- Federal Status: Threatened
- FL Status: Federally-designated Threatened
- FNAI Ranks: G3/S3 (Rare)
- IUCN Status: EN (Endangered)
The loggerhead sea turtle is a marine-dwelling species that ranges in size from 2.4 to 3.5 feet (74–107.5 centimeters) and can weigh between 155 to 412 pounds (70.2–186.8 kilograms) (Witherington, 2006). This turtle species has a reddish-brown carapace (upper shell section) and a light to medium yellow plastron (lower shell section). The name comes from its large block-like head. The jaws of the loggerhead are very powerful, which enables them to easily crush their armored prey. Loggerhead sea turtles have 11 to 12 marginal scutes (scutes that surround the perimeter of the carapace), five coastal (lateral) scutes, five vertebral (center) scutes, and one nuchal (cervical) scute (NMFS and USFWS 2008).
Named for its massive block-like head, the loggerhead is Florida’s most common sea turtle. Adults weigh 275 pounds on average with a shell about one yard long. Its shell, ruddy brown on top and creamy yellow underneath, is very broad near the head and tapers toward the rear. Each flipper has two claws. Adult males have longer tails than females.
Loggerheads can be found in subtropical and temperate oceans of the world (Witherington, 2006).
Florida’s sandy Atlantic and Gulf of Mexico beaches host one of the largest loggerhead nesting aggregations in the world. Females return to their nesting beach every two or more years to lay four to seven nests, one about every 14 days. Each nest contains about 100-126 eggs that incubate about 60 days.
The loggerhead’s powerful jaws allow it to easily crush and eat clams, crabs and other armored animals. It is a slow swimmer that may become prey for sharks. A loggerhead tagged in Melbourne Beach, Florida showed up about 400 miles and 11 days later in Cuba, demonstrating this species’ great stamina.
The diet of the loggerhead sea turtle primarily consists of jellyfish, crabs and a variety of mollusks.
Loggerheads mate every two to three years in shallow marine waters near nesting beaches and along migratory corridors. Nesting occurs between the months of April and September (NMFS and USFWS 2008). Male loggerheads tend to breed away from the beach they emerged from as juveniles (Witherington 2006). Female loggerheads will go onshore an average of four times a season to lay 100-150 eggs. Loggerhead eggs have a leathery surface and are the shape of a golf ball. When females come onshore they will dig a deep trench in the beach sand to nest in. The incubation period for the eggs is 49 to 58 days. Once hatched, the young will crawl to the ocean. The survival rate of the young during their first year is low, as they have an extensive amount of predators in the marine environment. Loggerheads reach sexual maturity at approximately 35 years old.
The main threat that the loggerhead faces is accidental capture in shrimp and fishing nets such as longlines, finfish trawls, beach seines, drift and set gill nets. When captured in these nets, the loggerhead cannot escape and will eventually drown. Longlines can entangle or snag sea turtles. Development of nesting beaches is also a threat to the loggerhead, as their nests can be destroyed, and available nesting sites limited. Coastal development also increases artificial lighting which can be detrimental to hatchlings causing them to migrate towards the light instead of the ocean. Increased predation on nests from raccoons and feral hogs is also a significant threat to the loggerhead. Beach armoring (ex. seawalls) is a threat as the structures prevent the natural maintenance of beaches and sand dunes. Other threats include exploitation for meat and eggs in other countries, habitat degradation from contaminants and pollutants, and boat strikes (NMFS and USFWS 2008).
Conservation and Management
The loggerhead sea turtle is protected as a Threatened species by the Federal Endangered Species Act and as a Federally-designated Threatened species by Florida’s Endangered and Threatened Species Rule, and by Florida's Marine Turtle Protection Act (379.2431, Florida Statutes).
Florida Statutes (F.A.C. Rule 68E-1) restrict the take, possession, disturbance, mutilation, destruction, selling, transference, molestation, and harassment of marine turtles, nests or eggs. Protection is also afforded to marine turtle habitat. A specific authorization from Commission staff is required to conduct scientific, conservation, or educational activities that directly involve marine turtles in or collected from Florida, their nests, hatchlings or parts thereof, regardless of applicant's possession of any federal permit.
National Marine Fisheries Service and U.S. Fish and Wildlife Service. 2008. Recovery Plan for the Northwest Atlantic Population of the Loggerhead Sea Turtle (Caretta caretta), Second Revision. National Marine Fisheries Service, Silver Spring, MD.\
Witherington, Blair, Richard Herren, and Michael Bresette. 2006. Caretta cartta – Loggerhead Sea Turtle. In Biology and Conservation of Florida Turtles. Pages 74 – 89.