Nothing is known about Salyan before the apocalypse except that he is an officer in the Mexican Navy.
After the apocalypse began, it is assumed that Salyan was part of the navy flotilla that patrols the coastal waters of Baja California as part of a military blockade. The main aim of the flotilla seems to be to prevent infected ships (or those refugees who cannot pay) from making landfall on the coast of Baja California , Mexico.
At some point after Madison's Group make landfall in Baja, Salyan, alongside Tintos and several others take The Abigail. They became infected and The Abigail. Victor Strand puts Salyan and the others down.