Fur seals were killed for their beautiful fur coats, composed of two layers to efficiently trap air and conserve body heat. An outer coat of coarse fur hides an inner layer of softer, denser fur. As this fur seal swims, twists and turns it leaves behind glistening trails of bubbles squeezed from its two-layered coat.
Guadalupe fur seal, bubbles emitted by dense fur coat. Guadalupe Island (Isla Guadalupe), Baja California, Mexico