David Fleetham / Humpback whale (Megaptera novaeangliae), mother and calf swimming just below surface in front of the West Maui Mountains. South of Lahaina, West Maui, Hawaii.

Claudio Contreras / Whale shark (Rhincodon typus) feeding view of tail, Isla Mujeres, Caribbean Sea, Mexico, August. Vulnerable species.

Floris van Breugel / Black and white photograph of humpback whale (Megaptera novaeangliae) tail slapping at surface, Glacier Bay National Park, Alaska, USA, August 2014.

Jeff Rotman / Queen angelfish close-up of tail base {Holacanthus ciliaris} Bahamas, Caribbean

Inaki Relanzon / Dead shark on beach with tail and pectoral fins removed, Bali, Indonesia, August 2014.

David Pattyn / Humpback whales (Megaptera novaeangliae), two, one with tail emerging from the water as it dives, the other showing fin. Anjajavy Private Reserve in background. Mozambique Channel, Indian Ocean, north...

Graham Eaton / Blacktip Reef Shark (Carcharhinus melanopterus) in clear shallow waters, rear view, Maldives, Indian Ocean.

Tony Wu / Humpback whale (Megaptera novaeangliae) adult female in foreground, with her male calf and their escort behind her. Vava'u, Tonga, South Pacific.

Espen Bergersen / Humpback whale (Megaptera novaeangliae) and Killer whales (Orcinus orca) most likely feeding on herring, off coast of Kvaloya, Troms, Norway, December

Espen Bergersen / Humpback whale (Megaptera novaeangliae) lobtailing / tail slapping on surface, Killer whale (Orcinus orca) in foreground, Kvaloya, Troms, Norway, October

Wild Wonders of Europe / Widstrand / Humpback whale (Megaptera novaeangliae) surfacing with fishing rope tangled around tail fluke causing wound, surfacing Orca (Orcinus orca) behind, Senja, Troms County, Norway, Scandinavia, January. Ce...

Yva Momatiuk & John Eastcott / Sockeye Salmon (Oncorhynchus nerka) group migrating upstream, Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada