The state of biodiversity for most of the world is largely unknowable due to a lack of long-term population monitoring data. Citizen science programs could substantially contribute to resolving this data crisis, but there are noted concerns on whether methods can overcome the biases and imprecision inherent to these programs. The authors of this study evaluated these concerns by comparing data collected as part of the REEF Volunteer Fish Survey Project, a long-term citizen science fish monitoring program for recreational divers and snorkelers, with data collected as part of fishery-independent survey coordinated by scientists from National Oceanic and Atmospheric Administration (NOAA). Both datasets were conducted over the same time period at the 60 sites off Key Largo, Florida (US), from 1993 to 2018, and both sampled populations of similar coral-reef fishes (n = 87 species). The majority of species exhibited similar trends over the 25-year time span in both population time-series datasets, but there was variation between the two datasets among certain taxonomic and trait-based groups. Overall, these results suggest that citizen scientists can be effective sentinels of ecological change, and that there may be substantial value in leveraging their observations to monitor otherwise data-limited marine species.
Appendix and Supplementary Materials available online here.
