Fish utilization and diversity associated with created wetlands within the lower White River watershed, Arkansas

Wetlands are valuable resources that have been exploited through the years for various purposes, mainly for agriculture or timber production. Programs such as the Wetlands Reserve Program (WRP) exist today to restore former wetlands as closely as possible to their historic state. Evaluations of fish community responses to WRP-created/restored wetlands are scarce. Thus, this study examines fish communities of WRP-created/restored wetlands (herein referred to as WRP-wetlands) and compares them to relatively undisturbed reference wetlands. Research was conducted in the lower White River watershed in east-central Arkansas, USA. Fish communities of pool and ditch habitats found on WRP-wetlands of various ages were sampled using mini-modified fyke nets and experimental-mesh gill nets from March through June 2003. Water quality variables and habitat characteristics were measured concurrently at each site. Water quality variables were used in a multivariate direct gradient analysis (canonical correspondence analyses [CCA]) to examine patterns in fish community composition relative to environmental gradients among wetlands, focusing on gradients related to wetland age and habitat type. Fish community diversity, species richness, and evenness also were measured and analyzed using repeated-measures analysis of variance (RMA), with habitat characteristics and water quality variables analyzed using single-factor ANOVA (SFA). A total of 8,988 fishes were collected during wetland sampling, comprising 49 species. RMA suggested that WRP wetlands, as young as 1 year old, were capable of supporting fish communities with levels of diversity and richness comparable to that of reference wetlands, which have existed historically and were considered permanent. CCA generally indicated that species composition of fish communities differed among different-aged wetlands. Analyses suggested that wetland fish community composition exhibited a possible successional trend, wherein generalist-type species were replaced by specialist-type species as wetlands aged, though this result was restricted to pool habitats only. Conversely, fish communities in ditch habitats remained relatively unchanged despite differences in wetland age. Results suggested that fish communities in pool habitats of created wetlands rapidly became rich and diverse, but that fish species composition changed slowly through time. Similarly, ditch habitats also populated rapidly through time, though fish species composition remained relatively stable through time. Overall, results suggested that WRP wetlands can create habitats and environmental conditions that mimic natural wetlands. Furthermore, in terms of fish community richness and diversity, WRP-wetlands can attain levels observed in reference wetlands in a relatively short amount of time. However, additional studies of similar scope are needed to validate current findings and better define benchmarks and expectations of future WRP projects.