ABSTRACT
Populations of both species require free flowing rivers to complete their lifecycle, although a few exceptions may exist where populations are sustained in reservoirs (Kolar et al, 2007). Adult spawning and production of their semi-buoyant eggs and larvae appear to be initiated in part by rising water (Schrank et al, 2001; Chapman, 2006; DeGrandchamp et al, 2007). Larval Asian carp drift for several days in the swiftly flowing main channel and then settle into shallow slackwater areas such as river backwaters, side channels and island sloughs (Kolar et al, 2007; Lohmeyer and Garvey, 2009). Adults of both species use habitat similarly, preferring areas with slow velocities such as the borders of rivers behind natural and humanmade structures, secondary channels and tributary mouths (Peters et al, 2006; Kolar et al, 2007; DeGrandchamp et al, 2008). Distance moved by adults increases with increasing flow velocity, reaching a maximum of 30km per week (DeGrandchamp et al, 2008). This ability to freely and rapidly move throughout rivers allows them to disperse and establish in novel areas.
