Summer Habitat Selection of Largemouth Bass with a Focus on Dissolved Oxygen

Factors influencing movements and habitat selection of fishes are often poorly understood and require consideration of abiotic, biotic and physical habitat characteristics. We used a full lake three-dimensional acoustic telemetry array to track largemouth bass movements throughout a Central Illinois lake while concurrently measuring habitat variables. Fish positions and habitat characteristics were determined for the fall through summer seasons. Variables measured included depth, distance from shore, temperature, dissolved oxygen, substrate, vegetation coverage, course woody habitat and prey density. Using GIS technology, collected measurements were placed into data layers displaying spatial and temporal changes in habitat characteristics and compared with fish positions. Home ranges and habitat preferences were examined in response to changing inter- and intra-seasonal habitat variables. Inter-seasonal movements were strongly influenced by abiotic and physical habitat characteristics while intra-seasonal fine-scale movements were more strongly influenced by changes in abiotic and biotic variables. Through our exploration of fish movements in response to available abiotic, biotic and physical habitat characteristics, we are able to present a thorough examination of factors influencing largemouth bass habitat selection.