The Ray the World Forgot: Wedgefish under Threat

Wedgefishes are majestic rays that you can guarantee will be a highlight for any divers lucky enough to encounter them. The bottlenose wedgefish (Rhynchobatus australiae) is often found on sand bottoms near reefs. Individuals like this one, seen near Malé in the Maldives at a dive site dubbed ‘Fish Tank’, frequent an area next to a fish-processing factory, usually at dusk. A local dive operator says these rays are most commonly seen at a depth of about 30 metres (100 feet).
Photo by Sirachai Arunrugstichai | Crossroads Project | Singha Estate Copyright

In the tropical Indo-West Pacific there is substantial fishing pressure on marine resources. Trawl fisheries are non-discriminatory in their catches and little of the catch comprises the target species. Large quantities of the by-catch are considered trash fish. Fishing vessels, such as large demersal trawlers, unload their catches at huge fishing ports where the most valuable fish are auctioned. Photo by Sirachai Arunrugstichai

Photo by Sirachai Arunrugstichai

Wedgefishes are a common sight in the by-catch of a number of demersal fisheries, which use gear such as gill nets, long-lines, trawls, trammel nets and tangle nets. This juvenile bottlenose wedgefish, displayed for auction at a fish landing site in Ranong Province, Thailand, would not yet be mature.
Photo by Sirachai Arunrugstichai

Wedgefishes are highly prized species whose fins are the most sought after in the international shark-fin trade. Mature wedgefishes, at about three metres (10 feet) long, have very large fins that can fetch more than US$700 per dry kilo in the South-East Asian fin market trade. Sadly, localised population depletions have been recorded and in areas like Indonesia, where these species are targeted, fishers have had to move long distances from their home ports to locate them.
Photo by Sirachai Arunrugstichai

Fins from small sharks and shark-like rays are aired on drying racks at a shark processing factory in Ranong Province. According to a 2015 Food and Agriculture Organization report, Thailand has surpassed China in terms of the export (including re-export) of shark fins and specialises in small, low-quality fins. The fins of wedgefishes are marketed by traders as those of sharks, adding finning to a long list of threats to these rays’ survival.
Photo by Sirachai Arunrugstichai

Two juvenile bowmouth guitarfishes (Rhina ancylostoma) are displayed for auction at a fish landing site in Ranong Province. This species is the sole member of the genus Rhina and is distinguished by knobbly ‘thorns’ on the bony ridges of its head and by its short, wide snout. These rays live in deep waters on the sea floor and are consequently often caught by commercial otter board trawlers.
Photo by Sirachai Arunrugstichai

The bony ridges of a bowmouth guitarfish have been cut off, exposing part of the cartilaginous skull below. Once the thorns on the bony ridges have been removed, the rays are often finned and butchered and the meat is salted in brine before being dried and sold as unidentified ‘salted fish’. The internal organs and skeletons are mostly processed into animal feed or fishmeal. Photo by Sirachai Arunrugstichai

The ‘thorns’ from the bony ridges of bowmouth guitarfishes are sold at a roadside souvenir store in Kawthaung, Tanintharyi Region of the Republic of the Union of Myanmar. These are commonly used for decorating rings and are widely believed to contain magical properties. It is illegal to sell these parts in Thailand, where the species is protected. Photo by Sirachai Arunrugstichai

A bowmouth guitarfish that was found stranded is treated at the Eastern Gulf Fisheries Research and Development Centre, Rayong Province. The people of Thailand are growing increasingly aware of the rarity and decline of this species. Photo by Sirachai Arunrugstichai

In spite of good potential for recovery, the same guitarfish died after the salinity in its pool changed suddenly in the wake of a tropical storm. Now all that is visible is the tail during a necropsy at the Veterinary Medical Aquatic Animals Research Centre in Bangkok. Photo by Sirachai Arunrugstichai

A neonate bottlenose wedgefish, its unhealed umbilical scar still visible, is handled by a fisherman in a holding pond after being caught in a crab net in Chonburi Province, Thailand. Wedgefishes are aplacental viviparous: the embryos develop inside eggs that are retained in the mother’s body until hatching. The reproductive biology of these rays is for the most part still poorly understood.
Photo by Sirachai Arunrugstichai

Bottlenose wedgefish neonates are tranquillised with dexamethasone by aquatic veterinarians for transportation to a rehabilitation centre in Chonburi Province. These individuals were bought from fishers by a group of scuba divers and veterinarians. Divers usually want to help maintain wedgefish populations in Thai seas, given the limited management strategies to conserve these species in South-East Asia.
Photo by Sirachai Arunrugstichai

A juvenile bottlenose wedgefish is released into the sea by an aquatic veterinarian after being treated for a week. Twenty-eight other juveniles and neonates that were bought by scuba divers from fishers in Ranong Province died during treatment for injuries sustained in gill nets.
Photo by Sirachai Arunrugstichai

A bottlenose wedgefish swoops over a sandy sea floor while a scuba diver observes from a distance. The concern and interest shown by recreational divers in these otherworldly rays is a heartening sign that there is a will to halt their declines. A similar drive from the management and political sector would help to secure a future for them across South-East Asia.
Photo by Sirachai Arunrugstichai | Crossroads Project | Singha Estate Copyright