Dolphins have been a popular plot device since the time of Flipper, but scifi has long had a particular fondness for them. Some are awesome; others verge on utterly ridiculous. Here are our favorites.
Illustration by T-KONI.
The Dolphins of Pern, by Anne McCaffrey
Intelligent, English-speaking dolphins accompanied the human settlers Pern with essentially the same motivation — fleeing from an overcrowded, polluted shell of a planet. Two and a half millennia later, the species have completely lost touch (understandable, given the humans' preoccupation with the Thread. As this is an Anne McCaffrey novel, an intrepid teen named Readis eventually rediscovers the creatures can speak and devotes himself to rebuilding relations.
Uplift Series, by David Brin
Dolphins play a major role in Brin's Uplift series, which posits a universe where almost every species has to be "uplifted" to intelligence. Humans have already started the process with dolphins and chimps when they invent FTL technology and attract the attention of the intergalactic community. That gives us patron status, which protects the planet from any aliens on the make who'd claim humanity as a new client race. The second book in the series, Startide Rising (which won basically every SF award there is), takes place on a ship crewed almost entirely by dolphins.
Seaquest DSV
An aquatic crew member is an obvious invaluable asset to any team working underwater. Nathan Bridger's relationship with Darwin the Dolphin predates his command of the Seaquest, as he began working out how to communicate with the creature. During the show itself he communicated via a device called a vo-corder (though it made him sound rather like a precocious toddler).
"Johnny Mnemonic," by William Gibson
There are significant differences in the short story and the movie, but both versions feature Jones, the retired Navy dolphin/hacker. Johnny rents his brain for use as a high-security dropbox for extremely sensitive data. Only the intended recipient has the password required to access that data. When Johnny gets stuck with some dangerous info and needs the password, Molly Millions takes him to Jones, who has the requisite skills and sensors from his days disrupting enemy mines. (In the short story, she offers heroin in exchange for assistance — the Navy has all its dolphins hooked so they won't just swim off.)
So Long, and Thanks For All the Fish, by Douglas Adams
The entire species comes off as a class act in Adams's Hitchhiker's Guide series. We already knew from the first book that dolphins were the second-smartest animals on the planet (after mice, of course). They tried to warn humans of Earth's coming demolition, but found they couldn't quite breach the language barrier. It's not until the fourth book that we discover the dolphins, before bailing, created a faithful replica of the planet and moved the humans, lock stock and barrel.
Known Space, by Larry Niven
Dolphins pop up regularly in Niven's Known Space books. Able to communicate with humans telepathically, they discover and lead the protagonist to the grasping alien Kzanol in World of Ptavvs, for example. Eventually, they're actually admitted to the United Nations and receive legal status that basically puts them on par with humans.
The Day of the Dolphin
You probably know George C. Scott for his roles in either Patton or Dr. Strangelove. But he also made some more interesting project choices. For example, in Day of the Dolphin, he plays Jake Terrill, a brilliant scientists training dolphins to speak English. Two of his subjects, Alpha and Beta, are kidnapped by the shady rich guy funding his research. Why, you ask? Because he wants to use them to assassinate the President of the United States on his yacht. Of course he does.
The Scar, by China Mieville
Lots of fictional dolphins are playful and cuddly. Not Bastard John, who runs security for Armada, the pirate city. A description shows him "passing through the brine with unique motion (as he swept in to punish some worker with a brutal beating)." This dolphin is abusive and violent and generally terrible, and no one would cast him in a children's TV show.
Porm, Aquaman (and Lobo and his spacedolphins)
Dumped in the ocean by the superstitious Atlanteans, Arthur is rescued and essentially raised by Porm, queen of the dolphins. As the boy grows up and into his superheroness, she becomes an advisor. Bonus extraterrestrial cetaceans: In one story, Porm is kidnapped and taken to an experimental facility. In his attempt to free her, Aquaman actually manages to work together with the deeply unpleasant Lobo. The alien bounty hunter is legendarily impossibly to get along with, but he's willing to be civil for the sake of rescuing one of his beloved spacedolphins, who's also been captured.
Hyperion, by Dan Simmons
Maui-Covenant is an idyllic ocean world, with a fertile ecosystem that includes living, moving islands. The planet's dolphins (able to communicate to an extent, but not super advanced) stay with the islands, herding them around the planet. The whole delicately balanced shebang is utterly trashed by the tourists that arrive after Maui-Covenant is connected to the WorldWeb, spurring an ill-fated rebellion that only wrecks the world further and kills much of the remaining dolphin population.