Dedicated to the Conservation of Southeastern Fishes
Rare Catch Could Spawn Resurgence Of Sturgeon In Bay
June 13, 2007
A dinosaur-era fish might experience a rebirth in the Chesapeake Bay.
For the first time in three decades, scientists have found a mature female Atlantic sturgeon full of eggs in the bay, where the species was thought to be nearly extinct.
The 7 1/2 -foot-long, 170-pound behemoth - with sharp bony plates along its back, sandpaper-like hide and a blubbery sucker mouth - was accidentally netted by a fisherman at the mouth of the Choptank River near Tilghman Island on April 29.
He turned it over to the Maryland Department of Natural Resources for a $50 reward. Now biologists hope to fertilize the eggs in a University of Maryland lab at Horn Point to produce perhaps 50,000 young sturgeon for release.
For 11 years, researchers have been holding males in tanks with the hope of someday finding a mate. Now the long-awaited courtship can begin.
"This is the first ripe female we've ever found," said Brian Richardson, a program manager at the state DNR. "It's very rare. ... Ultimately our goal is to reproduce these fish and stock them."
If the operation this month is successful, it will be the first wild Chesapeake Bay sturgeon bred in captivity, according to the University of Maryland Center for Environmental Science.
Sturgeon, a slow-reproducing fish that can live a century and grow to hundreds of pounds, were abundant in the Chesapeake and elsewhere until they were driven nearly to extinction by the caviar industry at the end of the 19th century. Their salty eggs were in high demand as an expensive delicacy.
Many biologists in Maryland assumed they were gone from state waters by the 1990s, with silt pollution making it difficult for the fish to rebound even after catching them was outlawed.
But starting in 1996, the Maryland natural resources agency has been offering cash rewards of $50 or $100 to watermen who turned them in. Most are tagged and released. Over the past decade, the numbers have varied widley but have slowly moved upward - from 13 in 1996, to 248 in 1998, 56 in 2000, 250 in 2005 and a record 450 last year, according to DNR figures.
The sturgeon aren't anywhere near recovery, and they probably aren't even breeding in the Chesapeake Bay yet, said Steve Minkkinen, a fisheries biologist with the U.S. Fish and Wildlife Service. Most of the fish caught so far in the estuary have been young, with no spawning-age females or newly hatched sturgeon.
But the capture of a record number in the bay last year suggests they are probably breeding in the Hudson River, Delaware Bay and James River and then migrating to the Chesapeake to feed, Minkkinen said.
"It's exciting. This is an indication that there is at least some reproduction going on in the East Coast," Minkkinen said. "And it shows that the Chesapeake Bay's water quality and habitat is still good enough to support these subadult fish."
Elsewhere in North America, small numbers of sturgeon of different species have been reappearing in Lake Saint Clair in Canada, the Detroit River in Michigan and Minnesota's Lake of the Woods.
In Rock Bluff, Fla., last weekend, a 32-year-old woman was knocked unconscious by a leaping sturgeon while she was boating on the Suwannee River.
That kind of violence is not normal for the slow-moving, half-blind species, which lacks teeth and uses hose-like mouth parts to suck up worms and mollusks.
A panel of scientists recently recommended that the Atlantic sturgeon be considered a threatened species, and the National Oceanic and Atmospheric Administration is expected to make a decision on the listing this summer.
"There is some evidence that Atlantic sturgeon may be doing better, especially in the Hudson River" in New York, said Jerre Mohler, fisheries biologist with the U.S. Fish and Wildlife Service. "But it's really difficult to get a handle on sturgeon populations because they are not easy to monitor."
The federal wildlife agency has been breeding wild Atlantic sturgeon caught in the Hudson River at the Northeast Fishery Center in Lamar, Pa., since 1993.
In Maryland, about 70 sturgeon from that Pennsylvania center have been kept by state biologists in tanks near the Chalk Point power plant in Prince George's County.
An additional 55 sturgeon, caught by watermen in the Chesapeake Bay, are being monitored in 17 tanks and two ponds in Cambridge, at the Horn Point Laboratory of the University of Maryland Center for Environmental Science.
The 7.5-foot-long female sturgeon was caught in the Choptank River this spring by a local waterman, C.R. Wilson, and was lifted out of the boat by a crane. The fish, roughly 12 years old, was hauled to the Horn Point lab by a state truck with a specially designed tank.
Andy Lazur, an aquaculture specialist at the lab, said he has been carefully monitoring the sturgeon's eggs to determine when they are at the right stage for fertilization.
Visitors to the tank are limited because they don't want stress to ruin the pregnancy, he said.
Sometime in the next two weeks or so, Lazur said, he and a team of colleagues from the state and federal wildlife agencies will remove the eggs from the sturgeon by making a small surgical incision. Then they will sew up the fish so she can survive and be released back into the bay, he said.
Her eggs will be fertilized with sperm from males in captivity. If all goes well, as many as 50,000 young sturgeon could hatch. In a few years, a new generation could be released into the Potomac, Choptank and Nanticoke rivers, although those plans haven't yet been finalized, Lazur said.
It's too early to tell whether this breeding effort will help lead to a sturgeon resurgence. "But," said Lazur, "there is a glimmer of hope and some good news."