Port Alberni is a city located in the province of British Columbia in Canada. It is the location of the head offices of the Alberni-Clayoquot Regional District. The city has a total population of 17,743, and the census agglomeration area a total of 25,396.Port Alberni lies within the Alberni Valley at the head of the Alberni Inlet, Vancouver Island's longest inlet. Recently the salmon population has decreased significantly in Port Alberni and other areas of British Columbia.Port Alberni is the sister-city to Abashiri in northern Japan.