santora et al, 2020;Saez et al, 2021;Tackaberry et al, 2022), and underwater sound (e.g., sonar; Southall et al, 2019). Assessing and managing these threats require information on their distributions and areas of most critical use for feeding, breeding, and migrating (Harrison et al, 2023). A number of studies have examined density and distribution of different cetaceans along the U.S. West Coast through a variety of data streams, including sightings from linetransect surveys (Becker et al, 2012;Jefferson et al, 2014;Becker et al, 2017;Becker et al, 2020a, b), satellite tracking data (Bailey et al, 2009;Irvine et al, 2014;Scales et al, 2017;Lagerquist et al, 2019;Palacios et al, 2019), acoustic detections (S ̌irovićet al, 2015;Ryan et al, 2022), historical whaling catch data (Mizroch et al, 2009), and sightings data from non-systematic survey efforts and citizen science platforms (Halpin et al, 2009;Falcone et al, 2022).…”

“…As part of a nation-wide process coordinated by the National Marine Fisheries Service, we delineated and scored Biologically Important Areas (BIAs) for cetaceans off the U.S. West Coast (Van Parijs et al, 2015;Harrison et al, 2023). BIAs are times (months, seasons) and areas that are important to cetacean species, stocks, or populations for reproduction (R-BIAs), feeding (F-BIAs), or migration (M-BIAs; Harrison et al, 2023;Ferguson et al, 2015). BIAs can also be defined for small and resident populations (S-BIAs) based on their range and core areas.…”

Biologically Important Areas for bowhead whales (Balaena mysticetus): Optimal site selection with integer programming

“…The second round of the BIA delineation and scoring process, known as BIA II, is underway. For a comprehensive overview of the BIA delineation and scoring methods and intended use, see Harrison et al (2023); we provide a concise summary here. For simplicity, hereafter "species" is used to refer to species, populations, or stocks and "BIA" implies NOAA's BIAs.…”

“…NOAA's BIA II process is nearing completion (Clarke et al, 2023;Harrison et al 2023). Although the basic BIA delineation protocols remain unchanged in BIA II compared to BIA I, NOAA developed methods for BIA II to rank BIA intensity, evaluate the strength of supporting information (raw data, analytical methods, and derived parameters), characterize uncertainty, and classify BIAs as ephemeral, dynamic, or static.…”