Sea Turtles of Delaware

Of the seven species of sea turtle, six of them are listed as threatened or endangered as a result of human activity. The more we know and understand about these ancient creatures (they are estimated to have lived around the same time as the dinosaur), the more we can do to help protect them to ensure they remain free to swim the oceans for another 100 million years.

Four of these species are common visitors to Delaware waters. This week, we will take a deeper dive with sea turtles. Please remember, if you encounter a sea turtle on the beach, living or dead, contact the Marine Education Research and Rehabilitation (MERR) Institute hotline at 302.228.5029.

• Loggerhead Turtle (scientific name Caretta caretta) Notable by its large head and strong jaws (used for cracking open horseshoe crabs, mussels, clams, and other invertebrates), Loggerhead turtles have two claws on its front flippers and rear flippers with two to three claws. They can grow up to about 3 feet and weigh up to 375 pounds. The Loggerheads are highly sensitive to water temperatures, and can become cold-stunned by when the waters get between 55 and 59 degrees, so they avoid the cooler waters during their migration. The females will travel thousands of miles to lay their eggs on the same sands which they were born. Having survived about 110 million years, these turtles are now endangered in the U.S. due to the destruction of their nesting habitat (largely from coastal development), predation of their nests, human disturbance and pollution.

• Fun fact: Temperatures during egg incubation can affect the sex of the hatchling.

• Leatherback Turtle (scientific name Dermochelys coriacea): The only sea turtle without a hard shell, the leatherback has a layer of tough, rubbery skin that is strengthened by thousands of bone plates. They can grow up to 6 feet and weigh up to 1,100 pounds. When leatherbacks lay their clutch of eggs (usually around 100, 80 of which are fertilized), they undergo the longest migration between breeding and feeding, averaging about 3,700 miles each way. Even though they are classified as reptiles, they are able to maintain warm body temperatures in colder water.

  • Fun fact: They are the best divers of any sea turtles, plunging to depths of 4,200 feet and able to stay underwater for up to 85 minutes. The leatherback is considered endangered in the U.S., due primarily to incidental catches during commercial fishing, pollution and human disturbance.

• Green Sea Turtle: (scientific name: Chelonia mydas): Perhaps one of the most identifiable of sea turtles due to a pair of scales in the front of its eyes, the green sea turtle is marked by a small head and a single claw on all its flippers. They grow up to about 4 feet (weighing in at about 400 pounds) and are notable for taking rests below the surface under rocks and ledges to help protect themselves from predators. Young green sea turtles tend to be carnivorous, but evolve to be herbivores as they age. And while the green sea turtle can be found in temperate and tropical waters all over the globe, they are endangered due to commercial harvesting of their eggs, meat and leather and incidental catches from commercial shrimping.

  • Fun fact: The colder the water, the longer they can hold their breath when submerged. Because they are cold-blooded, green sea turtles can hold their breath for hours at a time in the right water climate.

• Kemp's Ridley Turtle (scientific name Lepidochelys kempii) One of the smallest of the sea turtles found in the area (growing up to 3 feet and about 100 pounds), they are also the most rare, and are listed as the world’s most endangered sea turtle. Mostly juvenile Kemp's Ridley can be found in Delaware and other east coast states, while adults usually stay in the Gulf of Mexico in shallow areas with sandy bottoms. There are estimated to be about 7,000 to 9,000 nesting females, but numbers suffer due to human collection of eggs and meat and incidental catching in commercial shrimping.

  • Fun fact: The Kemp’s Ridley is the only species that nests primarily during the day. They also nest in mass, similar to their relative the Olive Ridley.

Originally appeared in Cape Gazette and Beach Paper on June 25, 2019