Flatback turtles

Flatback turtles face numerous threats throughout their nesting range, including plastic and other pollution, artificial lighting, beach development and modification, predators, sea-level rise, and rising ocean and beach temperatures. These threats can affect nesting success in different ways depending on the location. For example, artificial lights from coastal development can disorient hatchlings and draw them away from the ocean, while predators such as feral pigs, dogs, foxes, and monitor lizards may dig up nests and consume eggs. Increasing sand temperatures can also influence hatchling survival and sex ratios, while sea-level rise and stronger storms can flood or erode nesting beaches, reducing the availability of suitable nesting habitat.

Marine debris

Marine debris, like plastic bags, fishing lines, ghost nets, bottles, and other human-made trash, can enter coastal and ocean habitats. Flatback turtles are especially threatened by marine debris because they spend their entire lives in shallow and coastal and continental shelf waters, where their feeding and nesting areas are contaminated by trash. Flatbacks can ingest plastics and become entangled in fishing gear, and beach debris can block nesting females or hatchlings.

Altered onshore and nearshore light conditions

Artificial lighting from coastal buildings, roads, ports, ships, and other industrial sites can disrupt the natural darkness of flatback nesting beaches and nearby waters. Flatback hatchlings rely on natural light cues to move from nest to ocean, but artificial lights can draw them inland or cause them to linger nearshore, increasing the risk of exhaustion and predation. Lighting also discourages adult females from nesting in an otherwise suitable area.

Beach modifications

Human activities such as coastal construction, dredging, beach nourishment, seawalls, vehicle use, and changes to dune vegetation can destroy nesting habitat. Because flatback turtles nest only on Australian beaches, damage or alteration of nesting sites can negatively affect the entire species. Modified beaches can reduce suitable nesting spaces, make nests more vulnerable to flooding or erosion, and create barriers for hatchlings as they make their way to the ocean.

Non-native predators

Animals such as feral pigs, foxes, cats, dogs, and rats are introduced, non-native species that prey on turtle eggs and hatchlings. Flatback nests are especially vulnerable due to non-native predators that dig up eggs on remote nesting beaches, significantly reducing hatchling success. Flatback rookeries (designated, highly concentrated nesting grounds for females and hatchlings) rely on predator control as an important conservation effort.

Sea-level rise

Erosion, flooding, and saltwater overwash are exacerbated by sea-level rise, which severely threatens flatback turtle nesting beaches. Because of their specific nesting area along northern Australia and nearby islands, the protection of suitable nesting beach habitat is crucial for the survival of flatbacks. Low-lying rookeries are especially at risk when beaches cannot naturally shift inland.

Increasing beach and ocean temperatures

Warmer beach temperatures affect flatback eggs because incubation temperature influences hatchling survival and sex ratios. Extremely hot sand can lower hatchling success or produce mostly female hatchlings, which may affect future population balance. Warmer ocean temperatures may also change flatbacks’ shallow-water foraging habitats and the availability of prey such as benthic invertebrates.