Interesting, in the US there are several facilities that use Bluegills to detect water quality problems. https://www.army.mil/article/50369/bluegills_monitor_t

Interesting, in the US there are several facilities that use Bluegills to detect water quality problems. https://www.army.mil/article/50369/bluegills_monitor_treated_groundwater https://www.army.mil/article/50369/bluegills_monitor_treated... https://www.sfgate.com/news/article/Anti-terror-fish-guard-S-F-s-water-Bluegill-2553021.php https://www.sfgate.com/news/article/Anti-terror-fish-guard-S...