The state’s largest Alaska Native organization declared its opposition to a constitutional convention on Saturday, saying rural Alaska could have the most to lose if a convention is called.

The Alaska Federation of Natives also called for a potential reduction in the amount of fish caught in Area M, a state-managed fishery off the Alaska Peninsula, in order to protect salmon runs that have crashed on the state’s two largest rivers, the Yukon and Kuskokwim.

And, after passing several other measures, the organization voted in executive session to endorse Republican Sen. Lisa Murkowski in the U.S...