A comparison of participatory science seining and electrofishing for sampling fish assemblages in an urban river

Abstract Participatory science has increased the scope of ecological data collection and monitoring. Despite growing popularity, participatory science methods are rarely validated. Validation is important to ensure high quality data can be used in scientific studies, monitoring and management. The Rouge River (Michigan, USA), an Environmental Protection Agency Area of Concern, is considered a highly degraded river but has benefited from numerous restoration projects. These projects have improved abiotic conditions in the river, but improvements to the fish assemblages have not been assessed. Friends of the Rouge, a non‐profit, has collected fish assemblage data throughout the river network for 10 years by seining, a sampling method they selected due to low cost, safety and fit to the organization's volunteer‐based monitoring program. We compared seining conducted through the participatory science program to the electrofishing method recommended for standardized assessments of wadeable streams performed by fisheries professionals. We analysed data from 45 sites across the Rouge River watershed where both sampling methods were implemented. We examined: (a) the species captured, (b) the relationship between species richness and effort, (c) diversity metrics used for standardized evaluation and (d) assemblage similarity between methods across the watershed. Our results show that in the wadeable reaches of this urban river, electrofishing and seining were comparable. The majority of species captured within the reaches were shared across sampling methods although community similarity was lowest and highest in small branches. Differences in the species captured are mostly driven by rare and benthic species. Species accumulation curves were not significantly different at the watershed or subwatershed scale. Total species richness, the richness of species tolerant and intolerant to environmental degradation and Procedure 51 scores used by Michigan agencies to assess the status of fish assemblages sometimes differed between branches, but neither method was more effective overall at capturing fish diversity. Practical Implications . Participatory science methods can be validated by comparison with standard methods. Validating participatory science data enhances utility for monitoring, assessment, and management decisions.