Ghosts from the past may still haunt Bay waters
Discovery raises debate on how to save native Atlantic sturgeon
Many scientists have thought for years that the last Atlantic sturgeonnative to the Chesapeake Bay had gone the way of the passenger pigeon.
That hypothesis is now in doubt.
It appears likely that an Atlantic sturgeon - the largest fish native to the Bay - spawned in the Chesapeake basin this year, most likely in the James River.
Fishermen, responding to a $100 reward for live Atlantic sturgeon, have collected about 100 of the fish in the James and neighboring rivers. At least one of the fish was as small as 10 inches - thought to be too small to have migrated into the Bay from other river systems.
"If our knowledge of the life history of these fish is anywhere close, that fish certainly had not gone to ocean migration yet," said Albert Spells, a biologist with the U.S. Fish & Wildlife Service in Virginia. "I strongly feel that fish was spawned in the Bay." Further bolstering the possibility of reproduction was the Oct. 11 discovery of a dead, 8 1/2-foot female sturgeon on the banks of the James River near Upper Brandon.
Adult sturgeon typically remain at sea until returning to their native rivers to spawn. Usually, spawning takes place in the spring, though some areas report spawning during the fall as well.
The last clear evidence of sturgeon reproduction in the Bay was 1979, when recently spawned fish were found in the James River. Still, this year's discoveries do not change the dim outlook that many have for the species in the Bay.
"What it represents, if it is a Chesapeake Bay fish, is kind of a ghost," said David Secor, a biologist at the University of Maryland's Chesapeake Biological Laboratory who studies sturgeon. "It's a representative of something that once was - and probably no longer is - here."
With little evidence of spawning sturgeon for so many years, Secor said there are probably too few sturgeon native to the Bay left to sustain a population, and any that remain are fated to extinction. "The trends are too clear-cut," he said. Sturgeon populations have been severely depressed since they were overfished at the end of the last century. The giant fish do not begin reproducing until they are about 15 years old, and even then only spawn about every three years, and produce few eggs relative to other fish. That makes it hard for the population to rebuild.
Because evidence of reproduction in the Bay has been so rare, Secor said any mature fish that remain are probably increasingly old and the odds that males and females will meet in spawning grounds will continue to decrease over time. Secor estimated the dead fish found in the James could be 40 to 60 years old.
Studies elsewhere show that such "relic" populations gradually die out over a period of years - even decades - with fish being seen so infrequently that it is difficult to determine exactly when the last one died, Secor said. "They just kind of eke away," he said.
Not everyone agrees with that bleak prognosis. Spells said few Bay sturgeon have been found because agencies have lacked the money to mount a major search for the fish. "I think there's a few more fish out there than some of the experts credit," Spells said.
If fish native to the Bay still exist, it could ignite a debate over how any efforts to recover the sturgeon population in the Bay should proceed. Interest has grown in trying to restore sturgeon to the Bay, and the Maryland Department of Natural Resources last year conducted an experimental stocking of more than 3,000 sturgeon in the Nanticoke River.
The fish had been reared in a hatchery using eggs taken from fish collected on the Hudson River. (Fish from that release were tagged, and not counted among the 100 "wild" fish caught in the James and nearby areas this summer.)
Scientists believe the Atlantic sturgeon population is composed of several strains which are unique to the specific river systems or bays in which they were spawned. Presumably, sturgeon native to a certain area are better adapted to the local environmental conditions than other sturgeon.
In fact, genetic analysis of some fish collected in the James this year indicate they are different from other sturgeon. The genetic analysis can't show they are from the Bay, though, because there are no Bay samples to compare them to.
The potential presence of native fish raises the question of whether further stocking of fish from other areas should take place. Such an effort could quickly overwhelm and replace any native fish that remain.
Spells said that any hatchery program should use Chesapeake fish. "If we're going to err, I think we should err on the side of the fish and spend the extra effort to obtain brood fish from the Bay," he said. "That's a bigissue among a lot of us."
Given the poor condition of the Atlan- tic sturgeon in general, others contend it is important to try to rebuild the stock, even if fish from other rivers are used. Coastwide, the Atlantic sturgeon stock is in bad shape and is being considered for listing under the Endangered Species Act. Numbers in the Hudson River, thought to be the healthiest East Coast population, have been falling for several years, and sturgeon fishing has been closed all along the coast.
"I don't know if we have the luxury of waiting and doing nothing anymore once we have the technology to do something," said Richard St. Pierre, USF&WS Susquehanna River Coordinator, who has developed a stocking protocol for Atlantic sturgeon.
The discovery of the dead female sturgeon also adds fuel to what some scientists refer to as the "last sturgeon" debate. With so few fish in the Bay, any mature female that is found could be one of the last in existence. If one is caught, what should be done with it?
Some advocate "sacrificing" the fish and using its eggs to rear fish at the hatchery - a process that would preserve any unique genetic characteristics in the offspring. Any reproduction in the Bay, they note, would hinge on the female also finding a mature male.
On the other hand, Secor suggested that the sturgeon would be more valuable it were tagged and tracked through the Bay. By following the sturgeon to a spawning ground, scientists could learn what areas of the Bay and its tributaries are important to protect for spawning habitat as part of any future recovery effort. Right now, Secor said, no one knows exactly where sturgeon historically spawned in the Chesapeake. In addition, Secor said, the fish might lead scientists to other sturgeon in the Bay.
"The last sturgeon debate," Secor said, "is very active." Spells, though, argues that the Bay is not down to its last sturgeon. Relatively little research effort has gone toward studying sturgeon, he said, and much remains unknown about them - including the best survey techniques to capture and mark fish.
"All our information is anecdotal," Spells said. "I'm by no means saying the stock is not severely depressed. I do believe that to be the case. But there are adult fish spawning in the Bay. I truly believe that."
- The oldest Atlantic sturgeon on record was estimated to be 60 years old.
- The heaviest Atlantic sturgeon on record weighed 811 pounds. The longest was 14 feet.
- In 1890, nearly 7 million pounds of sturgeon were caught along the East Coast. Since 1920, the catch has never exceeded 300,000 pounds.
- Female sturgeon are about 7 feet at maturity, and may weigh anywhere from 100 to several hundred pounds.
- Males in this area do not reach maturity until they are 11-12 years old. Females reach maturity at about 15 years. They mature at older ages to the north and younger ages to the south.
- Females lay eggs in flowing water up to 60 feet deep.
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