Exploring Essential Fish Habitat Delineation for Atlantic Highly Migratory Species – Methods, Challenges, and Future Research Needs

Atlantic Highly Migratory Species (“HMS”; sharks, tunas, billfish, and swordfish) Essential Fish Habitat (EFH) was initially designated in 1999, and is periodically updated per requirements of the Magnuson-Stevens Act.  Delineation of EFH for Atlantic HMS is challenging due to the range of habitats utilized, the pelagic nature of some species, and a lack of available information for some species.  Additionally, the Atlantic HMS EFH process is dependent upon the integration of datasets from both agency and non-agency sources that are developed and maintained under a broad range of research objectives and protocols.  The variability in the methodology and type of data collected between research programs only allows the delineation of Atlantic HMS EFH based on Level 1 information (distribution data for species by life stages).  Furthermore, advances in tagging technology have resulted in increased prevalence of more sophisticated tag studies (e.g., acoustic, archival and PSATs); these data are fundamentally different from the types of data previously used to characterize Atlantic HMS EFH.  This presentation considers how Atlantic EFH delineation methodologies have been adapted through time to address these challenges; provides a summary of recent EFH exercises completed for Atlantic HMS; and speculates on improvements in process and methodology.