The webnovel 'Salvage' on Scribblehub is a weird sci-fi take. A human space salvager finds a cryopod containing a genetically engineered 'mer' from Earth's past. They end up on a sprawling, water-covered ecumenopolis (planet-wide city), and her aquatic adaptations and latent bio-magic become crucial for navigating and surviving the flooded urban wreckage.
The ocean magic is more like advanced biotech, and the 'urban' setting is an alien, derelict cityscape. It's a wild blend of genres, but the core dynamic of an ocean-adapted being using her innate abilities to master a drowned urban environment is there in full force. It's ongoing, but the archives are hefty and the world-building is incredibly creative.
I had a phase where I devoured this specific trope! A solid recommendation is 'Ocean Light' by Nalini Singh. It's part of her 'Psy-Changeling' universe, which is a futuristic urban fantasy/romance series. This specific book features a water-based changeling species (not literal mermaids but very close—aquatic shapeshifters) living in a hidden underwater habitat that has intense political and trade ties to surface cities.
The magic is more biological and psychic, but the world-building around how this aquatic society interacts with high-tech urban centers is meticulously done. The romance is central, but the political thriller elements show the nitty-gritty of interspecies diplomacy, underwater construction, and resource management. It's a smart, grown-up take on the concept.
Chloe is a scientist with a secret, she is a mermaid...without a mermaid, or so she thinks. She is a hybrid, half human and half mermaid whose father is disgusted and left her mother when he found out she was pregnant.
With the help of her best friend Kari, who finds out she is Royalty in the Werewolf Kingdom, she finds herself fitting in with the Werewolves when the King of the Sea finds her. He is disgusted with her father for abandoning her and pulls her into their world along with her werewolf mate but she finds out that she is special and she is hunted for her mermaids scales
Marilyn is a young mute mermaid who was forcibly taken out of the sea. She stays in a pool alongside other mermaids where they are displayed for werewolves to buy for sexual pleasure. She is determined not to be a possession of any wolf. But then, her determination is shaken when she met him.
Who is he?
Balin, the cold-hearted Alpha of the Bold Bite Pack. He suddenly develops a soft spot for a mermaid at first sight, making him take her home.
What happens when he realizes that the mermaid he took home is his mate?
Why was he unable to recognize her as his mate?
Will members of his pack let a sea creature become their Luna?
"Cry, Mermaid!" a sharp lash sliced into my back, forcing a yelp from my lips. Screams and sobs surrounded me on all sides, but no one would save me. Strong hands caught me beneath my arms and yanked me from the water. It was time for Tail Cut.
The operation lasted hours. I felt every last slice of their blades, every new tendon sewn into my muscles and nail hammered into my bones. I screamed. I begged. I begged for them to stop, for them to kill me, just ended the pain.
---
I have a secret, I am a mermaid.
I should live in the ocean, but my tail was cut and I only owned legs. After escaping to Asterion, I hid my identity. I thought I could finally live a peaceful life, until that day I met the famous bad boy, the future Alpha, Caspian.
---
I felt a strange prickling on the back of my neck. I spun around just in time to see Caspian prowling towards me through the darkened wings, his blue eyes positively glowing. Sharp white teeth flashed as Caspian's lips unfurled into a lethal grin, "Hello Mate."
Charlie is a member of Black Diamonds, they hunt for these inhuman beings called mermaid. When the ship is attack one night, Charlie is pulled into a whole new world under the sea.
Metamorphosis is the story of a woman’s struggle to regain her confidence and repair her shattered life following a random, brutal attack. With the help of the man she had pushed away, she chooses the path that she will follow for the rest of her life. She undergoes a metamorphosis—not by choice but by the will to survive.
When Moby and Piper collide—they just know. He didn’t have to shout his love from the mountaintops. The only heart that needed to hear his words listened silently to his soul’s communication. A bond that would transcend time and unexpected heartache.
The moment Piper laid eyes on Moby—she just knew. She didn’t have to await results. All the evidence she needed was there…taunting her, challenging her, testing their resolve. Daring her to persevere.
A broken man.
A shattered woman.
A crumbling marriage.
No one knew.
The Siren Song Series is created by Stephie Walls, an eGlobal Creative Publishing Signed Author.
Don't sleep on manga for this! 'Mermaid Saga' by Rumiko Takahashi is a classic horror-romance. It's about immortal beings who gained eternal life from mermaid flesh and the tragic, often bloody consequences. The romance elements are woven into stories of centuries-long longing, loss, and the curse of immortality.
The sea is a source of forbidden power and horrific transformation. The relationships between humans and those touched by mermaid magic are complex, painful, and never simple. It’s a masterpiece of the genre, but be prepared for it to be dark.
Okay, so diving into mermaid worldbuilding, I need to get something off my chest first: a lot of them just feel like Atlantis with a fresh coat of paint, you know? The cities are vaguely Greco-Roman, the politics are tired monarchy stuff, and the magic system is just... water bending. It's fine, but it rarely feels like a society that evolved entirely separate from human land-dwellers. That's why I keep returning to 'The Deep' by Rivers Solomon. It flips the script entirely. The mermaids there are descendants of pregnant African women thrown from slave ships, and their entire history, their very biology, is built around a collective, painful memory. The world isn't about coral castles; it's about the weight of trauma carried in song and the terrifying possibility of forgetting. The societal structure, the way they process experience—it’s profoundly alien and deeply moving. It makes you rethink what a civilization under the waves could even be, divorced from our terrestrial architectural and political blueprints.
For something that feels meticulously crafted from the seabed up, I'd point to Emily B. Martin's 'Creatures of Light' series, starting with 'Sunshield'. It's not strictly mermaids, but the aquatic-dwelling Lumin in the later books? Stunning. Their society is built around bioluminescent communication, a caste system linked to light production, and a culture that perceives depth and pressure in ways we can't. The worldbuilding isn't just a backdrop; it dictates the plot, the conflicts, the romance. It feels like a real ecosystem that shaped a people, rather than a people who just happen to live underwater. After that, a lot of other settings just seem a bit... shallow.