Despite its importance to anglers, the Arkansas River spotted bass (Micropterus punctulatus) fishery has not been intensively studied or managed. Thus, spotted bass populations in the lower nine navigation pools of the Arkansas River were assessed during 2004-2005 using nighttime boatmounted electrofishing. Across years and pools, size structure measures were within acceptable ranges for black basses (mean PSDQ = 38, range 21-56; mean PSDP = 10, range 0-19). Theoretical maximum sizes generated from growth models were not large for spotted bass (mean L∞ = 395 mm TL, range 351-429 mm total length), though populations exhibited good condition and growth. Total annual mortality estimated from catch curves averaged 49% and ranged from 43%-57% across pools. Although population metrics exhibited few longitudinal relationships within the Arkansas River, spotted bass populations compared favorably to other populations from similar impounded river systems. Spotted bass populations exhibited significant relationships with macrohabitats in the river. Spotted bass catch-per-unit-effort was directly correlated to long-term areal and proportional increases in main channel and dike pool habitats, whereas condition was inversely correlated to area of diked secondary channel habitat. In light of the documented long-term (1973-1999) macrohabitat changes, results suggested that main channel and associated habitats may be important for the continued health of spotted bass populations in the Arkansas River.
