An experiment has shown green sea turtle embryos are much more likely to die when they are inside eggs that go underwater for six hours.

Scientists say the study shows the turtles, which rely on low-lying coastal habitats, are likely to feel the early impacts of rising sea levels.

"In some places it only takes a small rise in sea levels, when combined with a storm or a king tide, to inundate what had previously been secure nesting sites," said lead researcher Dr David Pike of James Cook University.