Aloha Colleagues, My co-authors and I are pleased to inform you about our paper "Diurnal increases in depths of humpback whale (*Megaptera novaeangliae*) mother-calf pods off West Maui, Hawai’i: A response to vessels?" just published in the journal *Marine Mammal Science*. Below, please find the full citation for the article and the abstract. This is the fourth recent paper in our series examining variations in habitat use in humpback whales in Hawaiian waters. If you would like to receive a pdf of this paper, please contact me at pack@hawaii.edu. Wishing everyone in our community good health, happiness and peace. Mahalo, Adam *Citation: * Pack, A. A., Waterman, J. O., & Craig, A. S. (2022). Diurnal increases in depths of humpback whale (Megaptera novaeangliae) mother-calf pods off West Maui, Hawaiʻi: A response to vessels? Marine Mammal Science, 1–17. https://doi.org/10.1111/mms.12926 *Abstract*: Studies of humpback whale (*Megaptera novaeangliae*) habitat use in their Hawaiian breeding grounds have revealed that mother-calf pairs favor shallow waters to avoid harassment from males. However, human activity in these same waters may exert an opposing force on habitat use. To investigate this hypothesis, instantaneous scan samples of whale and vessel distribution were collected from NW Maui, Hawai’i. Theodolite position fixes were combined with GIS techniques to determine the depths and seabed terrain type occupied by 161 humpback whale pods containing a calf (calf pods) and 872 pods without a calf (non-calf pods). We found no significant diurnal trends for non-calf pods, but calf pods occupied progressively deeper water over the course of each day. There was no evidence that this shift was related to (1) a “spillover” resulting from high mother-calf density in shallow water, (2) harassment by males occupying the same space as mother-calf pairs, or (3) the presence of mainly older and larger calves. However, while diurnal trends of whale-watching vessels largely mirrored those of mother-calf pods, non-whale-watching vessels tended to remain in shallower waters throughout the day. These results suggest that nearshore vessels may negatively impact the natural preference of mother-calf pairs for shallow waters. -- Adam A. Pack, Ph.D. Professor and Chair (Psychology) Departments of Psychology and Biology University of Hawai'i at Hilo 200 West Kawili Street Hilo, Hawai'i 96720 (Office Voice): 808-932-7082 (Email): pack@hawaii.edu (Faculty Webpage): https://hilo.hawaii.edu/faculty/adam-a-pack/ (UH Hilo Lab): https://hilo.hawaii.edu/faculty/adam-a-pack/marine-mammal-lab/ (Non-profit organization): https://thedolphininstitute.org/ "Do or do not; there is no try." Yoda