Legal Protection

• Endangered Species Act (ESA) 
• Hawaii state law

Green turtles are found throughout the world, occurring primarily in tropical, and to a lesser extent, subtropical waters. The Hawaiian green turtle is genetically distinct from the other green sea turtle populations, nesting primarily in the French Frigate Shoals of the Northwestern Hawaiian Islands and feeding in the coastal areas of the main Hawaiian Islands. This species was in a steep decline as of the 1970s because of direct harvest of both turtles and eggs by humans.  The population has grown steadily over the last thirty years after protection began in 1978.  Greens are the most common species of sea turtle found in Hawaiian waters. 

Map: French Frigate Shoals (click for larger view). Christine Taylor

Physical Description

• A typical adult green turtle has a carapace length of 40 inches and can weigh from 200-500 lbs. 
• Green turtles exhibit counter-shading with a carapace (shell) that can range from olive brown to black in color and a much lighter yellow plastron (underside). 
• Green turtles have five vertebral scutes running down the middle of their shell and four costal scutes on each side.  (Unlike the hawksbill turtle which has the same number of scutes, the scutes of the green turtle do not overlap). 
• Another distinguishing characteristic of this species is their two large prefrontal scales located between the eyes.

• Adults primarily eat algae.  Over 275 different species of seaweed have been found in the stomachs of Hawaiian green turtles.  In order to deal with this diet of roughage, green turtles have microflora living in their large intestine that help breakdown the cellulose that is otherwise undigestible.   Other food items they consume in lesser amounts include jellyfish, salps, mollusks, sponges, and tubeworms.  East Pacific green turtles tend to eat more animal prey than other populations.

Lifespan

• The lifespan for sea turtles in generally unknown but for green turtles is thought to be around 60-70 years.

Reproduction

• Green turtles become sexually mature at 25-35 years, and some may be as old as 40 before being able to reproduce. 
  
  
  Photo: Mating Hawaiian green sea turtles. Dr. Malia Rivera
  
  
  
• The length of reproductivity has been estimated to range from 17 to 23 years. 
• They return to nesting beaches to lay eggs every two to three years and will deposit three to six clutches per nesting season with an average of twelve days in between.  Each clutch consists of about 100 eggs that will incubate for 60 days.
  
  
  Photo: Hawaiian green sea turtle hatchlings emerge from a nest on Tern Island in the French Frigate Shoals.
  

• More than 90% of the Hawaiian population of green turtles nests at French Frigate Shoals in the Northwestern Hawaiian Islands.  They migrate to feed mainly in the coastal areas of the Main Hawaiian Islands.    Limited nesting locations and important coastal foraging areas for green turtles are found throughout the Pacific islands.

Historically, green turtles have played a large role in Polynesian and Micronesian cultures.  In addition to being used as a food source, native peoples all over the Pacific utilized all parts of the turtle making tools and jewelry out of the bones, and containers and utensils out of the carapace.  Turtle fat was sometimes used for medicinal purposes to treat burns and other skin disorders.  Turtles were often considered the property of the tribal chief and their utilization was regulated by some form of island council. 


Photo: Hawaiian green sea turtle at Lanikaea beach



In the Hawaiian Islands, there were families that considered the green turtle a personal family deity or aumakua, not to be eaten or harmed.  One legendary example is the story from the Big Island of Hawaii of the turtle named Kauila.  She was believed to be able to change at will into human form to watch over the village children playing near the shore.  Artistic elements of green turtles have also been featured prominently in some cultures of the region, such as petroglyphs and tattoo designs.

• Disease - Disease is considered the primary threat to green turtles in Hawaii.   Fibropapillomatosis causes tumor growth on the exposed soft tissue including flippers, head, and neck areas.  While the tumors do not appear to be accompanied by any other symptoms or negative effects, their location could be detrimental to the survival of an individual.  For example, if a tumor obstructs a turtle’s mouth or eyes enough, it may starve due to inability to locate and/or ingest food.  Tumors around the eyes may also impair vision so that a turtle’s ability to avoid predators is reduced. 
• Harvest - In a American Samoa, Guam and the Commonwealth of the Marianas Islands, direct harvest remains a serious threat to green turtle populations.  Hawaiian green turtles have been sucessfully protected from these threats for over 25 years and their population growth is evidence of the success of such protection.
• Incidental take in fisheries
• Indestions of marine debris
• Entanglement
• Habitat loss
• Nest and hatchling predation

• The Protected Resources Division (PRD) has the responsibility to implement the Endangered Species Act (ESA). The division is tasked with the recovery of all ESA listed species, including all five species of sea turtle that occur in the region.  This includes writing and implementing species recovery plans and conducting analyses under Section 7 of the ESA for activities that may affect turtles such as commercial fisheries, construction activites, beach renourishment, etc..
• Public outreach and education.
• Partner with state and local governments and other entities to successfully manage endangered species and provide funding for research and conservation.

• If you see sea turtles out basking on the beach or in the water while snorkeling, admire them from a reasonable distance and do not alter their natural behavior.
• Please do not attempt to touch, feed or harass sea turtles.

• If you encounter an entangled or stranded sea turtle, please call: (808) 983-5730 or view see Marine Turtle Stranding Contact Information for more numbers

• Honu Guardian Program, Haleiwa, North Shore, Oahu

• Recovery Plan for the U.S. Pacific Populations of the Green Turtle (Jan 1998, pdf 623kB)
• NOAA Fisheries - Office of Protected Resources - Green
• Marine Turtle Research Program, Pacific Islands Fisheries Science Center (PIFSC)