Relocated sea turtle nests yield fewer, smaller hatchlings and skewed sex ratios

Researchers on Heron Island, off Queensland's southern Great Barrier Reef, monitored 48 green-turtle clutches over two nesting seasons to evaluate nest relocation. Eggs were either left in place, moved to a new site under shade cloth, or moved without shade. Unshaded relocated nests were warmer, leading to an estimated sex ratio of about 8% males during one season, while shaded nests achieved a more balanced ratio.

Despite temperature control, shaded relocated nests still showed lower hatching success, produced smaller hatchlings and reduced righting performance compared with natural nests. The study suggests that factors such as moisture levels, sand texture, gas exchange and nest depth may be disrupted by relocation. These results caution that rescuing nests from immediate threats may compromise hatchling quality, emphasizing the need for careful site selection as climate change intensifies pressures on nesting beaches.