The Leopard Whipray is caught across its range as target and incidental catch by a wide range of coastal fisheries that include demersal trawl, Danish seine, gillnet, dropline and longline, and handline gears (White et al. 2006, Blaber et al. 2009). It is retained in some parts of its range for the meat and high-value skin. Its preference for inshore coastal waters increases its susceptibility to capture with much of its range outside of Australia intensively fished.
In the Western Indian Ocean (FAO region 51), marine fisheries catches 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. There is concern for serial depletion with the number of species landed near-doubling from only 85 in 1971 to 152 reported in 2000. More than 60 million people reside within 100 km of the coast of the Western Indian Ocean and there is great dependence on marine resources for food and employment (van der Elst et al. 2005). In contrast to many other regions of the world, where industrial fisheries with high-technical gear predominate, fishers in the Western Indian Ocean operate primarily at the subsistence and artisanal level. For example, in Tanzania in the early 2000s, no more than 5% of fishers were active in industrial fishing, the other 95% being artisanal (van der Elst et al. 2005). Artisanal catches are underreported and most small-scale, artisanal, and subsistence coastal fisheries within the Western Indian Ocean are considered to be fully- or overexploited, especially where they are found close to population centres. The number of underexploited fisheries in the coastal zone has tended to decline and by the early 2000s, such fisheries were an exception (e.g., Pierce et al. 2008). Whiprays, including Leopard Whipray, dominated the small-scale fisheries marine megafauna catches (elasmobranchs, marine mammals, and sea turtles) across Kenya, Zanzibar, and northern Madagascar from 2016–2017 and were captured by handline, longline, bottom-set, and drift gillnet gear (Temple et al. 2019).
In Pakistan, in 2017 about 2,000 trawlers operated in shelf waters, targeting shrimp in shallow waters and fish in outer shelf waters (M. Khan pers. comm. 6 February 2017). Since approximately 2010, there have been targeted fisheries for stingrays in Pakistan and Islamic Republic of Iran using demersal-set gillnets (Moazzam and Osmany 2021). In Iran, there is increasing fishing effort with the number of licensed vessels increasing over the last two decades from 9,977 in 2001 to 10,739 in 2022 (IFO 2008, 2022). Coastal rays faces two threats in the Iranian waters. Firstly, the demersal shrimp trawl fishery operating in the Persian Gulf every year from August to December, where approximately 500 trawlers incidentally catch at least 8,000 t (roughly equal to 10 million individuals) of coastal rays. Secondly, the stingray targeted fishery using demersal gillnets operating in the Gulf of Oman that started over a decade ago, where about 6,500 t (roughly equal to two million individuals) of rays are landed at approximately 50 landing sites (Rezaie-Atagholipour et al. 2022).
In India, juvenile rays are found in estuaries and high fishing effort, particularly with stake and doll nets, occurs in this habitat. The majority of the geographic distribution of the Leopard Whipray in the region overlaps with intense coastal fisheries. For example, during the 2000s, there were approximately 24,554 trawl vessels operating in the Indian part of the range (CMFRI 2010). The shallow depth distribution means this species is unlikely to have a depth refuge. Since the 1970s, there has been a significant increase in coastal fishing effort and power with about 6,600 trawlers operating in the Indian state of Gujarat in the early 2000s (Zynudheen et al. 2004). This number increased to 11,582 trawlers in 2010 (CMFRI 2010). Furthermore, in 2010, there were 13,400 gill netters operating along the west coast, with many other types of net gear also deployed in coastal areas (CMFRI 2010).
In Sri Lanka, fishing takes place all around the coast, but primarily within the continental shelf. The potential yield from coastal fish resources was previously estimated at 250,000 t per year with 170,000 t per year from coastal pelagic species and 80,000 t from demersal species (Blindheim and Foyn 1980). By the early 2000s, coastal fisheries still accounted for about 67% of the marine fishes caught, but there were some uncertainties regarding further expansion of coastal fishing activities (Wijayaratne 2001). Most crafts operate in the coastal fishery which consists of traditional non-motorised crafts and fiberglass reinforced plastic boats with inboard engines. Both types of vessels are generally day boats, not venturing far from the coast.
In Bangladesh, the marine capture fisheries can be subdivided into subsistence (small-scale, non-commercial), artisanal (small-scale, commercial), and industrial (large-scale, commercial) fisheries sectors. Among the commercial catch, more than 90% is landed by artisanal fishing vessels, while industrial fisheries contribute around 6% to the total landed catch (Ahmad 2004). Each trawling vessel is equipped with trawl gear as well as demersal set longline gear to target shark and rays. There has been an increase in fishing vessels since about the mid-2000s. Many trawlers in the southwest region of the country will go to sea for 5–10 days and sometimes more than 15 days and return with greater landings of larger ray species (A.B. Haque unpub. data 2020). Bangladesh has a substantial artisanal fishing fleet that operates throughout the coastal regions. In 2017–2018 there were 67,669 vessels reported to be operating (DoF 2018). All benthic rays in Bangladesh are targeted with non-baited demersal longlines (1–10 km) with 10,000–30,000 hooks that operate in 5–40 m depth (A.B. Haque unpub. data 2020). Anecdotal reports indicate a steep decline in rays during the 2000s (Ullah et al. 2014, A.B. Haque unpub. data 2020). This decline is concurrent with steep increases in artisanal and subsistence fisheries effort (Pauly et al. 2020). The artisanal fishing vessels land 90% of the total marine catch and generally operate inshore at depths of 0–40 m but can operate to 80 m (Hoq et al. 2014, A.B. Haque unpub. data 2020).
In Myanmar, since 2004, sharks and rays are largely taken as incidental catch (Howard et al. 2015, Mizrahi et al. 2020). These inshore fisheries are relatively small-scale and include many subsistence level fishers. At times since 1950, significant numbers of foreign vessels have operated in Myanmar waters targeting fish and shrimp. These vessels have operated in both inshore and offshore areas. International Labour Organisation (2015) estimated the number of vessels participating in the small-scale inshore fishery to be about 26,000 in 2013, with about 50% of them unpowered. The number of locally operated larger offshore vessels numbered 2,846 in 2013, having increased nearly 30% since 2009. Foreign fishing vessels numbered 153 in 2013, but had historically been much higher. Foreign vessels were banned in 2014. In Thailand, the gulf coast is considered one of the most overfished regions of the world due to the rapid industrialization of their fishing fleet (Sylwester 2014). The number of Thai trawlers peaked in 1989 at ~13,100 boats (Poonnachit-Korsieporn 2000), which was reflected in the catch-per-unit-effort which declined from 300 kg per hour in 1963 to 20–30 kg per hour in the 1990s (Poonnachit-Korsieporn 2000). In Malaysia, fishing effort has been increasing since 1950 (Pauly et al. 2020). The number of vessels across all sectors more than doubled from 22,800 vessels in 1950 to 50,150 vessels in 2014 with fisheries fully exploited by the late 1970s (Teh and Teh 2014, Zeller and Pauly 2016). Small-scale inshore fisheries provide the main supply for local consumption (Teh et al. 2009).
In the Philippines, all incidental catch appears to be retained as discards are virtually non-existent (Palomares and Pauly 2014). The fishing fleet in the Philippines rapidly expanded in the 1960s and 1970s as small-scale artisanal fisheries became motorized and evolved into commercial fisheries. By the 1980s, overfishing was apparent throughout the Philippines, but government and foreign aid continued to subsidize motorizing of artisanal vessels into the late 1990s (Palomares et al. 2014). The commercial fleet operating in the Philippine EEZ tripled from the 1960s (2,100 vessels) to 2014 (6,400 vessels) (Palomares et al. 2014). ‘Baby trawlers’ operate intensively in inshore waters and in waters less than 13 m deep, waters traditionally reserved for small-scale artisanal fishers (Palomares et al. 2014). The small-scale fleet increased ten-fold from 1950 (30,500 vessels) to the mid-1990s ( 338,700 vessels) and while the fleet size has since remained relatively stable, the effort in terms of engine power has continued to rise, as has the number of subsistence vessels (Pauly et al. 2020).
In Indonesia, small-scale fisheries comprise most (~90%) of fisheries production (Tull 2014). In some regions, effort by these small-scale fisheries has tripled when taking population growth into account (Ramenzoni 2017). Sharks and rays are an important resource in Indonesia and are the main livelihood for some communities (Sadili et al. 2020). Indonesia catches the highest number of chondrichthyans in the world with the catch of rays rising as shark fisheries collapse. In 2003, rays comprise over 50% of chondrichthyan landings, up from 32% in 1981 (White et al. 2006). Stingrays contributed the most (95%) to elasmobranch catch by Danish seines (cantrang) that operated in the Java Sea (Fahmi et al. 2008). Intensive longline and gillnetting occurs throughout the Malacca Strait, with some mini-trawl operations and Danish seines operating throughout Kalimantan and the Java Sea (Fahmi pers. comm. 15 May 2020). Thus, the actual level of exploitation of this species could be extremely high throughout the Indonesian portion of its range.
In Papua New Guinea, this species is caught in the Gulf of Papua Prawn Fishery where it represented 95%, although juveniles may not be effectively excluded (Griffiths et al. 2006).
This species’ preference for inshore coastal waters means it is also threatened by extensive habitat degradation, including pollution and clearing, and destructive fishing practices. Large coastal areas, in particular mangroves, have been lost in Indonesia and Malaysia through land conversion for urban development, shrimp farms, and agriculture. Across Indonesia and Malaysia from 1980 to 2005, the area of mangroves was reduced by 30% (FAO 2007, Polidoro et al. 2010).
