It's the safest place on the earth for all creatures (supposedly) - aren't they all on their own to fend for themselves?
A true scientific study would reach a conclusion: mosquitoes are beating the giant turtles 14-3.
In the Galapagos Islands mosquitoes have an equal opportunity at life as the giant turtles. If the turtles can't make it, tough beans!
That is until the turtles mutate. Then the mosquitoes won't stand a chance...