DOC WHITE / Blue whale underwater close-up of head and mouth feeding with pouch inflated, Mexico

Theo Bosboom / Underwater view of bubbles in the mountain stream. La Hoegne, Belgian Ardennes/High Fenn near Hockai, Belgium

Theo Bosboom / Underwater view of bubbles in water and trees on land, La Hoegne mountain stream, Belgium.

Theo Bosboom / Maple leaf in autumn, viewed from underwater with bubbles and foam of mountain stream, La Hoegne, Ardennes, Belgium.

Theo Bosboom / Underwater view of bubbles and Beech (Fagus sylvatica) leaves Hoegne, Belgium.

Theo Bosboom / Yellow coloured Birch leaf (Betula) floating on the bubbles and foam of a stream, De Veluwe (Leuvenumse bos), Netherlands.

Tony Wu / Humpback whale (Megaptera novaeangliae) adult female at rest. The tubercles on the whale's head are clearly visible, as are the barnacles (Coronula diadema), whale lice (Cyamus boopis), and hairs on t...

Alex Mustard / Grey seal (Halichoerus grypus) young female opens her mouth and blows bubbles through her nose playfully while she looks up from the seabed. Lundy Island, Devon, UK, Bristol Channel. August. Highly co...

Claudio Contreras / American crocodile (Crocodylus acutus) exhaling bubbles underwater, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico, May.

Andres M. Dominguez / Dove's-foot crane's-bill leaf (Geranium molle) and algae in ice with air bubbles, Sierra de Grazalema Natural Park, southern Spain, February.

Kevin Schafer / Frozen gas bubbles beneath surface of frozen lake, Abraham Lake, Canadian Rockies, Alberta, Canada

Michael Pitts,Michael Pitts / Spinner dolphins (Stenella longirostris) small pod in within Midway atoll, Midway, Pacific.