Air Exposure Times for Trout Caught and Released By Anglers in Lentic and Lotic Waters

Air exposure is often emphasized as a significant stressor and sometimes a lethal consequence of anglers catching and releasing fish. However, to our knowledge no studies have reported the amount of time anglers - unaware that they are being monitored - hold fish out of the water when recreationally fishing. We surreptitiously observed 280 trout anglers on several lotic and lentic waters where catch-and–release angling was commonly practiced. We timed the longest interval and the total amount of time that trout were exposed to the air, and noted the type of gear (fly, lure, or bait), fishing mode (boat or other), landing method (hand or net), relative fish size, and a qualitative measure of their ostentation. All of these factors influenced air exposure, however, 96% of the anglers held fish out of the water for <60s (mean = 25.8s). Although excessive air exposure likely causes physiological harm to fish, our study suggests that the time fish are generally held out of the water by trout anglers in Idaho would not pose a risk to the fish they catch.