Sea turtles are among the world's most vulnerable marine animals, with all seven species classified as vulnerable to critically endangered. The nesting period — when females come ashore to lay eggs — creates unique welfare considerations as these air-breathing reptiles transition between marine and terrestrial environments.
Female sea turtles return to their natal beaches every 2-5 years to nest, a journey of potentially thousands of kilometers. Each nesting season, females may lay 3-7 nests at 2-week intervals. The nesting process — emerging from the surf, selecting a site, excavating a nest chamber, depositing eggs, and returning to the sea — takes 1-3 hours during which the female is highly vulnerable. Disorientation, harassment, artificial lighting, obstacles, and vehicle strikes during this period cause welfare harm to individuals.
Coastal development lighting is one of the most significant nesting welfare threats. Female turtles avoid brightly lit beaches for nesting, driving them toward high-energy surf zones or causing them to abandon nesting attempts entirely. Hatchlings emerging from nests normally orient toward the brightest horizon — the sea — but artificial lights disorienting hatchlings inland cause exhaustion, dehydration, and predation. Sea turtle-friendly lighting (long-wavelength amber LEDs directed downward, avoiding the beach) eliminates disorientation without impacting human use.
Sunbeds, beach furniture, and vehicles left on beaches overnight create physical obstacles for nesting females returning to the sea and for hatchlings emerging from nests. Individual turtles become entangled, trapped, or exhausted attempting to navigate obstacles. Beach furniture removal at sunset — required in sea turtle nesting areas in many countries — prevents these individual welfare incidents.
Nest protection programs — identifying, marking, and monitoring nests through the incubation period — protect eggs from predation, erosion, and human disturbance while generating data for population monitoring. Welfare-positive programs minimize disturbance during marking and monitoring, avoid relocating nests unnecessarily (relocation changes thermal environments and hatching success), and provide hatchery conditions that maximize temperature-dependent sex determination diversity.
Sea turtles frequently become entangled in fishing gear — longlines, gillnets, and trawls — and drown or are injured. Entanglement is painful and distressing; drowning in non-air-breathing fish may take minutes, but air-breathing sea turtles can remain conscious for extended periods while entangled. Turtle excluder devices (TEDs) in trawl nets, circle hooks in longlines reducing ingestion, and modified net designs substantially reduce bycatch mortality and its associated welfare costs.