Please find below the solution for: They must find a way to stop that shark.. This is level 13 of the Smith and Joe - Part 1 adventure. If something is wrong or missing please let us know and we will be more than happy to help you out.
Answer:
LURE THE SHARK WITH THAT FISH. GIVE IT TO JOE OR SMITH. TRY TO MAKE THE SHARK DIZZY BY RAPIDLY CHANGING ITS TARGET.