Loggerhead Sea Turtle
(Caretta caretta)Identification
Size
- up to 1.2 m
Colour
- reddish-brown
Shell
- smooth, rounded and thick at the rear
- scute behind the head is rectangular shaped
Surface behaviour
- surfaces to breathe for a few minutes
- holds head above water, then slowly sinks back down
Group size / social behaviour
- solitary
Other characteristics
- very large head (from which it gets its name) and jaws compared to other sea turtles
Can be confused with
- olive ridley sea turtle
- green sea turtle
Natural History
Loggerhead sea turtles are named for their exceptionally large head relative to the rest of their body. These turtles have large, powerful jaws that enable them to feed on heavy-shelled clams, crustaceans and encrusting animals such as mussels and limpets. Because of their diet, adult loggerhead turtles are usually found close to shore in coastal or estuarine areas, and are rarely seen at sea. However, juvenile loggerhead sea turtles have been known to migrate thousands of kilometres across the open ocean between their nesting beaches and their adult habitats.
Loggerhead sea turtles are slow moving. Their shell is very thick at the rear end, likely to protect them from attacks by sharks while foraging.
MARGARET BUSCHLER The Vancouver Aquarium helped rear endangered loggerhead sea turtles
Loggerhead sea turtles are normally found in temperate and subtropical waters around the world, in contrast to most other sea turtle species which inhabit tropical waters. In the Pacific Ocean, the main breeding beaches are in Australia and Japan. Every year, thousands of juvenile loggerheads migrate across the North Pacific Ocean from Japan to Baja California, where they feed on red crabs.
Loggerhead sea turtles are threatened by habitat destruction in their coastal environments, as well as by entanglement in high seas fisheries in the North Pacific. It is estimated that over 4,000 juvenile loggerheads are caught in drift nets every year during their migration from Japan to Mexico.
Although loggerhead sea turtles have never been seen in British Columbia’s waters, there have been reports from both Washington and Alaska. As our oceans change, we might expect to start seeing loggerheads on Canada’s Pacific coast.
Status in Canada
The loggerhead sea turtle is designated as Endangered worldwide by the World Conservation Union (IUCN) Red List. The IUCN has posted the following assessment of loggerhead sea turtles.
PUBLICATIONS
Bowen, B.W., Abreu-Grobois, F.A., Balazs, G.H., Kamezaki, N., Limpusi, C.J. and Ferl, R.J. II. 1995. Trans-Pacific migrations of the loggerhead turtle (Caretta caretta) demonstrated with mitochondrial DNA markers. Proceedings of the National Academy of Sciences of the USA. 92:3731-3734
Chaloupka, M., Kamezaki, N. and Limpus, C. 2008. Is climate change affecting the population dynamics of the endangered Pacific loggerhead sea turtle? Journal of Experimental Marine Biology and Ecology 356(1-2): 136-143
Kikukawa, A., Kamezaki, N. and Hidetoshi, O. 1999. Current status of the sea turtles nesting on Okinawajima and adjacent islands of the central Ryukyus, Japan. Biological Conservation 87(1): 149-153
Kobayashi, D.R., Polovina, J.J., Parker, D.M., Kamezaki, N., Cheng, I.-J., Uchida, I.,. Dutton, P.H. and Balazs, G.H. 2008. Pelagic habitat characterization of loggerhead sea turtles, Caretta caretta, in the North Pacific Ocean (1997-2006): Insights from satellite tag tracking and remotely sensed data. Journal of Experimental Marine Biology and Ecology 356(1-2): 96-114
Lee, P.L.M. 2008. Molecular ecology of marine turtles: New approaches and future directions. Journal of Experimental Marine Biology and Ecology 356(1-2): 25-42
