Ingo Arndt / "CTD" (instrument for collecting water samples from all water depths) at work 50 km from the ice floe base. ISPOL (ICE Station Polarstern) Expedition 2004/2005 from Alfred Wegener Institute; Bremerhav...

Roy Mangersnes / Marine iguana (Amblyrhynchus cristatus) feeding in deep water to find algae, off the coast of Fernandina island on Galapagos. April 2016. Much of the algae on coast and at shallower depths have been k...

Roy Mangersnes / Marine iguana (Amblyrhynchus cristatus) feeding in deep water to find algae, off the coast of Fernandina island on Galapagos. April 2016. Much of the algae on coast and at shallower depths have been k...

Franco Banfi / Green anaconda (Eunectes murinus) underwater, flicking tongue, Formoso River, Bonito, Mato Grosso do Sul, Brazil

Solvin Zankl / Deepsea smelt {Bathylagus antarcticus}, found in all the southern oceans as far south as Antarctica, from the surface to depths of 4,000 m, Atlantic ocean

Norbert Wu / Chambered Nautilus (Nautilus pompilius) comes up from great depths at night to shallows, Palau

Sergio Hanquet / Short-finned pilot whale (Globicephala macrorhynchus) emerging from depths with Squid (Cephalopoda) stuck on head. Tenerife, Canary Islands.

Alex Mustard / Sun beams spear down into the depths of the sea. Indian Ocean off Sri Lanka.

Nick Hawkins / Finger sponge (Isodictya sp.) growing in the depths off Bonaventure Island, Quebec, Gulf of Saint Lawrence, Canada. September.

Ingo Arndt / Helicopter transporting "CTD" (instrument for collecting water samples from all water depths) to research site 50 km away from the ice floe base. ISPOL (ICE Station Polarstern) Expedition 2004/2005 fr...

Igor Shpilenok / Small cone emitting steam from the depths of the caldera of the Uzon Volcano, Kronotsky Zapovednik Reserve, Russia.

Igor Shpilenok / Small cones emitting steam from the depths of the Caldera Uzon Volcano, Kronotsky Zapovednik Reserve, Russia.