Like sharks, dolphins cannot experience REM sleep. For different reasons, neither species can ever fall asleep in comfortable stillness, and leave their day time responsibilities—such as staying alive—to look after themselves.
Whereas other fish can sleep under a ledge of coral or stone while their gills keep moving water in and out, sharks must keep moving in order for oxygenated water to flow through their gills. Sharks must constantly move forward in order to remain alive.
And dolphins, air-breathing mammals like us, must remain awake in order to periodically surface, exhale and inhale, before sinking back down beneath the surface.
So how do dolphins relax and rest their tired brains? They can rest because their brains are able to function with enough awareness in either hemisphere to allow the other half to sleep.
I don’t pretend to understand whether this characteristic of the dolphin brain also involves something like the right-brain creativity and left-brain practical competence that humans have such difficulty bringing into balance. But there is no denying that there are minds in the sea which are deep, aware, and which–for thousands of years–have been offering humanity an invitation to engage and communicate.
But both humans and dolphins are most at home with others of their kind—within families, societies, pods and the bonds of spontaneous friendship.
Here is an interesting thought experiment. Do cetaceans, like humans, sometimes ponder their own death? Our spiritual traditions try to prepare us for an inevitable passage from this life, at which time we won’t take anything with us–not our friends, not our lounge chairs, and not our physical bodies. For dolphins and humans alike there will come a final exhalation after which no inhalation will follow. What might that moment be like for a cetacean, for example for a narwhale trapped under the ice?
. . . . .
Narwhales don’t migrate south to Florida when the Arctic ice closes over–like Monarch butterflies and Montreal retirees do. Narwhales can’t fire up a chainsaw and cut a hole in the ice, when winter builds a roof of ice over their heads—when the shadow glimpsed through the looking glass may be a polar bear waiting patiently for dinner.
A narwhale—when bitter cold shrinks his current breathing-hole to nothing—must embark on a perilous journey into the unknown. He must swim under the ice in the hope that an opportunity to take another breath will come before the end of his life. He is not a dolphin thrashing underwater snared in a fisherman’s tuna net. He is not a Pakistani man being water-boarded in order to save democracy. He is free to undertake a journey in search of one more breath.
On the edge of his lifetime, does he catch a hint of light in the water many leagues away? Does an act of faith blossom in his being as he sets out—his whole future dangling from a thread beneath the next gap in the ice sheet? From inside that swimming body, how does the world look? Is there a sweeping intelligence, alive to every nuance of light, every bubble, every stirring of current? Does a sense of the inevitability of life’s closure peer into his mind, as the burning in his lungs rises in pitch? Perhaps he is living out the New Testament injunction that, lest we give up this life we cannot gain a greater life. And then suddenly he is swimming in that greater life. Now every prismatic bubble in the ice above is a light shining into his world; and every sensation is chanting another name for water. And whether the future holds the black carcass of a narwhale, his unicorn horn banging silently against an unforgiving ceiling of ice, or whether it holds the joyous reunion of air and gasping lungs, the water all around is now full to the brim with light and calm acceptance.
And like “Smilla’s Sense of Snow”, human language has no word for that kind of water.