Mermaid, marine horse, pretty girl and spirit of the sea. These are the meanings of the name dugong. A gentle giant of the sea, it lives in the shallows of the Indo-Pacific Ocean, but the population is in danger. Unfortunately population growth is extremely slow: a 5% increase per year at maximum rates. This is due to a long gestation period of a year and high death rates where development is occurring.
Internationally, dugongs are listed of Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, meaning that they are threatened with extinction.
Why are the dugongs vulnerable?
The hunting of dugongs is an ancient tradition of the indigenous people of Australia. The dugong is hunted for its meat which is used in traditional cuisine, which may be used in ritual ceremonies. The meat was also considered a medicine against many diseases (the meat is similar to beef) and is even associated with aphrodisiac powers. Dugong skin is used as leather and the oil can be used for cooking, fuel and medicine. Other uses include ornaments and jewellery from the tusks and bones of the animal. The hunting of the dugong is seen as an expression of aboriginal identity in Australia. It therefore seems that nothing of the dugong goes to waste, probably one of the most efficient uses of a carcass and it is claimed that this is how the aborigines ‘express their identity’. Unfortunately these practices are maybe more than ‘expressing’ themselves. The hunting used to be carried out by using dynamite and is still done this way in the Philippines and some Indonesian islands, even though these countries including many others signed the Memorandum of Understanding on the Conservation and Management of Dugongs and their Habitats throughout their Range in 2007-2010. When the dugongs come up to the surface to breathe, dynamite is thrown into the water blast them to death (this also commonly causes destruction of the coral and sea grass, of which the dugong feeds off). In Australia, the hunting is carried out with a harpoon. This involves, to be clear, the dugong being struck twice, once in the neck and another time in the lower back, then the animal is tied to the boat after a long and tiring chase with its head held in a way so it drowns. Sometimes a shot may be taken to the head which reduced the time it takes for the animal to die. It still may take a few minutes for the dugong to die. This is supposed to be an ‘expression of identity’, and although traditional practices can be respected and made allowances for, how far can we respect this? It is important to note that very few dugongs are being killed in this way, but it still has an impact and that the hunting of dugongs is allowed under the Native Title Act for domestic or personal needs.
The practice of fishing causes the greatest deaths of dugongs. The use of large, nylon nets in industrial fishing can catch dugongs and causes them to drown when sharks are meant to be caught. Between the 1970-80s around 550-1000 dugong annually were being caught in these nets. Trawler nets are used illegally often in shallow areas and not only trap the dugongs, but destroy the sea grass and there is mass habitat degradation. Often the Australian authorities have to contend with illegal fishing boats coming from Indonesia and Taiwan.
Habitat Loss and Degradation
There has been extensive habitat degradation in the last 50 years in all countries that dugongs inhabit, due to coastal development. Where development occurred, so an increase in traffic of ships, ferries and boats was experienced, making the shallows more crowded than ever before. The increase in traffic lead to an increase in pollution, which also came from dumping of rubbish from on-shore facilities.
One of the greatest impact was the pollution from the use of pesticides, herbicides and other toxic chemicals. In 2010, 96 dugongs washed up in Queensland in one summer, compared to 76 in 2009 for the whole year. The dugongs were believed to have died from starvation when the pesticides, sediment and freshwater from floods decimated the sea grasses.
Pollution has also come from large industries, dumping hot water and toxic chemicals that alter the balance within the sea, resulting in loss of seagrasses and possible of bio-accumulation in the fatty tissues in the dugong from mercury.
The loss of seagrass can be devastating and particularly for pregnant dugongs, who may calve later and produce fewer offspring, which is a problem when population growth is so slow.
Unlike manatees, the dugongs stay well clear of boats, but in busy ports with many recreational boats in Australia, dugongs are always injured and sometimes even killed. Of the 96 dugongs that washed up on the shores in Queensland, 6 had died from injuries from vessel strikes.
In Queensland there are 16 dugong protection parks where fishing, large boats and dumping of any waste is strictly prohibited. The dugongs and turtles along the Great Barrier Reef have received greater protection under a $5 million plan announced by the Coalition on 15th August 2013 and there are many campaigns to make any hunting, for any reason illegal. Australia is a signatory to both the Convention on International Trade in Endangered Species of Wild Fauna and Flora and the Convention on Migratory Species where work is occurring to make traditional hunting sustainable and more humane and to protect dugong habitats from coastal development.
There are many threats facing the dugong. However, it seems that we are long off the species becoming extinct. There are around 85,000 animals in Australian waters, but increasing development may cause mass deaths. There is more concern over the practices of indigenous hunting and whether it is humane. It is justified because of cultural and social values, but the for example, dog fighting and bear baiting have been stopped because it was immoral. Even in indigenous communities, underage girls are not married off any more as this is not tolerated. It may be time to ask the question: is this humane? They are gentle giants and at some point, there has to be a line drawn.