Researchers are tracking a female sea turtle nicknamed Motherload during her journey from Oahu’s North Shore to the French Frigate Shoals at Papahanaumokuakea Marine National Monument to lay her eggs.
Every spring, field researchers from the National Oceanic and Atmospheric Administration are deployed to the remote Northwestern Hawaiian Islands at Papahanaumokuakea to study the sea turtle and Hawaiian monk seal populations.
This year, turtle researchers Marylou Staman, Leah Kerschner, and Christina Coppenrath from NOAA’s Marine Turtle Biology and Assessment Program placed a satellite tag on a female Hawaiian green sea turtle to see where she would lay her eggs.
Researchers used ultrasound to confirm that one of the turtles basking on Oahu’s North Shore was fertile, then attached a satellite transmitter and etched her shell with “OA48.” They nicknamed her Motherload because she was large, healthy and very fertile.
Motherload departed the North Shore and was on her way past Kauai about two weeks after she was tagged. She journeyed some 600 miles to French Frigate Shoals in about mid-April.
NOAA’s research team departed Oahu for Papahanaumokuakea in mid-May. On May 24, the turtle team was patrolling the waters around the atolls at French Frigate Shoals when Motherload approached as they were floating off Trig Island. Her satellite tag appeared to be in good shape, and a few days later, they also saw her basking among a group of turtles on Trig Island.
Then Motherload was observed in late May digging a nest chamber and laying 85 eggs on the beach of Tern Island, and she has been keeping busy. She was seen laying eggs at Tern again on June 12.
Sea turtles lay multiple nests per season, according to NOAA, so researchers will be monitoring every clutch that Motherload lays for the next three months, as well as her movements around the atoll until she returns to Oahu. Researchers are counting the number of eggs per clutch, and using a tiny data logger to monitor the nest temperature during incubation. The data will allow scientists to predict the sex ratio of hatchlings.
NOAA researchers are tracking Motherload because they are particularly concerned about the loss of nesting habitat for turtles after Hurricane Walaka headed straight for the French Frigate Shoals, an atoll at Papahanaumokuakea made up of several tiny islets — including East, Tern, Trig, Gin and Little Gin — last October.
Those isles were the nesting locations for the majority of green sea turtles. Hurricane Walaka washed away almost all 11 acres of East Island. This happened after Trig Island was also completely washed away earlier in 2018, according to NOAA, and now barely breaks the surface at low tide.
Researchers wanted to document how turtles respond to the loss of East Island as well as Trig Island. Their findings will be used to help predict how the sea turtles might adapt to ecosystems altered by climate change in the future.