Marine Species Conservation
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Dugongs are large grey mammals which spend their entire lives in the sea. Fully grown, they may be three metres long and weigh 400 kilograms. They have nostrils near the top of their snouts. Dugongs swim by moving their broad spade-like tail in an up and down motion, and by use of their two flippers. Dugongs' only hairs are the bristles near the mouth.
Dugongs are highly migratory, which means Australia shares populations with other neighbouring countries. In Australia, Dugongs swim in the shallow coastal waters of northern Australia from the Queensland/New South Wales border in the east to Shark Bay on the Western Australian coast. They are also found in other parts of the Indian and Pacific Oceans in warm shallow seas where seagrass is found.
Dugongs are usually found in shallow waters protected from large waves and storms. They surface only to breathe, and never come on to land.
Female Dugongs give birth underwater to a single calf at three to seven year intervals. The calf stays with its mother, drinking milk from her teats and following close by until one or two years of age. Dugongs reach adult size between 9 and 17 years of age.
Dugongs are sometimes called 'Sea Cows' because they graze on seagrasses. These marine plants look like grass growing on a sandy sea floor in shallow, warm water. Dugongs need to eat large amounts of seagrass.
Dugongs are slow-moving and have little protection against predators. Being large animals, however, only large sharks, Saltwater Crocodiles and Killer Whales are a danger to them. Young Dugongs hide behind their mothers when in danger.
Dugongs are protected under the Environment Protection and Biodiversity Act 1999, which lists dugong as marine and migratory species. Dugong are subject to a range of human threats in Australia, including entanglement in shark, mesh and gill nets, loss and degradation of important habitat such as seagrass meadows, and collisions with boats (also known as boat strikes).
The Australian Government is actively addressing these threats. For example, in 2003, marine debris was listed as a Key Threatening Process under the EPBC Act. As a result, a Threat Abatement Plan is being developed that will build on existing activities to reduce the impact of marine debris on threatened marine species, including marine turtle and dugong.
Internationally, dugong are listed on Appendix I of the Conservation of International Trade in Endangered Species (CITES), and on Appendix II of the Convention on Migratory Species (the CMS). Australia is a signatory to both these conventions.