T.C. Boyle has taken on "issues" in his other works of fiction, most notably illegal immigration in his novel "The Tortilla Curtain." Here the topical theme is environmental stewardship, and Boyle's handling of it demonstrates the perils such an enterprise often presents.

The novel is overly schematic, pitting two story lines and two protagonists against one another. On the one hand, we have a National Park Service biologist, Alma Takesue, who is directing a plan to eradicate non- native species from the Channel Islands off California's coast; in blunt terms, this means poisoning rats and shooting feral pigs. On the other hand, we have Dave LaJoy, a dreadlocked, wealthy local entrepreneur who, with his (of course) exquisitely beautiful folksinger girlfriend, is dead set against letting any killing whatsoever take place.

Unfortunately, Alma is straight out of some writer's environmentally-conscious-character playbook. To her boyfriend, who's equally invested in the cause and might be expected to know what she does, she makes speeches like this about her opponents: "These people don't want facts, they don't want to know about island biogeography or the impact of invasive species or ecosystem collapse or anything else. All they want is to stick their noses in. And shout. They love to shout." Everything about this woman is oddly programmatic, as if her high-strung sensibility had been charted on a storyboard.

Then there's her intended nemesis, LaJoy. He's simply awful, and just plain unbelievable: the owner of a chain of phenomenally successful high-tech shops who's become a militant vegetarian and PETA-type animal rights advocate, who nonetheless is perfectly happy to transplant alien species (such as raccoons and rattlesnakes) to the Channel Islands to foil his rival.

Sure, LaJoy is complex, a type-A personality who happens to have put his energy into this cause, and Alma is uptight, jam-packed with too much environmental consciousness. But they're both little more than detailed outlines for characters, and, because it's virtually impossible to care about them, their stories bring little interest, light or urgency to the ideas they represent.

Boyle, as ever, writes a neat and often impressive prose. And his book says a good deal about the ecology and natural history of the Northern Channel Islands. And yet, this novel is not the place to find the best of that natural history, or the best of fiction, which at the very least makes you care.

Ellen Akins is a writer in Cornucopia, Wis.