US Geological Survey


Date of this Version



Fisheries Research 201 (2018) 38–43


© 2018 Elsevier B.V. All rights reserved.

This document is a U.S. government work and is not subject to copyright in the United States.


Catch-and-release regulations are among the most common types of fishing regulations. In recent years, concerns have arisen regarding the exposure of fish to air during catch-and-release angling. The purpose of our study was to quantify the length of time angled fish were exposed to air by anglers in a typical catch-and-release fishery and relate it to the lengths of time reported to produce negative effects. In total, 312 individual anglers were observed on the South Fork Snake River, Idaho, from May through August 2016. Fight time varied from 1.1 s to 230.0 s, and average fight time was 40.0 s (SD=36.8). Total air exposure times varied from 0.0 s to 91.8 s and averaged 19.3 s (SD=15.0). Though not statistically significant, a trend in reduced fight times was observed when anglers were guided and increased air exposure times when a net was used and a picture was taken. Results of the current study suggest that anglers expose fish to air for periods that are much less than those reported to cause mortality.