<p>The habitat specialist Indian Ocean humpback dolphin (Sousa plumbea) is the second most common cetacean in the Persian Gulf. Mousa Bay in the northwestern Persian Gulf is an important, but highly industrialised habitat for this species. We developed a systematic and comprehensive distance sampling survey carried out from 2014 to 2016 to estimate abundance and population density of humpback dolphin in this bay. To evaluate distribution pattern of the species, eight environmental variables were measured and employed in a zero-inflated generalised additive model (ZINB GAM). With an estimated abundance of 92 animals (64–131, 95% CI) and density of 0.123 animal / km2 (0.086–0.176, 95% CI), our results revealed Mousa Bay as one of the largest populations of humpback dolphin in northern latitudes of its global range. </p>
