Biologists hope to fertilize sturgeon’s eggs

CAMBRIDGE, Md. (AP) — The rare capture of a ripe female sturgeon has biologists hoping they can fertilize her eggs and grow as many as 50,000 young fish for release into the Chesapeake Bay, where the valuable species was thought to be nearly extinct.

The 7½-foot-long, 170-pound sturgeon was caught accidentally in a net by a fisherman on April 29 at the mouth of the Choptank River near Tilghman Island.

The fisherman turned over the fish to the state Department of Natural Resources (DNR), which offers rewards for sturgeons and other species of interest to its biologists.

The biologists hope to fertilize the eggs at the University of Maryland’s Horn Point laboratory, using sperm from male sturgeons they have been keeping in tanks for 11 years while they searched for a mate.

Biologists have been taking egg biopsies every few weeks from the female and are waiting for the eggs to fully mature before removing them surgically, said Brian Richardson, a DNR program manager.

The eggs then will be separated into about a half-dozen lots and manually fertilized with sperm from various males, Mr. Richardson said.

“We can’t really say for sure when. We’re monitoring and we’re hoping within two or three weeks,” Mr. Richardson said. “So far, she’s tolerating it very well.”

If successful, the resulting fry will be the first wild Chesapeake Bay sturgeon bred in captivity, according to the University of Maryland Center for Environmental Science.

The slowly reproducing fish, which can live 100 years and weigh hundreds of pounds, were once abundant in the Chesapeake and elsewhere and prized for their salty eggs. They were driven nearly to extinction by the caviar industry at the end of the 19th century.

Since 1996, the DNR has been offering rewards of $50 or $100 to watermen who turn in the sturgeon, with most tagged and released back into the wild. The numbers of fish have slowly increased from 13 in 1996 to 450 last year.

Steve Minkkinen, a fisheries biologist with the U.S. Fish and Wildlife Service, told the Baltimore Sun that most have been young, and none has been a spawning-age female or newly hatched sturgeon.

However, the large number captured last year suggests they are breeding nearby, perhaps in the Delaware Bay or James River in Virginia, and migrating to the Chesapeake to feed, Mr. Minkkinen said.

“It’s exciting. This is an indication that there is at least some reproduction going on in the East Coast,” Mr. Minkkinen said. “And it shows that the Chesapeake Bay’s water quality and habitat is still good enough to support these subadult fish.”