The Mountain in the Sea by Ray Nayler

 

The cover copy seems kinda reluctant to admit this, but this novel is basically a cyberpunk novel--AI and hacking and science past the recognizable bleeding edge that manages to feel plausible; also literally murderous corporate maneuvering--though this novel has the advantage of being (or feeling) at least a couple decades closer to its future than, say, Neuromancer. There's more biology, specifically marine biology, on several levels of premise; the results of decades of chronic overfishing are part of the background, and very foregrounded in several of the arcs. The setting is at least as dark as one might guess: in addition to the murderous corporate maneuverings, there's human trafficking as one of the narrative engines. There's a thread that doesn't meet up with the rest of the novel until the epilogue, but that thread is playing a neat counterpoint, and I don't think I would want it excised. The prose is solid, occasionally sparkling and witty; the dialogue fits the characters well; the characters are mostly plausible. There are things floating around about what it means to be human (a classic SF theme) as well as some thoughtful takes on the problems of alien intelligences--and how shockingly alien other intelligences could be here on Earth. Really, really good.