The Ornate Eagle Ray (Aetomylaeus vespertilio) is a large (to at least 300 cm disc width) eagle ray that has a widespread but patchy distribution in the Indo-West Pacific. It has been recorded over soft sandy substrate, coral reefs, and inshore muddy bays to at least 110 m depth. The species is rarely reported but is highly susceptible to capture in a variety of fishing methods in regions where the level of exploitation of marine resources is intense and increasing. The Ornate Eagle Ray is likely to have some refuge in Australian waters where there are few threats and where most contemporary records have been reported. However, its large size, presumed limited biological productivity similar to other myliobatid rays (including a low fecundity), and preference for coastal habitats increases the species' risk to capture and overexploitation from fisheries. Eagle rays are retained for human consumption, and fish meal, and in some regions (e.g., Indonesia), eagle ray meat is preferred and more valuable than that of other rays. Like other eagle rays with similar distributions, a lack of contemporary records suggest the Ornate Eagle Ray may be locally extinct from parts of its range. Applying a precautionary approach, the Ornate Eagle Ray is suspected to have undergone a population reduction of >80% over the past three generation lengths (39 years) based on actual levels of exploitation and documented declines, and it is assessed as Critically Endangered A2d.

The Ornate Eagle Ray has a widespread, yet patchy, distribution in the Indo-West Pacific Oceans, occurring in South Africa and Mozambique, the Red Sea, India and the Maldives, Southeast Asia and the Philippines, China and Taiwan, across northern Australia and Papua New Guinea, and in New Caledonia (White et al. 2016, Jabado et al. 2017, Araujo et al. 2020). Since the previous assessment (White and Kyne et al. 2016), the distribution map has been refined to map this species to its known bathymetric range.

There is no species-specific information on population size or structure. The Ornate Eagle Ray is considered rare across its range (White and Kyne 2016, Araujo et al. 2020, Venables et al. 2021). Like other eagle rays with similar distributions, the lack of contemporary records suggest the Ornate Eagle Ray may be locally extinct from parts of its range (White 2006, Rigby et al. 2020). For example, the last known record of the species from a long-term monitoring program at landing sites in Sabah, Malaysia was in 1996 (Araujo et al. 2020). In the Gulf of Thailand, the related Mottled Eagle Ray (Aetomylaeus maculatus) no longer occurs in the region, where eagle rays were historically common (White 2006). Despite extensive baited remote underwater video surveying sharks and rays across 391 coral reefs in 67 nations and territories between 2009 and 2019, the Ornate Eagle Ray was only recorded three times (two off the Western Australia and one in Palau) (Simpfendorfer 2023).

There is evidence of population reduction of sharks and rays across the range of the Ornate Eagle Ray. Reconstructed catch data of sharks, rays, and skates can be inferred to represent reductions in their populations, as fishing effort has increased substantially since the 1950s and continued to increase as landings declined (Teh et al. 2014, Pauly et al. 2020). In China, reconstructed data showed a 67% decline in landings, from around 90,000 tonnes (t) in 1950 to around 30,000 t in 2014 (Zeller and Pauly 2016). Across the Malaysia Exclusive Economic Zone (EEZ), reconstructed landings showed declines of 30–54% from 1979 to 2014, with a peak in most regional catches by the late 1990s which subsequently declined (Pauly et al. 2020). There are very few records of the Ornate Eagle Ray from Taiwan (Ebert et al. 2013), where the catch-per-unit-effort for all rays has remained stable over 17 years, i.e., 1997–2013 (H. Hsu, Taiwan National Fisheries Statistics pers. comm. 2019). In Thailand, combined ray species landings data showed an 89% reduction over 16 years from 2003 to 2018 (Krajangdara 2019), although inferring a population trend is difficult as the decline in catches from 2003 to 2018 coincided with a decline in fishing effort. In Indonesia, shark and ray landings in Indonesia rapidly increased from the 1970s to 2000, and have remained relatively steady at about 90,000–120,000 t annually between 2005 and 2014 (Prasetyo et al. 2021). Research survey data from 1976 to 1997 shows a ~ 50% decline in ray catch-per-unit effort from 1976–1997 throughout the Java Sea (Blaber et al. 2009).

In the Arabian Seas and adjacent waters (Red Sea and Arabian/Persian Gulf), the Ornate Eagle Ray was recorded during market surveys in countries surrounding the Red Sea and Gulf of Aden (Bonfil 2003). One report of a live individual was reported in 2018 from Sharm El Sheikh, Egypt (Araujo et al. 2020). The species was only recently confirmed from Cochin, India and the Andaman Islands, India with several specimens landed (Benjamin et al. 2012, Bineesh et al. 2014, Tyabji et al. 2020). The Ornate Eagle Ray was very infrequently reported from landing sites along the east and west coasts of India between 2010 and 2022 (K.K. Bineesh unpub. data 2023). In Pakistan, there have been no published records of this species since the 1970s (M. Khan pers. comm. 2023). Populations of myliobatid rays in general are declining in the region, especially in India and Pakistan where there is an overall decline in batoids from intense fishing (e.g., Raje and Zacharia 2009). For example, the annual average catch of rays landed by trawlers at New Ferry Wharf, Mumbai, between 1990 and 2004 was 502 t. During this period trawler hours doubled, and consequently, the catch rate declined by 60% from 0.65 kg/hr in 1990 to 0.24 kg/hr in 2004 (Raje and Zacharia 2009). The same study showed a similar (63%) decline in landings of the Spotted Eagle Ray (Aetobatus ocellatus), which is equivalent to a 94% decline over three generation lengths (39 years).

There are very few records of the species from the Western Indian Ocean, where regional fishing pressure is intense and largely unmanaged (Temple et al. 2018, Temple et al. 2019). Catches are not often reported to species level, but myliobatids are commonly landed. From 1990 to 2019, the Western Indian Ocean accounted for the third highest reported chondrichthyan catch levels globally, with Tanzania, Mozambique, and Madagascar contributing to 20% of the total regional chondrichthyan catch (FAO 2021, Bennett et al. 2023). Throughout the Mozambique Channel (including Union of Comoros, Madagascar, Mayotte, and Mozambique) small-scale fishing effort increased nearly 60 times while overall catch-per-unit-effort declined by 91% across the region between 1950 and 2016; much of this decline was observed in earlier decades, driven by motorization and growth in vessel numbers (Zeller et al. 2021). Despite extensive surveying conducted throughout the Inhambane Province of Mozambique over the past two decades, only two contemporary records of the Ornate Eagle Ray are available (Venables et al. 2021). There is also a record from Richard's Bay in South Africa (Araujo et al. 2020). Between 2017 and 2023, 18 Ornate Eagle Rays have been reported from artisanal fisheries operating in the Seychelles, with 10 individuals reported over a 12-month period between 2022 and 2023 (J. Neville pers. comm. 2023).

The Ornate Eagle Ray is likely to have some refuge in Australian waters where there are few threats and where most contemporary records have been reported (Araujo et al. 2020). The number of observations from Australia, however, remains limited (Last and Stevens 2009). Overall, considering declining catch trends and limited number of specimens recorded in contemporary surveys and fisheries in many localities where the species previously occurred, the level of intense and largely unmanaged fisheries that operate throughout most of its range, and noted significant declines in eagle rays in general in several parts of its range, the Ornate Eagle Ray is suspected to have undergone a population reduction of >80% over the past three generation lengths (39 years) based on actual levels of exploitation and documented declines. It is also threatened by habitat loss and degradation close inshore but has some refuge from this threat in deeper parts of its range. Thus, the species is assessed as Critically Endangered A2d.

The Ornate Eagle Ray is pelagic and epi-pelagic over soft sandy substrate, coral reefs and inshore muddy bays from the surface to at least 110 m depths (Compagno and Last 1999, Last et al. 2016). It reaches a maximum size of at least 300 cm disc width (DW), and possibly up to 350 cm DW (Last et al. 2016). Males mature at ~170 cm DW and female size-at-maturity is unknown. Little is known about its biology, but like other eagle rays, reproduction is likely to be viviparous with low litter sizes (up to four pups). There is no information on this species' age-at-maturity and maximum age and hence, generation length was inferred based on its congeners. Age-at-maturity is estimated as 5–8 years based on the Naru Eagle Ray (A. narutobiei, to 290 cm DW) and maximum age estimated as 20 years based on the Whitespotted Eagle Ray (A. narinari, to 230 cm DW). When scaled to size, this results in a generation length of 13 years (Yamaguchi et al. 2021, Boggio-Pasqua et al. 2022).

The Ornate Eagle Ray is highly susceptible to a variety of inshore demersal fisheries, including trawls and gillnets. Significant risks to the species are posed by its large size, preference for inshore habitats and coral reefs and hence availability to a wide variety of inshore fishing gear (e.g., beach seine, gillnet), and the generally intense and unregulated nature of inshore fisheries across most of its range.

With the exception of northern Australia, there is a high level of fisheries resource use across the range of the Ornate Eagle Ray. Throughout the East China Sea and Southeast Asia, heavy exploitation levels, intensive fishing, and growing demand for fish consumption has caused declines in fish stocks, and a reduction in fish size and their trophic levels; the ‘fishing down’ effect from 1979 to 2014 is one of the highest estimated globally (Heileman and Tang 2009, Liang and Pauly 2017). In the East China Sea, over 30% of the catch now consists of fish that are too small for human consumption but are still retained to produce fish meal (Cao et al. 2015, Liang and Pauly 2017). In the territorial waters of countries including Viet Nam, Thailand, and Cambodia, most fisheries are now considered overexploited, where fishing effort has been increasing since 1950 across subsistence, artisanal, and industrial fisheries (Pauly et al. 2020).

Eagle rays were previously marketed in considerable numbers in Thailand and Malaysia (Compagno and Last 1999), but are now very rarely landed (Araujo et al. 2020, Rigby et al. 2020). Indonesia catches the highest number of chondrichthyans in the world with sharks and rays an important resource and the main livelihood for some communities (Sadili et al. 2015). Since 2016, rays have overtaken sharks in terms of reported catches, comprising approximately 60% of reported catches (Prasetyo et al. 2021). Between 2005 and 2018, eagle rays made up 8% of ray production across Indonesia (Prasetyo et al. 2021). The Ornate Eagle Ray is occasionally landed in low numbers in the fish markets of Jakarta (Indonesia) by trawlers and is caught by the rhynchobatid tangle net fishery that operate across Indonesia (D'Alberto et al. 2022). Net and trawl fisheries in Indonesia (especially the Java Sea) and elsewhere are very extensive and as a result, many shark and ray species are highly exploited and stocks of most species have declined by at least an order of magnitude (Blaber et al. 2009).

Across the northern Indian Ocean, fishing effort is increasingly intense and largely unregulated. For example, there were about 6,600 trawlers operating in the Indian state of Gujarat in the early 2000s (Zynudheen et al. 2004). This number increased to 9,905 by 2016 and across all of India, 30,772 trawlers and 6,548 gillnetters were operating in 2016 (CMFRI_FSI_DoF 2020). In the Saudi Red Sea, the number of traditional vessels operating more than tripled from about 3,100 to 10,000 between 1988 and 2006 (Bruckner et al. 2011). Fisheries in the Red Sea are primarily small-scale and artisanal vessels fish primarily in nearshore coastal waters using a range of fishing gears including traps, gillnets, hook-and-line, and longlines (Tesfamichael et al. 2012, Jabado et al. 2017). Yemen is one of the largest shark fishing nations in the world by reported catch (Dent and Clarke 2015), however the total biomass and number of species landed in Yemen from the Red Sea is unknown due to a lack of species-specific reporting (Spaet et al. 2012, Jabado and Spaet 2017).

Across the Western Indian Ocean (WIO), more than 60 million people reside within 100 km of the coast and there is great dependence on marine resources for food and employment (Samoilys et al. 2017). Marine fisheries catch in the WIO reported to the Food and Agriculture Organization (FAO) increased from the 1960s to the 1990s but have levelled off since 1999 suggesting stocks are fully fished. Artisanal catches are underreported and most small-scale, artisanal, and subsistence coastal fisheries within the WIO are considered to be fully- or overexploited, especially where they are found close to population centres (Samoilys et al. 2017). Information on sharks and rays in the western Indian Ocean is limited. Landings have often not been reported to the species level (Marshall and Barnett 1997, Temple et al. 2018) and monitoring at major landing sites (including those in Tanzania and Kenya) only commenced around 2018 (Bennett et al. 2023). However, fisheries have been intensive and extensive throughout the region. Inshore fisheries deploy non-selective gears such as gillnets and beach seines, and drift gillnets are often used to target sharks and demersal gillnets to target rays (Kiszka 2012, Temple et al. 2018, Temple et al. 2019, Osuka et al. 2021). Eagle rays have been reported as both targeted catch and bycatch in many nations (Marshall and Barnett 1997, Temple et al. 2018, Nevill 2019). Off Mozambique, eagle rays are targeted by spearfishers (Nevill 2019, Venables et al. 2021). Despite its protected status in Tanzania, the Ornate Eagle Ray has been reported at landings sites throughout the country (Bennett et al. 2023). Small-scale migrant fishers operating across national territorial waters make monitoring catches difficult, and the occurrence of illegal, unreported, and unregulated (IUU) fisheries throughout the region mean true catches are likely to be much higher than what is reported (Le Manach et al. 2015).

The shallow, inshore soft-substrate habitats preferred by rays are threatened by habitat loss and environmental degradation (Stobutzki et al. 2006, White and Sommerville 2010, Jabado et al. 2017). Indirect and sublethal sources of mortality include coastal habitat destruction and degradation, conversion of coastal lagoons and mangrove deforestation for agriculture (e.g., rice and salt) and aquaculture (e.g., shrimp, fish culture, and fish production); extensive oil and gas exploration, drilling, and production; the effects of rapid urban expansion from growing coastal populations and unplanned tourism development; pollution (unregulated sewage effluents, agricultural runoff, hydrocarbon, and heavy metals); sedimentation and siltation; and changes to the hydrological cycle from the building of dams leading to dramatic levels of habitat loss evident across the region (Todd et al. 2010, Price et al.014).

Eagle rays are retained for human consumption and fish meal. Meat may be sold either fresh or dried for human consumption. Eagle ray meat is preferred and more valuable than that of other rays in some regions (e.g., Indonesia, India), while in other regions it may be used but is of limited value (Jabado et al. 2017, Rigby et al. 2020).

There are very few conservation measures in place for this species. In India, the Ornate Eagle Ray is protected under Schedule II of the Wildlife Act since April 2023 (K.K. Bineesh pers. comm. 2023) and in Tanzania, the species is protected under the Tanzania Fisheries (Amendment) Regulations of 2009 (Republic of Tanzania 2009). Although countries across its range have legislations concerning fisheries activities (including gear restrictions, and no-trawling zones in coastal waters), fisheries taking the Ornate Eagle Ray are generally unmanaged throughout large parts of the species’ range and it is unlikely that pressure will decrease in the near future. Many of the contemporary records for this species have occurred within marine protected areas (e.g., Ningaloo Reef, Australia) or marine managed areas where conservation measures specific for sharks and rays have been established (e.g., Cagayancillo in the Philippines, Palau, and the Maldives) (Araujo et al. 2020), highlighting the importance of marine protected areas for rare and highly threatened species.

Further research is needed on population size and trends, and life history, and catch rates should be monitored. To conserve the population and to permit recovery, a suite of measures will be required which may include species protection, spatial management, bycatch mitigation, and harvest and trade management measures (including international trade measures). Effective enforcement of measures will require ongoing training and capacity-building (including in the area of species identification). Catch monitoring is needed to help understand population trends and inform management.