How to Identify Sea Turtles in Alaska

Sea turtles are cold-blooded reptiles that cannot regulate their body temperature. They need water temperatures above 50 degrees Fahrenheit to survive for extended periods, and they thrive in water between 75 and 85 degrees Fahrenheit. Alaska's ocean temperatures range from 35 to 55 degrees Fahrenheit, even in summer months. The Gulf Stream and other warm currents have occasionally carried hatchlings and juveniles to northern latitudes, but these are rare strandings of animals far outside their normal range, not established populations. Sea turtles cannot adapt to cold water.

Sea turtles have a flattened shell called a carapace, which can range from 2 to 7 feet long depending on the species. Most species are dark green, brown, or black on the carapace and lighter colored underneath on the plastron. Their shells have a streamlined shape designed for swimming, and they have four flippers rather than legs. Unlike freshwater turtles, sea turtles cannot fully retract their heads into their shells. Their faces have large forward-facing eyes and small ear tympana visible on each side of the head.

The six sea turtle species are distinguished by shell pattern, head shape, and size. Loggerheads have exceptionally large heads with thick neck muscles. Green turtles have a smaller, more pointed head and a smoother shell. Leatherbacks are massive, up to 6 feet long, with a dark leathery carapace instead of a hard shell with scutes. Hawksbills have a pointed snout and an ornate, yellow-and-brown patterned shell. Kemp's ridleys are the smallest species and have a more rounded shell. Olive ridleys resemble Kemp's ridleys but are found in different regions. Field guides specific to your region will show these differences clearly.

Sea turtles have evolved several adaptations that freshwater turtles lack. Sea turtles have flippers designed for long-distance ocean travel rather than walking legs. Their shells are more streamlined and lighter relative to body size. Sea turtles have special salt glands in their eyes that excrete excess salt from ocean water, which is why they appear to cry. Most importantly, sea turtles are completely aquatic and come ashore only to nest, whereas many freshwater turtles bask on logs and spend significant time on land. Sea turtles also migrate thousands of miles across ocean basins, while freshwater turtles rarely move more than a few miles.

Sea turtles are reptiles and must breathe air like all turtles. They cannot extract oxygen from water the way fish do with gills. Sea turtles surface to breathe air through nostrils on top of their heads. When diving, they hold their breath and can stay submerged for extended periods. Their metabolism slows during dives, and their heart rate decreases to conserve oxygen. Some species can dive to depths over 1,000 feet. Sea turtles must return to the surface regularly, which is why they cannot survive in Alaska's ice-covered waters where surfacing becomes impossible.

Sea turtles inhabit tropical and subtropical oceans worldwide. Popular destinations for sea turtle observation include Hawaii, southern Florida, Caribbean islands, Mexico's Caribbean coast, and certain parts of Costa Rica. Green turtles and hawksbills are common in tropical reefs. Loggerheads range into slightly cooler waters and are found in the Atlantic and Pacific. Leatherbacks have the widest range and can tolerate the coolest water of any sea turtle species, but they still require temperatures above 50 degrees and are most abundant in tropical regions. Check state wildlife regulations before visiting any nesting beaches, as sea turtles are protected species and disturbance is illegal.

Sea turtle hatchlings are tiny, typically one to two inches long, with proportionally larger heads and flippers than adults. Their shells are dark gray or brown and very soft compared to adult shells. Hatchlings are incredibly vulnerable and must immediately make a dangerous journey from nest to ocean, navigating light and sound cues. They spend their first years in open ocean currents, feeding on small floating organisms and hiding among seaweed. Juvenile sea turtles, once they reach 4 to 8 inches, begin settling into coastal nurseries. The shells gradually harden and the body proportions normalize as the turtle grows. It takes 20 to 50 years for a sea turtle to reach sexual maturity, depending on the species.

Shell scute patterns and coloration are reliable identification features. Loggerheads have large, non-overlapping scutes on their carapace arranged in a specific pattern. Green turtles have a smoother appearance with overlapping scutes arranged in neat rows. Leatherbacks have a smooth, leathery surface without distinct scutes. Hawksbills have a serrated posterior shell edge that looks jagged, like a saw blade. Kemp's ridleys have a heart-shaped carapace. Examining the shape of the shell edge and the arrangement and texture of scutes will help narrow down which species you are looking at, especially when combined with head shape and size.

Sea turtles migrate to find food and to return to their natal beaches for breeding. Adult turtles can spend years or decades in feeding grounds, then undertake epic migrations of thousands of miles to return to the beach where they were born to lay eggs. They navigate using Earth's magnetic field and other environmental cues. Some populations travel from feeding grounds in one continent to nesting beaches on another. This behavior exposes turtles to ocean current changes, shipping traffic, fishing nets, and pollution. Understanding their migration patterns helps marine scientists protect critical corridors and feeding and breeding habitats. You can track some sea turtle populations via satellite tags that scientists attach to document their journeys.

All sea turtle species are threatened or endangered due to human activity. Habitat loss, fishing net entanglement, plastic pollution, climate change affecting sand temperature during nesting, and poaching for shells and eggs all reduce populations. Some species like the leatherback have declined sharply in recent decades. Sea turtles are legally protected internationally under the Convention on International Trade in Endangered Species, and most countries have laws protecting sea turtles. Conservation efforts include protected nesting beaches, fishing net regulations, plastic reduction programs, and hatchery management. Supporting marine conservation organizations and making ocean-friendly choices helps protect remaining sea turtle populations worldwide.