The fish, a strange-looking remnant from the age of the dinosaur, was once the basis of a thriving caviar industry on the Delaware, the nation's largest. In the late 1800s, the river swarmed with boats and nets during spawning season, the shores were lined with cleaning stations.
Then, largely because of overfishing and pollution, the population of Atlantic sturgeon plummeted to near-extinction in the early 1900s.
The fish never recovered.
One factor is their unusual biology: Females aren't sexually mature until they are 18 to 20 years old.
But researchers continued to look for the huge, weird fish, which can grow to 14 feet and are so ugly, some began calling it a Franken-fish.
The Atlantic sturgeon lives most of its life in the ocean, only coming up into bays and rivers to spawn.
Since 1991, Delaware biologists began catching and tagging adult sturgeon in the Delaware. Sadly, their annual catch of adults went from about 500 a year down to about 50 to 80 a year.
Theoretically, these fish could spawn. But were they? If so, were the young surviving? For eggs to hatch, they need lots of dissolved oxygen in the water. But maybe the water was still too polluted.
In 1994, biologists caught two newly hatched sturgeon, but they neglected to determine whether the fish were Atlantic sturgeon or a similar species, the shortnose sturgeon, which also is in trouble.
In 2007 and 2008, biologists netted Atlantic sturgeon that were one and two years old.
Since sturgeon don't usually leave their home waters for the Atlantic until they are older, this suggested that they had hatched in the Delaware. But it wasn't proof. Although a long shot, it was possible they had strayed in from a neighboring waterway.
This year, Fisher, a biologist with the Delaware Division of Fish and Wildlife, began a two-year sturgeon project that included trying to find more juveniles.
