BROUGHTON ARCHIPELAGO, B.C.—Alex Morton’s boat radio crackles as it picks up a stray transmission. “You’ve got one coming in … Not the good kind.” On this afternoon in early March, the marine biologist is speeding toward a fish farm in the Broughton Archipelago, a group of remote islands and sheltered inlets on Vancouver Island’s eastern shore. This is ground zero in a protracted battle over B.C.’s salmon farms. Morton gazes out at the ocean around her. She’s pretty sure the warning came from a fish farm worker — and she’s pretty sure it’s about her.