Australian Sea Turtle & Dugong Deaths

Date/Time: 2011:10:03 18:21:19 Source: The Courier-Mail

ABOUT 1500 marine turtles will have died before the end of the year, thanks to last summer's flooding rains and tropical cyclones in Australia.

James Cook University marine turtle ecologist Mark Hamann said yesterday that although the unusually high number of deaths was a concern, the population would be able to recover quickly.

The State Environment Department released the latest figures yesterday, showing 1048 turtles have been found stranded, including 158 that were released alive.

A total of 158 dugong also were found ashore, with three of those surviving. Read more about the dugong below.

It comes as leading conservation group, the International Union for Conservation of Nature finds that Australia, Brazil and Mexico are home to the world's healthiest turtle populations.

Dr Hamann, who is on the IUCN marine turtle specialist group and has been monitoring strandings with the department and Great Barrier Reef Marine Park Authority, said the scale of deaths had been taken out of context.

"Importantly, the numbers of green turtles breeding in the southern... reef have been increasing by about 4 per cent each year, so the population across the whole Great Barrier Reef will persist despite this year's high number of deaths."

To clarify the situation, green turtle populations were being monitored in areas not affected by the extreme weather.

Scientific classification of turtles and dugongs below:

Classification

Sea turtles are in Kingdom Animalia. In addition, they are classified as:

· Phylum Chordata

o CLASS - Reptilia :includes snakes, lizards, crocodiles, and turtles. Reptiles are ectothermic (cold-blooded) and are vertebrates (have a spine). All reptiles have scaly skin, breath air with lungs, and have a three-chambered heart. Most reptiles lay eggs.

§ ORDER – Testudines: includes all turtles and tortoises.

· FAMILY - Cheloniidae or Dermochelyidae: Family Cheloniidae includes sea turtles which have shells covered with scutes(horny plates). Family Dermochelyidae includes only one modern species of sea turtle, the leatherback turtle. Rather than a shell covered with scutes, leatherbacks have leathery skin.

o GENUS and SPECIES - Most scientists currently recognize seven living species of sea turtles grouped into six genera.

Hawksbill- The Hawksbill sea turtle's shell is about 30- 36 inches long, and it can weigh up to 100- 200 pounds. Hawksbill sea turtle's, are omnivorous and have a wide vegetating diet. It diet consists of small sea grasses and plants found in different ocean depths; and includes invertebrates, such as crustaceans, jellyfish, mollusks, sea urchins and sponges.
	Loggerhead- The Loggerhead is the largest sea turtle with reddish-brown markings. It can reach 33 - 40 inches in length and weighs 150 to 400 pounds. Loggerheads feed mainly on jellyfish
Kemp's Ridley- The Kemp's Ridley is the smallest sea turtles and the most endangered of all the sea turtles. The Kemp's Ridley has an oval-shaped shell that is olive-gray in color. On average, it reaches a length no more than 30 inches and weighs 80 to 100 pounds. They eat mostly invertebrates; various types of crab seem to be their favorite food, but they also eat shrimp, mollusks, fish, and starfish. They use their slightly hooked, strong beaks to crush their food. Like many other sea turtles, they migrate hundreds of miles from their coastal feeding grounds to their nesting beaches.
	Leatherback- This turtle is the largest living sea turtle. The Leatherback has large limbs and no claws. It has no shell, but instead has a leathery back with raised gray stripes. It can reach a length of 6 feet and weigh up to 1,400 pounds. Leatherbacks eattwice their own weighteverday. Usually consositing of jellyfish and other marine invertebrates.
Green- The Green sea turtle lives among the sea grass. It is usually 36- 43 inches long, and 200- 300 pounds. It has a carnivorous based diet. It is the most commonly known of all the sea turtles.
	Olive Ridley- The Olive Ridley has an olive colored, wide, heart shaped shell, with greenish- whitish under shell. It is 24- 30 inches long, and 90- 100 pounds. It dines primarily on marine invertebrates; including crabs, clams, shrimps and mussels. They crush and grind their food with their strong jaws. When feeding, these turtles can dive up to 550 feet.
Australian Flatback- The Australian Flatback measures up to 3.25 feet in carapace (shell) length, and weighs an average of 198 pounds. They eat sea cucumbers, jellyfish, mollusks, prawns, bryozoans, other invertebrates and seaweed. These kind of sea turtles are very limited; only found living in the waters of Australia and Papua New Guinea.

Above: A dugong (Dugong dugon), a close relative of the Florida Manatee.

The dugong (Dugong dugon) is a large marine mammal which, together with the manatees, is one of four living species of the orderSirenia. It is the only living representative of the once-diverse familyDugongidae; its closest modern relative, Steller's sea cow(Hydrodamalis gigas), was hunted to extinction in the 18th century. It is also the only sirenian in its range, which spans the waters of at least 37 countries throughout the Indo-Pacific, though the majority of dugongs live in the northern waters of Australia between Shark Bay and Moreton Bay. The dugong is the only strictly-marine herbivorous mammal, as all species of manatee utilise fresh water to some degree.