Southern Resident Orca share many characteristics and cultural traditions as the members of the Northern Resident community. Strong family bonds govern this endangered population and the bonds between members of related families remain stable over the course of their lifespans and are held together through generations by a matriarchal structure. Despite their similarities and a partial range overlap, Southern Residents and Northern Residents are not known to associate and maintain genetic and acoustic separation.

The population size of the Southern Resident community has been closely monitored and tracked through dedicated photo-identification surveys beginning in 1976. While the exact historic population size for Southern Residents is not known, intensive capture efforts for marine parks in the 1960s and early 1970s caused a severe reduction in the population size through the removal of at least 47 individuals. As of December 31st 2021 the population of Southern Residents was determined to be 73 individuals — this small population size combined with high food stress, ocean noise, and marine contaminants all contribute to the “Endangered” population status assigned by both Canadian and American governments.

All Southern Residents belong to the same acoustic clan (J-Clan) and share a variety of call types. Within this clan are three distinct pods — J, K, and L — with unique dialects. The data collected from our remote hydrophone sites located within the Salish Sea will be extremely valuable to detect the presence of Southern Residents in addition to tracking the noise levels this community must endure while trying to find enough salmon to survive.