Credit: Florida Fish & Wildlife Comission
Loggerhead Sea Turtle
Caretta caretta
Description
The Loggerhead is a reddish-brown sea turtle with a large head that grows to 70-125 cm in carapace length and 70-180 kg in mass. They have 5 or more costal on each side of their . The skin may range from yellow to brown, with the being pale yellow-green or cream coloured. Younger individuals have a prominent dorsal keel (ridge down their back) that becomes inconspicuous at larger sizes. The limbs have adapted to marine life and are flattened into flippers. Males and females can be differentiated by tail length; in males it extends past the tips of the hind flippers and in females it barely reaches the edge of the carapace. Juveniles are usually brown or reddish-brown and have 3 keels and 2 plastral keels. Hatchlings are usually 4-5 cm in shell lengths and about 20 g.
Listen to the Indigenous words for “turtle” here!
Similar Species
In Canada, the Loggerhead Sea Turtle may be confused with the Pacific Leatherback Sea Turtle, the Green Sea Turtle, or the Olive Ridley Sea Turtle; although all sea turtle species are accidental in Canada and are generally very rare. The Pacific Leatherback Sea Turtle has no scutes on the shell, but is instead leathery and lacks the bright colouration of the Green Sea Turtle. The Green SeaTurtle may be coloured similarly to the Olive Ridley Sea Turtle, but they are generally much larger and have 4 pairs of costal scutes, whereas Olive Ridley Sea Turtles usually have 6 or more.
Loggerhead Sea Turtle
Green Sea Turtle
Pacific Leatherback Sea Turtle
Olive Ridley Sea Turtle
Distribution
Loggerhead Sea Turtles are widely distributed in the Atlantic, Pacific, and Indian Oceans. The only confirmed (i.e. with photographic records) sighting of a Loggerhead Sea Turtle in the Canadian Pacific occurred west of Vancouver Island in 2015. However, sightings of Loggerheads in U.S. waters off Washington and Alaska suggest that they may occasionally occur in Canadian waters as well. Juvenile Loggerhead Sea Turtles are consistently found in Atlantic Canadian waters. They are normally associated with the warmer offshore waters of the Gulf Stream. Most Loggerhead Sea Turtles nest at the western rim of the Atlantic and Indian Oceans, with the largest nesting assemblages in Florida, USA and Masirah, Oman. North Pacific Loggerheads nest almost exclusively in Japan. Loggerhead Sea Turtles are a rare sight in the Northeast Pacific, so if you think you have seen one please report your sighting!
British Columbia Cetacean and Sea Turtle Sightings Network (BCCSN)
1-866-I SAW ONE (1-866-472-9663)
British Columbia Cetacean and Sea Turtle Sightings Network (BCCSN)
1-866-I SAW ONE (1-866-472-9663)
Habitat
Loggerhead Sea Turtles spend the majority of their lives at sea in marine habitats. After hatching from nests on sandy beaches, males will never return to land. Females will only return to land to nest. In the ocean, Loggerheads occupy different habitats as they age. Hatchlings disperse to neritic waters near the continental shelf (or areas where bottom depths are less than 200 m), and then onto to oceanic waters (deeper than 200 m). Juvenile Loggerheads make trans-oceanic migrations, and will return to neritic environments as they mature. Nesting females will return to nest at the same beaches where they were born. Habitat for mature Loggerheads, as well as the movements of adult males, is still largely unknown. Some research suggests that Loggerhead Sea Turtles in Canada concentrate in areas where water temperatures are above 22 °C.
Reproduction
Loggerhead Sea Turtles nest every 2-3 years. During the nesting season, they will lay 3-4 clutches of 100-120 eggs, with approximately 14 days between clutches. Hatching occurs after 7-13 weeks of incubation, depending on nest temperature. Hatchling sex is temperature dependent, with nest temperatures below 29 °C producing mostly males, and above 29 °C producing mostly females. Hatchlings emerge at night and use ambient light to guide them to the ocean. Loggerhead Sea Turtles do not reach sexual maturity until around 16-35 years of age and may live to 80 years or more.
Diet
Loggerhead Sea Turtles are carnivores, only occasionally consuming plant matter. During their open ocean phase, they feed on a wide variety of floating items, especially jellyfish, which unfortunately leads to many individuals consuming trash and other anthropogenic debris mistaken for food. Juveniles and adults in coastal waters are adapted to crushing and gridning, and feed on bottom-dwelling invertebrates like mollusks, crabs, shrimps, bivalves, sponges, cephalopods, and more. Loggerhead Sea Turtles have the longest list of known prey items of any of the sea turtles.
Conservation Status
Global: G3 (2014)
COSEWIC: E
SARA:1-E (2017)
Provincial: SNA (2018)
BC List: Accidental
Learn more about conservation status rankings here
Threats
The primary threat to Loggerhead Sea Turtles in Canadian waters is bycatch during pelagic longline fishing. Bycatch of juvenile-stage turtles is particularly significant because changes in survivorship at this stage has the largest impact on overall population growth. Around the world, Loggerheads are threatened by fisheries bycatch, poaching, construction and development on nesting beaches, pollution, natural predators, and plastic accumulation in marine environments. It is unknown how climate change may affect Loggerhead Sea Turtles. Changes to ocean currents may disrupt migration routes, while warming ocean temperatures may open up previously uninhabitable waters.
Did You Know?
Species Account Author: Marcus Atkins
References
COSEWIC. 2010. COSEWIC assessment and status report on the Loggerhead Sea Turtle Caretta caretta in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. viii + 75 pp. (www.sararegistry.gc.ca/status/status_e.cfm).
B.C. Conservation Data Centre. 2003. Species Summary: Caretta caretta. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Sep 13, 2021).