A smile appeared on Vinnie Giovinco's face, cracking through a thick black beard that he gained while fishing for eight days on Georges Bank, due east of here.

Although the fish were scarce and he was able to net only 11,000 pounds with his trawler, the 27-year-old captain was cheered by the "pretty good" prices at the fish auction here Thursday morning. His catch of cod went for 56 cents a pound.

"Thank God no Canadian trucks were here," said Giovinco in his heavy Italian accent.

"If Canadian trucks are here, we get an average of 30 or 40 cents for my fish. I couldn't even pay expenses," he added.

As he talked, "lumpers," the term on the fish docks for unloaders, filled big rubber barrels with the cod that had been kept under ice in the hold of the 72-foot Southern Belle.

Giovinco voiced the strong and continued complaints of New England fishermen that a heavily subsidized Canadian fishing industry is driving fish prices down and threatening to force them out of business.

"There's no way U.S. fishermen can sell products at the same price as the Canadians and stay in business," James Costakes, general manager of the New Bedford Seafood Producers Association, told an International Trade Commission hearing here Wednesday.

At an ITC hearing Friday in Portland, Maine, Sen. William Cohen (R-Maine) agreed with Costakes about the impact of Canadian subsidies.

"That government's fisheries policies provide extremely unfair market advantages to the Canadian fishing industry," Cohen said.

The Canadians had used "an array of subsidies as a conscious social welfare policy that is designed to allow the Canadian fishing industry to stay in business at any cost," he said. This allows Canada to sell its fish at below-market prices, "because any losses that may be realized are absorbed by the Canadian government."

Cohen called this "a countervailable subsidy," meaning that it can be matched under U.S. trade laws with penalty duties. He added that it is the underpinning of Canada's predatory practice that ensures a market share for its fishermen at any price.

Commissioner David Rohr went even further during the Portland hearing. He called the Canadian government actions "a very definite targeting program, designed to increase seafood sales in the U.S. market."

The ITC investigation was sparked by complaints that Canadian government subsidies amounted to unfair trade practices, and the commissioners got an earful.

Rhode Island fishing captain Jacob J. Dykstra told the ITC that, as recently as last winter, "We go fishing expecting a high price, in a gale of wind and subfreezing temperatures, only to arrive home and be told by our salesman that there is a lot of Canadian fish in Boston and the price is low."

Mark Godfried, owner of the Stella G, a 50-foot trawler sailing out of Gloucester, Mass., told the ITC he went out one Thursday and Friday after "a nice run of haddock . . . coming off a disastrous winter." The fish brought prices between 80 and 90 cents a pound, so he went out over the weekend, "expecting to do well."

Instead, he continued, "We found a million pounds of Canadian haddock in Boston, some being offered as low as 20 cents a pound, delivered."

One after the other, New England fishermen told their tales of woe, often providing personal financial data to back their views. Salvatore A. Parisi, whose family has been in the commercial fishing industry for three generations, described how his ship chandler's business has been going downhill because fishermen can't afford to buy new gear. He said sales decreased from $400,000 in 1979 to $130,000 last year.

The issue is an emotional as well as economic one in these northeastern states, where the fishing industry started with the first colonists. Massachusetts is second only to Alaska, for example, in the value of its fish catch.

But it is just as emotional and economically important in the five Atlantic provinces of Canada. The fishing industry, for instance, was described as being as critical to the economy of Newfoundland, one of the Canadian Maritime Provinces, as the U.S. government is to Washington.

Fishing is the oldest industry in the town of Gloucester, just north of here, with the first fishermen 350 years ago predating a permanent settlement. Gloucester is the leading northeastern fishing port in terms of the total weight of fish caught, while New Bedford, to the south, leads in the value of its catch.

In all, Massachusetts fishermen caught 376 million pounds of fish last year, worth $244 million. The mainstay of the fish catch is cod.

But the approximately 7,000 New England fishermen have been hit hard by imports, especially from Canada, which is the world's largest exporter of fish. More than 60 percent of its exports, moreover, are destined for U.S. markets.

According to James D. O'Malley of the Massachusetts Fisheries Trade Council, imports of Canadian-caught cod jumped from 85 million pounds in 1977 to 331 million pounds last year.

Officials from the Canadian fishing industry disputed charges that they receive heavy subsidies from both the national and provincial governments.

Ron W. Bulmer, president of the Fisheries Council of Canada, said fishermen on both sides of the border receive "some government assistance," which he described as "small, ad hoc and piecemeal." He told the ITC that Canadian exports are "a response to U.S. market demands" not filled by American fishermen and that they focus on the sale of frozen, not fresh, fish.

"Avoid the simplistic finger-pointing at Canadian imports as the villain responsible for U.S. fishermen's problems," Bulmer advised the ITC.

He told them the real "villain" is "bad U.S. fisheries management policies" that have led to gross overfishing in American waters, forcing U.S. fishermen to search farther and longer for a catch. This was hotly disputed by the American fishermen, who said the Canadians regularly sell fish far smaller than allowed under U.S. laws.

For their part, representatives of the American fishermen estimated that Canadian subsidies amounted to $704 million last year, in addition to special tax breaks that include an almost complete exemption from sales taxes.

The biggest move to aid the Canadian industry amounts to what the U.S. industry calls the nationalization of the Atlantic Province fisheries by government bailouts of failing processors.

David Bollivar, an official of National Sea Products, called this government move an "industry reorganization" and said the companies operate on a purely commercial basis. He is an official of one of two big companies that were formed from five smaller ones.

This didn't sit well with the American fishermen who crowded a hearing room on the 20th floor of the John Fitzgerald Kennedy Federal Office Building here.

"Subsidies given the Canadian fishermen are the root of our problem," said Dykstra, the Rhode Island fishing captain.

He accused the Canadians of having used subsidies to drive American producers out of the market for frozen fillets and of trying to do the same thing now with fresh fish.

The Americans see the Canadian program as more attuned to the social-welfare aim of providing jobs for its fishermen than allowing fair competition with the United States.

The testimony of fishermen here and in Portland appeared to be very effective in influencing the ITC members, many of whom toured fish-processing plants during their visit. Sen. George J. Mitchell (D-Maine) told the commission that the fishermen's testimony may be all it will get, because the industry did not have enough money to hire a major law firm specializing in trade cases "to organize its argument and polish its presentation."

It was clear from the auction at the crack of dawn Thursday at the New England Fish Exchange here that Canadian supplies were on everyone's mind. Three ships -- the Ruthie B., Southern Belle and Anna Maria -- as well as a truckload from Gloucester had catches posted on the board when auctioneer Butch Maniscalco rang the bell at 6:30 sharp to start the sale.

Ship captains and buyers had gathered in a little room in a building at the end of Boston's fish pier, the oldest one still active in the nation. Sales here affect prices in fishing towns north to the Canadian border, while the auction at New Bedford sets the prices for the more southern New England ports.

Buyers stand by telephones along the walls, constantly checking on customers' needs, prices elsewhere -- and the availability of truckloads of fish from Canada.

Even though the cod in Giovinco's boat drew what he considered a "pretty good" price, another fishing boat captain, James Bramante, said that was only fair considering how little fish was being offered.

"They know Canadian fish is around," Bramante said. Sometimes, sales agents for the Canadians walk around the room whispering to dealers that they have trucks on the way that will sell for a lower price than the auction bid, driving the price down, he said. When that happens, there is little that fishermen such as Giovinco can do. As the fish gets older, the price decreases. So he is forced to sell it for what he can get.