SEA TURTLES
Sea turtles have lived with the dinosaurs and, as far as we know, have remained almost unchanged for 100 million years. Of the seven species that occur in our oceans, two species, the leatherback and loggerhead turtle, are commonly reported or encountered. Profiles of these species can be found below.
Sea turtles are reptiles and, like cetaceans and pinnipeds, they are air-breathing. Sea turtles are different from freshwater turtles and tortoises because instead of legs, they have flippers to help them move more efficiently through the water. Sea turtles also differ from other turtles as they cannot withdraw their head or limbs into the shell. Instead their shell is designed to be hydrodynamic, as many may never leave the ocean unless they are ill or nesting; however, sea turtles do not nest in the Maritime provinces.
As reptiles are cold-blooded, the temperature of their body is greatly affected by the temperature of the air or water around them. In cold water they do not have the ability to warm themselves, and must instead migrate to warmer waters. Cold-stunning is a hypothermic reaction that occurs when sea turtles are exposed to prolonged cold water temperatures. Extremities, eyes and/or neck may be stiff or partially frozen. These occurrences typically happen during the summer and early fall.
Canadian species’ conservation status is first assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), followed by a process to determine if the species will be listed under the Species at Risk Act (SARA).
LOGGERHEAD TURTLE
Caretta caretta
Species at Risk Act Status: ENDANGERED
COSEWIC Status: ENDANGERED
Length: 3m
Key Identification Features:
- Carapace is reddish-brown with a pale yellowish-brown plastron (underside).
- Very large head with heavy strong jaws.
- Carapace is heart-shaped and bony without ridges.
- Carapace has large, non-overlapping, rough scutes (scales) present with 5 lateral scutes.
- Front flippers are short and thick with 2 claws, while the rear flippers can have 2 or 3 claws.
LEATHERBACK TURTLE
Dermochelys coriacea
Species at Risk Act Status: ENDANGERED
COSEWIC Status: ENDANGERED
Length: 4 to 6 ft (130 – 183 cm)
Key Identification Features:
- Dark grey or black with white or pale spots, while the plastron is whitish to black and marked by 5 ridges.
- Head has a deeply notched upper jaw with 2 cusps.
- Lacks a hard shell, but is composed of a layer of thin, tough, rubbery skin.
- Carapace is large, elongated and flexible with 7 distinct ridges running the length of the animal.
- All flippers are without claws.
