Bony Plates & Barbels
by Art Michaels
photos-Art Michaels
Atlantic sturgeon

The Atlantic sturgeon is one mixed-up fish.

It has four chin barbels and a sharklike tail.
An unusual suckerlike mouth extends from beneath its head like a retractable tube,
and covering its body are pinhead-sized to silver dollar-sized bony plates.

Atlantic sturgeon Northeast Fishery Center biologist Bill Fletcher (top photo) holds a four-foot, 25-pound Atlantic sturgeon. The Atlantic sturgeon has catfishlike chin barbels and a suckerlike mouth.

This Atlantic sturgeon (left) is about two years old. The largest sturgeon at the National Fishery Center are about six to seven feet long and weigh about 170 pounds. Covering the Atlantic sturgeon's body (photo below) are bony plates that range in size from a pinhead to a silver dollar. Atlantic sturgeon are classified with bony fishes, but their bone structure is primitive and noticeably different from Pennsylvania's more common fishes.

Atlantic sturgeon
Bony plates

Extinct sturgeon relatives date back more than 70 million years. You might think that a strange fish like the Atlantic sturgeon would have become extinct eons ago. But this fish, which looks as if it came from a different time and a different place, is still around. Biologists at the U.S. Fish and Wildlife Service's Northeast Fishery Center, at Lamar, Pennsylvania, have taken on the job of keeping the remarkable Atlantic sturgeon around.

The Atlantic States Marine Fisheries Commission (ASMFC) has determined that the Atlantic sturgeon is a species of special concern. ASMFC was formed some 60 years ago by the 15 Atlantic Coast states to assist in managing and conserving their shared coastal fishery resources. Pennsylvania is a member. In Pennsylvania, the Atlantic sturgeon is an endangered species.

"ASMFC has established management plans that will prevent the fish's becoming extinct," says Bill Fletcher, Chief of the Northeast Fishery Center's Technology Center. "We're writing a culture manual for Atlantic sturgeon. This 50-page document will include everything­how to capture and transport them, how to prevent and treat disease, how to help them survive in the hatchery from the wild, and how to spawn the fish and raise the young."

The ASMFC Atlantic sturgeon management plan has several parts. The Northeast Fishery Center's main objective is to develop culture techniques for Atlantic sturgeon. If stocking becomes necessary to restore this species, learning how to raise Atlantic sturgeon will be necessary, and starting now is better than waiting until it's too late to learn.

Another part of the plan is for the Northeast Fishery Center to raise brood stock to evaluate the potential of the species for aquaculture.

"Raising Atlantic sturgeon in a hatchery is very different from raising trout," says Fletcher. "An Atlantic sturgeon's life span is more than 60 years. They take so long to become sexually mature­males, around 10 years, and females, around 15 years. We're taking them through a full cycle. We've captured wild brood stock and are now raising their progeny in the hatchery environment all the way through to their reproducing again. It's already taken eight years to gain a good understanding of these fish and how to rear them."

The PA Fish & Boat Commission and the Northeast Fishery Center cooperate in the effort to restore Atlantic sturgeon. Because Atlantic sturgeon are endangered in Pennsylvania, the Fish & Boat Commission issues a special permit to the Northeast Fishery Center for the possession of Atlantic sturgeon. In addition, the Commission issues the Center a scientific collector's permit.

Several years ago, the PA Fish & Boat Commission and the Northeast Fishery Center conducted a joint Atlantic sturgeon study using sidescan sonar in the Delaware River. Atlantic sturgeon had gathered in certain river areas at 30- to 50-foot depths. Commission and Northeast Fishery Center biologists used the sidescan sonar to explore the habitat, and understand why the sturgeon gathered in the area.

The biologists found bottom ridges where the sturgeon were holding. During periods of high flow, the ridges provide some protection from the current. This cooperative effort was valuable because it helped biologists define one kind of cover that draws the sturgeon.

The Fish & Boat Commission and the Northeast Fishery Center also work together in American shad and striped bass restoration efforts, and in virology­fish health­work.

"In 1880, a representative of the federal government wrote, 'The Delaware River had a [sturgeon] fishery that exceeded all others,'" says Fletcher. "Before the tobacco industry grew in this country, sturgeon were the main export from colonial America. Habitat loss, overharvest and the inability of the natural population to rebuild caused their decline.

"Restoring the Atlantic sturgeon is important," says Fletcher. "So many times you hear that threatened or endangered species are insignificant and have no commercial value. The Atlantic sturgeon has a high commercial value. In addition, restoration is important conservation work because we don't know the role of the Atlantic sturgeon in the aquatic ecosystem."

Restoring our historical and cultural heritage is also part of the Atlantic sturgeon's story. And what an old, remarkable tale it is.

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September/October 2000 Angler & Boater


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