These amazing, gentle creatures are probably the original "mermaids". They have reached their present stage of evolution after over 50 million years and it is believed that they share a joint ancestor with the elephant. Now they are seriously endangered - at risk from pollution, habitat destruction, hunting, shipping and pleasure boating.
sirenian facts:
- Manatees and dugongs (the "sea-cows") are the two representatives of the aquatic mammal order Sirenia. All species of Sirenian are primarily herbivorous (plant-eating) including the dugong. pictured above.
- Manatees eat up to 8% of their body weight daily. consuming a wide variety of vegetation. including submerged aquatic plants. overhanging mangrove leaves. bank side plants and floating palm fruits.
threats
The slow reproductive rate of these mammals makes them extremely vulnerable to over-hunting, as seen in the case of the extinct Steller's Sea Cow: after its discovery in 1741 by Western sailors it was hunted ceaselessly for its meat and oil. Dugongs and manatees are still hunted throughout their range by indigenous people and although some capture for subsistence is permitted (i.e. Australian aborigines living in native communities) most is illegal poaching.
Entanglement and drowning in fishing and anti-shark nets is also a major threat. It is only moves such as the setting up of marine parks where fishing is banned and hunting is regulated (e.g. the Starke River Park. Australia) that will protect the group from further population decline.
As with all marine life, sea-cows are also threatened by deterioration and loss of habitat through pollution and coastal/river development.
Human recreation in areas populated by sirenians. for example in Florida. results in the deaths of numerous manatees from speedboat collisions. With low population sizes (e.g. 3.000 manatee in Florida) all four members of the Sirenia family are classified as vulnerable to extinction by the International Union for the Conservation of Nature (IUCN).
