Although the three papers that comprise this thesis analyze distinct problems they are all rooted in the study of human ecology. To that end they are based on the same data set and share the same goals. Participatory research methods involving semi-structured interviews with twenty community experts, seasonal rounds and human ecological mapping are employed to analyze the subsistence livelihoods of the Koykon Athapaskan people of Ruby Village as a manifestation of human ecological relations. Chapter 1 examines the contribution of indigenous knowledge to understandings of hydrologic change in the Yukon River and its tributaries including observations of alterations in sediment and river ice regimes. Chapter 2 considers the ethical dimensions of adaptation and vulnerability to climate change in indigenous communities who are situated within a political context influenced by a history of colonization. Chapter 3 seeks to develop a concept of water sovereignty that addresses the complex socio-cultural and ecological relations between indigenous peoples and water. The integrated perspective provided by this thesis illustrates the connections between indigenous knowledge, subsistence livelihoods, socio-cultural and ecological relations to water and the assertion of sovereignty in the face of global change.