page_title: Sirenia
section_title: Threats and conservation
hierarchical_section_title: Sirenia / Threats and conservation
caption_attribution_description: English: Picture of a baby Trichechus inunguis in Instituto Brasileiro de Meio Ambiente e Recursos Naturais Renováveis (IBAMA) in Breves - Pará State - Marajó Island - Brazil
context_page_description: The Sirenia, commonly referred to as sea-cows or sirenians, are an order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. The Sirenia currently comprise the families Dugongidae and Trichechidae with a total of four species. The Protosirenidae and Prorastomidae families are extinct. Sirenians are classified in the clade Paenungulata, alongside the elephants and the hyraxes, and evolved in the Eocene 50 million years ago. The Dugongidae diverged from the Trichechidae in the late Eocene or early Oligocene.
  Sirenians grow to between 2.5 and 4 metres in length and 1,500 kilograms in weight. The now extinct Steller's sea cow was the largest sirenian to have lived, and could reach lengths of 8 metres and weights of 8 to 10 tonnes. Sirenians have a large, fusiform body to reduce drag through the water. They have heavy bones that act as ballast to counteract the buoyancy of their blubber. They have a thin layer of blubber and consequently are sensitive to temperature fluctuations, which cause migrations when water temperatures dip too low.
context_section_description: The three extant manatee species (family Trichechidae) and the dugong (family Dugongidae) are rated as vulnerable on the IUCN Red List of endangered species. All four are vulnerable to extinction from habitat loss and other negative impacts related to human population growth and coastal development. Steller's sea cow, extinct since 1786, was hunted to extinction by humans.
  The meat, oil, bones, and skin of manatees are valuable items. In some countries, such as Nigeria and Cameroon, African manatees are sold to zoos, aquariums, and online as pets, sometimes being shipped internationally. Though illegal, lack of law enforcement in these areas induce poaching. Some residents of West African countries, such as Mali and Chad, believe that the oil of the African manatee can cure ailments such as ear infections, rheumatism, and skin conditions. Hunting is the largest source of mortality in Amazonian manatees, and there are no management plans except for in Colombia. Amazonian manatees, especially calves, are sometimes illegally sold as pets, but there are several institutions that care for and rescue these orphans, with the possibility of their releasing into the wild. The body parts of dugongs are used as medicinal remedies across the Indian Ocean.
  Manatees have also faced threats in Cuba, an area that is not always known for its manatee population. Manatees in Cuba have faced poaching, entanglement and pollution. The area has some of the most extensive and best manatee habitat in the Caribbean, but the population has been unable to thrive there for numerous reasons. Existing information about manatees in Cuba is limited and scarce, this makes it difficult to spread awareness which therefore enhances the situation of illegal poaching and entanglement within fishing nets in a majority of the coastal communities. Poaching of the manatees has been a significant issue since the 1970s when it was initially reported that the hunting was taking its toll on the manatee population in Cuba. In 1975 it was recorded that the manatees' status in Cuba was rare and declining at an alarming rate due to pollution and hunting. In 1996 manatees were placed under protection through the Fishery Decree law 164. This law provided penalties against those that manipulated, harm, or injured manatees. However, it was seen that the hunting of manatees in Cuba in the 1990s may have been the result of economic hardships in this country and the manatees were an alternative source of protein. Although there have been efforts made to protect the population of manatees in Cuba, it has not proven to be helpful or as impactful as those working to protect the population had hoped. Many of these areas are seen as "paper parks" or parks or protected areas that only exist due to their name and nothing else, and they do not have a significant impact on conversation and protections.
  Environmental hazards induced by humans also puts sirenians at risk. Sirenians, especially the West Indian manatee, face high mortality from watercraft collision, and about half of all West Indian manatee deaths are caused by watercraft collisions. An increased usage of hydroelectric power and subsequent damming of rivers increase waterway traffic, which can lead to vessel collisions, and manatees may become entangled in navigational locks. The urbanized coastline of areas such as the Caribbean and Australia can result in the decline of seagrass populations. Reliable areas of warm water in Florida are generally the result of discharge from power plants, but newer plants with more efficient cooling systems may disrupt the pattern of warm water refuges, and an increased demand for artesian springs for water, the natural source of warm water, decreases the number of warm water refuges. Sirenians can be caught as bycatch from fisheries, and they can be seen as pests with the interference of local fishermen and the destruction of their nets. African manatees have also been known to venture into rice paddies and destroy the crops during the rainy season, and these confrontations with locals may
caption: Rehabilitation of an Amazonian manatee calf by the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA)
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