The dugong is an endangered marine mammal related to the manatee. The dugong is the only strictly herbivorous marine mammal. Meanwhile, a dugong and green sea turtle are feasting on sea grass. This muscular upper lip aids the dugong in foraging. The number of growth layer groups in a tusk indicates the age of a dugong. Pig was the youngest dugong ever successfully reared in captivity. The bay is the only place in Australia where dugong gather into herds. The dugong is a Class I protected species. There were also fears for the dugong, a globally vulnerable species. Molecular studies have been made on dugong populations using mitochondrial DNA. The dugong (sea cow) is found here. In areas such as northern Australia, hunting remains the greatest impact on the dugong population. This is only possible through the sea witch Dugong. The remaining dugong, Pig, is the only captive dugong in Australia. The genus "Dugong" probably originated in the Indo-Pacific area.