Justification
The Tasselled Wobbegong (Eucrossorhinus dasypogon) is a relatively common and small (to at least 125 cm total length) shark that occurs in New Guinea and across northern Australia. It is demersal in shallow areas of the continental shelf and offshore reefs from the surface to at least 50 m depth, has a strong preference for coral reef habitats, and is nocturnal and mostly solitary. In Australia, it is a rare incidental catch in commercial trawl fisheries likely due to the lack of trawling in its preferred habitat and is not retained due to a trawl retention prohibition of sharks and rays. It is considered at low risk from northern Australian commercial fisheries because of its low susceptibility to capture. It is an occasional recreational catch though mostly discarded with likely high post-release survival. Marine parks in Australia provide significant refuge. The species may be occasionally taken by small-scale fisheries in New Guinea. There are currently no significant threats to the species, no evidence of population decline, and the species is not suspected to be close to reaching the population threshold. Therefore, the Tasselled Wobbegong is assessed as Least Concern.
Geographic Range Information
The Tasselled Wobbegong occurs in New Guinea and across northern Australia from Ningaloo Reef (Western Australia) to Bundaberg (Queensland) (Last and Stevens 2009, Ebert et al. 2021, Kyne et al. 2021). Since the previous published assessment (Huveneers and Pillans 2015), the distribution map has been updated to show occurrence within the known bathymetric limits.
Population Information
The Tasselled Wobbegong is relatively common and is commonly encountered on the Great Barrier Reef, Australia (Last and Stevens 2009). Its preference for coral reef habitats greatly limits interactions with fisheries in northern Australia which accounts for most of its range. It may interact occasionally with small-scale fisheries in New Guinea. There is no evidence of population decline and the species is not suspected to be close to reaching the population threshold.
Habitat and Ecology Information
The Tasselled Wobbegong is demersal and occurs in shallow areas of the continental shelf and offshore reefs from the surface to at least 50 m depth (Last and Stevens 2009, Ebert et al. 2021). It is commonly seen on coral heads and reef walls on coral reefs, and in reef channels, and is nocturnal and mostly solitary with a small home range (White et alet al. 2017, Ebert et al. 2021). Size-at-birth is ~20 cm TL and little else is known about the biology of this species; it is thought to be lecithotrophic viviparous based on the known reproductive mode of other orectolobid species (Huveneers et al. 2007, Huveneers 2011).
Threats Information
In Australian waters, the species is incidentally caught only rarely in some commercial trawl fisheries and occasionally in recreational fisheries. It is not retained due to a prohibition on trawl caught sharks and rays. The rare catches in trawl fisheries are likely due to trawling not taking place in its preferred reef habitat. The Tasselled Wobbegong has been reported from the Western Australian Exmouth Gulf Prawn Fishery and Pilbara Trawl Fishery (McAuley et al. 2005, Kangas et al. 2006), the Commonwealth Northern Prawn Fishery (Brewer et al. 2004), and the Queensland East Coast Trawl Fishery (Kyne 2008). It is a target species in the Commonwealth Coral Sea Aquarium sub-fishery (Furlani et al. 2007) which is a tightly managed fishery with a harvest strategy and only one vessel active in the 2020–2021 fishing season (Patterson et al. 2022). The species is assessed as at low risk from northern Australian fisheries mainly as it has a low susceptibility to capture (Salini et al. 2007). It also has refuge from fisheries in areas across northern Australia where fishing pressure is low.
In Western Australian, recreational fishing surveys in recent years (2011–2018) revealed a total of 9,994 individual wobbegongs (not species-specific) were caught over eight years with 84% released, and an estimated post-release mortality of 30% (Braccini et al. 2021). However, previous recreational fishing surveys estimated only 5% of all wobbegongs were caught from the North Coast region (Ryan et al. 2013), resulting in ~81 wobbegongs retained over the eight years within the distribution of the Tasselled Wobbegong (where several wobbegong species occur). Post-release survival of the species is likely to be high as wobbegongs have low at-vessel mortality and are robust species (Ellis et al. 2017, Kyne et al. 2021).
In Papua New Guinea, the Tasselled Wobbegong is possibly caught occasionally by spear fishers and line fishers and was not caught in the Gulf of Papua Prawn Trawl Fishery (White et al. 2017, White et al. 2019, Baje et al. 2021). In West Papua, Indonesia it may also be locally threatened by habitat destruction from dynamite fishing, especially in Biak, West Papua. The species is considered to have a low vulnerability to climate change (Chin et al. 2010).
Use and Trade Information
In Australia, wobbegong (family Orectolobidae) flesh is sold locally for human consumption through ‘fish and chip’ and fresh fish retail outlets. Most commercially landed wobbegong catch however, is comprised of larger species than the Tasselled Wobbegong. Due to their low commercial value, smaller wobbegongs are usually released alive. Wobbegong fins have no known commercial value. Historically, the attractive Tasselled Wobbegong skin was occasionally used as decorative leather (Last and Stevens 2009). It is targeted for the home and public aquaria trade with trade ongoing in 2023 (Furlani et al. 2007, Patterson et al. 2022). In some areas, it is a tourist attraction for divers. In West Papua, Indonesia, it is possibly used for its meat (dried and salted), skin, and cartilage as reported for other wobbegong species (White et al. 2006).
Conservation Actions Information
There are currently no species-specific conservation measures in place for this species. However, site attached species such as the Tasselled Wobbegong benefit from habitat protection and suitably designed and implemented no-take zones, where all forms of harvesting or fishing are excluded (Huveneers et al. 2006, Lee 2014). In Australia, the Tasselled Wobbegong benefits from occurring in the no-take zones within the Great Barrier Reef Marine Park on the east coast and Ningaloo Marine Park on the west coast. On the west coast, the species also has significant refuge because more than 90% of the area within the 200 m isobath may never have been trawled due to a combination of spatial trawl closures and marine parks (Gaughan and Santoro 2021). Within Australia, all sharks and rays are prohibited from retention in trawl fisheries and in Western Australia, retention of sharks and rays is prohibited in all commercial fisheries other than the State's managed shark fishery. Further research is needed on population size and trends, and life history, and catch rates should be monitored.