What kind of an animal is a sea turtle? Sea turtles are reptiles. There are only 7 marine species world wide out of the 225 species of turtles that live today. Brain size may not have anything to do with longevity considering the turtle's brain is smaller than a grape, and it has survived 225 million years. The largest turtle ever swam in the ancient seas that covered Kansas and South Dakota, weighed over 6,000 lbs. and its shell measured 12 feet in length. We see these curious sea turtles along our route off shore Kauai.
How many kinds of sea turtles live around Hawaii? There are three native Hawaiian sea turtles. The Green turtle, or Honu, is the most common. There are very small numbers of Hawksbill, or Ea, found around the islands of Molokai and Hawaii. The third turtle is the most rare, the Leatherback, and it is usually seen on the open ocean where it feeds almost exclusively on jelly fish. There was one documented case of a Leatherback laying eggs on the shores of Kauai four years ago - high surf washed the eggs away.
Are all Hawaiian sea turtles endangered? The Green sea turtle is threatened which means it isn't likely to go extinct as the Hawksbill and Leatherback which are both endangered . However, all of the sea turtles are federally protected and the penalties are severe if you bother these turtles in any way.
How did the green sea turtle get it's name? The fat of a green sea turtle is yellowish green and turns bright green when cooked (probably due to the green plant food that makes up the diet of an adult sea turtle).
Are there green sea turtles that actually nest on Kauai? Yes, there are between 6-8 nesting females that lay their eggs on both the north and south shores of Kauai. The females are on a two year nesting cycle and usually lay over a hundred eggs every two weeks from the end of May to September (a total of 1200-1400 eggs in a season!). Most of the green turtles swim over 800 miles to nest on the French Frigate shoals which are apart of the North West Hawaiian Islands.
What do green sea turtles feed on? As juveniles they feed on the small animals and plants that live among these clumps of vegetation. Eventually, the green sea turtles begin to forage near the coast and feed primarily on algae or limu which grows on coral reefs and on rocks close to shore at high tide. Like cows, green turtles depend upon bacteria in their guts for digestion of their food. As adults, the turtles are herbivores or vegetarians weighing as much as 500 lbs. (average is around 350 lbs. for Hawaiian green sea turtle).
How fast can they swim? 25mph (dive the length of an 80 story building or 800 feet).
How long do they live? No one knows for sure, possibly 100 years.
How long can they hold their breath? If they are resting, turtles can stay under water for days even weeks. However, for active greens 3 hours is maximum documented time. Greens in the Atlantic ocean can actually hibernate during winter, they will partially bury themselves in the mud to help keep warm. The critical temperature is 6.5° Centigrade, any colder and the turtles cannot survive for more than a few hours.
How do you tell the difference between male and female green sea turtles? The male has a tail that is almost a foot long extending beyond the shell or carapace where as a female's tail does not extend past the shell or carapace. However, you can only tell if you are looking at a male or female if they are sexually mature - 25-30 years of age for a green sea turtle.
Why does the male have such a long tail? The male uses his tail to hold onto the female during copulation, turtles are known to copulate for hours. It is thought that during this time the couple emits some type of shark repellent because sharks will not bother copulating turtles. Often, the male is fertilizing next years crop of baby turtles because the female can store the sperm for more than a year (this is common ability for reptiles).
Who eats the turtles? Man is the major predator of turtles and this is still a problem on Kauai. Turtle remains are often found discarded in the rivers. Unfortunately, unless the turtle is an adult, the turtle poachers don't know that they are killing valuable females who only begin nesting at 25 years of age. Tiger sharks are the natural ocean predators of the green sea turtles.
Do turtles get caught in nets, if so, what kind of nets? Dr. Don Heacock from Aquatic Resources on Kauai gets a call once a week about a green sea turtle entangled in some type of fishing line or net. Only 10% of these turtles survive, which means we lose around 50 turtles a year to nets alone. The ones that don't get tangled in nets, may die from ingesting plastic bags, pieces of plastics, or die from the dreaded disease fibropapilloma.
What is fibropapilloma disease? In humans a papilloma tumor is a benign growth that is spread by a virus, i.e. an ordinary wart. When they develop predominantly on fibrous tissues, they are called fibropapillomas. Fibropapilloma only attacks green sea turtles and these tumors debilitate and disfigure the turtle within a few years. These tumors are lobe shaped and grow on all soft parts of the turtle. Scientists do not know what causes this disease. They only know that it is a viral infection and it is caught in the wild (captive turtles don't contract the disease even when in close contact with diseased turtles). Green turtles in Florida and the Bahamas are also suffering in epidemic proportions from this disease. It is feared that if a cure is not found soon for this disease that it may wipe out this species of sea turtle completely. 10% of the green sea turtles tagged off Kauai have fibropapilloma compared to over 90% of the greens tagged off Maui. It is not known how this disease is spread but it would appear that females maybe more likely to contract the disease than males (at least, this is true for the turtle population in Maui).
Do boat captains have to worry about hitting green sea turtles, and how many actual documented cases are there of mortality caused by vessel impact? There have been 7 documented cases of green sea turtles dying from vessel impact over the last 10 years. Most of these turtles were found having seaweed in their mouths which means they were hit when they were feeding. Two of the cases were turtles that washed up in Haena. Whether these turtles were hit by commercial boats will never be known. According to Dr. Heacock, "Speed kills and it is important, to drive slowly and safely where turtles are known to be resting and feeding along the Na Pali Coast."
The only time it is ok, legally to approach a turtle, is if you see a turtle entangled in a net and can not get to a phone to call: 274-3344 or 241-6711 Dispatch for help. Then you should try to cut the net off the turtle (avoiding the head of the turtle i.e. the mouth) to free it.
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