Hey Justine.
You have a better chance of winning the lottery or hit by some flying object from mars than getting attacked by a shark in Aruba. Althoug anything is possible. Unless you swim miles and miles out in the middle of the ocean I wouldn't too much be worry about it. We have been to Aruba twice and stayed for a month each time and did not see or hear of any sharks. So just enjoy your time and leave the sharks on National Geographic.