While the anadromous — meaning that it migrates from the sea to a river to spawn — fish has been illegal to capture, kill or harm for more than a decade under the Endangered Species Act, the use of nets in commercial fishing has pushed it closer to the brink of extinction, according to a new lawsuit by environmental group Riverkeeper. Advocates allege the New York Department of Environmental Conservation, along with the state environmental agencies of Delaware and New Jersey, have failed to protect the Atlantic sturgeon and are turning a blind eye to illegal bycatch of the fish.