Mark Carwardine / Watching Killer whale underwater in aquarium {Orcinus orca} USA

Steven Kazlowski / Polar bear (Ursus maritimus) underwater view swimming in a pool, Anchorage Zoo, Alaska, USA. No release available.

Doc White / Girl in aquarium watching Beluga / White Whale (Delphinapterus leucas) in aquarium. Captive. Model released.

Alex Mustard / 2020VISION / A captive Yellow / Spiny seahorse (Hippocampus guttulatus) attached to plastic seagrass, Weymouth Sealife Centre, Dorset, England, UK.

Bryan and Cherry Alexander / Gentoo penguin (Pygoscelis papua) seen from underneath, using feet as rudders. Living Coasts, Torquay, England, UK.

Juergen Freund / Cyanide fisherman applying cyanide to coral crevices to stun fish. This is highly damaging fishing practice to catch live reef fish either for the aquarium or food fish trade. Palawan, Philippines, Ap...

Juergen Freund / Live reef fish in tanks beside seafood restaurants, Lei Yue Mun harbour, Hong Kong, China, April 2009.

Alex Mustard / A young Spiny / Longsnouted / Yellow Seahorse (Hippocampus guttulatus), aquarium image. This seahorse is part of a UK seahorse breeding program. Photographed at the SEALIFE quarantine and breeding fac...

Alex Mustard / A young Spiny / Yellow / Longsnouted Seahorse (Hippocampus guttulatus), in an aquarium attached to plastic seagrass leaves. This seahorse is part of a UK seahorse breeding program. Photographed at the...

Suzi Eszterhas / Sea Nettle (Chrysaora quinquecirrha / achlyos) Monterey Bay Aquarium, California, USA, Captive

Suzi Eszterhas / Two Purple / Striped Jellyfish (Pelegia / Chrysaora colorata) Monterey Bay Aquarium, California, USA, Captive

Hiroya Minakuchi / Beluga (Delphinapterus leucas) blowing toroidal bubble ring, Vancouver Aquarium, Canada