As the largest and most sparsely populated state in the USA, Alaska is home to a vast array of diverse wildlife ranging from caribou to whales to puffins and more. Turtles — and reptiles in general — are not native to Alaska, except for sea turtles that are occasionally found along the southern part of the coastline.
Ancient turtles may have inhabited parts of Alaska and the Canadian High Arctic region between 100 and 40 million years ago, but today, freshwater turtle sightings are limited to the occasional invasive red-eared slider (which may be able to survive mild winters in some parts of the state). Alaska is simply too cold with long periods of insufficient sunlight, which generally cannot support reptiles, although several amphibians can be found in parts of the state.
Though sightings are uncommon and potentially underreported, given Alaska’s 34,000 miles of shoreline, it is possible that many more sea turtles occur than are detected. Since all sea turtle populations are federally listed as threatened or endangered by the Endangered Species Act, gaining a better understanding of how and why sea turtles arrive in Alaska may help protect them since few are likely to survive the cold temperatures.
The following article describes, in order from most reported observations to least, the four sea turtle species that have been found in Alaska.
Alaska Turtles
1) Leatherback sea turtle (Dermochelys coriacea)
- Family: Dermochelyidae
- Other names: Lute turtle, leathery turtle, luth, trunk turtle
- Weight: 650 – 1,200 lbs (295 – 544 kg)
- Record weight: 2,016 lbs (914 kg)
The largest of all extant turtles, the leatherback sea turtle is easily identified by its highly unusual shell. Unlike most turtles which have a bony carapace (upper shell) covered in scutes (bony scales), the carapace of the leatherback sea turtle is covered by smooth black, dark grey, or bluish-black leathery skin. The carapace displays seven prominent longitudinal lines, and pink or white blotches may be found on the shell or on the skin of the turtle. The massive body is teardrop-shaped, allowing them to be powerful hydrodynamic swimmers.
They primarily feed on jellyfish, with backward-pointed spines in their mouth and throat to prevent their slippery snacks from escaping. As they are able to maintain a warmer body temperature due to their high levels of insulating fat and by using heat derived from constant swimming, leatherback sea turtles are much more tolerant of colder water than other reptiles. These turtles are also highly migratory, nesting in the tropics and then traveling thousands of miles — the longest migration of any reptile on earth — to feed in temperate and cold waters.
Leatherback sea turtles are found in oceans globally, often making journeys from one continent to another. Due to their unique adaptations, the leatherback sea turtle is the only sea turtle that can survive longer-term in cold waters and is the only sea turtle with many live sightings or captures in Alaska. Between 1960 and 2007, leatherback sea turtles were reported in Alaska 19 times.
Adult leatherback sea turtles are considered unpalatable due to their high fat and oil content and are therefore less threatened by intentional hunting. However, other human influences such as the destruction of nests and eggs, light pollution, and vessel-strike injuries pose serious threats to leatherback sea turtle populations.
2) Green sea turtle (Chelonia mydas)
- Family: Cheloniidae
- Other names: Green turtle, black sea turtle, Pacific green turtle
- Weight: 250 – 450 lbs (113 – 204 kg)
- Record weight: 650+ lbs (295+ kg)
Generally brown, olive, or black in coloration, the green sea turtle is so named because the fat found beneath the carapace is green due to their mostly herbivorous diet. Green sea turtles may have mottled, wavy, or blotchy markings, usually darker in color. The head is short with an unhooked beak and a single pair of plates between the eyes, which is a feature that can help distinguish them from hawksbill sea turtles (Eretmochelys spp.).
The range of these turtles includes tropical and subtropical oceans globally, with populations generally separated between the Atlantic and Pacific oceans. The diet of hatchlings is more carnivorous —they consume marine invertebrates, small fish, and algae — but they transition to strict herbivory over time with adults primarily consuming seagrasses.
Green sea turtles spend most of their time in habitats such as shallow coastal waters with abundant vegetation, with a distribution that is limited by their inability to tolerate ocean temperatures below 10°C. As such, while 15 green sea turtles were reported in the state between 1960 and 2007, most were carcasses and it is unlikely that a green sea turtle could persist in Alaska.
In 1996, a live green sea turtle was spotted in the Copper River Flats in southeastern Alaska and sent live to San Diego, California for rehabilitation and release. In 2020, another live green sea turtle was captured and released by fishermen near Prince of Wales Island. Patterns of the reports suggest that these turtles may follow the warmer waters of the North Pacific Current northwest through the Gulf of Alaska, then southwest along the Aleutians.
Green sea turtles are threatened by poaching of adults as well as eggs, bycatch or entanglement in nets, habitat loss of nesting areas, and more recently by sea turtle fibropapillomatosis.
3) Olive ridley sea turtle (Lepidochelys olivacea)
- Family: Cheloniidae
- Other names: Pacific ridley sea turtle
- Weight: 80 – 100+ lbs (36 – 45+ kg)
The second smallest of all sea turtles, the olive ridley ranges from olive-brown to gray-green in color, usually uniformly distributed, though the skin may be grayer. The carapace is heart-shaped with a variable number of scutes that may be present.
Olive ridley sea turtles are sexually dimorphic — adult males have a thicker tail, while females are slightly larger with a more rounded carapace. These are the most abundant sea turtle in the world, found in warm and tropical waters of the tropics and subtropics.
Olive ridley sea turtles are somewhat unique in exhibiting two strategies for nesting. They may use a nesting behavior called arribada — that is, synchronized mass egg-laying — or may nest solitarily. Like other sea turtles, females typically return every year to the same beach where they were born to lay their own eggs.
This species is largely carnivorous, consuming a variety of marine invertebrates including jellyfish, sea urchins, and crabs. In Alaska, 3 or 4 reports of olive ridley sea turtles were reported, at least two of which were carcasses.
Though more common than other sea turtles, olive ridley sea turtle populations are nonetheless in decline due to egg predation by other animals, unsustainable egg harvesting by humans, overhunting of adults, boat collisions, fishing entanglements, and ingestion of marine debris.
4) Loggerhead sea turtle (Caretta caretta)
- Family: Cheloniidae
- Weight: 180 – 440 lbs (82 – 200 kg)
- Record weight: 1,200+ lbs (544+ kg)
The name of the loggerhead sea turtle reflects its distinctly broad head, and its scientific name (which just means “turtle”) is among the zoological tautonyms. Second in size only to the leatherback sea turtle, the loggerhead is the world’s largest of the hard-shelled turtles.
The carapace is usually red, orange, or brown, with yellow along the edges with 11 or 12 marginal scutes along the rim. The neck and sides are brown with yellow tops on the sides and bottom and the underside is lighter in color. Adult males have longer tails and claws, with wider and less domed carapaces in comparison to females. Strong jaws allow these turtles to consume hard-shelled prey, such as conchs and whelks, as well as marine invertebrates, some fish, and occasional vegetation.
Loggerhead sea turtles have the widest geographic range of any turtle, found in tropical, subtropical, and temperate waters globally. These turtles can be found in the open ocean or in shallow coastal waters, and rarely come ashore. Nesting areas are also broad, with many sites found on gently sloping sandy beaches in many parts of the world. Most of the loggerhead nesting areas in the US are found in Florida.
Two reports are recorded in Alaska: one carcass and one live sighting in Cape Georgiana in July of 1993. Like the other hard-shelled turtle species, loggerhead sea turtles may be occasional visitors, but Alaska is probably far beyond their tolerable range. Loggerhead sea turtles are primarily threatened by human activities, especially bycatch from commercial fisheries as well as harvest, habitat loss, and light pollution
