Movement, home range, and structural habitat use of the Largemouth Bass complex in two large Texas reservoirs

Abstract

ObjectiveAngler complaints regarding perceived declines in angling quality prompted research to examine the home range, movement, water depth use, and structural habitat use and selection of the Largemouth Bass complex (LBC; Largemouth Bass Micropterus nigricans, Florida Bass M. salmoides, and Largemouth Bass × Florida Bass hybrids) in Toledo Bend and Lake Fork reservoirs, Texas.MethodsA total of 21 LBC individuals at Toledo Bend Reservoir (386–604 mm total length [TL]) and 22 LBC fish at Lake Fork Reservoir (364–545 mm TL) were implanted with radio transmitters and tracked over a 2‐year period.ResultAt both reservoirs, LBC home range areas were small (<50 ha) and overall movement was low (~40–100 m/week). Fish primarily occupied water column depths of less than 2 m in both reservoirs and were found in the shallowest depths during the spring. Although overall structural habitat occurrence and selection of LBC fish varied between reservoirs, primarily due to differences at shorelines and creeks (two times higher in Toledo Bend Reservoir) and drops (three times higher in Lake Fork Reservoir), fish selected for the shoreline, drops, points, and creeks in both reservoirs, while drains and flats reflected avoidance. Seasonally, habitat occurrence of LBC fish varied at Toledo Bend Reservoir, primarily due to differences in shoreline use, and flats had the highest fish occurrences during all seasons. At Lake Fork Reservoir, LBC occurrences at flats and drops were high and similar during all seasons.ConclusionOur estimates of small LBC home ranges and low movement in these large reservoirs were generally similar to those reported in previous studies, regardless of reservoir size. Fish preferred structural habitat types with abrupt slopes, were primarily located offshore, and occupied water column depths that are commonly targeted by LBC anglers.