Aboriginal peoples were a source of labour for various institutions and enterprises from the time of the first pilot station. Conflict with Europeans intensified during the middle part of the 19th century, leading to significant numbers of Aboriginal people being killed (including at the hands of the native police). Despite these conflicts other Aboriginal people were able to evade intense contact due to the lack of European activity on the bay islands. From the 1830s to 1865 there remained virtual exclusive Aboriginal possession of most of Quandamooka. However trade and social interaction with the mainland groups gradually diminished due to the outward march of pastoral settlement on the mainland. This resulted in irreparable damage to indigenous social networks and patterns of group intermarriage, as well as joint ceremonial activities.