John Hopkins University Press. 223 pp. $16.95

Tom Horton

In the 1930s, only a few thousand migrating wild geese would visit Maryland's Eastern Shore each fall, so why do nearly a million drop in nowadays? How do oysters get from place to place? (Please don't say, "Very slowly.") Where do dozens of eagles soar as cannon fire provides background music? What draws crashing shoals of herring back from the sea each year to Washington's Rock Creek, unerringly to the spot where they were spawned?

Tom Horton deals with such matters in "Bay Country," a collection of personal essays based on his 10 years of environmental writing for the Baltimore Sun. Sailing down the Chesapeake in this book is bracing, for Horton is knowledgeable, thoughtful, full of wonder about the natural world and outspoken.

He skewers those who want to have their environmental cake and eat it too; the list includes you and me, federal, state and local politicians, developers, industrialists, highway engineers ("the archenemy"), farmers, sport fishermen and, sometimes, the watermen he admires so much.

Horton has been on leave from The Sun to work on remote Smith Island for the 40,000-member Chesapeake Bay Foundation. He thus finds himself in the midst of the foundation's court battle to preserve the character of the tiny watermen's island on which 500 people live. A "foreigner" (island term for any nonislander) has won the approval of the Somerset County Appeals Board to build 100 luxury town houses there, plus an 80-slip marina and other yacht-clubbish accouterments.

In one of his essays, Horton introduces us to the developer and his grandiose schemes. As Horton makes clear, the island's 300-year-old, church-centered, hard-working, self-reliant traditions are fast disappearing, as the old-timers die, the young move away and the bay's picturesque but inefficient fleet of skipjacks endures hard times. Only a score ventured out this oyster season.

Horton warns that the bay's "epitaph has already been written, if not yet chiseled in stone." The best we can hope for, he asserts, is short-term gains (more fish, cleaner waters) resulting from the massive regional Save the Bay campaign. (Its second phase, recently approved, calls for a 40 percent reduction in nitrogen and phosphorus running off into the bay by the year 2000.) But we'd be doing well to return to the environmental status of the 1950s, before pollution and overfishing sent the rockfish, oysters and underwater grasses into steep decline.

A central problem is that the waters in the 64,000-square-mile watershed fall under federal and state regulations, "but land-use decisions remain the province of a thousand town and county governments, none of which wants its water to end up like Baltimore Harbor, but most of which will fight to the death to retain the option to use its land just as intensively as the state's largest city, should the opportunity arise."

As Rat tells Mole in "The Wind in the Willows," "There is nothing -- absolutely nothing -- half so much worth doing as simply messing about in boats." Horton agrees and describes his own 19-foot fiberglass outboard, which resembles a bathtub but which can float in nine inches of water and is perfect for messing about in the bay's shallow waters and marshy edges. He has added two large beach umbrellas at bow and stern, which, he fancies, "make a rather striking appearance."

"Otherwise the boat is utterly simple," he writes. "... You cannot enjoy peace of mind in something featuring pleated vinyl and shag carpeting ... the kind of boat that sports a little plaque saying 'Welcome Aboard. Remove Shoes.' "

Why does the Eastern Shore appeal to the migrating Canada goose? Since World War II, corn has become a major crop there, and the birds drop in for the free lunch. "Ironically, our expanded grain agriculture resulted in a huge increase in fertilizer washed by rains into the Bay in such unremitting quantities that it has killed the submerged grass beds. And these grasses were the prime food of ducks like the canvasback, which will not feed in cornfields ... The tradeoff is more than geese for ducks. It is the loss of balance and diversity ... The submerged grasses also were critical in absorbing pollutants from sewage, and in harboring dozens of aquatic species during one stage or another of their life-cycle."

The place where the eagles soar to the boom of cannon is that unlikely bird sanctuary, the Aberdeen Proving Ground. Larval oysters are not world travelers, but they can rise or fall slightly to find the proper level of salinity. River herring, it is thought, are guided back from the ocean to the place where they were spawned by an exquisite sensitivity to natural forces, including the distinctive smell and taste of their birthplace. Horton entitles this chapter "Eau de Rock Creek," and he quotes Proust: " 'The smell and taste of things remain poised for a long time, like souls, ready to remind us, waiting and hoping for their moment ... and bear unfaltering, in the tiny and almost impalpable drop of their essence, the vast structure of recollection.' "

As Smith Islanders might say, it's a "right smart" book. Let's hope Horton will be able to write a cheerier one in the near future.

The reviewer retired recently as book editor of the Cleveland Plain Dealer and has moved to the Eastern Shore.