The Battle of King Salmon - part two

The wild salmon run in Alaska is the biggest of its kind.

Each year over 50 million fish leave the Pacific Ocean and fight their way up to the headwaters of mighty river systems where they mate, spawn and die.

The young salmon make their way out to sea again and, year after year, as the fish swim back to their birthplace, fishermen are there waiting for them.

For this two-part documentary, the BBC’s Nick Rankin reports from Alaska during the wild salmon run and joins commercial and subsistence fishermen who live off this natural resource.