Delayed Hooking Mortality of Blue Catfish Caught on Juglines

Growth of blue catfish in Oklahoma reservoirs is very slow, with only a small percentage of the population ever reaching preferred size (762 mm TL). To prevent overharvest of rare larger fish, the Oklahoma Department of Wildlife Conservation recently implemented a regulation restricting harvest of fish over 762 mm to one fish per day. For this regulation to be effective, released fish must survive to be caught again. However, little is known about the delayed hooking mortality of blue catfish, so it is not clear if this is likely to occur. In this study we investigated the delayed hooking mortality for blue catfish caught on juglines. Blue catfish were caught seasonally from three different Oklahoma Reservoirs on either 5/0 Circle hooks or 5/0 J hooks baited with cut gizzard shad. Control fish were caught via pulsed DC electrofishing. One experimental fish and one control fish were then placed in field enclosures and monitored for mortality after 72 hrs. Overall mortality was low at 10.27 %. Mortality was significantly related to temperature (p= 0.014) with the greatest mortality during the summer (14.86%) and the lowest during the winter (near 0%). Fish size was also significantly related to mortality (odds ratio 0.40 for every 100-mm increase in length), with larger fish having a lower probability of mortality (< 5% mortality for fish greater than 700 mm TL). Hook type and depth in the water column did not significantly affect mortality.