America's forgotten dinosaurs are all set for a comeback
America's vanishing dinosaurs
Sturgeon were America's vanishing dinosaurs, armor-plated beasts that crowded the nation's rivers until mankind's craving for caviar pushed them to the edge of extinction.
More than a century later, some populations of the massive bottom feeding fish are showing signs of recovery in the dark corners of US waterways.
Increased numbers are appearing in the cold streams of Maine, the lakes of Michigan and Wisconsin and the coffee-colored waters of Florida's Suwannee River.
A 14-foot Atlantic sturgeon as long as a Volkswagen Beetle was recently spotted in New York's Hudson River.
The caviar rush
Following the late 1800s caviar rush, America's nine sturgeon species and subspecies were plagued by pollution, dams and overfishing. Steep declines in many populations weren't fully apparent until the 1990s.
Scientists are seeing increased numbers of them in some rivers because of cleaner water, dam removals and fishing bans.
Sturgeon swam with the dinosaurs. Bony plates line their bodies. Whisker-like barbels hang from their chins. Their toothless mouths telescope out and vacuum up anything from worms to mussels.
By 1900, American sturgeon populations were collapsing. Dams were going up. Pollution sucked oxygen from rivers.
Tribes at work
The species is benefiting from fishing limits and stocking programs, some by Native American tribes.
But dam construction over more than a century has slowed the recovery.
Still facing threats
The species still faces various threats including the Gulf Coast's ever-warmer waters, said Adam Kaeser, an aquatic ecologist with the U.S. Fish and Wildlife Service.
Decimated by dams, only one Alabama sturgeon has been caught since 2007, but DNA tests of river water confirm some are still there.