The oceanographic conditions of the Southern California Bight (SCB) dictate the distribution and abundance of prey resources and therefore the presence of mobile predators, such as Cuvier’s beaked whales (Ziphius cavirostris). Cuvier’s beaked whales are deep-diving odontocetes that spend a majority of their time foraging at depth. Due to their cryptic behavior, little is known about how they respond to seasonal and interannual changes in their environment. This study utilizes passive acoustic data recorded from two sites within the SCB to explore the oceanographic conditions that Cuvier’s beaked whales appear to favor. Utilizing optimum multiparameter analysis, modeled temperature and salinity data are used to identify and quantify these source waters: Pacific Subarctic Upper Water (PSUW), Pacific Equatorial Water (PEW), and Eastern North Pacific Central Water (ENPCW). The interannual and seasonal variability in Cuvier’s beaked whale presence was related to the variability in El Niño Southern Oscillation events and the fraction and vertical distribution of the three source waters. Cuvier’s beaked whale acoustic presence was highest during the winter and spring and decreased during the late summer and early fall. These seasonal increases occurred at times of increased fractions of PEW in the California Undercurrent and decreased fractions of ENPCW in surface waters. Interannual increases in Cuvier’s beaked whale presence occurred during El Niño events. These results establish a baseline understanding of the oceanographic characteristics that correlate with Cuvier’s beaked whale presence in the SCB. Furthering our knowledge of this elusive species is key to understanding how anthropogenic activities impact Cuvier’s beaked whales.

Sperm whales are a cosmopolitan species only found in ice-free regions. Understanding the distribution of sperm whales in regions undergoing rapid loss of sea ice and ocean warming is important. In 2014 and 2018, sperm whales were sighted in the Pond Inlet, Baffin Bay: the first recorded uses of this region. We investigated sperm whale distribution near the Pond Inlet using visual sighting and passive acoustic data from two recording sites between 2015 and 2019. We found no records of sperm whale sightings near Pond Inlet outside of the 2014/2018 observations. However, the acoustic data revealed whale presence yearly from 2015-2019 in the late summer and fall months. Sperm whale presence increased over the 5-year study duration and was closely related to sea ice extent. Monitoring climate change-induced range expansion of sperm whales is important to understand how increasing presence of a top-predator might impact the Arctic food web.