Delayed Hooking Mortality of Blue Catfish Caught on Juglines

Abstract

AbstractGrowing interest in catfish angling, particularly for trophy‐sized fish, has resulted in new regulations that limit the harvest of large Blue Catfish Ictalurus furcatus in several states. For these regulations to be effective, released fish must survive to further contribute to the fishery, either through reproduction or subsequent recapture. We investigated the effect of capture depth, hook type, water temperature, and fish size on the delayed hooking mortality of Blue Catfish caught on juglines. Blue Catfish (N = 559) were caught from three Oklahoma reservoirs with either 5/0 circle hooks or J‐hooks fished for 24‐h sets. One experimental fish (captured via jugline) and one control fish (captured via low‐frequency electrofishing) were then placed in field enclosures (N = 25) and monitored for mortality after 72 h. Mean mortality was low at 8.50% (range, 0.00–37.50%; SE, 1.81%). Mortality decreased significantly with decreasing water temperatures (P < 0.01; odds ratio 1.1). Mortality was highest (mean = 25.31%) at water temperatures >20°C and decreased to 3.89% in water temperatures <20°C. We observed 0% mortality in water temperatures <14°C. Hook type did not significantly affect mortality, nor did the depth in the water column where the fish was hooked. For every 100‐mm increase in total length, fish were six times less likely to die (odds ratio 0.17). Mean mortality for preferred‐size fish was low at 2.50%, and no mortalities were observed for memorable or trophy‐size fish. These results suggest that length regulations limiting the harvest of preferred‐size or larger fish should be effective as a large proportion of released fish should survive to further contribute to the fishery.Received July 23, 2012; accepted November 28, 2012