A conservation group’s discovery that no wild Atlantic salmon have returned to a key river in New Brunswick is prompting concern for the fish’s population health in the U.S. and eastern Canada. The New Brunswick-based Atlantic Salmon Federation has monitored the Magaguadavic River for the Canadian government since 1992. The group says this year is the first time since then that no wild salmon have returned to the river to spawn. Atlantic salmon were once abundant in the rivers of New England and eastern Canada, but they’re now endangered or have disappeared in parts of both.