FARLEY MOWAT has often written about humanity's offenses against wolves and whales and other wild creatures. Often, he has vented his indignation with humor and gentle self-mockery. In his very widely read and influential Never Cry Wolf, he hung his conservationist's message on an entertaining adventure story, and he made some of the book's human characters, including himself, nearly as likeable as the family of wolves he portrayed. Sea of Slaughter, Mowat's latest book, is an out and out tirade by comparison. In the introduction he describes his high hopes for this new volume, as follows: "Perhaps it will help to change our attitudes and modify our future activities so that we do not become the ultimate destroyers of the living world . . . of which we are a part." The ellipsis, commanding a breathless pause, is Mowat's. At the beginning of Sea of Slaughter, even his punctuation seemed overblown and a little self-righteous to me. By the time I got to the end, I didn't care. I still object to the tone of Mowat's introduction, but only on strategic grounds. I think that a writer with a message helps his cause by exercising restraint, at least until he has given his readers a chance to share his views.

As Mowat presents them, scientific and official explanations for widespread slaughter of wild species are obviously spurious. The great auk was bound to become extinct, and the proof is that it did -- that's the level at which Mowat's villains argue their cases in this book. Sea of Slaughter is frankly one-sided. It is intemperate, to say the least. "A roaring holocaust fueled by human avarice," snarls Mowat, about the hunting of the whales. 'Grist to the mill of human greed," he declares, writing of the walrus and other "finfeet." But I came to feel that there was probably no other way for Mowat to write this book. I can't vouch for its accuracy, but even if only half of it were true -- and I have no reason to doubt any of its claims -- Mowat's spleen would seem justified by the end. And I confess he made me share it.

The setting for Sea of Slaughter is the northeastern seaboard of North America, a region extending roughly from Labrador south to Cape Cod -- the part of the world, Mowat explains, that he knows best. The story -- actually a series of them -- describes what human beings have done to the region's fauna in the 400 years since the first Europeans settled there. The great auk goes first, the victim of huntings so wasteful and excessive as to seem fully insane and then of the curiosity of natural history buffs and scientists willing to pay handsomely for eggs and specimens of the increasingly rare bird. In the mid-1800s, a merchant after collectors' money arranged the destruction of the last known colony of great auks. "His name was Siemson -- let it be long remembered," writes Mowat of this merchant. Mowat seems to have a hard time resisting archaic turns of phrase, but the story of the careless smashing of the last auk egg, as Mowat retells it from contemporary accounts, really is heartbreaking.

MOST of these discouraging tales don't deal with extinct species such as the auk, but with surviving ones that have, as Mowat puts it, "suffered horrendous diminishment." He insists that many other parts of the world have been at least as recklessly exploited as the one he writes about, and he allows that he has made only a partial accounting of this one region's "biocides." But for sheer volume of slaughter, Mowat's accounting seems sufficient. This book keeps tolling. Pollution, gross overhunting (often for dubious sport), loss of habitat, destruction of food supplies, poachings and officially sanctioned "cullings" are the culprits of these tales. As for the victims, here's a partial list of the species Mowat writes about, animals that have become extinct and ones that have been greatly reduced in numbers and ranges: the storm petrel, northern gannet, great cormorant, tern (four varieties), Atlantic puffin, murre, razorbill, Eskimo curlew, long-billed curlew, Hudsonian godwit, oyster catcher, Cooper's hawk, rock ptarmigian, golden eagle, great gray owl. Among the abused fur-bearing mammals are these: the white bear (called the polar bear, Mowat says, only because of the narrowing of its range), the grizzly, marten, fisher, weasel, otter, wolverine, eastern buffalo, eastern elk, woodland caribou, moose, cougar, lynx, stump- tailed bobcat, white fox, gray wolf. Sea creatures, many of them especially hard- pressed since the 1960s, include: the cod (reduced to perhaps 2 percent of its aboriginal numbers), haddock, redfish, halibut, plaice, yellowtail, witch flounder, mackerel, capelin (a bait fish on which many other species depend). Also: Atlantic salmon, striped bass, bluefin tuna, basking shark. A lot of whales are gone or in trouble: the Atlantic gray, bowhead, blue, fin, fin back, sei, Brydes, humpback. Populations of the beluga and Minke have been decimated, Mowat writes, in order to feed mink at ranches -- those whales have been traded for fur coats, in effect. There's the harbor porpoise, the narwhal, the North Atlantic bottlenose, the pilot whale. The walrus has been treated savagely, too, and so have many kinds of seals -- the Canadian government has sanctioned mass clubbings of seals, Mowat writes, partly under the wrongheaded assumption that seals give fishermen stiff competition.

Not long ago, at the National Zoo, I overheard a woman exclaim to her young daughter, as they stood looking into the cage of one of the famous giant pandas, "Isn't it adorable? And the best thing about it is it's real!" She was obviously in earnest, obviously surprised. The ranges and the numbers of so many wild animals have shrunk so much that for many people it really is surprising to realize that such creatures exist outside of TV screens. Nowadays wild animals can surprise us the way dinosaur bones do. Mowat's angry book serves as a reminder of the former abundance and variety of nature and of the speed and thoroughness with which modern civilization has impoverished its own widening domain.