The long flat fields of Maryland's Eastern Shore are peppered with Canada geese these days, each bird trying to break through the stubborn crust of snow to the remnants of corn underneath. Their normal feeding areas are iced over.

In the towns between the fields, the stores are almost empty, the unemployment offices full. The ice covering the Chesapeake Bay has reduced the area's main industry, oystering, to a crippled imitation of its normal self, The cold - coupled with the inability of oil barges to break through the ice and deliver their cargo - has put most heating fuels in critical short supply. Two seafood processing plants had their natural gas cut off for a time last week.

The Eastern Shore is probably the region's most severly affected area, its prosperity being so intimately tied to fluctuations in the weather.

And when a waterman is out of work here, as thousands are, the multiplier effect is far more devastating than in an area with a more diversified economy. When there are few oysters, there is less work for the shuckers, the truckers and workers in all the other supporting industries. When they can't pay their bills, it hits the grocers, the druggists and everyone else reliant on their business.

From Rock Hall to Crisfield, from Kent County to Wicomico, the Shore, its animals, its people and its economy are under a temporary state of seige.

"You get bad winters; it's a cycle," said seafood processor William Harris, looking out of is window toward the ice floes moving up and down Kent Narrows. Amid the floes, watermen aboard the "Penelope Sue" and the "Madlyn" were manipulating the 20-foot, scissor-like hand tongs with a jerky, bowing motion, trying to get some of the last oysters from that fished-out area of open water.

"I've seen some winters as bad as this," added the proprietor of W.H. Harris Seafood. "But I've never seen one worse."

Even in this farming and fishing area, where the people are used to their dependence on nature's whim, this winter still seems a little too fierce. It's a vicious bite of cold coming on the heels of five warm years and a new disaster for an industry still recuperating from the lethal 1972 storm, Agnes.

After five years of gradual decline this year's oyster harvest is already down 280,000 bushels, or 10 per cent from last year's. The dockside value of those missing oysters: $2.8 million.

By the time the effects of that unspent money have percolated through the area's economy, the total cost to date may be closer to $15 or $20 million.

The result has been a gradual increase in the numbers of people in the unemployment lines in Easton, Cambridge and Salisbury. In Cambridge the case load has increased by a third, to 1,542 people, since Christmas.

With President Carter's declaration of Maryland as a disaster area on Wednesday, a flood of 1,089 people - most of them self-employed watermen - had applied for disaster relief by Friday afternoon. By Saturday, this number has grown to 1,243. An estimated 5,000 watermen have been hit by the freeze.

Speaking in general terms, one waterman said, "If you're spread thin anyway; this winter is really going to hurt you; if you've got something set aside, it won't be so bad."

Nonetheless, the cold is robbing most watermen of their oystering grounds and their incomes. Without oysters, the processing plants stay open fewer and fewer hours or shut down altogether. When this happens, the shuckers that work there, paid by each gallon of oysters they shuck, have nothing left to do.

"I just sit home when there's no work," said 57-year-old Helena Williams, who has shucked oysters each winter since she was 17. "This is the worst I've even seen," she added, grabbing another of the small twisted oyster shells from the pile before her at Harrison Oyster Co. on Tilghman Island. She twisted off the shell and mud from the Bay bottom splattered her arm. "It's hard on all of us."

Nearby, at Tilghman's Country Store, the charge accounts are getting bigger, the prices are getting lower, and some food just isn't selling. "I can't handle too much more credit; I've got five kids of my own," said owner Tom Norwood.

"In general, watermen are cash customers, pay-as-you-go people" explained Bob Prier, executive director of the Chesapeake Bay Seafood Industry Association. While the ice locks in their livelihood, he added, "even those who have a little money are hanging on to it." Said another waterman, "nobody's buying nothing but what they need."

And, according to Prier and other older watermen, this first bitter winter in 10 years has also thrown into sharp relief the divergence between the lifestyles of some of the younger watermen from those of the men who have been on the water for two decades or more.

"You learn to expect good years and bad years," said the white-haired Prier. "The older ones know this, they are wise enough to have a nest egg. "But some of the younger ones, they've bought more expensive boats, they've got a home and a car and a boat to make payments on, they will be feeling this."

Larry Simns, who has driven his boat out of Rock Hall above the Bay Bridge for 20 years, estimates that he's lost $4,000 in income since Christmas - he's only been able to get out 10 days since then.

"Sometimes you have to go to a (oyster) bed that's depleted because that's the only place you can get to. Sometimes you have to come back without catching anything and that's two or three hours in and two or three hours back, with the ice tearing up your boat," said Simns.

"But I've been anticipating a bad winter, and I worked to put aside for a cold winter so I could keep my head above water. It was this bad the first year I went out, '56, and I like starved to death," he added. "For some of the younger watermen, it's hard. They didn't prepare for it."

One of the young watermen, Norman Dorrell, agrees. He's been in the business and a mere 12 years, and the broad face under his strawberry blond hair is already permanently red. "Since Christmas I've made $800; instead of $3,000 to $5,000.

"I've got an old boat, a new boat - and $7,000 in the motor of that boat alone - a home, a car, and two trucks to make payments on. And I've got a wife and kids.

"It's hitting us younger ones hard with the payments to make and everything," Dorrell added."But," he said decisively, "I'd do it all again . . . If I get behind now, I'll be able to make it up later. Accummulated green money I don't have. I put every nickle I make back in my business. I'm spread thinner than I like, but my children don't want for anything - except my company sometimes."

While he's confident he can make up his loss, given a thaw or at least a good crab season this spring and summer, Dorrell is worried about the long-range effect of the freeze.So are the other watermen.

"I'm concerned about a late crab season," said Simns. "That happens after really cold winters. I don't know what happens to them. All I know is they die. If that happens, that's when we'll really feel the effects of this winter."

Biologists say this fear has some merit. "We don't really know what will happen," said George Krantz of the University of Maryland's Horn Point laboratory, "but in certain river systems crabs have been killed by ice."

Krantz and other scientists, who feel that there has never been a study done to give them clues as to the long-range effects of the freeze, have formed a task force - Bay Ice Team Experiment, or BITE - to fill this gap.

Among the dangers they are worred about is the possiblity of a sudden thaw that would do the same kind of damage that Agnes did by pouring heavy loads of fresh water from the swollen Susquehanna River into the upper Bay, changing its level of salinity and killing the shellfish that could not stand this change.

Another worry is that stiff March winds would blow ice floes shoreward piling them up until their weight ground into and destroyed shellfish beds.

There are possible beneficial side effects of the ice. Among other things, are more nutritious, hearty kind of plant life may develop, providing better food for the fish and shellfish.

In addition, since the ice has tempered the incessant movement of day waters, the water underneath should have clarified and this cleansing may be a help to the reproduction of oysters, which have reproduced at some of the lowest levels ever recorded in the five years since Agens hit.

On the land around the shore, the cold is also regarded as a neutral, or even beneficial force for agriculture. "The snow insulates the soil," said Tony Evans, a spokesman for the Maryland Agriculture Department. "The cold can also kill wintering insects while they're in grub form in the soil - things like Japanese beetles."

But it is no good for the geese, swans and ducks that have made the Eastern shore their winter home for decades. Above the fields, long V's of Canada geese are flying lower than usual looking first for food, then for shelter.

The ducks, some of whom won't leave their spot of open water to look for food have been freezing, their bodies littering some ice floes.

Still, the area residents force themselves to be flexible. In the midst of adversity they get philosophical. In an area, such as the Eastern Shore, with such dependence on the vagaries of the weather, "Disaster is the name of our business - of all the business around here," said waterman Simns. "We just live from one disaster to the next.

"Everybody gets all excited and passes laws each time" - (there are some bills in to extend the oystering season two weeks this year) - "but all the laws in the world aren't going to change nature."