It is uncommon for sea turtles to range north of Oregon, but their appearance in Alaskan waters occurs often enough that they can’t be considered accidental visitors. Just how common an occurrence are sea turtles in Alaska? Between 1960 and 20017, records show 19 leatherbacks, 9 green, 2 Pacific Ridley’s, 2 loggerheads, and 2 unidentified hard shell turtles either sighted or actually washed up on the state’s coastline—and almost 80% of those were found in the stretch between Yakatat and Hyder. Since Alaska has approximately 34,000 miles of shoreline, most of it uninhabited, sea turtles may be frequent visitors, but they simply go unsighted.
Sea Turtle Biology
Sea turtles are a class of cold-blooded (ectothermic) vertebrates known as reptiles. Their cousins include snakes, lizards, crocodiles, and fresh water turtles. They have scaly skin, breathe air with lungs, and possess a three-chambered heart. Sea turtles, with their broad, paddle like flippers are strong swimmers: different species have been clocked at speeds ranging from one to six miles per hour.
Though they possess the turtle’s characteristic shell-encased body, their neck and limbs are nonretractile. They are excellent divers, in part because of their ectothermic metabolism. Their slow metabolic rate allows them to stay submerged for long periods of time. Green sea turtles can stay underwater as long as five hours, with as many as nine minutes between heartbeats.
Like most other reptiles, they lay eggs. They are found in warm and temperate seas around the world. Together with saltwater crocodiles, marine snakes and marine iguanas, sea turtles are the only surviving seawater-adapted reptiles from the age of the dinosaurs.
Sea Turtles and the Gulf of Alaska
Though it is exciting to know that such fascinating creatures visit Alaskan waters, it is also bittersweet. All six species of sea turtle occurring in the United States are listed as threatened or endangered under the Endangered Species Act, primarily due to nesting habitat loss. When these threatened animals enter the Gulf of Alaska’s waters, they are most likely doomed. Only the massive leatherback turtle, which regulates its own body temperature, is capable of surviving in Alaskan waters; the other turtle species are not. The region’s cool waters eventually kill them.
What brings the turtles north? Researchers suspect they simply wander too far north from nesting grounds in Mexico and California and get caught in a current. The North Pacific Drift, a warm tongue of water crossing from the western Pacific, bifurcates around the latitude of Vancouver Island, British Columbia. Half the current goes north, and half goes south. The turtles end up following the warm tongue of water as far north as Southeast Alaska.
Once the season turns and surface temperatures start dropping, however, the turtles are in trouble. A turtles’ body temperature, as with all reptiles, is dependent on its surroundings. As mentioned previously, the massive Leatherback turtle is the exception. If their environment cools, the turtles’ body temperature does as well. It becomes increasingly difficult for them to digest food. When the turtles stop eating, they become dehydrated, because they take in fluids through their food. Their immune systems depress, rendering them vulnerable to infection.
As the turtles grow increasingly cold-stunned, they slip into a hibernated state. Eventually they drown, or succumb to abrasions in nearshore surf.
Sea Turtle Rescue
Against all odds, a beachcomber or hunter may find sea turtles on the Southeast Alaska seashore that is still alive. There is one instance where a sea turtle was found alive near Cordova in Prince William Sound. The animal was successfully transported to San Diego where it was rehabilitated, tagged, and returned to the wild. Ironically, it was last spotted off of Oregon, swimming north.
In light of this, despite the improbability of such a find, researchers urge anyone in Alaska finding a cold-stunned turtle to contact the National Marine Fisheries Service or US Fish and Wildlife Service as soon as possible, as it may be possible to save the animal. Owing to the threatened or endangered status of these turtles, every little bit helps, even if it arrives from such an unexpected place as Southeast Alaska.
- All You Need to Know About Sea Turtles in Southeast Alaska - April 16, 2022
Originally posted 2021-03-24 09:26:16. Republished by Blog Post Promoter