Claudio Contreras / Grey whale (Eschrichtius robustus) breaching, San Ignacio Lagoon, El Vizcaino Biosphere Reserve, Baja California, Mexico, March

Claudio Contreras / Grey whale (Eschrichtius robustus) tail, San Ignacio Lagoon, El Vizcaino Biosphere Reserve, Baja California, Mexico, March

Claudio Contreras / Grey whale (Eschrichtius robustus) calf, San Ignacio Lagoon, El Vizcaino Biosphere Reserve, Baja California, Mexico, February

Mark Carwardine / Grey whale (Eschrichtius robustus) at water surface with mouth open showing baleen plates, San Ignacio Lagoon, Baja California, Mexico

Tony Wu / Grey whale (Eschrichtius robustus) calf at ocean surface, with its mother visible, Magdalena Bay, Baja California, Mexico.

Jaymi Heimbuch / Leaf Barnacle (Pollicipes polymerus) group, California Mussels (Mytilus californianus), and White Acorn Barnacles (Balanus glandula), Lincoln City, Oregon

Jaymi Heimbuch / California Mussel (Mytilus californianus) group, Yaquina Head Outstanding Natural Area, Newport, Oregon

Franco Banfi / Grey whale (Eschrichtius robustus) skeleton on beach. Magdalena Island, Magdalena Bay, Baja California Sur, Mexico.

John Chan / Elegant terns (Thalasseus elegans) congregating on mussel beds at twilight during breeding season, Southern California, USA, April.

Mark Carwardine / Grey whale / gray whale (Eschrichtius robustus) aerial. Baja California, Mexico

Mark Carwardine / Grey whale / gray whale (Eschrichtius robustus) aerial. This individual has been feeding on seabed with clouds of sand and mud spewed out of mouth afterwards. Baja California, Mexico

Mark Carwardine / Grey whale / gray whale (Eschrichtius robustus) aerial, curious female and calf, San Ignacio Lagoon, Baja California, Mexico