The man at the filling station in Easton spotted the cooler and the rods in the back seat.

"You've been fishing," he said, "and I know what you have in your cooler. You got some perch and them damn blues."

"No," I said, "I got some perch, some rockfish and them damn blues."

"Rockfish? Hah. Let me see 'em. I know you didn't catch no rockfish."

Not long ago a good catch of striped bass, called rockfish in Maryland, would raise no eyebrows. But the gas jockey's disbelief echoed the bitter truth of Chesapeake striper fishing in 1981. It practically doesn't exist.

Today you could count the number of charter fishermen who guide principally for rockfish on your hat. That is to say, one.

The reason I could thumb my nose at the gas station man was one Jim Price of Oxford, Md., the last of the all-season rockfish guides. Price is willing to say, "I can just about guarantee rockfish every day of the year except in January, February and March."

I said show me and he did.

Price is of a fishing family, son of a waterman and inheritor of information about the Choptank River gleaned over a century of commercial and sport fishing there.

"There are about 20 spots that regularly hold fish in this river," he said., "In the 25 miles upstream from the mouth. I know every one of those spots."

"Jim, there must be a spot or two where I could catch some fish that you don't know about."

"Nope," he said, straight-faced. "I know 'em all."

The wind howled as we set off on our striper search. "Doesn't bother me," said Price. "If I set a date with you, We're going fishing."

A mile or two above the Choptank bridge at Cambridge he slowed the motor on his 20-footer and began lining up shore marks. He dropped anchor and the skiff settled back. The hook dug in.

"There," said the portly Price, a diamond and gold merchant when he isn't fishing. "We're right on top of them."

The depth meter showed flickers of fish just off the bottom in 20 feet of water. "There's an old wrecked fishing boat down there and the fish hang around it."

I dropped a hook baited with grass shrimp to the bottom, turned the reel handle once and felt the tug of a fish. A big fat perch, close to a pound.

"Bah," said Price. "We ought to get some rockfish. They're usually mixed up in here -- great big perch and rockfish all together."

But the balance was heavily in favor of perch, which struck the baits on every drop. They were truly monster perch, but that did not suit Price. He pulled anchor and set off for spot No. 2, "where I think the rockfish really are."

Same scenario. He lined up shore marks, dropped back on the anchor, checked the depth finder and determined that we were directly over a small bed of submerged pilings from an abandoned commercial stake net.

Same results. Drop bait, set hook and reel the fish in. Only this time the fish had stripes.

"Gee," I said. "This is almost too easy."

"Easy? Finding these spots took me a lifetime of work," said Price, who was not amused.

We spent the remainder of this breezy day on the stake-net spot and the fish never stopped biting. Price, who has becomes a conservationist over these troubled rockfish years, watched each come over the side and plotted ways to get it back to safety.

"I don't mind keeping a few good-sized rockfish and the big perch to eat," he said, "but the rest go back in."

He tags stripers he releases with yellow plastic ties labeled "American Littoral Society," and an address. When these fish are recaptured by sport or commercial fishrmen around the bay or off the coast in the Altantic, the tags are mailed in with date of capture and size of fish. The data is used to determine the habits of these troubled fish, which have not had an excellent reproductive year in the last decade.

One thing Price already has learned from his tagging is that the last decent year for striper reproduction, 1978, produced fish that are growing at a rate much faster than normal.

He has been catching plenty of 1978 fish, but they're growing so quickly that by this summer they'll likely be big enough to leave this, their home river, and head to sea.

Price likes that, and then he doesn't. Last year he caught more than 1,000 stripers. The year before was his lowest point ever -- about 350 fish. When the '78 fish depart, he doesn't want to see his revived success go with them.

"Used to be you could go anywhere in this river and catch fish," he said. "But today there just aren't that many fish here.You have to know the spots and there aren't that many of them."

"Funny," I said, "but I've had a hard time figuring out exactly where we are. I know you're lining up shore marks to get your bearings, but I can't figure which shore marks you're using."

"Yup," said Price, chuckling. "If you could figure out where you were, I'd never have taken you there."