(Editor’s Note: This story is part of a series on efforts by the U.S. Navy and the National Oceanic and Atmospheric Administration (NOAA) to understand the behaviors and migratory patterns of sea turtles in Pearl Harbor.)

Naval Facilities Engineering Systems Command (NAVFAC) Hawaii and NOAA Fisheries, also known as the Pacific Islands Fisheries Science Center (PIFSC), have collected new data from its turtle tagging project, which is part of a 10-year Interagency Agreement funded by the Navy to support the recovery of threatened and endangered sea turtles. Efforts include in-water surveys and telemetry tagging to understand their movement, feeding, breeding and behavior patterns.

The NOAA and NAVFAC team spent six days of surveys between Jan. 16 and Feb. 14 tagging turtles early this year. Trevor Johannsen, marine natural resources specialist for NAVFAC Hawaii, worked with Dr. Alexander Gaos, the PIFSC research marine biologist who is leading the project.

“It took six trips to the field with Alex and his team and they scouted around the harbor looking for turtles. With their snorkel gear, if they saw a turtle, they were able to jump in the water and grab it, bringing it in,” explained Johannsen. “We then worked on the turtles on the dock–tagging them with metal tags on their flippers that are numbered and putting the satellite tags on as well.”

Johannsen said data from two turtles that left the harbor revealed a surprising journey.

“They went straight from Pearl Harbor to Molokai and Kooholawe, and then it went all the way over to Kauai and is currently swimming around Niihau. It’s really interesting to see where the turtles are moving,” he said. “They traveled much further than we expected: traveling around the main Hawaiian Islands, and traveling out to the northwestern Hawaiian Islands.”

Johannsen said the team also discovered that the turtles like to wedge themselves into “resting caves” and in the process knocked off their satellite tags.

“But it won’t affect the data,” added Johannsen. “They are actually waiting for all the tags to stop responding before finalizing the data, which should be about a year from being deployed.”

Out of the 23 green sea turtles that were tagged at the beginning of the year, eight satellite tags were still transmitting data as of July 23.

According to NOAA’s latest progress report, although quantitative data are not available, the Marine Turtle Biology and Assessment Program has conducted in-water and basking survey around many of the main Hawaiian Islands and noticed turtles with the fibropapilloma virus (FP) — a tumor-causing disease commonly affecting green sea turtles that cause cauliflower-like tumors to form on the skin anywhere on the body, including the eyes and mouth — within Pearl Harbor was much higher than in other areas. The cause remains unclear. Future efforts may be conducted to measure the frequency of FP in Pearl Harbor.

Nicole Olmsted, natural resources specialist for NAVFAC Hawaii, explained the importance of the telemetry tagging project and the partnership between the Navy and NOAA.

“It’s fostering a relationship between the two groups to share information and it promotes learning more about our endangered resources and will inform future management decisions,” she said. “The Navy is committed to protecting our natural resources in Pearl Harbor and all other installations across the United States.”

Upcoming analyses of individual and combined turtle home ranges will provide a better understanding and visualization of sea turtle habitat use within Pearl Harbor. Additional captures and satellite tagging will provide new insights into these and other aspects of sea turtle biology and movement ecology in and around the Navy defense sea area of Oahu which includes Pearl Harbor, the Pearl Harbor entrance channel, and the waters immediately south of the Pearl Harbor entrance channel.

For more updates on the turtle tagging project, information and reports can be found on the NOAA website at https://www.fisheries.noaa.gov/pacific-islands/endangered-species-conservation/sea-turtles-pacific-islands-updates