Comparison of sampling methods for small oxbow wetland fish communities

Abstract

Throughout the world, wetlands have experienced degradation and declines in areal coverage. Fortunately, recognition of the value of wetlands has generated interest in preserving and restoring them. Post-restoration monitoring is necessary to analyze success or failure, thereby informing subsequent management decisions. Restoration of oxbow wetlands has become the focus of targeted restoration efforts to promote recovery of biodiversity and sensitive species, and to enhance ecosystem services. The fish communities of oxbows have been the subject of many monitoring studies. However, an optimal method for monitoring the fish communities of oxbows has not been described, thereby limiting our capacity to effectively manage these ecosystems. We compared four sampling methodologies (backpack electrofishing, fyke netting, minnow trapping, and seining) for fish community data collection with a primary objective of determining an optimal method for sampling fish communities in small oxbow wetlands. Seining and fyke netting were determined to be optimal methods for sampling oxbow fish communities. Backpack electrofishing and minnow trapping produced lower total catch and taxonomic richness values than seining and fyke netting. Although seining and fyke netting produced similar taxonomic diversity and abundance values, qualitative analysis revealed that seining caused greater habitat disturbance and potential stress to fish. Therefore, consideration must be given to how species present (especially sensitive species) within the wetland could be impacted by sampling disturbance when choosing between seining and fyke netting.