We observed diel patterns in CPUE, size and age-structure for freshwater drum (Aplodinotus grunniens) from Alabama waters during May–July 2003 . Drum were significantly more susceptible to capture along shoreline habitat at night. CPUE of freshwater drum was often zero during the day and increased up to 84.5 fish * h−1 at night suggesting that many drum shift location to nearshore habitat after dark. Drum captured at night were also significantly smaller and younger that drum captured during the day. Age-0 drum were the most abundant age-class in nighttime samples whereas age-8 drum were the most abundant age-class in daytime samples. The dynamic interplay between food availability and predation on juvenile fish likely drives diel habitat shifts of freshwater drum.
Vol. 157 • No. 1