About Hawaii’s Sea Turtles

As indigenous species in Hawaii, sea turtles play an important role in Hawaiian cultural traditions and mo‘olelo (stories).  The honu (Green turtle) and ‘ea or honu‘ea (Hawksbill turtle) are mentioned in the fourth verse of the Kumulipo, the Hawaiian creation chant.  Some families continue to revere sea turtles as their ‘aumākua, or spiritual guardians.  Traditionally, sea turtles were incorporated into native practices, religious ceremonies, and diet. Shells, bones and oil were used to make fish hooks, tools, medicine, and jewelry. Harvest was tightly regulated by traditional management practices of the kapu system (cultural rules and code of conduct) enacted by Hawaiian chiefs or ali‘i.

The Green turtle (Chelonia mydas) is listed as threatened under the Endangered Species Act and is found throughout the main Hawaiian Islands.  Historically, Green sea turtles were abundant and nested throughout the entire Hawaiian Archipelago. However, after European colonization (around 1819), the kapu prohibition system began to erode.  During the 20th century, the numbers of Hawaiian sea turtles dropped precipitously as harvests intensified and became commercialized.  In 1978, green turtles received protections under the Endangered Species Act (ESA) and harvest was prohibited.  The population has increased over the last 2 decades by 5.4% per year with almost 800 females nesting annually (compared to 35 turtles in 1973).  The Hawksbill turtle (Eretmochelys imbricate) is listed as endangered under the Endangered Species Act and in the main Hawaiian Islands, is mainly found around Hawaii Island.  Both species rest under the management responsibilities of the National Oceanic and Atmospheric Administration (NOAA) and its National Marine Fisheries – Protected Resources Division.  Three additional species of marine turtles occur within Hawaiian waters but their appearances are not common.  These include the endangered Loggerhead turtle (Caretta caretta), the endangered Leatherback turtle (Dermochelys coriacea) and the endangered Olive ridley turtle (Lepidochelys olivacea).

In Hawaii, the key threats to sea turtles are fishery interactions (i.e. hookings and entanglement), boat strikes, coastal development, pollution, disease, human disturbance and illegal hunting.

As the number of marine turtles has increased in Hawaii in recent years, so has the incidence of basking as well as situations involving turtle health and species recovery such as strandings, fishery entanglement, cases of Fibropapillomatosis (tumors), nest/hatchling disturbance and predation, and turtle deaths on shorelines.  To address these incidents NOAA has entered into an agreement with HMAR to act as first responders on the island of Oahu and to perform needed interventions and transport involving sea turtles.

 

Common name:  Green Sea Turtle
Hawaiian name:  Honu
Latin name:  Chelonia mydas
Status:  Protected & Threatened
Common name:  Hawksbill Turtle
Hawaiian name:  ‘Ea / Honu‘ea
Latin name:  Eretmochelys imbricata
Status:  Protected & Endangered

 

Did you know …
  • Green and Hawksbill turtles evolved as species 40 to 50 million years ago.  The oldest turtles lived 200+ million years ago.
  • Both species are indigenous to the Hawaiian Islands.
  • Green turtles are the most common in Hawaii.  They are the only Hawaii turtles that basks on land to rest and regulate their temperature – basking can last 2 to 3 days.
  • Green turtles are threatened because of its small isolated population (less than 4,000 nesting females) and because 96% of nesting occurs at a single vulnerable atoll, French Frigate Shoals, in the Northwest Hawaiian Islands.  The Green sea turtle species is recovering.
  • Green turtles are named as such due to the color of their fat, not their shell or skin
  • Hawksbill turtles are endangered and are rarely seen on Oahu.  The forage mostly around the Hāmākua coast on Hawaii Island and west Maui.  They nesting on the Ka’ū coast on Hawaii Island, south Maui and east Moloka’i.  The Hawksbill turtle species is not recovering

 

Comparison of the Green turtle and the Hawksbill turtle:

Green Turtle
Hawksbill Turtle
Hawaiian Name
Honu
‘Ea / Honu’ea
Status
Threatened
Endangered
Distribution
Common
Not common, mostly Maui & Big Island
Adult Weight
Up to 500 lbs.
Up to 200 lbs.
Adult Shell Length
3-4 ft.
2-3 ft.
Diving Depth
Up to 1500 ft.
Up to 1500 ft.
Breathing Cycle
Resting up to 3 hours
Normal – every 15 to 30 mins.
Up to 3 hours
Normal – every 15 to 30 mins.
Diet
Limu, seagrass and invertebrates
Sponges, algae & invertebrates
Sexual Maturity
25-35 years
20-29 years
Lifespan
80-100 years
30-50 years
Hawaii Nesting Activity
500-800 per year
20-25 per year
Basking
Yes
No
Carapace (shell)
High domed
Non-overlapping scutes
Smooth edge
Olive to black color
Flatter, more colorful
Overlapping scutes
Jagged edge
More colorful
Claws
1 per flipper
2 per flipper
Nesting Frequency
2 to 8 years
4 years
Intervals During Nesting
4 nests / 14 days apart
1 to 6 nests / 20 days apart
Eggs/Clutch & Incubation
~100 eggs / ~2 months
~180 eggs / ~2 months