The Procession of Mollusks, a novel by Eric E. Olson.
(Disclosure: I received a free copy from the author and am thanked in the acknowledgements.)
It's the 49th annual March of the Mollusks festival in the Pacific Northwest town of Newport Bay and a strange murder has taken place: the body of Board of Supervisors Chairman Snodgrass is found hanging upside down, naked, drained of all blood, with a saucer-shaped wound on his back. The initial suspect is Dr. Roberto "Berto" Fiori, a malacologist with controversial theories about mollusks, in whose house the body is first found. But things become more complicated as the victim has trouble staying dead.
Olson's first novel is told through the narration of two characters: Torrence Haflek, a reporter with a fondness for parks who may-or-may-not actually be employed; and Jimmy Wilson, a 13-year-old fascinated with sealife and videography. Both discover they're suffering from an unexplained medical condition that gives Haflek waking hallucinations and Jimmy a voracious appetite.
The plot thickens as the two -- along with Berto and Angela Angraboda, Haflek's ex -- uncover Snodgrass' involvement in a plan to end the danger of red tide poisonings for shellfish consumers (and thereby promote the shellfish industry,) with a neuromodulator implant, now undergoing clinical trials in Newport Bay. And then there are the giant, seemingly-friendly snails that have begun to appear in the area by the thousands, bringing with them the attention of Sir Richard Attenborough.
Also, the Pacific Northwest Tree Octopus plays a role in Dr. Fiori's research. I won't go into details, but if the sasquatch find out what humans have been doing to their food supply, there's gonna be some delimbings. Tree octopuses are watching from the woods and parks around Newport Bay, and they've taken an unusual interest in Haflek, whose relation to them is reminiscent of Tyrone Slothrop's relation to V-2 rockets.
The Procession of Mollusks is an enjoyably bewildering tale of hermaphroditic gastropodan sex, transhumanism (of a sort), and the existence of objective reality itself in a world mediated by nature documentaries.