The August 12 review of The Wild Edge, by Philip Kopper (Times Books), mistakenly ststed that the book had no index.Book World regrets this error. CAPTION: (NEW-LINE)Illustration, no caption, FROM "THE WILD EDGE"

The era of careless rapture for the shore is over. In the 1970s most people notice that the coast's natural functions are failing. Fish are scarce, waters are polluted, beaches disappear; erosion cuts away expensive waterfront acres, winter storms wreak unexpectedly violent disaster. The new era of man on the coast besets the nation with decisions - what next? A hard question. It gets harder with the humbling discovery that there is no technological fix that can bring back the good old days when we could use the coast as we wanted without any obvious ill effect.

Fortunately, huge advances in knowledge have been made in this decade, yielding facts no one has known before. These facts provide a new ability to make informed, intelligent decisions for the coast. The Beaches Are Moving provides one cornerstone of this burgeoning power.

Authors Wallace Kaufman and Orrin Pilkey have turned out a stunning, no-nonsense account of the simple and simply overlooked fact that the shore moves. "If anywone were taking bets on whether man or the sea will win the struggle of the beaches, we would be heavily on the sea," they say, and provide a staggering assemblage of evidence.

The notion of a mobile coast is not entirely new to me. But this is the first book to explain why the shore must move to continues its age-old functions and what the present coast culture does as it tries to stop this necessary motion - how utterly foolhardly we are to armor our coast against the unbeatable force of nature. As long as the earth spins on its axis this force must keep shore and sea on the move, an arrangement that happens to be felicitious for people and other forms of life.

The force is as profound as ocean deeps, as wild as hurricane winds, as determined as the melting of the polar ice cap or the energy of waves. The book makes sure we understand these phenomena and realize that the shore persists despite them, but only where convenient to itself. We find out that "the whole world is eroding," and that the rate of erosion increases when people interfere. Galveston County, Texas, could be destroyed before the year 2000; water is already in the streets. When we interfere with sand, sand goes away; withness Cape May, New Jersey, Miami Beach and Southern California, "a region strangling in the tentacles of its own desires."

The best part of this valuable book is its logical conclusion that what must change is not the fact that the shore moves, but our ideas of how it should be used. "There are no catastrophes or disasters in nature," the authors say. Erosion is not a catastrophe; geologists such as Pilkey prefer to call it beach retreat, a known and accepted universal law. It becomes a disaster only when we buy, build on and try to keep shorefront in place. The tendency of barrier islands to move back is only a catastrophe when we occupy them "like people who have built cities on the backs of giant sea turtles...[and] will not tolerate the beast moving"; in nature, the hurricane is but an enlargement of a breeze, obeying the same principles.

The Beaches Are Moving proposes that we adjust to the everlasting fact of the title, a sensible-enough idea, if we can't do anything about it anyway. Sand, it says, is no more subject to private ownership than the air or sea; we have to stop trying to catch it, own it, sell it. We must let sand run free, and the same is true for cliffs that will tumble into the ocean and for dunes that must march across shores, rivers and bays.

"We must lay aside our pride and stop setting up history to repeat itself. The next time nature offers us a clean or even a partially clean slate, let us be prepared to write on its a new idea, one that proves our ability to learn and to within our means." For shore use to be born again is a compelling idea for coast-wise minds to work on, the sooner the better. Some of the new ideas Kaufman (a real-estate man as well as a conservationist) and Pilkey suggest seem a peace offering to shorefront owners and developers: movable cottages (although they really prefer tents). They also weaken their arguments by including a checklist for buying or building on the beaches; however sensible, it confuses the reader who just has been convinced that there should be no such activity to have a checklist for. And the book is so intent on the moving of the shore that it neglects to place this system in relation to the many other natural wonders that together make a functioning coast.

The Beaches Are Moving tells the story like it is Minor reservations aside, it is a clear, assured addition to the new coast literature which has sprung from upwelling facts. Decisions about the coast will be wiser because this book exists.

In less cataclysmic days, beauty and the beach attracted coast-minded writers. Love for the shore was uncomplicated by problems of deterioration; much less was known about coast systems. Philip Kopper, a reporter intrigued by the shore, set out to write the one book that would embrace the coast in its entirety. The Wild Edge is the result, a mix of field guide, cookbook and first aid manual, sprinkled with personal musings ("Driftwords"). You might open it to a description of oysters' sex life - "involves a degree of togetherness that borders on mass hysteria" - the founding of Atlantic City, even beach erosion. "I'm drowning in information," the author tells us.

This uncomfortable sensation may have deterred Kopper from organizing his material to give the reader confidence. A bibliography and an index woul have helped; and it would be an easier beachcombing bible and the author kept his promise to "ignore obfuscatory terminology. What's sauce for scientific method," he says, "can be souse for simple clarity..."

Simple clarity has been beautifully achieved by Anne E. Lacy's illustrations, which recall the balanced marvel of a clam shell or a shorebird in clean, meticulous lines. Her work gives this book a distinctio missing in the text.