However, I can give you some possible reasons for why sea turtles lay their eggs on land instead of in the ocean. To begin, I must tell you about how turtles evolved. Turtles have lived on earth for a long time. The first turtle fossils found date back to Triassic period, the age of the dinosaurs, some 200 million years ago. Therefore turtles were first land animals, and some species, like sea turtles, went back to living aquatic environments.
All turtles lay eggs, none produce live young.
Turtle eggs are similar to bird eggs, in that the eggs have a hard shell. Since turtles evolved on land and then some moved to the ocean, their eggs are originally terrestrial. It would be difficult to evolve a new egg that can withstand harsh aquatic environments. You may wish to contact conservation organizations or researchers that specialize in Sea Turtles. There are links to a few organizations on OceanLink's page of links.