A BURLEY Louisiana shrimp fisherman named Tee John Mialjevich wrote to President Carter on March 2 in opposition to a Federal government proposal, a "management measure," to institute new regulations for shrimp fishing in the Gulf of Mexico. As of last week, Mialjevich hadn't received an answer from the president, but through lobbying efforts elsewhere implementation of the plan has been postponed and it will be "restudied."

Mialjevich, who heads a group called the Concerned Shrimpers Group of Louisiana, had come to Washington and tromped through the halls of Congress and the Department of Commerce. To all who would listen, he painted a classic portrait of Big Government siding with Big Business in the name of efficiency And, in this case, conservation) to the detriment of small, independent fishermen. He had at least one influential supporter, Rep. John Breaux (D-La.), who is chairman of the House Subcommittee on Fisheries, Wildlife Conservation and the Environment.

Perhaps one reason President Carter has not yet replied to Mialjevich's letter is that it and the supporting documentation covered 13 pages. It's a very complex situation (a battle between Louisiana and Texas interests with Mexico getting into the act by closing their shrimp beds to foreign fleets). But the object of the conflict -- shrimp -- is of considerable interest.

Shrimp is Washington's (and American's) favorite shellfish. It is the nationwide leader among all fish sold in restaurants. Yet the retail price for frozen shrimp is now as high as $10 a pound, and is threating to go much higher. Rain and floods in the South have produced what one Louisiana merchant called "the worst early crop since 1964."

While fishermen are quick to point a finger at Federal regulations and management policies, those same fishermen begged for government aid against the encroachments of foreign fishing fleets into American waters and all too often have been unable to resolve internal differences among themselves.

The potential for jurisdictional problems is enormous. There are local, country, state, national and international regulations, but fish heed neither state lines nor traffic signals.

There are zones for fishing, along beches and inland waters, out to 3, to 9, to 12 nautical miles, and out to 200 miles.

There are different types of shrimp white and brown being the most important, and different seasons for each. Also, they come in different sizes, as many as seven grades based on the average count per pound. The smallest sold are 60 to 70 the pound; the largest are 21 to 27. Small shrimp are the most sweet and tender, but are more trouble to process.

Also, the industry itself is not monolithic. Independent fishermen like Mialjevich, who own and operate a single boat, have different objectives than vertically integrated companies that own large, longrange craft with freezing equipment on board (called "super slabs") and process and market shrimp as well as gather them.

The quarrel about the "Texas option" centers on the government's recommendation to restrict fishing in the 24 million-acre Fisheries Conservation Zone -- Gulf waters under Federal jurisdiction -- to brown shrimp of 39 count (heads on) size or larger. Smaller shrimp would be thrown back as a conservation measure and allowed to grow larger.Texas already forbids catching the small shrimp withing territorial waters.

A resolution from Mississippi Department of Wildlife Conversation advanced nearly a dozen objections including the possibility of higher prices to the consumer. Mialjevich and his supporters argue that the smaller shrimp would still be caught and would be dead before they were thrown back. He talks of a territorial war if U.S. as well as Mexican waters are restricted, predicting that boats from other states would come into Louisiana waters and be met by armed local fishermen.

Beyond the surface confusion, there is uncertaintly about the shrimp themselves. As a Georgia shrimp boat captain said recently, "there is a lot of ignorance surrounding commercial fishing. People who own fleets are ignorant of the science and biology of shrimp. So are government people. Some of those rules they make can't be written by anyone who has ever been on a shrimp boat."

Most of us have not been on a shrimp boat either, so here is a brief sketch of how one works:

Some, as small as 20 feet, work inland waters only. This one is a little more than 70 feet in length and will cost more than $200,000 if purchased new. It can cruise several hundred miles and is very seaworthy. There is modern communications and sounding equipment on board, a complete gallery and bunks.

Generally the captain will hire two sailors, called "stinkers" in Georgia. Depending on seasonal regulations, he may depart at 4 a.m. for a day trip, make a week to 10-day cruise or go far afield (to Mexico before the ban) for two or three weeks or more. Once a boat reaches the fishing grounds and shrimp are found in a small "try" net, large nets are run out on either side of the boat, supported by outriggers and towed along behind. As a net is emptied on deck, the strikers sit on wooden crates, separating out the shrimp from various trash fish (some of them very good to eat but of no commerical value) and junk. Depending on what the processing plant wants, they may remove the heads before putting the shrimp on ice in the hold.

How long the shrimp last depends on how they are treated and stored, the fishermen insist. Shrimps with heads sill last five days or so without decay, they say. With heads off they may last three or four we weeks. Sometimes a chemical powder called sodium trisulphite is sprinkled over the shrimp to prevent the shells from turning black. One processor estimated that as much as 95 percent of the shrimp catch is frozen at some point before it reaches the consumer.

Finding crew is not difficult when shrimp prices are high. Money from the catch is divided into three portions, with equal shares going to the owner, the boat and the crew. On a very good day, a single boat might gross $3,500 or more. But one captain quickly began subtracting: He gave as an example a boat grossing $150,000 the previous season. After paying the crew, operating expenses, insurance, maintenance and payments on the boat itself, he said the net was $20,000.

"One guy I know made $90,000 last year," the captain said."But our costs -- gasoline especially -- are going up and they are all committed before we go out. But you never know how you've done until you get back in. You don't know if the shrimp will be there. Prices go down as well as up. He could have lost money. This year maybe he will."

Those interviewed in Georgia last month echoed the sentiments of the Lousianians when speaking about the role of the government in their industry. Aquabusiness, they charge, is showing the same appetite for devouring small enterprises as Agribusiness and is being aided by government and the grant money fed to university researchers.

"They've got the money, the time and the strings to pull," said Jack Amason of Sea Garden Seafoods in Valona, Ga. "I've got a business to run. I haven't got to time to get involved."

Ten years ago he took over the processing plant his father had begun in the mid-1940s. He has expanded it, buying and packing crab and shrimp and selling ice. He is angry about a proposed giant seafood processing port that is scheduled to be built near Brunswick.

"Even with grants and subsidies it can never make money. They did a study that showed that. But they want to eliminate the 'inefficiencies' of small producers like me and in the process Uncle Sam will kill free enterprise."

Government low-cost loans stimulated an increase in boat building, so the fleet is considerably larger today than it was 10 years ago. But for this reason fishermen complain that stricter regulation will only decrease the size of the total catch, of which they now take a smaller share. "They should measure pounds per boat before they begin talking about how good the industry's doing," said one of them.