Hardly anybody considers the Chesapeake Bay from the perspective of the copepods.

Copepods are difficult to sympathize with. The minute crustaceans are ugly, hard to interview and too small to see without a microscope. But from their vantage, North America's largest and most productive estuary looks startlingly like a tenement.

A few copepod facts: If left to its own devices, each copepod will filter a quart of water a day. About as much water as it takes to fill a bathtub contains 3 million copepods. In the entire bay, there are so many copepods that if they could somehow remove the water they handle and spit it out in Utah or someplace, they could drain the entire bay in three days.

Lucky for us all, the copepods are content to leave well enough alone.

It takes but a few days' instruction in the ways of the copepods and the bay at the Johns Hopkins Alumni College to grasp that the Chesapeake is not just another indentation on the eastern seaboard, as it appears to an untutored eye, but a multifaceted subject that commands the attention of dozens of disciplines.

At times it seems there is not one bay but a thousand: the bay of a waterman's livelihood, the bay of the scientists' ecosystem, the bay of a cook's larder. For all its limits, the Chesapeake remains an inexhaustible theme.

The Johns Hopkins Alumni College, now in its eighth year, is a summer camp for intellectually minded people, offering an academic retreat from city life under the loblolly pines of St. Marys College, little more than an hour's drive from Washington. All last week, a class on the elderly side schooled themselves in the art and science of the Chesapeake.

The tuition of $375 for the week pays for a room in a dorm, meals in a dining hall, morning lectures, field trips, midnight canoeing parties, several outings, the run of a specially imported reference library and enough gin and tonic to keep the bookishness in perspective. You also can enroll your children and rent fans for your room, which is advisable, since you quickly learn that the prevailing climate here in the Holocene Interglacial period -- to which we owe the existence of the bay -- makes for uncomfortable summer nights.

Half of the 88 scholars who were graduated Saturday (their "diplomas" consisted of a lithograph of a bluejay and a seedling) were veterans of past summer sessions. Past colleges have examined such topics as Concepts of Leadership and Linear and Cyclical Conceptions of Time. Four years later, people still were talking about quarks after a college devoted to particle physics.

"Where else can you hear such interesting breakfast conversation," asked Samuel L. Bass, an applied experimental psychologist who spent part of one morning determining whether the definition of the word "set" in the Oxford English Dictionary was longer than Milton's "Paradise Lost." (Not even close.) "Last year the subject was Language as Commodity. Every three words, I had to say: 'What's that mean? What's that mean?' "

This year's session, with the focus on the bay, was perhaps more accessible and a natural topic for the alumni college, as Johns Hopkins runs the Chesapeake Bay Institute at Shady Side, Md. and owns a research catamaran, the Ridgely Warfield. For taking salt measurements and sampling 500-year-old mud off Cedar Point at a spot known as 818 Poppa, the Warfield is a handy vessel for learning oceangraphic techniques and doing fieldwork on your tan.

The dean of this year's college, Charles Stine, a dentist with, of all things, a Ph D. in animal behavior, chose to overlook gloomy studies marking the decline of the Chesapeake in favor of a more hopeful curriculum.

"I'm so sick of negative stuff about the bay," he said. "We want this to be a celebration, a birthday party for the Chesapeake."

And it was, except that the most specific the scientists could get about the bay's age was between 3,000 and 10,000 years. But this uncertainty did not trouble the diverse array of speakers who presented their versions of the Chesapeake.

Choptank poet Gilbert Byron, 79, recalled the lives of sea captains who were "one pint coffee and the rest . . . Chesapeake," and remarked on the evocative landscape of marsh and sky that raised at evening "a great emptiness within me." He celebrated the skipjacks and bugeyes and seafarers of the Eastern Shore with unabashed love, a far cry from Maryland's first poet, Ebenezer Cooke, who disparaged it as "that shore where no good sense is found."

John W. Taylor, a landscape painter specializing in birds of the Eastern Shore, spoke of the light over the sky of the Chesapeake, its "misty gray pearliness" that is said to resemble no other light.

Maryland archivist Edward C. Papenfuse traced the folly and adventure of Maryland's first settlers in the history of Chesapeake cartography, showing maps that ranged from a 17th-century chart indicating the Pacific Ocean lapping at the Allegheny Mountains to infrared satellite mosiacs depicting the Chesapeake from space.

Dr. Jerry R. Schubel's audience was pleasantly appalled to learn that the bottom of the bay is covered with a blanket of fecal pellets. Dr. Jay L. Taft treated one class to a detailed discussion on the role of phosphorous in the food web.

A more savory discussion of food webs took place upstairs in room 104, where chef William Taylor of Great Mills, Md. conducted a class in making hors d'oeuvres, using the bounty of the Chesapeake region: crabs, tomatoes, even locally produced sausage. In the course of the week, many mysterious phenomena were explained, such as why the west side of the Chesapeake is saltier than the east. (It has to do with effect of the earth's rotation on the heavier salt water.) One that was never solved was the meaning of the cooking-class blackboard that was chalked with the following cipher:

M . M . M . M . M . M . M . M May Ma

Mo Moo 2x

O-ee-o-ee-o-ee-o-ee

Zung-ah 2x

Real Eggs

Toward the end of the week, the scholars were led up the Patuxtent River aboard the Tennison, run by the Calvert Marine Museum and captained by a singing guide named Jim Tallant, a Buddy Hackett-lookalike who has a habit of breaking into renditions of "When You're Smiling" that could quell a riot in a penitentiary.

"This is the beeyootiful Chesapeake Bay," the captain said before turning the Tennison, the oldest licensed passenger-carrying boat on the Chesapeake, upstream en route to the Sotterly Plantation, where the scholars sat down to a lavish supper under towering shade trees.

After supper, the collegians repaired to the lawn with their china coffee cups for a concert of Chesapeake folk songs by Tom Wisner. Wiz, as he's known, showed slides, and sang a song that listed the plants, animals, minerals and geographic features of the bay that he wanted to merge with.

"I want to become one with the striped bass," he said. "I want to become one with the tube worms."

Though not widely shared, it was yet another point of view.