Manta rays are threatened because they are caught faster than they can reproduce. The IUCN Red List classifies the oceanic manta ray (Mobula birostris) as Endangered, after a suspected global decline of 50–79% over three generations (87 years), and the reef manta ray (Mobula alfredi) as Vulnerable, after a suspected decline of 30–49% over the same period. Fishing is the main cause, driven largely by international demand for their gill plates, and because each female produces so few pups, recovery from a population crash can take decades.
This guide is written by the scientists of the Marine Megafauna Foundation, whose research described all three manta ray species and underpins their IUCN Red List assessments.
The threats are well understood, and so are most of the solutions. This chapter sets out what is killing manta rays, where the steepest declines have happened, and where protection on paper has yet to become protection in the water.
Why are manta rays endangered?
Two traits combine: manta rays are among the slowest-reproducing animals in the sea, and they are unusually easy to catch.
The life history comes first. A female gives birth to a single pup after a pregnancy of about a year and usually waits a year or more before her next, a cycle our reproduction guide covers in detail. The Red List assessment for the oceanic manta uses a generation length of 29 years and estimates that the average female may produce only 4–7 pups in her lifetime. A comparison of 106 sharks and rays placed the manta ray’s maximum population growth rate among the lowest known for any of them. As a result, even modest fishing can remove adults faster than births replace them, and a depleted population recovers over decades rather than years; the lifespan guide explains how these figures are estimated.
Catchability is the second half of the problem. The Red List notes that manta rays are easy to target because of their large size, slow swimming speed, tendency to aggregate, predictable habitat use, and lack of human avoidance. The same site fidelity that lets scientists recognize and count individuals at cleaning stations and feeding grounds lets fishers find them. Because aggregations are widely separated and exchange few animals, the assessment concludes there is a high likelihood of local depletion: a fished-out site is not quickly restocked from elsewhere.
The assessments also draw a contrast that points directly at fishing. Where manta rays are protected, and hence not fished, sighting trends appear stable. Where they are targeted or caught as bycatch, recorded declines range from 71% to 95% over 13 to 21 years, all within a single generation. The third species, the Atlantic manta ray (Mobula yarae), was only formally described in 2025, with MMF scientists among the authors, and has not yet been assessed for the Red List; its situation is covered on the Atlantic manta ray page.
How many manta rays are left?
Nobody knows the global population of any manta species. What exists are site-level estimates, most of them small, and a series of steep local declines.
The Red List judges that most regional populations of oceanic mantas number fewer than 1,000 individuals, and that photo-identification at particular aggregation sites has yielded minimum estimates of only 42 to 500. Most reef manta populations are likewise fewer than 1,000, with the Maldives, at roughly 10,000 reef mantas, the main exception. The coast of Ecuador and Peru is the outlier for oceanic mantas: a study we co-authored identified 2,803 individuals between 2005 and 2018 and estimated a superpopulation of about 22,300, the largest known anywhere. Because mantas are mobile and only some of them visit the sites where they can be photographed, all of these figures are best read as lower bounds.
The declines are better documented than the totals. In eastern Indonesia, the oceanic manta assessment records that manta landings at Lamakera fell 75% between 2001 and 2014 despite increasing fishing effort, landings at Tanjung Luar in Lombok fell 95%, and aggregations disappeared altogether from Lembeh Strait, South Sulawesi, and northwest Alor. In the Bohol Sea in the Philippines, manta landings are estimated to have declined by 50–90% since the 1960s, and at Cocos Island, Costa Rica, diver sightings of oceanic mantas fell 89% over 21 years. Mozambique, where we have monitored manta rays for two decades, has its own section below.
Why are manta rays fished?
Mostly for their gill plates, the comb-like filtering structures inside the gills, which are dried and sold in Asian markets as a health tonic. Their meat is also eaten locally in many countries.
A survey of 525 traders in Hong Kong, Singapore, Macau, Taiwan, and southern China found that Guangzhou handled 99% of the dried gill plate market, and that its volume doubled from 60.5 tons in 2011 to 120.5 tons in 2013, equivalent to roughly 130,000 mobulid rays (that is, manta and devil rays) a year, about 4% of them mantas. Vendors sell the product, under the trade name pengyusai, for ailments ranging from acne to cancer, although it is a recent addition to traditional Chinese medicine literature and rarely prescribed by its practitioners. Encouragingly, the Guangzhou market had declined sharply by 2015, reportedly because of conservation campaigns and government policies. The trade did not disappear, though: a 2024 global assessment found significant mobulid landings in 43 countries, gill plates extracted in 14, and dried gill plates selling for up to US$1,260 per kilogram, with the number of retailers rising from 41 to 135 between 2011 and 2023 as sales moved online.
It would be wrong to picture every manta fishery as an export business. In many coastal communities, manta and devil ray meat is ordinary food: it is consumed locally in at least 35 countries, and some artisanal fisheries still target these rays mainly for food and local products. The largest documented targeted fisheries have been in Indonesia, the Philippines, India, Sri Lanka, Mexico, Taiwan, Mozambique, the Gaza Strip, and Peru. A global review we co-authored identified 13 fisheries in 12 countries that specifically target mobulid rays, and a 2026 synthesis estimated that fisheries worldwide catch about 264,520 manta and devil rays a year, 87% of them in small-vessel fisheries, with the highest-risk hotspots in India, Indonesia, Sri Lanka, Peru, and Myanmar. That synthesis found mortality was highest in countries that export gill plates, which is why reducing demand and regulating trade matter as much as regulating boats.
Are manta rays caught as bycatch?
Yes. Mantas are caught accidentally in gillnets, purse seines, longlines, trawls, and the nets set to protect swimming beaches, and accidental capture is a major source of mortality alongside targeted fishing.
The same global review identified 30 fisheries in 23 countries that catch mobulid rays as bycatch, with tuna purse seines a substantial source. Observers in the western and central Pacific recorded 4,176 manta rays caught in purse seines and 226 on longlines between 2010 and 2015. Unfortunately, accidental capture is often fatal even when the animal is not kept: rays released from tuna purse seines are frequently injured, post-release mortality is likely to be high, and because gill plates are valuable, many bycaught mantas are retained rather than released.
Small-scale fisheries can matter more than industrial ones. In Sri Lanka, nine years of landing-site surveys found that the artisanal gillnet fleet catches more mobulid rays each year than all of the world’s industrial purse-seine fisheries combined, and that catch rates had fallen tenfold over the study period. Shark nets are a further source. A 41-year record from the bather-protection nets of KwaZulu-Natal, South Africa, showed manta catches declining since the late 1990s, with 52% of the animals caught being juveniles.
Bycatch is also one of the more solvable threats, and the relative economic costs of mitigating it are minimal. When researchers asked purse-seine crews in the eastern Pacific what stopped them releasing mobulids, the answers were practical: the rays are rarely seen before capture, vessels lack suitable equipment, and large individuals are hard to release. A sorting grid developed with those crews then released even the largest mantas in about three minutes.
What happened to Mozambique’s manta rays?
Sightings of reef manta rays off Praia do Tofo in southern Mozambique fell 99% between 2003 and 2023, and sightings of oceanic mantas fell 92.5%. These are among the steepest declines documented for any manta population, and fishing is the most likely cause.
Our long-term dive surveys first reported the trend in 2013: an 88% decline in reef manta sightings between 2003 and 2011; over those first eight years, oceanic mantas showed no significant decline. A 20-year analysis led by MMF’s Stephanie Venables then found declines of 99% for reef mantas and 92.5% for oceanic mantas, and the trends persisted after accounting for weather and ocean conditions. The authors considered the possibility that the rays had simply shifted to other reefs, but concluded that rising fishing mortality was the most likely explanation, noting that large-mesh gillnets, often set from the shore out to about 500 meters (1,600 feet), have increased markedly off the Inhambane coast. The decline was not confined to Tofo. At Závora, 175 kilometers (109 miles) to the south, a study led by MMF’s Nakia Cullain found reef manta sightings fell 82% between 2009 and 2023, with the mantas changing from year-round residents to a seasonal aggregation.
The same research shows where protection would do the most good. Acoustic tags on 42 reef mantas, tracked by receivers along 350 kilometers (217 miles) of coastline, showed that existing marine protected areas covered only about 24% of the mantas’ estimated home range, and only for animals using the Bazaruto Archipelago; the study recommended protecting critical habitat at Tofo and Závora and restricting gillnets outside protected areas. A newer study led by MMF’s Nakia Cullain, which tracked 48 tagged reef mantas between 2022 and 2025, measured the gap a different way: 90% of the individuals detected in Mozambique were detected outside marine protected areas, whereas mantas in South Africa’s iSimangaliso Wetland Park showed high residency in its strictly protected offshore wilderness zone, which may act as a refuge. Because about 30% of the tagged mantas crossed the border, the authors recommend harmonized fishing and trade regulations across the two countries, stronger enforcement, and transboundary management; the movements chapter covers the tracking itself. Mozambique banned the capture of manta and devil rays under its 2020 marine fisheries regulations, in force from January 2021. Whether the region’s mantas recover now depends on enforcement and on protecting the reefs where they feed and clean, and our Mozambique manta ray program continues to monitor them.
Do boats and fishing line injure manta rays?
Yes. Where mantas share water with heavy boat traffic and recreational fishing, a substantial share of them carry injuries from propellers, hooks, and line.
Florida shows the pattern clearly. Our first study of the juvenile mantas along the highly developed coast of Palm Beach County found that 27% carried fishing-line entanglement injuries, and documented vessel-strike injuries as well, although wounds healed rapidly. When MMF’s Jessica Pate and colleagues surveyed 198 pier and jetty anglers, most had no interest in catching a manta and 82% supported their conservation, but many knew little about the threats mantas face or their protected status, and few used tackle strong enough to land a ray and remove the gear. That gap between goodwill and information is what our Florida Manta Project outreach targets. Farther north, recreational anglers find cobia by casting at the mantas they follow, a practice that interviews suggest risks entangling, injuring, and disturbing mantas, particularly when inexperienced anglers are involved; experienced anglers proposed best practices themselves.
Elsewhere the numbers are similar. In Mexico, oceanic mantas at Bahía de Banderas, an area of heavy vessel traffic and small-scale fishing, had an injury rate of 31.7%, compared with 5.2% at the remote Revillagigedo Archipelago. Across 73,638 photo-identification sightings in the Maldives, most injuries were natural, chiefly predator bites, but fishing-line entanglement was the most common human-caused injury, and human-caused injuries were highest at the atolls where boat traffic, fishing, and tourism are concentrated. In Brazil, 70 of 270 manta records showed wounds from human activity, 29 of them lethal. Movement adds to the exposure: in Indonesia, photo-identification showed reef mantas traveling up to 450 kilometers (280 miles) between protected areas through waters that are heavily fished and used by shipping.
Is manta ray tourism harmful?
Well-managed tourism is one of the strongest economic arguments for protecting manta rays, but crowding and poor diver behavior can interrupt feeding and cleaning. The difference lies in how it is run.
A 2013 estimate put the direct economic impact of manta ray tourism at US$140 million a year across 23 countries, and our own study estimated that manta tourism was worth US$34 million a year to Mozambique’s Inhambane Province.
The behavioral costs are measurable, though. At feeding sites in the Maldives, chasing, obstructing, or approaching mantas from the front caused them to stop feeding, yet only 44% of human interactions complied with existing guidelines. In Florida, drone footage showed juvenile Atlantic mantas spent 37% of their time avoiding divers when divers were present, and the authors concluded that this small population is unsuitable for tourism development, which is why we do not promote swimming with them. Our tourism guide covers the disturbance studies, the interaction distances behind the evidence-based code of conduct, and how to choose an operator.
Do climate change and plastic pollution threaten manta rays?
Both are plausible pressures, but neither has yet been shown to drive manta population declines, and their contribution has not been quantified. The Red List assessments record no direct evidence of their effects, only concern about climate change, ocean acidification, oil spills, and other pollutants, alongside the loss and degradation of shallow nursery habitat.
On climate, the evidence so far shows that mantas track ocean conditions closely. In Raja Ampat, Indonesia, oceanic manta sightings rose sharply during the 2015–2016 El Niño despite constant survey effort, which suggests the species is sensitive to large-scale climate variability, while in Ecuador recruitment into the population peaked in the coolest, most productive year of the study. How a warming ocean will alter the zooplankton that mantas depend on, and therefore where they feed, is not yet known; our feeding guide covers what they eat.
Plastic is better measured. As filter feeders processing large volumes of water, mantas are exposed to microplastics and the toxic chemicals associated with them, a risk our scientists reviewed in 2018. At Nusa Penida in Indonesia, MMF’s Elitza Germanov and colleagues found plastic up to 44 times more abundant in the wet season than the dry, estimated that a feeding manta could swallow up to about 63 pieces of plastic an hour, and confirmed ingestion from material the mantas expelled. Remoteness is no refuge: reef manta feeding areas in the Chagos Archipelago, a large protected area far from any city, averaged 1.1 microparticles per cubic meter. What that exposure does to manta health remains an open question, which our microplastics research is designed to answer.
Are manta rays protected?
Yes, extensively on paper. Manta rays are listed on both appendices of the Convention on Migratory Species, all manta and devil rays have been on CITES Appendix I since March 2026, and more than a dozen countries protect them nationally. Enforcement is now the main gap.
International protection built up over 15 years. The oceanic manta was listed on Appendices I and II of the Convention on Migratory Species (CMS) in 2011, and the reef manta followed in 2014. International trade in manta rays has been regulated under CITES Appendix II since 2014 (agreed in 2013), which permits exports only where a country finds them sustainable. At the 20th CITES Conference of the Parties in Samarkand, Uzbekistan, in November and December 2025, all manta and devil rays were moved to Appendix I, a ban on international commercial trade that entered into force on 5 March 2026. Tuna commissions have acted on bycatch as well: the Inter-American Tropical Tuna Commission prohibited keeping or selling any mobulid ray in 2015 and required their prompt release, the Indian Ocean Tuna Commission adopted similar measures in 2019, and at the time of the 2020 oceanic manta assessment, the Western and Central Pacific Fisheries Commission was expected to adopt similar measures in January 2021.
National laws now cover much of the species’ range. The Philippines banned targeting of oceanic mantas in 1998, and Brazil protected all mobulids in 2013. Indonesia, home to some of the world’s largest former manta fisheries, introduced national protection for manta rays in 2014, and Peru banned the capture of oceanic mantas in 2015, later extending protection to all mobulids. The United States listed the oceanic manta as Threatened under the Endangered Species Act in January 2018, and Florida prohibits harvesting manta rays. Mozambique banned the capture of manta and devil rays in regulations in force from January 2021. Protections are also in place in Hawaii, Australia, the Maldives, the United Arab Emirates, Yap in Micronesia, and Thailand. Whether Florida’s Atlantic mantas, described as a separate species seven years after the US listing, are covered by it remains an open question that our team is helping to inform with data.
Turning those laws into fewer deaths is the remaining task. In Peru, catches of oceanic mantas did not fall significantly after the 2015 ban, with economic hardship among the barriers to compliance that fishers described, and fisheries monitoring since has confirmed that mobulids are still landed in large numbers. In East Java, a decade of market surveys recorded illegal landings of both manta species and gill plates intended for export. In the Chagos Archipelago, photographs taken by enforcement officers revealed about 79 mobulid rays on just seven illegal fishing vessels inside one of the world’s largest no-take marine protected areas, showing what good patrol records can bring to light. The 2026 global review reaches the same conclusion, recommending full legislative protection in high-risk fishing nations, closures in critical habitats, limits on drift gillnets, and fishers’ involvement in management.
What has MMF’s research changed?
Our scientists described the species now being protected, supplied much of the evidence of decline behind their Red List status, and continue to measure whether protection is working.
The foundation is taxonomic. In 2009, MMF co-founder Dr. Andrea Marshall led the study that separated the reef manta ray from the oceanic manta ray, which made it possible to assess and protect each species on its own terms, and in 2025 our Florida team contributed to the description of the Atlantic manta. MMF scientists then led the Red List assessments for both established species, and the reef manta assessment’s headline example of decline, a 98% fall in sightings over 15 years in southern Mozambique, comes from our surveys. We co-authored the global review of mobulid fisheries and took part in setting the international research priorities for manta and devil ray conservation with 30 other researchers. In 2024, our Mozambique analysis recommended that mobulids be listed on CITES Appendix I to fully prohibit commercial trade; that uplisting was adopted in 2025, and our long-term science is part of the evidence base behind it.
We also measure what protection achieves. At Nusa Penida in Indonesia, MMF’s Janis Argeswara and colleagues used 11 years of photo-identification to show that the reef manta population grew from about 170 in 2012 to about 447 in 2022, within a marine protected area and under national protection since 2014, with 79.5% of individuals seen more than once. The authors suggest that Nusa Penida’s mantas may demonstrate recovery potential when given adequate protection and time. Farther east, in Raja Ampat, a separate long-term program reports that reef mantas appear to be thriving after two decades of conservation effort. Our Indonesia manta ray program continues that monitoring, and the same work runs through our African manta ray research and the Florida Manta Project.
How can you help manta rays?
Support long-term research, choose tourism operators carefully, and avoid products made from manta and devil rays. Each of these addresses a threat documented above.
Adoptions fund the fieldwork, from survey dives to tags, that produces the population trends behind Red List and CITES decisions; you can adopt a manta ray, or adopt a Florida manta ray to support the nursery work there. If you dive or snorkel with mantas, stay at least 3 meters (10 feet) away, never chase, touch, or block them, and go with an operator that briefs its guests and limits group sizes; the Maldives research found that passive interactions caused significantly less disturbance. Take a photograph of the manta’s belly spots and share it with the researchers working at that site: at Nusa Penida, citizen science contributions improved the accuracy of abundance estimates, and the Manta Matcher photo-identification database was built to make such contributions usable. Gill plate demand is what drives the targeted fisheries, so declining to buy gill plates, often sold as pengyusai, and explaining why, works on the root cause. If you fish in Florida, avoid casting near mantas: they are frequently seen foul-hooked or entangled in fishing line there, and most of the anglers we surveyed support manta conservation. You can also see these animals with our scientists on an MMF expedition.
Why it matters for conservation
Manta rays show both possible outcomes. In southern Mozambique, two decades of expanding gillnet fishing coincided with the near-disappearance of a once-famous aggregation, while at Nusa Penida, a protected population more than doubled in a decade. The two places differ in more than protection, from ocean conditions and movement patterns to how the mantas were surveyed, so the contrast does not prove a single cause. It does support the conclusion of the Nusa Penida study, that the island’s mantas may demonstrate recovery potential when given adequate protection and time. Protection on paper is now close to complete; the work that remains is enforcement, site protection, and the long-term monitoring that shows whether either is working. Recovery can take decades, which is exactly why it needs to start now.
You can adopt a manta ray to support new research on manta rays. For more, see the manta ray facts page and the manta ray hub.