EATING FISH used to be so easy. It was a lighter and healthier alternative to beef and it was easier on the environment than factory farmed beef or pork. While that may have once been true, it's not anymore.

Americans eat 2.5 times more fish than 20 years ago, and it now comes from all over the world instead of local waters. That means our consumption habits have far-reaching consequences on the health of fisheries and the oceans. Depleted fish stocks, bycatch, environmentally destructive fish farms, mercury contamination and other concerns have made what was once a feel-good choice fraught with complications. It's enough to make a fish lover look elsewhere for dinner.

That's why Paul Johnson's Fish Forever: The Definitive Guide to Understanding, Selecting, and Preparing Healthy, Delicious, and Environmentally Sustainable Seafood (John Wiley & Sons; 438 pages; $34.95 cloth) comes at just the right time. The text-book-size tome will convince you it's safe to go back into the water—culinarily speaking. The book offers a practical guide to selecting seafood in this age of PCB contamination and overfishing.

Johnson is the owner of the Monterey Fish Market, a business he founded in 1979 after working as the fish buyer for Chez Panisse. He has a retail shop in Berkeley and a wholesale operation on San Francisco's Pier 33. He is recognized as one of the country's authorities on seafood and is a champion of sustainably harvested fish.

The book is full of practical tips, like why grilling is better than frying (frying traps in any pollutants that might be in the fish's fat, while grilling, broiling, poaching, allows fat to drain away). Another more far-reaching tip is "fishing down the food chain." Seafood one step up on the marine food chain—such as clams, mussels and oysters that filter their food—is nutritionally well balanced and accumulates plant sterols that block the uptake of cholesterol, Johnson says. Some fish like anchovies, sardines, herring and sockeye salmon are rich in omega-3 fatty acids and don't accumulate pollutants like other long-lived top-of-the-food-chain species.

But the heart of the book is an alphabetic list of fish species with biological information, health benefits, preparation tips and recipes. In addition to describing specific species to seek out, he also advocates fish-harvesting methods like hooks, harpoons and traps, fishing techniques that are more selective and reduce by-catch. There are also entertaining stories about fishermen and the fishing industry, like when a friend of Johnson's older brother sold a nearly 800-pound bluefin tuna caught off Rhode Island for $40,000 at Japan's Tsukiji fish market auction.

The fish included here don't belong to an environmental "green list" of seafood that's OK to eat. Most come from sustainable fisheries, but Johnson says some fish like grouper and monkfish are included because they're popular. That seems a poor rationale for someone who's made a name for himself as a proponent of sustainable fisheries. I also wish this section contained more photos of fish, but it's still a great resource.

Most of us don't have access to neighborhood fishmongers like the folks at Monterey Fish Market who can provide in-depth information about the fish they sell. Instead we rely on big supermarkets where the guy behind the counter may not know the difference between a halibut and a flounder. Johnson's book will help make you a more informed fish consumer.

Every once in a while cookbook comes around that I know will become indispensable as both a cookbook and reference. Fish Forever is one of those books.

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