Recovery Of Visual Function In Pacific Halibut (Hippoglossus Stenolepis) After Exposure To Bright Light

Commercial fishing exposes Pacific halibut (Hippoglossus stenolepis) to a myriad of stressors during capture, processing, and discarding, including exposure to direct sunlight that causes diminished retinal sensitivity. It is unknown, however, whether recovery occurs. We therefore employed both electroretinography and a behavioral assay to measure recovery of retinal sensitivity and visual function in halibut exposed to 15 min of simulated sunlight. We used electroretinography to measure changes in retinal light sensitivity after recovery periods of 2, 4, 6 and 10 weeks and a behavioral assay to measure responsiveness to simulated prey (i.e., in behavioral trials) to measure visual function after recovery periods of 2 to 6 d. Exposure to simulated sunlight significantly reduced retinal sensitivity to light with no apparent recovery after 10 weeks. Although retinal sensitivity was reduced, fish exposed to direct sunlight displayed no demonstrable deficits in visual function during behavioral trials.