Marine Reptiles
Green Turtle
Size
198.00cm
Genus
Chelonia mydas
Avg. Size
93.0cm
Depth
0.0metres
Endangered?
High
Local Hotspots
Diver Interaction
Like the Loggerhead and Hawksbill, Greens are occasionally encountered by divers on reefs, often amongst areas of broken coral. Can often be approached, especially if they are too distracted whilst feeding. Divers are warned not to hassle sea turtles as when these mammals panic they tend to dive down further to avoid danger. This can leave them susceptible to drowning as they are too over-exerted to head to the surface to get a fresh supply of air.
Habitat & Lifestyle
Green turtles alternate between three habitat types depending on their current life history stage. Nesting beaches are where the turtles return to lay eggs. Mature turtles spend most of their time in coastal, shallow waters with lush seagrass beds. Seagrass meadows within inshore bays, lagoons and shoals are common locations where adult Chelonia mydas can often be found. This particular species is known to be very selective about their feeding and mating sites and entire generations will often alternately migrate between the same feeding and nesting areas. After hatching, turtles in their first five years are known to spend a majority of their early life stages in convergence zones within the open ocean. These young turtles are rarely seen as they swim in deep, pelagic waters where they spend the first few years of their lives.
Distribution
WThe range of Chelonia mydas extends throughout tropical and subtropical oceans worldwide. There are two major subpopulations of C. mydas, the Atlantic and the Eastern Pacific subpopulations. Each population is genetically-distinct, with has its own set of nesting and feeding grounds within the population's known range. Were once abundant, but nmbers have greatly declined due to overharvesting.
Unique Physique
Shell plates lie side by side (not over-lapping). They have only two plates between the eyes, where Hawksbills have two pairs. The first of their four coastal plates does not touch the nuchal, which helps distinguish them from Loggerheads and Ridleys.
Abundance
Common - Sighting as are frequent, but not necessarily on every dive.
Leatherback Turtle
Size
300.00cm
Genus
Dermochelys coriacea
Avg. Size
100.0cm
Depth
0.0metres
Endangered?
Critical
Local Hotspots
Diver Interaction
This generally pelagic species, which feeds on jellyfish, is rarely encountered by divers. The diver's best chance of seeing them is during the breeding season when the Leatherbacks come up to the beaches to lay their eggs.
Habitat & Lifestyle
Leatherbacks are commonly known as pelagic animals, but also forage in coastal waters. In fact, leatherbacks are the most migratory and wide ranging of sea turtle species. Thermoregulatory adaptations such as a counter-current heat exchange system, high oil content, and large body size allow them to maintain a core body temperature higher than that of the surrounding water, thereby allowing them to tolerate colder water temperatures.
Distribution
The widest distribution of all sea turtles. A cosmopolitan global range; Leatherbacks reach as far North as the Artic Circle, Alaska and Norway and as far south as the Cape of Good Hope, Africa and the southernmost tip of New Zealand. They are found in all tropical and sub-tropical oceans but in three major, genertically distinct populations: Atlantic, Eastern and Western Pacific.
Unique Physique
The largest of all living turtles and fourth largest reptile behind three crocodilians. They are easily distinguished by their lack of shell plates. Instead, their back is covered with a tough, leather-like, oily, slate-black to bluish black skin. Seven prominent ridges run down the back.
Abundance
Rare – Sightings are exceptional
Hawksbill Sea Turtle
Size
102.00cm
Genus
Eretmochelys imbriocota
Avg. Size
60.0cm
Depth
0.0metres
Endangered?
Critical
Local Hotspots
Diver Interaction
Occasionally encountered by divers on reefs, often amongst areas of broken coral. Can often be approached, especially if they are too distracted whilst feeding. Divers are warned not to hassle sea turtles as when these mammals panic they tend to dive down further to avoid danger. This can leave them susceptible to drowning as they are too over-exerted to head to the surface to get a fresh supply of air.
Habitat & Lifestyle
Adult Hawkesbills are primarily found in tropical coral reefs. They are usually seen resting in caves and ledges in and around these reefs, throughout the day. As a highly migratory species, they have also been seen in a wide range of habitats, from the open ocean to lagoons and even mangrove swamps in estuaries. Not a great deal is known about the habitat preferences of early-life stage of Hawksbills, however like other sea turtles' young, they are assumed to be completely pelagic and thus make the open sea their home until they mature.
Distribution
Hawksbill turtles have a wide range, found predominantly in tropical reefs of the Indian, Pacific and Atlantic oceans. Of all the sea turtle species, E. imbricata is the one most associated with tropical waters. Two major subpopulations are acknowledged to exist, the Atlantic and Indo-Pacific subpopulations.
Unique Physique
1. An overhanging upper beak resembles a ‘hawk’s bill’. 2. Four coastal plates, the first of which does not touch the nuchal, further distinguish them from Loggerheads. They also have two pairs of plates between the eyes, which distinguishes them from similar appearing Greens which have only a single pair of plates between the eyes.
Abundance
Occasional - Sightings are not unusual, but not on a regular basis.
