|Scientific Name:||Orectolobus parvimaculatus|
|Species Authority:||Last & Chidlow, 2008|
|Taxonomic Notes:||Orectolobus parvimaculatus has been confused in the literature with the larger O. maculatus (e.g., Compagno 1984, 2001, Last and Stevens 1994, Compagno et al. 2005, Hoese et al. 2006, Last and Chidlow 2008) and was believed to be juvenile O. maculatus. Taxonomic revision of Western Australian species showed that O. parvimaculatus differs from O. maculatus by having have relatively larger and more densely distributed ocelli, and dorsal fins with blackish marginal blotches (absent in O. maculatus). The dorsal fins of O. parvimaculatus are also taller and more upright than those of equivalent size O. maculatus (Last and Chidlow 2008).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Huveneers, C. & McAuley, R.B.|
|Reviewer(s):||Walls, R.H.L. & Kyne, P.M.|
|Facilitator/Compiler(s):||Kyne, P.M., Walls, R.H.L., Simpfendorfer, C. & Chin, A.|
The Dwarf Spotted Wobbegong (Orectolobus parvimaculatus) is a recently described, small (to at least 94 cm total length) wobbegong shark, endemic to Australia. This species is known from 33 specimens taken as bycatch of commercial gillnet and trawl fisheries from the inner continental shelf off southwest Australia, between Shark Bay and Mandurah, at depths of 9–135 m. Although little is known about the biology of the species, this wobbegong is a minor bycatch component of the Western Australian temperate demersal gillnet and demersal longline fisheries, which only catch ~40 tonnes of wobbegongs per year. In addition, the Dwarf Spotted Wobbegong is unlikely to be retained due to its small size and post-release survival of wobbegongs is expected to be high. Further research is required on the species' biology, occurrence, and capture in fisheries, but there is no evidence to infer or suspect population decline, so the species is listed as Least Concern.
|Previously published Red List assessments:||
|Range Description:||The Dwarf Spotted Wobbegong is an Australian endemic, known only from the inner continental shelf off southwest Australia from Shark Bay (26°54′S, 113°00′E) to Mandurah (32°26′S, 115°41′E) (Last and Chidlow 2008, Last and Stevens 2009).|
Native:Australia (Western Australia)
|FAO Marine Fishing Areas:||
Indian Ocean – eastern
|Lower depth limit (metres):||135|
|Upper depth limit (metres):||9|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There is no information available on population size or trend. This species is much less frequently observed in gillnet and trawl bycatch than other wobbegongs (family Orectolobidae).|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The Dwarf Spotted Wobbegong is found on the continental shelf at depths of 9–135 m. The species reaches at least 94.3 cm total length (TL). Male specimens were mature by 70.6 cm TL and females by 87.6 cm TL. The smallest early postnatal juvenile measured 20.8 cm TL (Last and Chidlow 2008). Little is known about the biology of this species, but it is thought to be lecithotrophic viviparous based on the known reproductive mode of other wobbegongs (Huveneers et al. 2007, Huveneers et al. 2011).|
|Use and Trade:||
In Australia, wobbegong 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. Due to their low commercial value, smaller individuals are usually released alive. Given its small size, use and trade of the Dwarf Spotted Wobbegong in Western Australian commercial fisheries is therefore expected to be minimal. Wobbegong fins have no known commercial value. Historically, the attractive skin has been used as decorative leather (Last and Stevens 2009), although it is unknown if this practice is still occurring.
The Dwarf Spotted Wobbegong is a minor bycatch component of the Western Australian temperate demersal gillnet and demersal longline fisheries. The species, along with other wobbegong species occurring within the region, is primarily caught by demersal gillnets off the southern and lower west coasts of Western Australia. Wobbegongs were historically also caught by a few vessels using demersal longlines in the same fishery until the use of that gear was restricted in 2006. The Western Australian temperate demersal gillnet and demersal longline fisheries mean annual wobbegong catch was about 40 tonnes per year (range 28-68 tonnes) between 1999 and 2014 and does not show any sign of decline (Department of Fisheries WA Fishery Status Report 1998-99 to 2013-14, for example, Braccini et al. 2014). Although wobbegong catches are generally not reported to individual species, small wobbegongs (<150 cm) are selectively discarded alive (Chidlow et al. 2007, R. McAuley, unpubl. data) due to low flesh recovery rates from smaller individual. Thus, the Dwarf Spotted Wobbegong is believed to be a minor component of those aggregated catches. In addition, post-release survival of wobbegongs is thought to be high.
Smaller wobbegongs also occur in commercial rock lobster pots throughout temperate coastal Western Australian waters (Chidlow et al. 2007). However, as all sharks and rays are now commercially protected throughout Western Australia, wobbegongs cannot generally be retained by State-managed commercial fishing vessels unless they are operating in the managed shark fishery.
The retained catch of wobbegongs by recreational fishers off the west coast of Australia has been estimated at approximately 1,000 animals per year (Sumner and Williamson 1999), while the estimated annual catch during 2011–12 by recreational fishing from boat licence holders was 1,535 wobbegongs, with 20% or 304 individuals retained (Ryan et al. 2013). Assuming the species composition of recreational wobbegong catches is similar to that of the commercial gillnet fishery, the Dwarf Spotted Wobbegong is also likely to be a minor component of recreational catches.
All sharks and rays are commercially protected under Western Australian law. This regulation essentially restricts the retention of all shark and ray products by commercial fishing vessels other than those operating in the State’s managed shark fishery. The probably small quantity of incidental Dwarf Spotted Wobbegong bycatch is therefore believed to be discarded alive. Although not directly tested, observational evidence suggests that wobbegongs are a hardy group. Trap caught individuals can be released in good condition and post-release survival is presumed to be high.
Relative to the area known to be occupied by the Dwarf Spotted Wobbegong, shark fishing effort (mainly demersal gillnet) is sparsely distributed and managed within specific regional limits via time-gear input controls. For example, the Metropolitan Fishing Zone, between Lancelin and south of Mandurah, was closed to commercial line and gillnet fishing in 2007 as part of a fishing reform package to ensure sustainability of fish for the future. The managed shark fishery's catches and fishing effort are also routinely monitored through analyses of statutory daily/trip logbook data and the fishery's target stocks are subject to regular stock assessments.
The use of commercial shark fishing gear (large mesh gillnets and demersal longlines) is prohibited north of 26°30’S latitude to 120'E longitude off the north coast, which may includes the northern extent of the species’ range. The use of metal snoods (gangions) is commercially prohibited throughout Western Australian waters (except for a small amount of demersal longline effort in the managed shark fishery and pelagic mackerel troll lines). Recreational fishers are subject to a daily bag limit of two sharks per person.
Site attached species such as wobbegongs may also 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). This species is potentially protected in the following Australian marine protected areas, marine parks and nature reserves:
Shark Bay Marine Park, WA
Jurien Bay Marine Park, WA
Hamelin Pool Marine Nature Reserve, WA
Shoalwater Islands Marine Park, WA
Marmion Marine Park , WA
|Citation:||Huveneers, C. & McAuley, R.B. 2015. Orectolobus parvimaculatus. The IUCN Red List of Threatened Species 2015: e.T161651A68639242. . Downloaded on 01 May 2016.|
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