Defining the ecological impacts of water extraction from free-flowing river systems in altered landscapes is challenging as multiple stressors (e.g., flow regime alteration, increased sedimentation) may have simultaneous effects and attributing causality is problematic. This multiple-stressor context has been acknowledged in environmental flows science, but is often neglected when it comes to examining flow-ecology relationships, and setting and implementing environmental flows. We examined the impacts of land and water use on rivers in the upper Ringarooma River catchment in Tasmania (south-east Australia), which contains intensively irrigated agriculture, to support implementation of a water management plan. Temporal and spatial and trends in river condition were assessed using benthic macroinvertebrates as bioindicators. Relationships between macroinvertebrate community structure and environmental variables were examined using univariate and multivariate analyses, focusing on the impacts of agricultural land use and water use. Structural changes in macroinvertebrate communities in rivers in the catchment indicated temporal and spatial declines in the ecological condition of some stretches of river associated with agricultural land and water use. Moreover, water extraction appeared to exacerbate impairment associated with agricultural land use (e.g., reduced macroinvertebrate density, more flow-avoiding taxa). The findings of our catchment-specific bioassessments will underpin decision-making during the implementation of the Ringarooma water management plan, and highlight the need to consider compounding impacts of land and water use in environmental flows and water planning in agricultural landscapes.

Item Type:	Refereed Article
Keywords:	water use, land use, macroinvertebrates, multiple stressors, environmental flows, adaptive management
Research Division:	Environmental Sciences
Research Group:	Environmental management
Research Field:	Environmental assessment and monitoring
Objective Division:	Environmental Management
Objective Group:	Marine systems and management
Objective Field:	Assessment and management of benthic marine ecosystems
UTAS Author:	Hardie, SA (Dr Scott Hardie)
ID Code:	115556
Year Published:	2018 (online first 2017)
Web of Science® Times Cited:	4
Deposited By:	Zoology
Deposited On:	2017-03-30
Last Modified:	2018-05-08
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