CHARACTERIZATION OF FLOODPLAIN LAKE FISH COMMUNITIES IN THE LOWER WHITE RIVER, 
ARKANSAS 

Benjamin J. Lubinski1, John R. Jackson2 and Michael A. Eggleton3
1 Present address:  Illinois Natural History Survey, Great Rivers Field Station, 
8450 Montclair Ave., Brighton, IL 62012. 2 Present address:  Arkansas Tech 
University, Department of Biological Sciences, McEver 4, Russellville, AR  7280.  
3 Present address:  University of Arkansas at Pine Bluff, Aquaculture and 
Fisheries Center Pine Bluff, Arkansas  71601  USA

The lower White River, Arkansas represents one of the least altered river-
floodplain ecosystems (RFE) in the United States.  The lower White River 
floodplain encompasses approximately 65,000 ha of bottomland hardwood forest 
that contains over 300 lakes scattered throughout public and private lands.  
River regulation, including irrigation and navigation channel projects, 
threatens to alter the natural hydrology of the lower White River RFE.  The 
objective of this research was to examine relationships between fish communities 
and environmental variables associated with river/lake morphology and flooding 
regimes in lower White River floodplain lakes.  Fish communities were sampled by 
experimental gill nets, mini-fyke nets, and night time electrofishing during the 
summer and fall 2002.  Multivariate direct gradient analyses suggested that lake 
depth, water clarity, dissolved oxygen and, to a lesser extent, degree of 
flooding (reflecting connectivity of floodplain lake and the main river channel) 
were most important in the structuring of lake fish communities.  Fish species 
richness was positively correlated with degree of flooding, whereas evenness 
exhibited a significant positive relationship with dissolved oxygen and 
significant negative relationships with water temperature and conductivity.  
Species diversity exhibited a significant positive relationship with linear 
distance to the main channel.  Conversely, species diversity had significant 
negative relationships with water temperature and total dissolved solids (TDS).  
Assessment of empirical fish community-environment relationships prior to 
alteration of the lower White River should help guide river management and 
species conservation efforts by identifying environmental factors that affect 
fish community composition.  This project also aids in defining baseline 
ecological conditions for temperate-zone RFEs.

Keywords: floodplain lake, fish, diversity, gradient analysis, physical 
variables, White River