Dear MARMAM community, We are excited to share our recent publication in Diversity and Distributions: Alksne, M. N., Kok, A. C. M.,Agarwal, A., Frasier, K. E., & Baumann-Pickering, S. (2024).Biogeographic patterns of Pacific white-sided dolphins based on long-term passive acoustic records. *Diversity and Distributions*, 00, e13903. https://doi.org/10.1111/ddi.13903 *Abstract:* *Aim: *This study investigates the biogeographic patterns of Pacific white-sided dolphins (*Lagenorhynchus obliquidens*) in the Eastern North Pacific based on long-term passive acoustic records. We aim to elucidate the ecological and behavioural significance of distinct echolocation click types and their implications for population delineation, geographic distribution, environmental adaptation and management. *Location:* Eastern North Pacific Ocean. *Time Period:* 2005–2021. *Major Taxa Studied:* Pacific white-sided dolphin. *Methods:* Over 50 cumulative years of passive acoustic monitoring (PAM) data from14 locations were analyzed using a deep neural network to classify two distinctPacific white-sided dolphin echolocation click types. The study assessed spatial, diel,seasonal and interannual patterns of the two click types, correlating them with major environmental drivers such as the El Niño Southern Oscillation and the North PacificGyre Oscillation, and modeling long-term spatial-seasonal patterns. *Results:* Distinct spatial, diel and seasonal patterns were observed for each click type.Significant biogeographical shifts in presence were observed following the 2014–2016 marine heatwave event. *Main Conclusions:* Distinct spatial distributions of the two click types support the hypothesis that Pacific white-sided dolphins produce population-specific echolo-cation clicks. Seasonal and diel patterns suggest spatio temporal niche partitioning between the populations in Southern California. Interannual changes, notably initi-ated during the 2014–2016 marine heatwave, indicate climate-driven range expansions and contractions related to gradual tropicalization of the Southern California Bight. The article is open access and available here: https://onlinelibrary.wiley.com/doi/10.1111/ddi.13903 Please reach out with any questions. Best, Michaela -- Michaela Alksne (she/her/hers) PhD Candidate NDSEG Fellow <https://ndseg.org/> Scripps Acoustic Ecology Lab <https://sael.ucsd.edu/> Scripps Institution of Oceanography, Ritter Hall 105