Delayed Hooking Mortality of Blue Catfish Ictalurus Furcatus Caught on Juglines in Oklahoma Reserviors

Abstract

Growth of blue catfish in Oklahoma reservoirs is typically slow, with only a small percentage of fish reaching preferred size (762 mm). To prevent over harvest of larger fish, the Oklahoma Department of Wildlife Conservation recently implemented a law restricting harvest to one fish per person, per day for preferred-size or larger fish. For this regulation to be effective, released fish must survive to further contribute to the population, but little is known concerning the delayed hooking mortality of blue catfish. We investigated the delayed hooking mortality for blue catfish caught on juglines. Blue catfish (N=559) were caught seasonally from three reservoirs on 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 pulsed-DC electrofishing) were then placed in field enclosures and monitored for mortality after 72 h. Mean mortality was low at 8.5%. Mortality increased with water temperature, and, for every 1C increase in temperature, the fish were 1.1 times more likely to die (odds ratio = 1.1). At temperatures of less than 15 C, mortality decreases to 1.6%. Hook type did not significantly affect mortality, nor did the depth in the water column where the fish was hooked. The odds of dying were 6 times lower for every 100-mm increase in the total length of the fish. Mean mortality for preferred-size fish was negligible at 2.5%; no mortalities were observed memorable and trophy-size fish. These results suggest that the new regulation limiting the harvest of preferred-size fish should be effective, even when fish are harvested with 24-h jug fishing sets.