In a hopeful sign for a ravaged species, an estimated 129,000 American shad returned to the upper Chesapeake Bay this spring to spawn, more than 2 1/2 times as many as showed up last year.
The estimate, released by state biologists last week, is evidence that the gradual comeback of shad in the upper bay has resumed despite a downturn in 1993.
Officials hope for eventual restoration of the severely depleted and nearly forgotten fish, which once eclipsed rockfish and even crabs in popularity.
But conservationists note that this spring's spawning run was tiny compared with the millions of shad that once swarmed from the ocean into the bay and up the Susquehanna River as far as Binghamton, N.Y.
And the rebound in the upper Chesapeake is tempered by sharp, mysterious declines in robust shad populations in other East Coast rivers, notably the Hudson and Connecticut. Those problems are prompting renewed calls for curtailing shad catches in the Atlantic Ocean off Maryland and other states.
The upper bay population estimate is the second highest since the state imposed a shad fishing moratorium 14 years ago to save the few thousand that remained after more than a century of overfishing and loss of spawning habitat to dams.
The "imperial shad," as the late Eastern Shore poet Gilbert Byron dubbed it, is prized for its roe, or eggs, and its tasty but bony flesh. It helped feed colonial America each spring and remained the most valuable food fish in the mid-Atlantic region until a half-century ago.
Because of relentless fishing and dams blocking major spawning rivers, Maryland's shad catch plummeted by more than 90 percent until an outcry from conservationists prompted the state to impose the moratorium in 1980. Unlike rockfish, which rebounded from a similar decline after a five-year catch ban, the shad's recovery has been agonizingly slow.
Now, says W. Peter Jensen, Maryland's fisheries director, "We feel like we've got the bay recovery pretty much in hand."
Adding to his optimism is the record number of shad -- more than 32,000 -- that were lifted over the Conowingo Dam and transported by truck up the Susquehanna so they could spawn above the four dams that now block fish migration in the bay's largest tributary.
Virginia joined Maryland this year in banning shad fishing, and both states have launched efforts to boost the recovery by restocking rivers with fish spawned in hatcheries. Pennsylvania already has a hatchery program for the Susquehanna.
Building on their experience in reproducing rockfish, or striped bass, in hatcheries, Maryland fisheries officials are turning their efforts to shad. "We're trying to move away from just stocking fish in rivers . . . to environmental restoration," said Benjamin Florence, Maryland's hatcheries director.
Working with shad collected from the Delaware River, Maryland's Joseph Manning hatchery in Cedarville State Forest near Brandywine produced 1.3 million shad larvae that were dumped in the Susquehanna near Port Deposit this spring. An additional 200,000 are to be raised to "fingerling" size in ponds maintained by Potomac Electric Power Co. and released in the Patuxent River, which hasn't had shad in years.
Last spring, however, there was little optimism about shad restoration.
The number of fish at the Conowingo fish lifts fell to 13,546, from a high of 27,227 in 1991. And the upper bay population estimate, based partly on the fish-lift count and partly on independent sampling, also declined, from a high of 141,000 in 1991 to 47,500.
The upper bay decline coincided with dramatic drops in shad runs measured in other East Coast rivers, prompting biologists to wonder if the fish were being intercepted in the ocean, possibly by foreign fishing fleets, or if unusually cold and stormy weather or some other environmental factor was depressing spawning runs.
Despite the large shad turnout in the upper bay this spring, the outlook is bleak elsewhere on the Atlantic Coast.
"The wheels have come off the wagon," laments Victor A. Crecco, a Connecticut state fisheries biologist. "We had a showcase shad run on the Connecticut River, and now we're down to (almost) nothing." The river's shad population, estimated to be 1.2 million two years ago, was only about 300,000 this spring, he says.
The commercial shad catch on New York's Hudson River, which until recently had an estimated 4 million shad, also has dropped dramatically, officials report. Similar declines in shad runs have been noted in other New England rivers, and the catch is said to be off in the Delaware and some southern rivers.
The declines mystify biologists. Mr. Crecco believes that juvenile Connecticut River shad are being gobbled up by rockfish. But other biologists are not convinced.
Meanwhile, Maryland has proposed extending its bay fishing moratorium to the ocean, where about two dozen anglers caught nearly 80,000 pounds of shad off Ocean City last year.