Developing a multimetric index to assess resaca ecosystem health

As the only freshwater ecosystem in the lower Rio Grande Valley aside from the Rio itself, resacas are critical habitat for many species of flora and fauna. Old distributaries of the Rio Grande, resacas provided conveyance routes moving floodwater to the Laguna Madre. Today these wetlands are novel ecosystems and are artificially maintained. Urbanization and agriculture have lead to sedimentation, habitat loss, contaminants, poor water quality, and invasive species. The objective of this study was to assess and monitor resaca pools and to compose the Resaca Health Index (RHI) from selected indicators of ecosystem structure and function including leaf litter decomposition rates, a riparian habitat assessment index, the trophic state index, and a fish community index. Overall, the RHI adequately discriminated among resacas in various ecosystem statuses, and can be a valuable management tool allowing for more accurate assessment and monitoring of ecosystem health in urban and suburban resacas