New York, New Jersey and Delaware were accused in federal lawsuits Thursday of improperly allowing Atlantic sturgeon to be killed by commercial fishing operations even as the prehistoric fish is on the brink of disappearing.

The three parallel lawsuits filed by the Delaware Riverkeeper Network and Hudson Riverkeeper accuse the states of violating the Endangered Species Act by not obtaining necessary permits that allow commercial fisheries to catch and kill Atlantic sturgeon while they fish for other species such as striped bass and summer flounder. The environmentalists say the once thriving fish’s recovery is threatened because they are unintentionally caught in commercial nets as “bycatch.”

Atlantic Sturgeon in the Delaware River and Hudson River were listed as endangered under the Endangered Species Act in 2012.

“The Atlantic sturgeon of our two rivers are at risk from being wiped from the face of this earth within our lifetime,” Delaware Riverkeeper Maya van Rossum said during an online news conference.

The environmental groups say they want to compel the states to comply with the Endangered Species Act, which they believe will reduce the bycatch and help Atlantic sturgeon recover.

The environmental agencies of New York and New Jersey declined to comment on the litigation.

An email seeking comment was sent to Delaware's environmental agency.

Sturgeon, notable for bony plates lining their bodies, date to the time of dinosaurs. Atlantic sturgeon are born in freshwater and migrate to the sea.

Sturgeon populations began to drop steeply more than 100 years ago amid pollution, dam construction and overfishing. The decline was driven in part by demand in the 1800s for caviar, a delicacy of salt-cured sturgeon eggs.

Rossum said the Delaware River, once teeming with an estimated 180,000 females, now has fewer than 250 spawning adults remaining. Tracy Brown, the Hudson Riverkeeper, said numbers also are down in New York.

“Despite the endangered species listing, our Hudson River sturgeon population has not seen improvement,” Brown said. “It is, quite frankly, disgraceful that so little progress has been made towards recovery.”