|
|
| | | Navigate the Atlas:  | |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| | | Marine Reptiles |
Maintained by CoML
 |
| |
Text-only Printer-friendly version
| | Sea Turtles | | |  There are seven species of marine turtles in the world: Loggerhead Caretta caretta, Olive Ridley Lepidochelys olivacea, Green Chelonia mydas, Hawksbill Eretmochelys imbricata, Leatherback Dermochelys coriacea, Flatback Natator depressus, and Kemp’s Ridley Lepidochelys kempii. A further species, the Black Turtle Chelonia agassizii, is recognized from the east Pacific but appears to be a variant of the Green Turtle.
The conservation and management of marine turtles globally presents a formidable challenge. Many communities still utilise marine turtles for their meat and eggs, as a source of protein, and their shell for artisanal crafts. At the same time, marine turtles have both intrinsic and ecological values as important components of marine ecosystems. Threatened or endangered in many parts of the world, they are considered as flagship species on which to base interventions aimed at protecting habitats of importance to a myriad of other marine species.
Major threats to marine turtles include unsustainable exploitation, destruction of nesting and feeding habitats, and incidental mortality in fishing operations. Ongoing management focuses on reducing threats, conserving critical habitat, exchanging scientific data, increasing public awareness and participation, promoting regional cooperation, and seeking resources for implementation. | | Photo title: Sea turtle, American Samoa | | Photo credit: anon - International Ocean Institute | | | | Marine Iguana | | |  The only sea-going lizard is the marine iguana, Amblyrhynchus cristatus, of the Galapagos Islands, Equador. All their social interactions occur on land although they are efficient swimmers. The diet is generally herbivorous, grazing on marine algae in intertidal and nearshore environments. Threats include predators such as hawks, owls, snakes and crabs feeding on their eggs and hatchlings, as well as feral cats, dogs and rats. Invasive (introduced) algae have also displaced native seaweeds leading to local starvation. Water pollution and oil spills are a concern. | | Photo title: Marine Iguana underwater, Galapagos Islands, Ecuador | | Photo credit: Phillip Colla Photography Oceanlight.com | | | | Saltwater Crocodiles | | |  The saltwater crocodile, Crocodylus porosus, is the largest of the living reptiles, growing to 10 m with males larger than females. This species is found around coastal areas such as mangroves and estuaries of the southeast Indian Ocean and Pacific Regions, but has also been observed swimming in the open ocean between islands in the Pacific. Modified salivary glands on their tongues maintain the internal salt balance. Diet consists of fish, crabs, waterbirds and small coastal mammals. They are ambush predators, waiting for their prey to approach and then taking birds, mammals and even humans from the riverbank or coastline. The saltwater crocodile has an extremely high commercial value for its skin and meat. They are farmed in Australia, Papua New Guinea and Indonesia; concerns exist about wild harvest in many areas. | | Photo title: Saltwater crocodile, Cape York, Australia | | Photo credit: Ellen K. Rudolph, 2docstock.com | | | | Sea Snakes | | | Sea snakes are the most abundant marine reptiles on earth, with about 55 species worldwide; there are two subfamilies: the true sea snakes and the sea kraits. Most species are found in coastal waters in Southeast Asia and Northern Australia. One species, the yellow-bellied sea snake Pelamis platurus is truly pelagic and occurs in waters throughout the tropical and sub-tropical Indian and Pacific Oceans. Sea snakes are elongate like eels, but have scales and a flattened tail. All true sea snakes give live birth while the sea kraits crawl ashore to lay eggs. Most sea snakes feed on sedentary bottom fish. Some specialize in preying on fish eggs. The venom of certain sea snakes is more deadly than that or rattlesnakes, coral snakes or the cobra. Juveniles are preyed upon by birds, pufferfish, octopus and mangrove crabs; adults are preyed upon by birds of prey, sharks, saltwater crocodiles, fish and marine mammals. Threats to these species come from boat propellers and incidental capture in fishing gear.
With thanks to Tim Harvey, President, IPSTCG and “Sea Turtles. An Ecological Guide” Dave Gulko and Karen Eckert. Mutual Publishing, Honolulu, USA. 2004. 124 pp ISBN: 1 56647 651 8 |  | | Photo title: Olive sea snake, Aipysurus laevis, Gladstone, Australia | | Photo credit: L. Zell, Great Barrier Reef Marine Park Authority | | | | |
 | | | | |
|
|
979 Topics - 5275 Related Knowledge - 11277 Members - 48 Editors |
freeMem:146,564,344 totMem:462,225,408 reqNum:133435 openSessions:0 generationTime:2013/06/19 03:09:53 |
E-Mail Topic link