Tales of people under the sea are likely as old as humanity. Ancient religions peopled the deep oceans with sea gods and their courts, sailors told tales of mermaids, Plato’s mythical city of Atlantis lived on in myths of peoples adapted to an underwater world, and the bells of villages lost to coastal erosion or sea-level rise were heard to ring. In more recent times, fantasy has been succeeded by science fiction which explores what it would mean for humanity to live as natives in water, and how that might be achieved.

Echoes of Atlantis

Doctor Who engaged with the Atlantis myth, neatly straddling the boundaries between science fiction and science fantasy, in 1967’s “The Underwater Menace” [1]. Here the survivors of an ancient, culturally archaic but technologically-advanced civilisation were shown as living in a network of caverns sited below a volcanic island. Originally at the surface, it has long been submerged. For growing and maintaining their food supply, the Atlanteans employed a race of fish people - captured shipwrecked sailors from the surface who are adapted through surgical and genetic techniques to breathe through implanted plastic gills and survive underwater, acquiring fish-like scales and eyes in the process. This fate was narrowly avoided by one of the Second Doctor’s companions. Oppression of the fish people eventually allowed the Doctor to encourage a strike and revolt, as part of a series of events which eventually led to the destruction of the civilisation. Interestingly the Doctor’s allies in raising the fish people to revolt included a young woman, and sailors of Irish and African descent - all themselves members of marginalised groups in this context, able to sympathise with the discrimination but with marginally more privilege than the fish people in Atlantean society.

The same basic premise, shorn of the Atlantean overtones, can be found in the (frankly terrible) 1966 science fiction movie Terror Beneath the SeaLink opens in a new window (dir. Sato) [2]. Here a secret underwater base provides a home for a (theoretically) science-motivated totalitarian regime. Again, human beings are adapted through surgery and radiation therapies to survive beneath the water. Indeed, scenes show artificially grown gills being implanted into the unlucky victims, and the process is begun on the lead characters, reporters Ken and Jenny. In this case, the implantation leads to the fish people being described as cyborgs (despite a lack of externally visible technology) and they are also described as being free of sexual distinctions and without volition - another fishy slave race.

Damage to the base’s equipment appears to break the control of the scientists and the cyborgs turn on their masters, murdering the man responsible for their processing. As one of the characters notes dramatically: “killed by a cyborg he, himself, created!”. It is not clear what happens to this race at the end of the film although they likely went extinct.The base is eventually destroyed, and as the cyborgs lack sexual distinctions it is unlikely that they would breed.

Both of these examples are likely indebted to earlier examples of undersea novels. A notable example is City Under the Sea (1957) by Kenneth Bulmer. Here again we encounter a group of surgically-altered slaves, described as Menfish, forced to work on undersea farms. However here the villains are not politically motivated or particularly scientific. Instead, the motivation for press-ganging, forced labour and surgery is purely financial: overpopulation and starvation on the surface has led to immensely powerful commercial corporations fighting unchecked in a lawless underwater frontier that can't be policed without disrupting the much needed aquiculture outputs.

Necessity of Survival

As genetic science has become more complex, the somewhat non-specific processes used in earlier fiction have been replaced by gene-modification techniques. Stephanie Saulter’s ®evolution trilogy (Gemsigns, 2013; Binary, 2014; Regeneration, 2015) posits a near-future world in which global information technology triggers a pandemic known as the Syndrome, which has made it necessary to genetically modify the next generation. This, together with a dramatically-reduced population in need of labour, opens the door to commercial human gene engineering and the indenture of the engineered individuals. Decades later, the resultant genetically-modified humans, or Gems, are forced to fight first for freedom from enslavement and then for recognition as human with the rights that entails. Despite the post-population-collapse scenario, this discussion is deeply rooted in contemporary culture. Indeed direct parallels and connections are drawn with the treatment of enslaved Africans and their segregated descendants, and with the first peoples of America and Australia.

Amongst the Gems are a subspecies of humans bioengineered with gills and other aquatic mutations known as Gillungs. Again their role as formerly enslaved individuals taking back what they are entitled to is highlighted. Speaking of the London dockers abandoned after the Syndrome, Saulter tells us:

Some of the first galling prototypes were put to work restoring the channel and clearing and expanding those old berths, a practical demonstration of the uses to which the hardy new water-breathing subspecies could be put. When emancipation came in the form of the Declaration, London's gillungs reclaimed the area as the fruits of their forebears' uncompensated labour, and expanded the dredging and reclamation even further. (Regeneration, 2016 edition, pg 103)

The third book in the trilogy, Regeneration, discusses technological innovations introduced by gillung engineers, and the opposition they face. Since this group breeds true, and since it also occupies a distinct environmental niche not normally in competition with “normal” humans, it faces fewer problems than other Gems, who must integrate with wider human society. This in turn raises the gillungs’ potential threat level to xenophobic normals - this is a viable and (by the third book) entirely free and autonomous population of a new species with little need or inclination to crossbreed with the rest of humanity. From being yet another aquatic slave race, they are establishing their equality and perhaps even superiority to conventional humans.

Another, very different, post-apocalyptic scenario can be found in the novel SevenEves (Stephenson, 2015). Here the surface of the Earth becomes uninhabitable for thousands of years. While the bulk of the book focuses on the efforts of a population to survive in space, forced to genetically engineer a variety of human strains to account for a genetic bottleneck, it is later revealed that a small population (known as the Pingers) also survives in deep ocean bases:

“As the first one ascended into shallower water, the shape of his body became clearer; round, and, in general, sort of projectile like... “

“At first the Pingers had seemed black, but as they came out of the water it became clear that their skin was dark grey, and mottled with patches of lighter grey, shading towards blues and greens. Their bellies were of lighter hue than their backs, and the mottling tended to run up their sides.”

“The underlying skulls probably looked the same as rootstock humans. But eyes, ears and nostrils were guarded by systems of muscled flaps that were always in some amount of motion.”

Although this new subspecies is described as having used selective breeding to adapt themselves to their new environment, this seems unlikely in the matter of a few thousand years under consideration. Given the capabilities of the parent pre-apocalyptic civilisation it seems likely they embraced a never-clearly-defined amount of genetic engineering as well.

New Horizons

Although these examples are the product of desperate attempts by humanity to avoid extinction, other science fiction considers the idea of aquatically-adapted humanity as a deliberate choice made to exploit the new niches offered as technology widens our horizons.

A number of stories deal with the idea of adapting humanity as part of a terraforming process aimed at exploiting water-rich worlds, or exploiting Earth’s own underused ecological niches. In some cases, an aquatic modification is expected to be part of the long term genetic reservoir of the human population, as is the case for example in The Lazarus Effect (Herbert & Ransom, 1983) or Blue Remembered Earth (Reynolds, 2012). In others, it is intended as an intermediate step, which facilitates the terraforming but is expected to be abandoned in favour of a return to terrestrial life, for example as in Blueheart (Sinclair, 1998). In this story, a number of worlds have been terraformed by populations individually engineered to be adapted to the alien environment, before those adaptations are phased out. Blueheart is the first world encountered with a viable ecosystem of its own, and by the time the novel begins, adapted populations have adopted a tribal, 'pastoral' culture which diverges substantially from that of the 'primary' humans living in raft-supported towns. More importantly, as the plot develops, it becomes clear that they are now able to adapt their own children without recourse to primary scientists, and have a larger-than-realised population. This raises the question of whether the terraforming needs to proceed at all.

Understandably such cases carry the potential for friction between modified humanity and the unmodified “normal’ humans. This is often both practical and ideological. As an authority-figure in Blueheart states plainly:

"The whole history of the species is marred by our tendency to include and exclude. Us/Them. The greatest divisions were between human subtypes, between races. Even now, on Earth, the vestigal subtypes remain. But out here we are integrated, united. Yes, we may divide temporarily into subtypes, but only to achieve an end. The integrity and unity of the human race must endure."
- Cesar Kamehameha, Blueheart (pg 175, Millenium paperback edition)

The focus of Blueheart, as well as some of the other texts mentioned here is to explore the question of whether uniformity is a necessary prerequisite for human cooperation (as the character quoted above and others seem to believe) or whether diversity can be embraced and used to enrich the race, as well as asking questions regarding intergenerational responsibility and the rights and obligations of everyone in a shared society.

A new race?

Aquatic humans are perhaps unlikely to be limited to specific oceans. Taking this premise to its logical extreme, a variety of science fiction explores the idea that a space-borne, interstellar humanity would fragment into a number of related factions that eventually diverge into subspecies or even full species (something the characters of Blueheart fear). This can be seen for example in Alistair Reynold’s Revelation Space trilogy (Revelation Space, 2000; Redemption Ark, 2002; Absolution Gap, 2003). Here “gillies” are engineered humans, adapted to a fluid environment in order to provide support and buffering from the rapid accelerations required for short-range interplanetary space manoeuvring [3][4]. But positive examples such as this are very much outnumbered by stories evoking conflict and oppression.

A running theme in the literature of aquatic humanity, through examples including Doctor Who, Terror Beneath the Sea, Blueheart and the Gemsigns trilogy, is the creation of a servitor race and - whether implicitly or explicitly - a commentary on racism and prejudice in our own times. These texts reflect on the oppression and dehumanisation of a sub-population defined by physical characteristics, as well as on the ethics of scientific experimentation. In each case scientists act immorally or irresponsibly in the creation of aquatic humans, with little regard for their self-identity, aspirations or consent. This is particularly true of texts involving forced surgical transformation, but the same questions arise in the many stories which consider genetic manipulation prior to birth - the resulting offspring cannot consent to their modifications.

Most recent science fiction in this area, including the examples given above, venture into a subgenre now known as post-humanism. In asking whether the aquatic people are human, they question what humanity itself might mean or become in the future. SevenEves and Saulter's ®Evolution trilogy confront this question directly: after their respective near-future catastrophes, all of humanity descends from genetically-modified rootstock. Naturally-evolved humans no longer exist. In other stories, “root”, “base” or "primary" humanity continues, but now in parallel with modified beings. It’s unsurprising that these form cliques or social groupings, given common experiences, but at what point do physiological, sensory, psychological or hidden changes become significant enough to fundamentally change an individual’s identity?

And do they matter at all?

History teaches us that humans are quite capable of identifying the smallest cosmetic or cultural differences as a cause of conflict. Questioning another individual’s humanity has never presented a challenge to some, even in the absence of genetic manipulation. And human priorities and norms have evolved over time naturally - the goals and aspirations of today’s humanity might be unrecognisable to our ancestors. It is not clear that any set of criteria could fairly exclude our genetically-engineered descendants from humanity. But on the other hand, if the priorities, perceptions and psychology of different groups become truly incomprehensible to one another, rather than merely different, then which group has the stronger claim to inheriting the legacies of humanity?

None of these questions are easily answered, and inevitably most fiction in this area is most straightforwardly read as a commentary on our own society, its mores and expectations. Indeed, aquatic adaptations through genetic means alone are almost certainly impossible in any case - water at habitable temperatures and pressures simply cannot carry enough oxygen to sustain a human metabolism through any naturally occurring gill structure. Technological support would almost certainly be necessary. And we are a long way from seriously considering adaptations of humanity to different habitable environments, given the difficulty in reaching, or even establishing the existence of, such niches. Nonetheless, the oceans of Earth will doubtless exercise their ongoing pull on our imaginations, and permit such thought experiments to continue.