“The spectacular Sea of Cortez is among the biologically richest 1% of all marine ecosystems. It is also home to one-third of all marine mammal species, as well as one of the world’s few known endemic porpoises, increasingly threatened with extinction.” Those sentences were written on behalf of Conservation International in a 1991 issue of Baja Explorer, with the endangered porpoise in question being the vaquita, the world’s smallest cetacean — …