Honu Count: Help Us Find Numbered Sea Turtles in Hawai‘i
You can help us track Hawaiian green sea turtles (honu) by reporting the location where you see turtles with white alpha-numeric markings on their shells. Become a citizen scientist and contribute to a valuable source of data for sea turtles in Hawai‘i!
To report your honu sightings, go to our Honu Count Sighting Survey!
What is Honu Count?
Imagine swimming 1,200 miles round-trip to bring new life into the world. While an impossible feat for humans, this is what many Hawaiian green sea turtles (honu) do each year. Our researchers track their migration, but we need your help! By reporting sightings of turtles with white alpha-numeric etchings on their shells, you can help us understand foraging habitats, migration, distribution, and the survival status of that particular turtle—it’s the “Honu Count”!
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Most adult honu that live around the main Hawaiian Islands travel northwest during the spring to reproduce at Lalo, or French Frigate Shoals, an atoll in the Papahānaumokuākea Marine National Monument. This round-trip migration begins at their foraging habitats around the main Hawaiian Islands and extends more than 1,200 miles to remote islands and atolls in the Northwestern Hawaiian Islands. Sea turtles have an internal compass that uses the earth’s geomagnetic signposts to help them navigate back to the beaches where they were hatched, to reproduce. Approximately 96 percent of all honu nest at Lalo; the rest nest at other areas within the Hawaiian Archipelago.
Join a great team of citizen scientists to report turtles! Since the inception of the Honu Count in 2017, nearly 600 citizens reported 688 sightings of 253 individual turtles. This valuable scientific information is used to track recently rehabilitated turtles, resident turtle habitat use, or when nesting turtles from Lalo return back to their foraging grounds. We also use the data collected from Honu Count to determine the resilience of the Hawaiian green sea turtle in the face of climate change.
Tips for Spotting Honu
- Look for turtles with a white alpha-numeric etching on the right side of the shell near their hind flipper.
- Keep a respectful distance of 10 feet on land or in water. Use binoculars or zoom on a camera if you want a closer look.
- Take a photo of the etching without disturbing the turtle.
- Record the date, time, and location.
- Go to the Honu Count Sighting Survey to submit your sighting.
The collection of Honu Count information is authorized under the OMB Control Number included in the Citizen Science & Crowdsourcing Information Collection page.
Tips for Using the Online Survey Platform
To report your honu sightings, go to our Honu Count Sighting Survey.
- Survey123 is supported in Chrome, Microsoft Edge, Firefox, and Safari. However, Chrome is the most suitable platform.
- The Honu Count Sighting Survey, generated through ArcGIS Survey123, can be accessed using your smartphone, computer, or tablet.
- Certain fields are required when submitting your survey, so please fill those fields out to the best of your ability.
- An interactive map is included in the survey to help gather accurate location data on basking and foraging habitats for this population. Zoom in or out to drop a pin for the location of your turtle sighting.
To report any emergencies (dead or injured animals), call NOAA’s Marine Wildlife Hotline at (888) 256-9840.
What Do the Letters and Numbers Mean?
When our biologists conduct field research and surveys in the main and Northwestern Hawaiian Islands, they carefully etch letters and numbers using a dremel tool that is similar to those used by nail technicians. Then, using the clean, dremeled area as a guide, they apply non-toxic paint to the turtles’ shells to make it visible from afar. The etch indicates where the turtle was found. This is a painless process, and many turtles actually sleep through it!
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You can decode the etch using the illustrative map, which shows the codes for each island. (Note: turtles are only given shell etches on islands in the Hawaiian archipelago that have codes on the map). For assistance with decoding the shell etching you have sighted, take a photo of the honu from a responsible, safe distance, upload your photo to the Honu Count Sighting Survey, and our researchers will be able to help you decode the shell etch. For turtles, shell-etched within Lalo only, males are designated with an additional letter “M”—look for a long and thick tail as this also signifies the turtle is a male.
The numbering and lettering order of IDs for the turtles at Lalo and other Papahānaumokuākea Marine National Monument sites varies every year. For example, in 2021, the first female sighted on Tern Island was given a shell etch of “1T,” but in 2022, the first female sighted on Tern Island was given “T1.”
Frequent Sightings
These turtles are sighted and reported frequently by members of the public, providing us with a lot of data already acquired on these particular turtles at these specific locations. Continued reporting of these frequently sighted turtles gives us a complete picture of honu behavior and foraging habits.
| Honu ID | History |
| 129 | First tagged and sighted in 2016, this immature honu likes to spend time around Hawaiʻi Island in the Kona area. |
| HA20 | Since 2019, HA20 has often been seen around Hawaiʻi Island on and off Puakō Beach. |
| HA21 | HA21 was initially tagged in 2017 on Puakō Beach. The immature turtle bounces between Puakō Beach and Waikōloa on Hawaiʻi Island. |
| HA25 | HA25 is an immature turtle first sighted in 2019 on Puakō Beach, Hawaiʻi Island. |
| HA27 | HA27 is an immature turtle first sighted in 2019 on Puakō Beach, Hawaiʻi Island. |
| HA33 | HA33 is an immature turtle first sighted in 2019 on Puakō Beach, Hawaiʻi Island. |
| HA103 | HA103 is a Hawaiʻi Island immature green sea turtle first tagged and sighted in 2022. |
| MA100 | MA100 has commonly been seen around Kāʻanapali, Maui since 2021. |
| MA101 | MA101 is commonly seen around Kīhei, but was first sighted at Māʻalaea Bay, Maui in 2021. |
| MA108 | First sighted in 2021 at Kāʻanapali, MA108 can also be seen at Lāhainā, Maui. |
| MA130 | First sighted at Makena Landing Beach Park in 2021, MA130 can be seen around Kīhei and at Keawakapu Beach, Maui. |
| MA143 | First sighted in 2021 in Kīhei, Maui, MA143 can still be seen in that vicinity. |
| MA145 | MA145 was sighted on Maui in 2021 at Kamaʻole Beach Park. |
| MA165 | First sighted in 2021, MA165 can be seen basking on many beaches around Lāhainā, Maui. |
| MA168 | This Maui turtle was first sighted in 2021 and is most often seen at Kāʻanapali. |
| MA190 | Since 2021, MA190 is most often seen around Waialae-Makena on Maui. |
| MA198 | In 2022, MA198 was usually seen around Kīhei, Maui. |
| MA42 | Initially sighted and tagged in 2021, MA42 is often sighted around Wailea-Makena on Maui. |
| MA72 | First sighted in 2021 at Nāpili-Honokōwai, MA72 can still be seen in and around the waters of Lāhainā, Maui. |
See How You’re Making a Difference!
This map shows locations of honu with shell etchings reported through Honu Count with GPS coordinates throughout the years. Red labels represent honu sighted within the main Hawaiian Islands, and yellow labels represent nesting/basking honu marked with shell etchings at Lalo and subsequently seen at their foraging grounds in the main Hawaiian Islands. Reports with GPS coordinates provide valuable, accurate information on where the population of honu are foraging and living, as well as the final stop of their migration after reproducing at Lalo.
It is normal for honu in Hawaiʻi to lay on the beach and soak up the sun, or “bask.” We are lucky here in Hawaiʻi to be one of two places in the world where honu bask! While honu may sleep or bask for long periods of time, if you suspect one is injured or if it has been there for over 48 hours, this honu may be considered “stranded.” If you see a stranded turtle, please call NOAA’s stranding response hotline at (888) 256-9840.
NOAA’s stranding response partners within the main Hawaiian Islands will respond to stranded sea life.
- Oʻahu: Hawaiʻi Marine Animal Response
- Maui: Maui Ocean Center Marine Institute
- Hawaiʻi Island:
- Kauaʻi/Molokaʻi/ Lānaʻi: Department of Land and Natural Resources
The data on this website is provided by the Marine Turtle Biology and Assessment Program; however, the data is preliminary and is subject to change without notice. For these reasons, we advise users to consider this data for illustrative purposes only. If you wish to pursue scientific inquiries using the data on this site, please contact the Pacific Islands Fisheries Science Center to ensure that the data meets your intended needs.
Data disclaimer: The Pacific Islands Fisheries Science Center takes great strides to ensure the data provided on this site meets the highest data quality and assurance standards.
Contact Information
If you encounter any problems with the Honu Count Sighting Survey, have ideas for new tools, would like to learn more about the data, or are interested in research at the Pacific Islands Fisheries Science Center, please contact pifsc.info@noaa.gov or respectwildlife@noaa.gov.