Stress Response and Avoidance Behavior of Fishes as Influenced by High‐Frequency Strobe Lights

We examined the effects of strobe lights on plasma cortisol concentrations and avoidance behavior across a broad range of fish taxa. Representative fish taxa from five families were evaluated and included: Centrarchidae (largemouth bass Micropterus salmoides), Cyprinidae (fathead minnow Pimephales promelas), Ictaluridae (channel catfish Ictalurus punctatus), Percidae (yellow perch Perca flavescens), and Salmonidae (Chinook salmon Oncorhynchus tshawytscha). Mean (±SE) plasma cortisol concentrations for channel catfish (89 ± 22 ng/mL), yellow perch (81 ± 39 ng/mL), and Chinook salmon (173 ± 27 ng/mL) increased significantly compared with those in control groups (50 ± 11, 3.0 ± 1.9, and 102 ± 35 ng/mL, respectively) after 1 h of exposure to strobe lights. After 7 h of exposure, plasma cortisol levels were similar to those in control groups for all fish taxa. Fathead minnow showed no detectable response to strobe lights at either 1 or 7 h of exposure. Behavior experiments showed that the mean distanc...