MIAMI (AP) _ Silently the hunter banked left and spotted her prey. She moved closer and struck.

''Could I have a one-pound fillet of shark?'' Maria Suarez asked the seafood clerk at a Miami market. ''And do you have any lemons?''

Sharks, feared kings of the ocean food chain, are increasingly ending up as dinner meat in your local supermarket chain. They've become a main course for Americans who have discovered the fish to be inexpensive but tasty.

In addition, the expansion of trade with China since the mid-1980s dramatically boosted demand for Atlantic and Gulf shark fins, used for a soup considered an Asian delicacy.

But a nearly six-fold increase in shark catches since 1985 has alarmed environmentalists, who fear populations are dwindling to dangerously low levels off the Southeast coast. Despite their ferocious image, many sharks perform a useful function, cleaning the sea floor and controlling other fish populations. Federal officials are drafting a proposal that would limit catches and could temporarily ban shark fishing.

Unlike other fish, sharks reproduce slowly and may take up to 15 years to mature. In areas of intensive fishing, it could require up to 30 years for the shark population to recover, said Jose Castro, a shark specialist at the National Marine Fisheries Service in Miami.

The proposed regulations, which may take effect this summer, would limit the U.S. commercial harvest to the 1988 level of about 12.76 million pounds, up from 2.13 million pounds in 1985. The draft proposal also seeks to outlaw the practice of capturing sharks only for their fins.

Florida and Alabama account for about 80 percent of the nation's commercial shark catch.

The catch limit will probably already be reached if the regulations take effect in late July or August, said Lt. Eric Hawk, an official at National Oceanic and Atmospheric Administration who is helping draft the final plan.

''Whether you call it retroactive to January or an all-out ban, commercial shark fishing will probably close the day the rules go into effect,'' said Hawk.

Meanwhile, federal officials will study shark populations and revise the regulations for the summer of 1991, he said.

''They are beautifully adapated in their environment,'' said Castro. ''But they haven't had time to adapt to this new predator in the sea, which is man.''

Most are caught on baited hooks connected to cables stretching for miles behind fishing boats. The most prized species for meat include the sand bar, mako and thresher sharks, said Wayne Swingle, executive director of the Tampa- based Gulf of Mexico Fishery Management Council.

Some species, such as hammerheads, often have bloody, unappetizing meat and may be used only for their fins, he said.

''We were promoting shark back in the early '80s when it was something real unusual,'' said Donna Florio, seafood marketing director at the South Carolina Wildlife & Marine Resources Department. ''Now, we don't have to do too much. People are learning about shark and are not afraid to eat it. Cost is a big factor.''

Shark meat brings fishermen about 65 cents a pound and shark fins about $10 a pound, said fisherman John Bonnell of Madeira Beach, the hub of Florida's Gulf Coast shark fleet.

But Bonnell said he believes the proposed regulations could drive shark fishermen out of business and force U.S. seafood retailers to turn to Mexico, and perhaps Cuba, as main suppliers.

''Why would they come to us if we can only fish for half the year when Mexico can provide them all the shark they want all year round?'' said Bonnell, a former grouper fishermen who refitted his boats for shark years ago.

Bonnell and other shark fishermen are calling for officials to wait at least a year before making regulation proposals.

''We're not totally against regulation, but so little is known about the effects on the sharks that we should wait until better data is collected,'' said Bonnell. ''We would be the first to recognize a collapse in the shark population and we've seen no decrease in the number or size of our catch.''

In the shark-fin market, high-flying profits have dipped since Chinese-U.S. relations cooled because of Beijing's violent suppression of a pro-democracy movement in June, but Gulf shark fins remain the most prized in the world, said Sonya Girard, a shark fin dealer in Golden Meadow, La.

The U.S. fins are sought because of the high content of a noodle-like substance in species such as lemons and blues, whose fins can retail for more than $20 a pound dried.

''The noodles are like pasta and come in all different sizes, from thick like linguine to angel hair,'' said Ms. Girard, who once received $300 worth of shark fins in the mail from a fisherman.

Ms. Girard noted sharks have non-culinary uses ranging from cancer research to an aphrodisiac made from ground backbone cartilage favored by Japanese geishas.

In the 1940s, shark livers provided a high source of vitamin A, which now can be made synthetically.

Like many in the shark trade, Ms. Girard doubts the practice of ''finning'' is as common as portrayed during public hearings on the proposed federal regulations last year.

''It's an emotional issue,'' she said. ''I don't think too many fishermen are going to cut off the fins and dump $800 worth of meat back into the sea.''

Sid Preskitt at Trans Ocean Inc. shark fin dealers in Port Orange, Fla., attributed the growing popularity of shark meat to better knowledge by fishermen on how to process the fish.

To be edible, sharks must be caught alive and the tail and head severed immediately to allow drainage of blood, which contains a high urea content and turns to ammonia quickly after the shark dies. The carcass is then submerged in a cold brine solution that leaches out more blood.

''Shark is something a little different to eat and it's cheap,'' said Ms. Girard. ''It's become a real yuppie food.''

End adv for Monday Feb. 12