|Scientific Name:||Orectolobus hutchinsi|
|Species Authority:||Last, Chidlow & Compagno, 2006|
Orectolobus sp. [Last & Stevens, 1994] subspecies A
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor/s:||Huveneers, C. & McAuley, R.B.|
|Reviewer/s:||Valenti, S.V. & Pollard, D. (Shark Red List Authority)|
The Western Wobbegong (Orectolobus hutchinsi) is a relatively recently described, medium-sized (to at least 149 cm TL) wobbegong shark, endemic to Australia. This species is known only from shallow waters on the continental shelf off southwestern Australia, between Coral Bay and Groper Bluff, at depths of 0.1?106 m. The Western Wobbegong is captured as bycatch of a commercial gillnet fishery targeting sharks, a rock lobster (pot) fishery and some small demersal trawl fisheries. Although some information is available about the reproductive biology and age and growth of Western Wobbegong, not enough is known about the impacts of commercial wobbegong catches to assess the species beyond Data Deficient. Further research is required on the possible fishery impacts on this species.
|Range Description:||Eastern Indian Ocean: an Australian endemic, known only from the inner continental shelf off southwestern Australia from Coral Bay (23°08?S, 113°46?E) to Groper Bluff (34°30?S, 118°54?E) (Last et al. 2006).|
|FAO Marine Fishing Areas:||
Indian Ocean – eastern
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Unknown, but more frequently observed in gillnet and trawl bycatches than other smaller orectolobids (i.e., O. floridus and O. parvimaculatus).|
|Habitat and Ecology:||
Found on the continental shelf at depths of 0.1?106 m (Chidlow et al. 2007). The species reaches at least 149 cm TL (Last et al. 2006). Male specimens were mature at 112 cm TL and female specimens at 110 cm TL. Females probably breed every two or three years and produce 18?29 young per litter after a gestation of 9?11 months, with parturition occurring between July and September (Chidlow 2003). Offspring are born at a size of 22?26 cm TL with an embryonic sex ratio that does not significantly differ from 1:1 (Chidlow 2003). Orectolobus hutchinsi are considered opportunistically-selective feeders that prefer a diet of demersal teleosts and octopi (Chidlow 2003).
Von Bertalanffy growth parameters estimated from vertebral cross-sections and an assumed annual banding pattern were L = 149.45 and K = 0.117 year-1. Although the periodicity of vertebral band formation in captive animals did not support synchronous annual vertebral band deposition, captive growth rates matched those predicted with an annual band-deposition frequency (Chidlow et al. 2007).
Orectolobus hutchinsi is a component of the bycatch of a commercial fishery that targets sharks, primarily with demersal gillnets, off the southern and lower west coasts of Western Australia. Wobbegongs are also caught within the rock lobster (pot) fishery and some small demersal trawl fisheries. Wobbegongs were targeted by a few vessels using demersal longlines in the same fishery until the use of that gear was restricted in 2006. That fishery?s mean annual wobbegong catch was about 45 tonnes year-1 (range 35?68 tonnes) between 1999 and 2006 (McAuley 2007). Although wobbegong catches are generally not reported to individual species, small wobbegongs (<150 cm) are selectively discarded alive (Chidlow et al. 2007, McAuley unpublished data). Thus, O. Hutchinsi is believed to be a small component of those aggregated catches with only large specimens being kept.
Small orectolobids 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 generally cannot 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 year-1 (Sumner and Williamson, 1999). Although the species composition of recreational wobbegong catches is unknown, it is suspected that the majority may be comprised of O. hutchinsi.
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.
Relative to the area known to be occupied by O. hutchinsi, shark fishing effort (mainly demersal gillnet) is sparsely distributed and managed via time-gear input controls. The managed shark fishery?s catches and fishing effort are 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 include 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.
This species is potentially protected in the following Australian Marine Protected Areas, Marine Parks and nature reserves:
Ningaloo Marine Park, WA
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. 2009. Orectolobus hutchinsi. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 12 March 2014.|
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