Adult male north Pacific humpback whale bubble streaming underwater in the midst of a competitive group.   The male escort humpback whale seen here is emitting a curtain of bubbles as it swims closely behind a female, .  The bubble curtain may be meant as warning or visual obstruction to other nearby males interested in the female. Maui, Hawaii, USA, Megaptera novaeangliae, natural history stock photograph, photo id 05998