Donald R. Harrison

Blue catfish (Ictalurus furcatus) were first detected in the Altamaha River, Georgia, during an access creel survey in 2005 and subsequently in 2006 during annual ictalurid sampling. Introduction of this species in the Altamaha River is believed to have occurred via escape from normal upstream reservoir releases from Lake Sinclair and Lake Oconee. Relative abundance, as indexed by electrofishing catch rate (fish per hour), has increased from 2.9 ± 1.0 SE in 2006 to 38.8 ± 8.2 SE in 2011. The size of blue catfish captured ranged from 56 to 820 mm total length and 0.001 to 7.7 kg. Using...

This study examined factors which can affect the quality of fluorescent oxytetracycline (OTC) marks on walleye (Stizostedion vitreum) otoliths. A 1 -time exposure to a strong ultraviolet (UV) light source, such as is done when viewing under a UV microscope, significantly decreased mean OTC mark qualities from an initial value of 2.8 (3.0 is maximum and 0.0 is no mark) to <1.0 3 months following the initial examination. Mark intensity continued to decrease over time (<0.5 after 6 months, 0.3 after 12 months). Otoliths that were stored in an unlit environment consistently had higher...