At a time in Chesapeake Bay's history when I have little optimism about its future, Alosa sapidissima, the American shad, gives me hope.

From as far off as the Bay of Fundy in Nova Scotia, for thousands of years shad have headed toward the Chesapeake to throng its spawning rivers when the shadbush and the dogwood blossom each spring. The shad followed the rivers' springtime flows, going all the way to Cooperstown, NY, at the top of the Chesapeake drainage basin, 600 miles from Bay's mouth.

But two centuries ago, humans began to dam the Susquehanna, the Chesapeake's mightiest tributary and one of the nation's great fish highways. By 1928, the Susquehanna was completely and finally sealed off by Conowingo Dam, rising 100 feet high across the river just above Havre de Grace, MD.

All over the Bay it was a similar story. Dams across the James and Rappahannock in Virginia, the Patapsco above Baltimore, the Potomac above the District of Columbia and countless smaller obstructions, like roadway and rail culverts, amputated thousands of miles of prime shad runs, deadening the watershed to one of spring's great enthusiasms.

Overfishing abetted damming. The shad's numbers plummeted. Maryland and Virginia banned shad fishing decades ago, and I, who was drawn as a boy into the wider web of Chesapeake connections by catching shad in my hometown stream far from the Bay, have raised two children to adulthood who have never had the pleasure.

Spring after spring these remnants of a once-great nation, insistently pressed soft faces (shad filter plankton to feed, and their mouths are almost fragile) against armored fortresses. Keeping the faith, butting flesh against yards-thick concrete; it seemed an unequal contest, hopeless.

But it is the dams that are yielding.

In recent years, as part of the Chesapeake Bay restoration program, society's desires have aligned with the shad's. One goal of the restoration pact among the federal government and the six states of the Chesapeake watershed has been the reopening of historic spawning reaches for shad and other species. On the James at Richmond, at Fredericksburg on the Rappahannock, at Little Falls on the Potomac, at all four of the Susquehanna's hydro dams, we have breached and notched and blown up dams to provide passageways over, around or through them. This year more will give way, including the Woolen Mills Dam on Virginia's Rivanna River and the McCoy-Linn Dam on Spring Creek in Pennsylvania.

Nearly 2,000 miles of Chesapeake arteries have been reopened to the fuller possibilities of spring, and a thousand more are scheduled for liberation. A shad can again travel from the ocean to the foothills of the Appalachians.

A recovery will take years. In August, the Atlantic States Marine Fisheries Commission, which manages fisheries for migratory species along the East Coast, concluded that, coastwide, the shad stock is at an all-time low and does not appear to be recovering. Yet in one of its few bright spots, the report noted the shad that do return to spawn in the Potomac and some of Virginia's rivers have shown signs of rebounding. Stocking programs in Maryland show promise. And biologists plan to negotiate new deals with dam owners on the Susquehanna to improve the effectiveness of fish passages to aid that river's struggling stock.

I am not optimistic that we will recover the Bay I once knew. Yet, in my heart I do dare hope to one day again cast a line for the shad on my boyhood river, the Nanticoke and its tributary, Marshyhope Creek, where I first encountered Alosa sapidissima. If I extend myself-for the root of "hope" also means to "hop up"-I can see the way to Bay recovery.

No other estuary on Earth has been better studied. We know the sources of its troubles and we know how to resolve them. We know the most cost-effective solutions and know that they are affordable. We could very quickly be making rapid progress to recover this Bay.

Perhaps I should take courage from the shad. I don't know if hope can be ascribed to a fish. But surely, if they had a point of view, the situation must have looked hopeless for a long, long time. Yet they just kept returning, pushing upstream even after all memories of upstream should have faded.

We need to be smart to restore the Bay, and also too dumb to know when we're licked. We need to be dauntless. I propose we do no less than the shad-keep pushing upstream, the dams be damned.