A Comparison of Seining and Electrofishing for Fish Community Bioassessment in a Mexican Atlantic Slope Montane River

Tropical freshwater fish monitoring and conservation strategies depend on data from surveys made with a variety of sampling methodologies. These methodologies have inherent biases that can lead to different data interpretations. We compared two commonly used sampling techniques-seining and electrofishing-in the calculation of community parameters and ecosystem bioassessment in a montane river in the Gulf of Mexico drainage in the state of Veracruz, Mexico. We specifically evaluated whether seining was sufficient for fish community assessment. Electrofishing produced higher estimates of species richness (45%), diversity (similar to 30%), and biomass (similar to 80%) than seining. It also produced higher biotic integrity scores. Species' relative abundance was generally similar for species captured with both techniques, but seines failed at capturing fast-swimming and benthic species. Thus, seining alone offered an incomplete perspective on the fish community and may not be adequate for bioassessment. Our results and methodology can help in the design of future survey efforts and the creation of correction factors that can aid managers to better sample biological communities and apply adequate conservation strategies.