Blues by John Hersey (Knopf: $16.95; 166 pp., illustrated by James Baker)

They could be songs, melancholy moods, naval uniforms, Yale men or the spectrum of tints from robin’s egg to midnight, but they’re not, they’re the predacious marine fish, sometimes quite greenish, found only along the Atlantic coast of North and South America. Because John Hersey--novelist, essayist, environmentalist, humanist and professor--is the author, the book is elegant, graceful and pensive, packed with factual information enhanced by recipes, poetry and philosophical insight, but it is specifically, literally and entirely about fish and fishing. Since Hersey wrote it, the bluefish might well be functioning as a metaphor for something far larger and more significant--the life force itself, the relationship between man and his environment, the grand design of the universe. There are various strong indications this could be the case.

“Blues” is written in the form of a Platonic dialogue; the sage, elderly Fisherman identified as F, the eager young acolyte called S, for Stranger. Their conversation has a somewhat elegiac quality, considerably above and beyond ordinary speech; not “Pass the Bud” or “Anymore of those sandwiches?” but “F: You’re right, Stranger, we, too, will be played on the end of a line, sooner or later.” . . . “S: I realize that my landsman’s habit of thinking--mostly about my relationships with human animals--may have been blinding me, much as the mirroring surface of the sea has been, to the unfamiliar life beneath it.”

The poetry excerpts are a delightful surprise. Some of the world’s most celebrated bards, including Homer, Shakespeare, Donne, Robert Penn Warren, Ted Hughes, Richard Wilbur, W. H. Auden and James Merrill, have written about fish, or perhaps “employed” fish as symbols would be more accurate. The prose tradition is equally long and honorable; the Bible, Izaak Walton, Hemingway--the list is extensive and impressive. While this material is woven seamlessly into the text, bluefish remain the matrix in which all else is embedded. “Every time I haul in a blue, big or little, . . . I’m moved by the fury of the fish, I’m astonished every time by the energy of the negation in its leaps, by its thrashing refusal--to the very limit of its endurance in the poisonous air--to accept my views of its place, and my place, in the food chain: in the universe.”

“Blues” is a meditation, a literary anthology, a cookbook, a conversation between youth and age, but most of all, it’s a book that Hersey wanted and needed to write. One way and another, it distills a set of experiences and concerns that have preoccupied him throughout his life; a love of the sea, of the islands off the coast of Massachusetts where he spends his summers, of good company, of learning, of family, and man’s place in nature and responsibility toward preserving that exquisite, imperiled balance. Idiosyncratic as it may seem, “Blues” is a classic and original summing up. “F: These calm, final fall evenings are cruel. This may be the last hour of the last day of one more season of my life. S: Eating fresh-caught fish at a round table with friends--what could be better?” You put down the book in complete accord.