Traditionally persecuted by humans throughout much of their range for their meat, hide and oil; their rather slow movement, large size and dependence on coastal habitats has made dugongs particularly vulnerable to human impacts (2). Fishing nets have also been a major cause of population decline as dugongs are unable to hold their breath for more than about 12 minutes and therefore easily drown once entangled (3). Dugongs have decreased in number throughout their range to the extent that in some areas only relict populations remain, but a significant stronghold still persists in Australia (3). Even here however, these animals are under threat from fishing nets, habitat loss from the silting of sea grass beds, pollution, boat traffic and illegal hunting (3).