With little to show for more than two decades of effort, Virginia officials next year plan to suspend shad stocking efforts in the James River, conceding defeat for now in restoring what had once been a major spawning ground for the migratory fish.

“We’re not going to fund work next year to continue what we’ve been doing,” said Bob Greenlee, who oversees the program for the state Department of Game and Inland Fisheries.

The stocking effort in the Bay’s third-largest tributary began in 1992 with the hope of bolstering depleted American shad numbers and, ultimately, build a self-sustaining population. Biologists also hoped the fish would become so numerous that they would push past a fish ladder at Boshers Dam in Richmond and repopulate the river far upstream.

But 25 years after the first shad were stocked, numbers remain low and tend to be driven by hatchery production of shad fry rather than natural reproduction, as biologists had hoped. Only a few dozen spawning fish typically make it beyond Boshers each year.

“Our overall assessment for the James River is that the stock remains at historically low levels and is dependent on hatchery inputs,” scientists from the Virginia Institute of Marine Science wrote in a report last year.

Shad are anadromous, meaning they return to their native freshwater rivers to spawn, but spend most of their lives in the ocean off the East Coast. They, and closely related river herring, once migrated up the James and other rivers in such large numbers that one historian observed in 1705 that “it is almost impossible to ride through (the water) without treading on them.”

As recently as the 1950s, they were the most valuable fishery in the Chesapeake. In recent decades, though, their spring spawning runs in most East Coast rivers have fallen to historic lows. Overfishing, pollution, loss of habitat and the construction of dams that closed off historic spawning grounds have all contributed to the population collapse, scientists say.

States in the Bay region have worked to restore populations by stocking hatchery-reared shad, reducing pollution, removing dams and — on the Susquehanna River — ordering utilities to spend tens of millions of dollars on fish lifts or ladders to carry shad over hydroelectric facilities.

There have been some bright spots. The Potomac River has had one of the strongest shad comebacks on the East Coast, and monitoring by the Maryland Department of Natural Resources suggests shad numbers in the Upper Bay have been increasing in recent years.

But little progress has been made on the Susquehanna and the James, which along with the Potomac, were historically the three largest and most important rivers in the Chesapeake Bay for spawning shad.

Virginia’s Greenlee, like some other biologists, said that he believes recent restoration efforts are being harmed by fisheries off the coast, where some studies suggest large numbers of shad and river herring are being caught unintentionally as fleets trawl for other fish.

“I think it is an offshore impact that is likely the bottleneck to this thing,” Greenlee said. “Until we tackle what the bottleneck is that is preventing the recovery of American shad, we are just throwing money at a river system that has shown no response.”

Greenlee said he was open to restarting the program in the future if things begin turning around in other rivers. But the department’s budget has been frozen for several years, he said, and while the shad operation is not particularly costly, the workers devoted to it could be better focused on other efforts.

He said biologists later this year would discuss alternative actions they could take to benefit shad on the river.

Others agree that current efforts aren’t working in the James.

“Hatchery efforts might be good to jump-start a recovery, but this has been going on for over 20 years, and doesn’t seem to be a good tactic — certainly not in the James,” said Greg Garman, a fisheries biologist with Virginia Commonwealth University, who was involved in the project in its early years.

Jamie Brunkow, the Lower James riverkeeper, agreed that “it doesn’t appear the stocking is necessarily having the results that we wanted.” But, he added, “it definitely doesn’t feel good to step away from the program, so I’m wondering how we are going to meet our goals restoring shad.”

Brunkow suggested the state might find other ways to help shad, such as promoting underwater grass restoration. A surge in grass beds has been cited as one factor helping the shad comeback on the Potomac.

“We need to refocus the resources,” the riverkeeper said, “and not take away from the underlying goal.”

Shad harvests in the James River were as high as 1 million pounds as recently as 1973. But by 1993, only 3,100 pounds were harvested. A ban on shad harvests in Virginia rivers went into effect the next year.

By the time the stocking program began, biologists couldn’t find enough female shad in the James to supply eggs for the hatchery. They quickly turned to the nearby Pamunkey River instead.

Biologists estimated early on that about 10 million shad a year should be released in the James to rebuild the population, but that never happened. The best year, 2000, saw only slightly more than 7 million stocked.

More recently, a combination of tight budgets and difficulty collecting broodstock — low shad numbers in the Pamunkey have sent biologists to the Potomac for fish in recent years — have resulted in only a few million being stocked annually.

This year, the U.S. Fish and Wildlife Service Harrison Lake Fish Hatchery produced 1.85 million shad that went into the James River near Scottsville.

How many come back in four or five years, though, is uncertain, because heavy rains this spring that fell a week after the small shad “fry” were released may have pushed the fish downstream into less suitable habitat, said Mike Odom, manager of the Harrison Lake hatchery.

“We had flooding on the James, so we might have had a recruitment failure after the stocking,” he said.

Elsewhere around the Bay, shad stocking results are mixed.

The Potomac is one of the few places along the East Coast where shad populations are growing. This was the seventh straight year that the river has exceeded its restoration target, and numbers continue to increase, according to the Potomac River Fisheries Commission.

Expanding underwater grass beds, improved water quality and a fish passage at Little Falls dam outside Washington, DC, are among factors that helped, said Jim Cummins, a retired biologist with the Interstate Commission on the Potomac River Basin who worked for years with the river’s shad restoration effort.

But he said the 17 million shad stocked in the river from 1995 to 2002 likely helped as well. “In the Potomac, it was one of several factors that helped,” Cummins said. “It was not the factor.”

On the Nanticoke River, biologists stocked a record 1.3 million shad fry this year — nearly double the previous high mark of 700,000 in 2009.

“We had an amazing year,” said Johnny Moore, a fisheries biologist with the Delaware Division of Fish & Wildlife. He said it’s been easier to catch broodstock from the river in recent years, which he attributed at least in part to the hatchery effort launched in 2000. “We still think it is paying off,” he said. “We are a smaller river. It is easier for us to have a more noticeable impact.”

On the Susquehanna, Pennsylvania biologists stocked 3.8 million fry this spring — nearly double last year’s mark. But it was far below numbers seen more than a decade ago, when production frequently exceeded 10 million. The decrease is primarily due to difficulty in getting eggs, as shad populations are low in so many other rivers.

“We do the best we can with what we can get,” said Josh Tryninewski, a fisheries biologist who manages stocking efforts for the Pennsylvania Fish and Boat Commission.

About 40 percent of the shad caught in surveys below the Conowingo Dam are hatchery fish, he said.

On the Choptank River, the Maryland DNR this year stocked 2.53 million larval shad, along with 403,000 larger juvenile shad, which was just below its annual goal, said Chuck Stence, of the DNR’s anadromous fish program.

Gauging success has been difficult because until the last two years, biologists had a hard time finding good survey sites on the river, Stence said. With the establishment of new monitoring sites, they will be able to monitor trends.

But signs of hatchery success might come from the Patapsco River, where the DNR has been stocking American shad, and a smaller relative, hickory shad, for five years.  This year, they released 225,000 American shad larvae, exceeding their goal of 200,000, while meeting their goal of releasing another 75,000 juvenile shad.

They also released 750,000 hickory shad larvae and 87,000 juveniles, exceeding targets for both.

The project was funded with mitigation money from a river dredging operation. That money is running out, but the DNR plans to tap other sources to maintain the effort because of hints  that it may be boosting shad numbers in the Baltimore area river.

“You really hate to stop stocking after just three or four years,” Stence said.