Dear MARMAM Community I am pleased to announce the publication of the below two papers on marine mammals and underwater noise: 1. Shabangu FW, Yemane D, Stander N, Estabrook BJ. 2025 Underwater soundscape indicates low anthropogenic influence around two sub-Antarctic islands. Royal Society Open Science 12: 250677. https://doi.org/10.1098/rsos.250677 Abstract Contributions and effects of anthropogenic activities on the underwatersoundscape of the sub-Antarctic regions remain poorly studied. Over a 21-monthperiod (April 2021 to December 2022), we recorded underwater noise levels amid twosub-Antarctic Prince Edward Islands (PEIs) within an offshore marine protectedarea with the aim to quantitatively investigate the sources of underwater noiseand the impact of such noise on the detectability of marine mammal vocalizations.We measured underwater noise levels within the low (20–120 and 121–800 Hz),medium (801–25 000 Hz) and high (25 001–48 000 Hz) frequency bands. Wind speed wasthe primary predictor of low and medium frequency underwater noise levels,whereas iceberg volume was the primary predictor at the high frequency band.Probabilities of detecting vocalizations of Antarctic blue, fin, humpback, Antarcticminke and killer whales decreased with increasing noise levels. On thecontrary, probabilities of detecting sei and Madagascan pygmy blue whalevocalizations increased with noise levels. Overall, these novel resultsindicate that geophonic noise dominates the underwater soundscape of the PEIsin the absence of intense anthropogenic activities such as marine traffic, andthat the detectability of marine mammal underwater vocalizations isspecies-specific. 2. Shabangu, F.W. 2026.Sperm whale acoustic ecology around two sub-Antarctic islands. MarineEnvironmental Research 215: 107805. https://doi.org/10.1016/j.marenvres.2025.107805 AbstractSpermwhales are cosmopolitan in nature, but very little is known about theiroccurrence in the sub-Antarctic region. This study aimed to investigate theacoustic occurrence of sperm whales relative to environmental conditions andunderwater noise around two sub-Antarctic Prince Edward Islands (PEIs) usingpassive acoustic monitoring data collected between early 2021 and early 2023.Sperm whale clicks were detected continuously throughout the study period withhigh presence of calls in February through August, highlighting the PEIs as anessential habitat with sufficient year-round prey for this species. Moreover,the February through August peak occurrence corresponds to the migration periodof males from Antarctica to the low latitudes for mating. Diel vocalizingpattern revealed high nighttime vocalization that varied slightly betweenseasons. Wind speed was classified by the random forest model as the mostimportant predictor of sperm whale acoustic occurrence, indicating possiblemasking and attenuation of whale signals by wind-induced noise and wind-inducedair bubbles respectively. Generalized additive model showed that theprobability of detecting sperm whale clicks decreased with increasing highfrequency band (25001–48000 Hz) noise, reflecting a significant influence ofthe high frequency noise on this species’ ecology. This is the first study todocument the acoustic presence of sperm whales around the sub-Antarctic PEIs,showcasing the capability of bioacoustics method to effectively study marine mammalsthat are rarely sighted. Sperm whales should be considered in the spatialmanagement and conservation plans of the PEIs given their year-round presencein this region. The sperm whale paper is openly accessible through this share link: https://authors.elsevier.com/a/1mIN5W5UJVTdv I wish you all and your loved ones a very Merry Christmas and a blessed 2026. Kind regards,Fannie _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Fannie W. Shabangu, PhD (He/Him) Marine BiologistDepartment of Forestry, Fisheries and the Environment Cape Town, South Africa E-mail: fannie.shabangu@yahoo.com Research Fellow Mammal Research InstituteWhale Unit University of PretoriaHatfield, South Africa