Status and Biology of American Eel in the Ouachita and White Rivers, Arkansas, USA

The American eel has experienced declines from historical population sizes in parts of their range, but limited data exist for rivers discharging into the Gulf of Mexico.  Our objectives were to describe demographics of American eels in rivers of the Ouachita River basin, and we documented migratory phenology of eels migrating from the White River into the Arkansas River Navigation System at Norrell Lock and Dam.  From June 2011 – 2013, we collected eels by boat and backpack electrofishing.  We collected 264 eels during the study, which doubles the total number of occurrences for the State of Arkansas.  Mean total length was 395 mm (236 - 940 mm).  Mean CPUE was 27 eels/hour with a range of 0 to 78.  In both the White and Ouachita rivers, eels collected in tailwaters were significantly smaller than eels collected from main channel sites, and the greatest CPUE was observed in tailwaters.  Potentially, small eels collected directly below dams were attempting upstream migration but were impeded by barriers.  American eels were only present below Norrell Dam within a defined temperature (18-27 °C) and discharge range (55,000-10,000 cfs), indicating upstream migration in the Arkansas River System may be coupled to these two environmental cues.