Southern Great Plains River Ecology: A Story of Anthropogenic Ecological Change

The unique climate and rivers of the Southern Great Plains of the United States have shaped both ecological and human communities. Historically, the rivers of this region supported a wide variety of endemic species evolutionarily adapted to the particularly harsh environment, characterized by flow variability, periodic flooding and drying, and overall complexity. In this review, we provide an extensive overview of the many perils that the rivers of the Southern Great Plains are now facing due to the anthropogenic changes centered on river dam construction, high agricultural water demand, and groundwater depletion. These factors have fundamentally reshaped the flow regime of the Southern Great Plains rivers, resulting in a decline of native fish assemblages and increases in invasive species as a consequence of modified sediment transport, decrease in microhabitat diversity, changes in channel morphology, and an increase in habitat fragmentation. The case that we describe in the present article represents a prototypical example of the ecological consequences of human-induced alterations of river ecosystems. Here, we present this case as an example of damming-induced alteration of the riverine ecosystem, and we propose possible conservation measures to restore the original riverine environment and protect the currently threatened native fish diversity.