Editing Manta ray (section)

===Threats===
[[File:Elinkine3.JPG|thumb|right|Dead mantas ashore in [[Senegal]]]]
The greatest threat to manta rays is [[overfishing]]. ''M. birostris'' is not evenly distributed over the oceans, but is concentrated in areas that provide the food resources it requires, while ''M. alfredi'' is even more localized. Their distributions are thus fragmented, with little evidence of intermingling of subpopulations. Because of their long lifespans and low reproductive rate, overfishing can severely reduce local populations with little likelihood that individuals from elsewhere will replace them.<ref name="IUCN">{{Cite iucn | author = Marshall, A. | author2 = Bennett, M.B. | author3 = Kodja, G. | author4 = Hinojosa-Alvarez, S. | author5 = Galvan-Magana, F. | author6 = Harding, M. | author7 = Stevens, G. | author8 = Kashiwagi, T. | name-list-style = amp | title = ''Manta birostris'' | volume = 2011 | page = e.T198921A9108067 | date = 2011 | doi = 10.2305/IUCN.UK.2011-2.RLTS.T198921A9108067.en }}</ref>

Both [[Commercial fishing|commercial]] and [[Artisan fishing|artisanal]] fisheries have targeted mantas for their meat and products. They are typically caught with nets, [[Trawling|trawls]], and harpoons.<ref name="IUCN"/> Mantas were once captured by fisheries in California and Australia for their liver oil and skin; the latter made into [[abrasive]]s.<ref name=flmnh/> Their flesh is edible and is consumed in some countries, but is unattractive compared to other fish.<ref name="manta fisheries"/> Demand for their gill rakers, the cartilaginous structures protecting the gills, has recently entered [[Chinese medicine]].<ref>{{cite web|author=Radford, B.|date=September 22, 2012|title=Unproven Chinese Medicine Killing Manta Rays|publisher=Discovery News|access-date=April 13, 2013|url=http://news.discovery.com/animals/endangered-species/unproven-chinese-medicine-killing-manta-rays-121022.htm}}</ref> To fill the growing demand in Asia for gill rakers, targeted fisheries have developed in the Philippines, Indonesia, Mozambique, Madagascar, India, Pakistan, Sri Lanka, Brazil, and Tanzania.<ref name="manta fisheries">{{cite web | title = Manta Fisheries | publisher = Manta Trust | year = 2011 | url = http://www.mantatrust.org/threats/manta-fisheries/ | access-date = February 21, 2013 | archive-url = https://web.archive.org/web/20130127060340/http://www.mantatrust.org/threats/manta-fisheries/ | archive-date = January 27, 2013 | df = dmy-all }}</ref> Each year, thousands of manta rays, primarily ''M. birostris'', are caught and killed purely for their gill rakers. A fisheries study in Sri Lanka and India estimated that over 1000 were being sold in the country's fish markets each year.<ref>{{cite web | title = Sri Lanka Manta Project | publisher = The Manta Trust | year = 2011 | url = http://www.mantatrust.org/in-the-field/sri-lanka/ | access-date = February 21, 2013 | archive-url = https://web.archive.org/web/20130127165733/http://www.mantatrust.org/in-the-field/sri-lanka/ | archive-date = January 27, 2013 | df = dmy-all }}</ref> By comparison, ''M. birostris'' populations at most of the key aggregation sites around the world are estimated to have significantly fewer than 1000 individuals.<ref>{{cite web | title = Manta Hotspots | publisher = The Manta Trust | year = 2011 | url = http://www.mantatrust.org/about-mantas/manta-hotspots/ | access-date = February 21, 2013 | archive-url = https://web.archive.org/web/20130127172157/http://www.mantatrust.org/about-mantas/manta-hotspots/ | archive-date = January 27, 2013 | df = dmy-all }}</ref> Targeted fisheries for manta rays in the [[Gulf of California]], the west coast of Mexico, India, Sri Lanka, Indonesia, and the Philippines have reduced populations in these areas dramatically.<ref name="IUCN"/>

Manta rays are subject to other [[Human impact on the environment|human impacts]]. Because mantas must swim constantly to flush oxygen-rich water over their gills, they are vulnerable to entanglement and subsequent [[suffocation]]. Mantas cannot swim backwards, and because of their protruding cephalic fins, are prone to entanglement in fishing lines, [[fishing net|nets]], [[ghost net]]s, and even loose mooring lines. When snared, mantas often attempt to free themselves by somersaulting, tangling themselves further. Loose, trailing line can wrap around and cut its way into its flesh, resulting in irreversible injury. Similarly, mantas become [[bycatch]] when entangled in gill nets designed for smaller fish.<ref>{{cite web | title = Bycatch | publisher = The Manta Trust | year = 2011 | url = http://www.mantatrust.org/threats/bycatch/ | access-date = February 21, 2013 | archive-url = https://web.archive.org/web/20130127171053/http://www.mantatrust.org/threats/bycatch/ | archive-date = January 27, 2013 | df = dmy-all }}</ref> Some mantas are injured by collision with boats, especially in areas where they congregate and are easily observed. Other threats or factors that may affect manta numbers are [[climate change]], tourism, pollution from [[oil spill]]s, and the ingestion of [[microplastics]].<ref name="IUCN"/>