Can Climate-Induced Changes in Freshwater Game Fish Abundance Be Inferred From Digital Catch Log Data?

The growing popularity of digital catch logs may present a low-cost opportunity to monitor climate change effects on the distribution and relative abundance of game fishes over large spatial scales. We analyzed data from a popular fishing app to identify spatiotemporal trends in freshwater game fish catches throughout the contiguous the United States during 2015–2021. Warm-water species became more common than cool-water species in many locations. Increases in relative abundance tended to occur in northern range boundaries or non-native ranges, and declines tended to occur at southern range boundaries. Although catch log data can be biased and results may reflect alternative phenomena operating or interacting at similarly large spatial scales (e.g., cultural eutrophication, changes in game fish popularity), climate change remains a viable explanation. Future research should further explore app data as a potential tool for monitoring game fish responses to climate change and other stressors over longer time frames and at multiple spatial scales.