ST. MARY'S CITY, MD. -- When Shep McKinney moved here 10 years ago, he settled into his spacious, waterfront farm to enjoy hunting, fishing and boating in the land of pleasant living. Everything hasn't worked out exactly as planned, but he loves it still.

For reasons unknown, the wild ducks never took to his marsh and quail haven't occupied the field edges as numerously as they might. Rockfishing was an even greater disappointment.

First, the prized Maryland state fish pulled a disappearing act in the early 1980s as years of overfishing and declining Chesapeake water quality took their toll. Then in 1985 the state shut the season altogether.

When it finally reopened last fall with an abundance of rockfish reported in the Bay, McKinney, who spends part of every summer salmon fishing in Canada, looked forward to a month of flyfishing local waters in his Boston Whaler.

But as every tidewater angler now knows, rock didn't turn up everywhere in the Bay in October -- they were mostly in upper stretches of the huge waterway and its rivers, far from where McKinney fishes, and were caught up in a hurry by hordes of Upper Bay anglers who dredged them from the bottom on heavy tackle.

A mob tens of thousands strong snatched the recreational quota of 318,750 pounds so quickly, in fact, the season was prematurely halted after just nine days. McKinney and others waiting for a more sporting chance later in the season wound up with no chance at all.

McKinney has spent some hours since sitting before a crackling fire here, gazing out his window at the brooding St. Mary's River and wondering if there isn't a better way to enjoy and honor the state's premier fish than with a greedy, nine-day waterborne carnival. Based on his Canadian experience, he reckons there is.

When he goes to Quebec or the Maritimes for Atlantic salmon, McKinney buys a special license that comes with tags for each salmon he's permitted to keep. Depending on the province, it ranges from two to 10 tags a year for fish of specified sizes.

Every salmon he elects to keep gets one of the nonreusable tags strapped on immediately, where it stays until fish hits frying pan. Anyone caught with an untagged salmon is in a heap o' trouble.

The effect, says McKinney, is to permit a long, relaxed season and encourage people to fish where, when and as often as they like, releasing much of what they catch but maintaining the option to keep a few, and assuring authorities that overall conservation objectives won't be exceeded.

He sees rockfish and salmon as similar. Both roam the sea as adults but return to home waters to spawn, and both are justifiably prized as sport and table fare. The big difference, as McKinney sees it, is that Canadian officials over the years have refined regulations to squeeze maximum sport and revenue from a very limited resource.

What could be fairer, he asked, than splitting the allowable catch evenly among all who fish?

Maryland officials wrestling with next year's rockfish proposals say they're aware of the Canadian system and have given fleeting consideration to it. But the rockfish situation is so complex, with commercial, charter and sport groups vying competitively for cuts of a very small pie, that elegant refinements like tags loom distant on the horizon.

"I've brought it up at a couple of meetings," said Bill Goldsborough, a Cheasapeake Bay Foundation biologist who chairs Maryland's volunteer Striped Bass Advisory Board, "but I haven't got anyone to bite."

Yet, says Goldsborough, "We have to look at ideas like this, because we can't be doing again what we did." Last fall's nine-day melee involved massive state enforcement and monitoring using planes, helicopters, boats and shoreside checking stations. "It worked," said Goldsborough, "but it was hugely resource-intensive and cost $200,000. That's obviously not a permanent solution."

Moreover, Goldsborough agreed, distribution was unfair as folks up the Bay caught more than their share and those down the Bay got skunked.

The hectic nature of the October season, as hordes of boats went nose-to-tail trolling around little pods of rockfish in isolated spots, "was one of its worst aspects," said Harley Speir, rockfish specialist for the state Department of Natural Resources. "Tagging would spread the season out," he said. "It's something to look at, for sure."

Everyone agrees, though, that the numbers create a problem. Close to 200,000 anglers bought 1990 Maryland tidewater fishing licenses entitling them to fish for rock. But under the quota, they all had to quit after catching a total of about 60,000 fish, less than one for every three license holders.

Next year the quota probably will be increased, perhaps to 500,000 pounds. And requiring a rockfish permit for a few extra dollars in addition to the standard tidewater license could cut the number of eligible anglers.

Say 60,000 bought rockfish stamps, and say the average fish size dropped from last year's unexpectedly high six pounds to four pounds in 1991. A 500,000-pound quota still would mean just 125,000 fish available, or two per permit holder.

Is it enough to satisfy the public? Does it really matter? However the pie is cut, its ultimate size is going to be too small, and tough to split to everyone's delight.

If tagging is an answer, Goldsborough thinks the concept will need a strong advocate to advance it in his panel and with DNR. McKinney has some allies, notably in various Trout Unlimited chapters around the state, said Potomac-Patuxent TU stalwart Jay Sheppard, who's suggested a tag system himself in informal talks with state officials.

McKinney is thinking of taking the time to press the case himself, but is reluctant to get in too deep, too fast.

"I want to be sure it's feasible before I sink too much in it," he said. Nor does he relish the thought of abandoning the pleasures of life down on the farm to wade into the notorious riptide of Maryland politics.

"I guess," he said, chuckling, "it would help if I was a Democrat, too."

Maryland's Striped Bass Advisory Board meets again to discuss 1991 season proposals at 6 p.m. Dec. 18 at the state Agriculture Department on Harry S. Truman Drive, Annapolis. The public is welcome.