In his first book of nonfiction, Matt Rigney deftly navigates that symbolic tightrope between straight, fact-based narrative reporting and passionate advocacy that often taints works about nature.

An avid sportfisherman and ocean conservationist, Rigney has crafted a smart, lyrical, passionate-but-not-too-preachy call to arms. In Pursuit of Giants should appeal to recreational anglers who dream of catching 12-foot, 1,000-pound black marlin off the Great Barrier Reef and to conservationists and policymakers fretting about the permanent damage that has been wreaked over the last half century.

Rigney spent five years criss-crossing the globe, tracing the historic decline of big-game marlin, sailfish, swordfish and three species of tuna — yellowfin, bigeye and the rapidly disappearing giant bluefin. He logged long hours at sea with commercial and recreational fishermen off Cabo San Lucas, Nova Scotia, Japan, South Australia and New Zealand, and with Greenpeace activists in the decimated bluefin habitats off Malta of the Mediterranean. He visited the world’s largest fish market in Tokyo, where up to 10 percent of the world’s catch is sold each day, and a pioneering tuna-farming operation in Australia.

Some common patterns quickly emerge. With the human population and its bottomless appetite continuing to explode, commercial fishing interests have consistently placed profits and short-term “resource extraction” before the long-term worth of allowing fished-out populations to replenish themselves.

Corporate-backed fishing fleets, using long-lines and huge drift nets, and scallopers deploying bottom-scraping dredges, are laying waste to massive populations of sea creatures and the deepwater habitats that have allowed them to thrive for millenia. In Rigney’s view, “the industrial fallacy” of increasingly powerful technology applied for short-term gain does not equal progress.

He vividly illustrates the collateral damage of “by-catch,” the tons of turtle, shark, sea lion, porpoise, whale, undersized juveniles and less-market-worthy fish that are killed and thrown back by commercial fishing interests for the marketable items they are legally permitted to catch.

Smaller multi-generation independent fishing families are being driven out of business by larger fleets with political muscle that are backed by global operators. Government regulatory bodies theoretically overseeing these international waters are usually inept, corrupt or controlled by the large corporate interests whose lobbyists promote ineffective, deceptive or unenforceable rules that focus on short-term food yields rather than long-term viability. The lack of global standards only makes the hodgepodge of inept government fisheries management policies that much easier to exploit.

Rather than examining the best scientific evidence aimed at replenishing overfished populations, fisheries management is geared largely toward extracting the highest yields possible. Like the overfished cod and Atlantic salmon populations before it, Rigney fears the bluefin tuna may be doomed.

Rigney’s respect for many of his characters that make their living at sea and his near-spiritual connection to the big creatures below resonates throughout. In one of the funnier segments, a Nova Scotia fisherman dupes Rigney into eating the beating heart of a recently harpooned swordfish, in honor of his first “big catch.” A few pages later, the salty, hard-bitten patriarch of this same family laments the destruction he’s witnessed over the last 50 years, as one of the most vibrant habitats on the planet has been by overfishing and greed.

Each segment is punctuated with scientific data provided by top marine biologists and credible reports. They paint a bleak picture of what remains — and a more dire one for where we are heading if the status quo prevails.

“The evidence has been building for decades that we have entered a dangerous, new and unstable age,” Rigney concludes, “and yet we continue to conduct ourselves as if this were not the case.”

While most of his ire is aimed at the commercial fishing interests, Rigney, to his credit, doesn’t spare his friends in the sportfishing industry. His suggestions for altering hook design could lead to better catch-and-release practices and fewer maimed big-game fish.

Rigney is aiming high — and largely succeeding. Can this deserving work reach a broader audience like Michael Pollan’s The Omnivore’s Dilemma or Eric Schlosser’s Fast Food Nation? Rigney recognizes that’s no small feat. Consumers are disconnected and complacent. As they stand in line at the local fish market or stuff their gobs with tonight’s sushi special at their favorite restaurant, they aren’t thinking about how their next meal has been procured or its long-term effects on the environment.

Larry Lebowitz is a Miami writer and co-owner of a small ecotourism business.