Sensor disguised as a sea turtle egg allows conservationists to remotely predict nest breeding season

A new low-cost sensor, resembling a sea turtle egg, allows scientists to monitor nests remotely and predict almost to the day when the hatchlings will emerge, providing valuable information for conservation efforts and turtle nest management. Erin Clabough of the University of Virginia and Samuel Wantman of Nerds Without Borders led the study, which will be published Oct. 26 in the open-access journal PLUS ONE.

Sea turtle populations worldwide are declining due to human activity, with loggerhead, hawksbill, hawksbill, Kemp’s ridley, leatherback, and olive ridley sea turtles all listed as threatened species. Sea turtle conservation efforts are primarily focused on protecting vulnerable hatchlings as soon as they emerge to ensure they head out to sea rather than approaching the bright lights of cities. Conservationists can count the days since eggs were laid to predict when they will hatch and then monitor the nest, but these efforts are imprecise and labor-intensive.

In the current study, researchers used the TurtleSense system to monitor loggerhead turtle nests at Cape Hatteras National Seashore to see if they could more accurately predict when the turtles would emerge from the nest. They buried an egg-sized sensor in the nest and attached a cable to a communications tower that remotely transmitted data on the movement of hatchlings in the nest.

The researchers identified a pattern of intense hatchling movement around the nest, followed by a pause that allowed them to predict almost the exact day when the hatchlings would dig out of the sand. Their results suggest that hatchlings can detect movement, allowing them to communicate with each other and set off as a group. The system also accurately identified non-viable nests when monitoring was no longer required.

The new TurtleSense system has the potential to reduce the cost and labor of monitoring endangered turtle nests and help conservationists make better nest management decisions. The system can also reduce beach closures and allow communities to engage in turtle-based ecotourism, benefiting both the community and sea turtle conservation efforts. While this study focused on loggerhead sea turtles, researchers also monitored Olive Ridley and Green Turtle nests and saw similar patterns, suggesting the system will work for a range of sea turtle species.

Adds Erin Clabough, “It’s absolutely magical to see baby turtles pop their heads out of the sand and sprint towards the ocean, but it’s an event that can be very difficult to predict. The TurtleSense system is a low cost, creative solution that remotely enables us to see in real time how baby turtles are synchronizing their developmental movements within the nest. We can use the system to detect hatching and better predict when the hatchlings will come to the beach.”

Adds Samuel Wantman: “As each turtle emerges from its shell, it climbs up to join its siblings at the top of the clutch, causing a wave of excitement among all the other baby turtles in the nest. When there is no more excitement there is a period of calm that can be the impetus for all the hatchlings to gush out of the nest together.”