Chesapeake Bay watermen are gearing up for their annual assault on the beleaguered Maryland state fish -- the striped bass (rockfish).

The stripers' first spawning runs up the Bay are only a few weeks away. Commercial fishermen are readying gill nets to trap the prized table fish.

But this year for the first time they will be putting fish into the Chesapeake as well as taking them out.

The Maryland Watermen's Association has been working over the winter to prepare the first major striped bass fingerling hatchery ever on the Bay. Unless things go terribly wrong, the watermen's facility at Elkton should be producing anywhere from 100,000 to 500,000 baby stripers this spring for introduction into the Chesapeake.

The watermen have two goals. They will follow up the stocking program by studying migration habits and survival rates of the hatchery-reared juvenile stripers. And they are hoping that the fish they plant in the Bay will grow up and eventually boost striper populations, which have been declining steadily and dramatically for the last nine years.

Their effort isn't the only one. At Horn Point, near Cambridge on the Eastern Shore, a small hatchery is shaking down. Dr. George J. Krantz, a marine biologist for the University of Maryland, will hatch a few striper fry there this year. He has asked for better than $500,000 in state money to expand his hatchery over the next four years.

Krantz hopes that in a year's time he will have the facilities to produce 500,000 to 1 1/2 million striper fingerlings a year to stock in the Bay for research. He, too, hopes an offshoot of the scientific effort will be more rockfish in the bay.

The two projects are very different, although they are aimed at much the same thing.

The watermen's effort grew from the most humble origins and until recently survived on the sweat and goodwill of the people who make their living and take their pleasure from the Bay.

The Cecil/Harford County watermen's association and the Cecil County Hunters Association dreamed up the plan more than a year ago. They each came up with $250, according to Skip Bason, a biologist who is assisting them.

The groups asked the town of Elkton for permission to revive a degenerated hatchery that had been ceded to the town by the state.

They got use of the hatchery and every weekend since last fall groups of 10 and 20 watermen have descended on the little town at the head of the Bay, armed with chain saws and hand tools. As the project grew, watermen from around the state joined in.

They cleaned out most of the 22 hatching and rearing pools, all but a few of which were overgrown with brush and trees.

With a few more weekends of work, they expect to be ready to hatch and rear fingerling stripers when the big spawning fish arrive.

Recently the state appropriated $39,080 to help the watermen.

Both the Elkton group and Krantz intend to hatch their stripers from eggs taken from roe-laden females netted on the way up the Bay this spring. The females will be returned to the water unharmed.

Krantz will be hatching a few fish this year using equipment he normally uses for oyster research at Horn Point.

But where the watermen started small, he has big plans. Horn Point is a University of Maryland research station and Krantz said the university has requested better than a half-million dollars in state funds to build and maintain a full-scale striper hatchery there.

He said $100,000 is sought to build rearing ponds. The rest will be for incidental expenses and $90,000 a year in operating expenses over the next four years. He said indications from the legislature are that the funds will be approved.

All this comes about because of scientific and financial concern over failing striper stocks. The Chesapeake is the hatchery and nursery for the vast majority of striped bass on the East Coast. There hasn't been an excellent reproduction year here since 1970, according to state scientists. No one knows exactly why.

Excellent reproduction years, or socalled "dominant year classes," are what kept the striper populations booming in the past. In the 1950s and '60s, they were common, occurring three or four times a decade. But there hasn't been one in the '70s, and as a result the catch of stripers from North Carolina to Cape Cod has plunged.

Whether or not the introduction of striper fingerlings by the watermen's group or Krantz's operation will have any significant effect on the population and the resulting catch is a matter of vigorous conjecture.

Ben Florence, striper specialist for the state Department of Natural Resources, has his doubts. He offered some figures to back them up.

"We have 750,000 acres of striper nursery in the Bay system," he said. "In the fall, we calculate that there are 137 fingerlings per acre in that area.

"To increase that number by just 50 percent we would have to add 68 fish per acre. That would mean stocking about 51 million fingerlings, which is impossible."

Even at that, Florence said, natural mortality would claim half those fish the first year, then half of the remaining ones the second year, leaving one-fourth by the third year, when they would reach harvesting size.

Nonetheless, Florence won't down-grade either effort. He feels research knowledge generated by the projects easily will be worth the time and expense.

Bason, the biologist at the Elkton hatchery, hopes the stocking will indeed have an impact on the harvest by sport and commercial fishermen in a couple of years.

He pointed to a spill of white bass/ stried bass hybrids into regions of the upper Bay two years ago. The hybrids, which can't reproduce, were stocked in a lake upstream but about 50,000 of them came over the dam and entered the Chesapeake system.

"I'm not saying it (the striper stocking) will work the same way," said Bason, "but there's certain things about these hybrids that just don't add up, and we're never going to know what's going on until we try this thing."