By Courtney Mattison for Mission Blue

Imagine rolling backwards off an inflatable boat into icy Arctic waters… on purpose. Enveloped in protective gear, you stay mostly dry as the cold sinks into your body and you descend into the frigid depths below.
“The first thing that hits you is just the shock of the cold,” says Dr. Helena Reinardy, Associate Professor of Ecotoxicology at The University Centre Svalbard (UNIS) and member of the Longyearbyen Dive Club. She continues, “You think, I’ve got to get out right now!… But then you very quickly get used to it.”
Beneath the waves, you find yourself immersed in planktonic life, including some surprisingly large zooplankton—pulsing golden green jellies the size of marbles, skittering shrimplike amphipods and graceful sea angels (Clione limacina).…