‘Lords of the Fly’ Review: Long Live the Silver King!

“Fly rod” is an important modifier. Trying to bully a tarpon into coming within reach using just the delicate traceries of a fly rod is like choosing a Mazda Miata to tow an 18-wheeler. Sure, you can land a tarpon with a fly rod, but it requires outsize portions of patience, strength, endurance, mental toughness and finesse. Madness and obsession also help, are probably equally requisite. If it involves setting records for the biggest tarpon ever caught with this or that calibration of gear, we could throw in ego as well—a bushel and a peck of that.

Ms. Orlean found her mad, obsessive egotist in the laser-focused horticulturist John Laroche. Monte Burke finds his in Tom Evans, a wealthy New York stockbroker, a former athlete and the child of an emotionally abusive father (cruel or absent fathers are phenomena Mr. Burke finds common in this particular world). In adulthood Mr. Evans became a weekend fisherman to relieve weekday stress. In 1968 he went to Florida, hooked a tarpon and got laser-focused himself.

Mr. Evans is now in his 80s, still chasing tarpon as of last year, and over the decades has set enough world records in various gear/weight categories to be compared by Mr. Burke to Babe Ruth. “He is, by the book,” says Mr. Burke, “the greatest big tarpon angler alive.”

But Mr. Evans is different from Ruth in one respect, Mr. Burke says, and different from almost all his competitors, in that he has no interest in fame or self-promotion. Mr. Evans craves only the primal lust of the hunt, the adrenaline rush of a battle tilted steeply against him—and the similar rush of outdoing his rivals.

His rivals are, and have been, legion, and this is a lush, panoramic book full of characters no less crazy than Mr. Evans, some a good deal crazier. Its setting is chiefly around the mouth of the Homosassa River on Florida’s Gulf Coast, though we also spend some time in Key West, a trippy haven for artists and gays in the ’70s, where the novelists Thomas McGuane, Jim Harrison and some others “brought a sense of cool to fly fishing for tarpon.”

In 1976, after a bad stretch fishing in the Keys, Mr. Evans and his guide Steve Huff tried the brackish sand flats outside the Homosassa, where there were rumors of big tarpon. On the first day, in heavy swells, they anchored between two rock piles. “And then they saw them arcing through the waves,” Mr. Burke writes. “Tarpon. Almost too large to believe. Evans says that in the odd light emanating from the bruised sky, the fish took on an ethereal golden hue.”

Soon Messrs. Evans and Huff were fishing exclusively there, and so were a lot of other wealthy, elite and maybe-a-little-cracked fishermen, most any of whom might have made as fascinating a protagonist as Mr. Evans. Mr. Burke is particularly good on the awkward, push-pull relationship between rich clients and their usually more skilled—but much less financially secure—local guides. “Fiddly” is how Mr. Burke describes it, and the mutual devotion and ongoing tensions between Messrs. Evans and Huff form one of this book’s many fine plot lines.

The big fish off the Homosassa inaugurate an era of “record fever.” And indeed, for the next two decades, records get broken and broken again by Mr. Evans and others. Increasing numbers of boats and egos roll in on a tide of money, which leads to high-tide levels of drugs, sex and bad behavior in. Mobster/elite fisherman Bobby Erra might have set the worst example, but even he had rivals.

And then, suddenly, the catches started to dwindle. Have you heard this one before? Since 2013 the Florida tarpon fishery has been catch-and-release—unless you’re submitting a world-record candidate, which still must be killed in order to be formally examined and weighed. Mr. Burke concedes, however, that catch-and-release is torture for a fish, and sometimes fatal.

But Mr. Burke is probably right that in this case the problem wasn’t overfishing. “Put simply,” he writes, “without fishermen, there would be fewer fish.” That’s a little too simple, actually. Commercial fishermen, in general, are conservationists, but theirs is a fiddly balancing act between making a living or not. Sport fishermen do have a pretty clean track record, however, of protecting the species they pursue. Thank sportsmen for most of the trout in your streams.

As Mr. Burke says, tarpon numbers around the Keys are relatively strong. With the Homosassa, though, so much water has been drawn from the aquifers feeding it that its bay is now saltier—too salty for the blue crabs upon which the tarpon feed. The reduced flow of the Homosassa and other rivers is blamed by the Southwest Florida Water Management District on long-term drought. The data don’t support that, but political interests do. To Mr. Burke, the decline of this small but epic fishery is Florida in a microcosm. He writes, “Ill-thought-out development, bought-and-paid-for politicians, the drying up of aquifers, the unsustainable development of coastal lands, the intentional misinformation, the worshipping of economic progress above all other types of progress . . . all of this has led to an ecological catastrophe that’s yet to be fully acknowledged.”

Which is also our world in a microcosm, speeding on its way via habitat loss and species extinction to what entomologist E.O. Wilson has called the Eremocene—the Age of Loneliness. Today fly fishing’s Babe Ruth is ailing and crippled, yet still cruising sand flats grown lonely of tarpon. He persists in homage to that ethereal golden hue, to how glorious it was—once upon a time.

—Mr. Carey’s books include “Against the Tide: The Fate of the New England Fisherman.”