If you want to catch a turtle your line length needs to be below 350m, then it is like a fish and hooks up.
Dinosaur Island
To be able to get to this island you must first earn 90,000 points so you can buy the time machine to reach it. The quickest way to earn the 90,000 is to go to the 1,000m mark as ALL of the fish there have a greater currency or value.