A submersible device submersible within an algae slurry contained within a pond of an algae bioreactor, the submersible device including a drive motor operable to actuate one or more driven devices that move the submersible device within the pond, a circulation device operable to circulate the algae slurry through the submersible device and discharge the algae slurry back into the pond from a discharge port provided on the submersible device, and a computer system that controls operation of the drive motor and the circulation device.