From the hunting guide:

Hunting from a Vehicle or Boat

Mammals and birds may not be taken or chased from, by the use of, or with the aid of any motor-driven conveyance (including boats), except:

1. By an individual authorized to hunt from a stationary vehicle with a Persons with Disabilities Hunting Permit.
2. To check traps that are lawfully set and maintained.
3. To hunt waterfowl from a motorboat if the boat is beached, resting at anchor, tied to a stationary object, or otherwise without motion except as provided by wind, water current or hand-operated oars or paddles.

Even if you could, you would have to shoot it in the river or below the high water mark and hoped it dropped before it crossed the high water mark. Otherwise your at the property owner's mercy to grant permission to retrieve it.