Biology, Spawning, and Movements of Cycleptus meridionalis in the Lower Alabama River, Alabama

The goals of this study were to describe the biology, spawning season, and movements of Cycleptus meridionalis (Southeastern Blue Sucker) in the lower Alabama River, and evaluate possible spawning-site fidelity to Millers Ferry Lock and Dam. We also present fisheries, river discharge, and lock-use data in support of our recommendation to implement fish-passage operations at Claiborne and Millers Ferry locks and dams. We collected a total of 1094 Southeastern Blue Suckers-704 males, 355 females, and 35 sex-undetermined individuals-below Millers Ferry and Claiborne locks and dams from 1995 to 2005. Females were significantly longer and heavier per given total length than males. Spawning season lasted from March through April. Peak spawning occurred in mid-March when the water temperature was 15-20 degrees C. Age estimates ranged from 4 to 34 years for males and females. We recaptured 20% (206) of 1049 anchor-tagged fish multiple times (range = 1-10) at intervals between captures of 1-3618 d, and recaptures occurred 1-99 km downstream after release. We detected 75% (111) of 149 sonic-tagged fish 1-19 times at intervals between detections of 1-1288 d at distances of 4-250 km downstream after release. Spawning-site fidelity was confirmed by the recapture of 57 anchor-tagged fish and the detection of 15 sonic-tagged fish in or near Millers Ferry tailwater. Daily fish-passage operations completed at Claiborne and Millers Ferry locks and dams from January through April should increase upstream fish-migration success into the upper Alabama and Cahaba rivers without adversely affecting navigation, hydroelectric generation schedules, and industrial water needs along the river.