Data from: Tracking interannual variation of a large-scale ocean front influences foraging in a mesopelagic predator

Macroscale ocean fronts aggregate significant biomass and provide critical
foraging habitat for large marine predators. These frontal systems shift
in response to ocean climate variation, including basin-scale
oscillations, and the degree to which marine predators track these
movements affect their foraging and reproductive success. Using two
decades of adult female northern elephant seal (Mirounga angustirostris)
movement data, we assessed their use of the Subarctic Frontal Zone (SAFZ)
in the Northeast Pacific Ocean, the SAFZ’s influence on their diving
behavior, and its importance to their foraging success. We found that
elephant seals followed the interannual movement of the SAFZ and their
diel diving behavior became more extreme as they moved closer to the SAFZ,
likely reflecting a different vertical distribution of prey in the region.
During their short foraging trip, elephant seals that spent time north of
the SAFZ, where day and night diving depths were more similar, had greater
foraging success. During the long, gestational foraging trip, their
geographic distribution relative to the SAFZ did not influence foraging
success, but larger animals were more successful, likely due to more
efficient diving. Understanding the relationship between dynamic foraging
habitat and the response capacity of predator species is critical for
assessing the resilience of species and ecosystems as ocean climates
become less predictable.