When they are picked up still as eggs off the beach by locals, they are brought to the turtle hatchery where they are cared for until they hatch.
Then, when the are merely a day or two old they are released back into the sea where they will have a greater chance of survival than they would have had if the eggs remained on the beach.
The reason they are released at night is so the birds etc wouldn't see them as clearly, but still they have only 1 in a 100 chance of survival!