Short-Term Impacts of Remeandering Restoration Efforts on Fish Community Structure in a Fourth-Order Stream

Abstract

Channel reconfiguration is a common but debated method used to restore streams, often causing disturbance and producing subsequent negative impacts on biota. Here, we report results from short-term assessment (i.e., one and three years' post-restoration) of habitat variables (e.g., reach depth, substrate, and canopy cover) and fish community composition and structure (using electrofishing surveys; e.g., proportion of juveniles and tolerant fishes) from a 675 m section of Eagle Creek (Portage County, OH, USA) restored using channel remeandering in August 2013. Mesohabitat analysis was not conducted as part of this study. Sites upstream and downstream of restoration efforts were also monitored. Surveys were completed in 10 separate 50 m stretches: one upstream control site, three new channel sites, two old channel sites, and three downstream sites. Following restoration, fish communities in downstream sites became more similar to new channel sites and diverged from the upstream control site over time, as reflected in increased proportions of juvenile and tolerant fishes. Shifts in fish communities were not explained by habitat variables. Diversity was significantly lower in new channel sites post-restoration than in the upstream control, while downstream sites remained similarly high in diversity compared to the upstream control site over time. Overall, in the short-term, new channel colonizing communities were unable to recover to reflect upstream community composition and structure, and fish communities downstream of restoration were negatively impacted.

Linking fish trait responses to in‐stream habitat in reconstructed valley‐plugged stream reaches of the Coastal Plain, U.S.A.

“…This treatment of temporally replicated data collection is not uncommon in evaluations of fish-habitat associations that employ ordination techniques (e.g. Li et al 2012) or those that evaluate fish response to stream restoration (Clark & Montemarano 2017).…”

Issues of Meander Development: Land Degradation or Ecological Value? The Example of the Sajó River, Hungary

“…Recent studies found 're-meandering' as an effective practice for the restoration of habitat diversification at shortand medium-terms [34], since lateral erosion and the channel migration maintain sediment supply for vegetation colonization [35]. However, long-term ecological consequences of re-meandering have not been well-studied yet [36]. Only a few studies found positive trends in diversification but many restoration projects were not able to demonstrate significant differences in biodiversity between the before and after periods of the restoration project over short (5 to 10 years) time periods [9,37,38].…”