Sci-fi novel set on an ocean planet with genetically modified aquatic humans and terraforming process

Question

I borrowed this novel from my local library several years ago. Set on a waterworld, it has genetically modified aquatic humans who are now in conflict with the original plan to terraform it. Any ideas? I can't remember title or author and have googled to no avail.

The background is that the standard colonisation pattern for not quite Earth type planets are initially colonised by genetically modified humans as terraforming is begun, but as this reaches its final phases the altered humans are phased out. However on this planet they are trying to challenge the process.

The people aren't radically altered, no gills or tentacles! Just a bit plump, and better swimmers, more like Selkies than mermaids.

Answer 1

I was searching for the same thing/same terms and Blueheart (1996) by Alison Sinclair was the right answer for me.

There’s all the stuff about modified humans, terraforming and the conflict between those interests, but there’s also a murder mystery at the heart of the plot. There’s also this critical element that almost everywhere is under surveillance, but the camera feeds are fully public.

It is set in a larger universe but travel between worlds is very rare.

From Goodreads:

Of all the worlds discovered by star-wondering humanity, Blueheart with its endless, storm-tossed seas is the most beautiful. And the most doomed. Plans are already being made to terraform the planet into another Earth.But deep under the floating forests, the renegade Adoptives -- the planet's first colonists -- have another dream: The creation of a new aquatic human subspecies. As their struggle erupts into violence, Rache is called back to the seas, where he must choose between his humanity and his world.

Answer 2

I can't say for sure, but I've read Blueheart (1996) by Alison Sinclair and your description reminds me of it. Here is the book's page on the author's website.

Answer 3

Another possibility is The Songs of Distant Earth (1986) by Arthur C. Clarke. From Wikipedia:

The novel is set in the early 3800s CE, and takes place almost entirely on the faraway oceanic planet of Thalassa. Thalassa has a small human population sent there by way of an embryonic seed pod, one of many sent out from Earth in an attempt to continue the human race before the Earth was destroyed.

The story begins with an introduction to the native Thalassans – the marine biologist Brant, his partner Mirissa and her brother Kumar. They are typical examples of the Thalassan culture; quiet, stable and free from religion and supernatural influence. Their peaceful existence comes to an end with the arrival of the Magellan, an interstellar spaceship from Earth containing one million colonists who have been put into cryonic suspension.

In a series of descriptive passages, the events leading up to the race to save the human species are explained.

I do seem to remember some humans genetically modified to make use of the aquatic environment but didn't seen anything to that effect in the plot description.

Answer 4

Check these out; A Door into Ocean, by Joan Slonczewski, 1986, and its sequel Daughter of Elysium, 1993.

Both are about a pacifist but pragmatic purple-skinned female race of humanoids who can do bioengineering and live on a waterworld. In the first book they certainly resist impending terraforming. Maybe it's the one you're looking for.