Students on a school field trip who cast a net into the James River caught more than than they had bargained for—the most concrete evidence to date that sturgeon may still spawn in a Bay tributary.
The students, on a Chesapeake Bay Foundation field trip, netted the fish about 20 miles downstream of Richmond on March 24. They knew they had something unusual when they pulled the leathery fish out of the trawl net, so they turned it over to the U.S. Fish and Wildlife Service.
“We didn’t see the fish out there spawning, but it strongly suggests that spawning took place last spring,” said Albert Spells, Virginia fisheries coordinator for the USF&WS.
Atlantic sturgeon are the largest fish native to the Chesapeake Bay—historically reaching lengths of 12 feet—and supported a major fishery a century ago. But overfishing and increased pollution have nearly wiped out the population.
Scientists have debated for years whether any native Chesapeake sturgeon remain, or whether those occasionally seen in the Bay are transients from other areas.
No sturgeon have spawned in Maryland’s portion of the Chesapeake for decades. Some scientists have suspected that sturgeon still spawn occasionally in the James based on past surveys that found large numbers of sturgeon measuring 15 inches or less. Those fish are thought to be too small to have migrated into the Bay from other areas because young sturgeon generally live several years near their spawning habitats before moving to coastal waters where they spend most of their lives.
But the 6-inch fish is the smallest—and most conclusive evidence so far that a remnant population may remain.
After news of the catch made the newspapers, another angler contacted Spells to report catching and releasing a slightly smaller sturgeon in the James also in spring 2003. “That doesn’t tell us the fish are on the road to recovery by any means,” Spells said. “It certainly does indicate there are spawning fish out there.”
Spells said he would like to start a survey to determine what habitats the sturgeon are using, and whether many potential spawners remain in the river.
He said genetic material was taken from the small fish for analysis before it was released. Sturgeon native to different river systems along the East Coast are thought to be genetically unique. Such an analysis could reveal whether the James River fish is truly distinct, or whether its parents merely strayed from another river system, such as the Hudson.
That could affect discussions expected to take place this fall when biologists are expected to gather for a workshop aimed at developing a hatchery-based stocking program to restore sturgeon to the Chesapeake and rebuild the severely depleted Delaware River population.
Because of a lack of fish in the Chesapeake, it has been presumed that any such effort would depend on sturgeon from the adjacent Delaware Bay, where a small spawning population persists, and from the Hudson River.
But the presence of fish in the James will likely raise several questions. If it is indeed unique, some effort might be made to collect sperm or eggs from other James River fish—if they could be found—as part of any breeding program.
On the other hand, some may argue that no stocking program take place because it could interfere with any recovery with unique Bay fish. Others believe that, even if fish are spawning in the James, there are too few to recover on their own.
“I guarantee you, that there will be a debate,” said Steve Minkkinen, who heads the USF&WS Maryland Fisheries Resource Office and is organizing the fall workshop. “They may be hanging on by their fingernails in the James. The question in my mind is whether that is sustainable.”
The workshop would discuss where suitable spawning and nursery habitat may remain in the Bay watershed, and what kinds of threats sturgeon may face.
Sturgeon require higher levels of oxygen in the water than almost any other fish, and also need clean gravel river bottoms on which to deposit their eggs. With the Bay’s chronic low-oxygen conditions in the summer, and decades of heavy siltation, some biologists question whether it offers enough habitat for a restored population.
Maryland’s Department of Natural Resources has about 150 fish—some left from an experimental release in 1996, and others collected from the wild in the Hudson and Delaware Rivers—which are nearing maturity.
“Now is the time to start getting everything in place,” Minkkinen said. “The worst thing I could see happening is suddenly having fish reach maturity and be able to spawn them and then say, ‘Now what?’ “We need this stuff laid out ahead of time.”