|Scientific Name:||Orectolobus maculatus (Bonnaterre, 1788)|
|Taxonomic Notes:||In New South Wales, O. maculatus is often confused with O. halei, but differs from O. halei by having more (6-10 dermal lobes at the posterior preorbital group) and saddles containing whitish rings and blotches (unlike O. halei).
In Western Australia, O. maculatus was previously synonymised with O. parvimaculatus. Taxonomic revision of Western Australian species showed that O. maculatus differs from O. parvimaculatus by having have relatively smaller and less densely distributed ocelli and dorsal fins lacking dark markings (blackish marginal blotches present in O. parvimaculatus). The dorsal fins of O. maculatus are also smaller and less upright than those of O. parvimaculatus (Last and Chidlow 2008).
Records from Japan and the South China Sea are likely to be mis-identified O. japonicus or another undescribed species.
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Huveneers, C., Pollard, D.A., Gordon, I., Flaherty, A.A. & Pogonoski, J.|
|Reviewer(s):||Walls, R.H.L. & Kyne, P.M.|
|Facilitator/Compiler(s):||Kyne, P.M., Walls, R.H.L., Simpfendorfer, C. & Chin, A.|
The Spotted Wobbegong (Orectolobus maculatus) is probably an Australian endemic species. Previous records from Japan and the South China Sea are either misidentified Japanese Wobbegong (O. japonicus) or a different species of wobbegong (family Orectolobidae). The Spotted Wobbegong is a biologically sensitive species, site-attached within its relatively shallow water range (0–218 m) and caught in commercial and recreational fisheries as a target species and as bycatch. In New South Wales, wobbegong catches combining all fishing methods and fisheries declined by more than 50% between 1997-1998 and 2007-08 after which it stabilized to around 20 tonnes. This led to all three species of wobbegongs occurring in New South Wales, including the Spotted Wobbegong, being regionally listed as Vulnerable in New South Wales. However, fishing effort reported as the number of days fished also declined between 1990-91 and 2008-09, resulting in catch rate being relatively constant around 15 kg per fishing day from 1990-91 until 2009. Fishing effort and ensuing catch rate should, however, be used with caution because it is coarsely reported as the number of days fished and does not account for the number of hooks used or soak times. Since September 2006, wobbegongs have been included in the daily trip limit for a specific list of shark species to one tonne for a 24 hour period and two tonnes for 48 hours or greater. New management regulations in May 2008 introduced a daily limit of six wobbegongs. A minimum size limit of 130 cm total length for the Spotted Wobbegong implemented between 2008 and 2013 protected juveniles. Although the minimum size limit is no longer applicable, wobbegongs are no longer targeted to the same extent as they used to because of the trip limit implemented in 2008. In addition, further investigation of the New South Wales fishing catches and effort revealed that the catch per unit effort did not decrease as thought in the previous assessment. Wobbegongs are not targeted and catches are low in other Australian states (Western Australia, Queensland, South Australia, and Victoria). As a result, there is no evidence to infer or suspect population decline of the Spotted Wobbegong, and current catches are relatively low, resulting in a listing of Least Concern.
|Previously published Red List assessments:|
|Range Description:||The Spotted Wobbegong is most likely an Australian endemic wobbegong and has been recorded from tropical eastern Australia with confirmed reports from Gladstone (22°S), Queensland (Kyne et al. 2005) southwards to Hobsons Bay (37°52'S), Victoria, westwards to St. Vincents Gulf (35°10'S, 137°55'E), South Australia, and north-westwards to Bessieres Island (21°23'S, 114°41'E), Western Australia (J. Chidlow, pers. comm., 2007). Tasmanian records are probably invalid (Last and Stevens 2009).|
Previous sources (Last and Stevens 1994, Compagno 2001) show that the global distribution of the Spotted Wobbegong includes Japan and the South China Sea. However, wobbegongs from these areas are either misidentified Japanese Wobbegong (O. japonicus) or different undescribed species.
Native:Australia (New South Wales, Queensland, South Australia, Victoria, Western Australia)
|FAO Marine Fishing Areas:|
Indian Ocean – eastern; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
There is currently no information available on the population size or trend of this species. A phylogeographic study showed no evidence of subpopulations in Queensland and New South Wales (Corrigan 2009), but the Dwarf Spotted Wobbegong (O. parvimaculatus) population was previously considered the juvenile of the Spotted Wobbegong (Last and Chidlow 2008).
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Compagno (2001) describes this species as 'an abundant, temperate to tropical, inshore to offshore bottom shark of the continental shelves of the western Pacific, commonly on coral and rocky reefs, in coastal bays, in estuaries, in seagrass beds, under piers, and on sandy bottoms.' Juveniles occur in estuaries and are occasionally found over seagrass beds. It can occur in water barely deep enough to cover it, and has been observed climbing ridges between tide pools with its back out of water (Compagno 2001). In a study in Port Stephens, New South Wales, a sympatric species of wobbegong (the Ornate Wobbegong O. ornatus) was shown to prefer sponge gardens, artificial structures and barren boulders habitats with a high topographic complexity and crevice volume (Carraro and Gladsone 2006). However, the Ornate Wobbegong did not seem to select habitat on the basis of prey availability and habitat selection may therefore be related to predator avoidance (Carraro and Gladsone 2006). The Spotted Wobbegong occurs on the continental shelf to at least 218 m depth (Kyne et al. 2005). It is often found in murkier water than the closely related Banded Wobbegong (O. halei) (Lieske and Myers 1994).|
A survey on wobbegongs shows evidence of site attachment with divers observing individual sharks in exactly the same positions over consecutive dives (The Ecology Lab 1991). An acoustic telemetry study within a small ∼0.2 km2 no-take marine reserve off Sydney showed that the Spotted Wobbegong seasonally resided inside the reserve over the warmer months (September-March), with one individual returning to the reserve every year for five years (Lee et al. 2015). None of the tagged individuals remained inside the reserve throughout the year (Lee et al. 2015). A sympatric species of wobbegong (the Banded Wobbegong) has also been recorded within the same area for over 2.5 years (Huveneers et al. 2006, Huveneers unpubl. data).
Although the Spotted Wobbegong was reported to mature at about 60 cm total length (TL) (Compagno 2001), this size at maturity is likely to be related to the Dwarf Spotted Wobbegong from Western Australia (Last and Chidlow 2008), whereas the Spotted Wobbegong matures at about 120 cm TL (Huveneers et al. 2007b). Similar to the Ornate Wobbegong and the Banded Wobbegong, the Spotted Wobbegong has a triennial reproductive cycle with follicles taking two years to enlarge before ovulation. During the first year, follicles remain small, then grow rapidly during the second year prior to ovulation during November. Gestation lasts about 10-11 months with parturition occurring during September-October (Huveneers et al. 2007b). The Spotted Wobbegong is lecithotrophic viviparous with a litter size of about 21 with up to 37 young recorded (Grant 1978) and a size at birth of about 23 cm TL (Huveneers et al. 2007b). Maximum length is about 320 cm TL, but with most individuals caught being smaller, up to 150-180 cm TL (Compagno 2001).
Growth parameters were estimated from vertebrae of 232 individuals collected off New South Wales. Taking into account biologically meaningful estimations of L∞ and k, the models with the best fit to the data was the von Bertalanffy growth function, and estimated growth parameters were: 163 cm total length for L∞ and 0.09 for k, and the maximum number of growth bands was 22 (Huveneers et al. 2013).Verification and validation undertaken using edge and marginal increment analyses, as well as chemical marking of captive and wild wobbegongs, suggested that growth band deposition in orectolobids is more likely to be linked to somatic growth than seasonality (Huveneers et al. 2013). Neonates of ~32 cm TL grew ~2.4 cm month-1, whereas neonates of 41–45 cm TL grew ~1.7–2.0 cm month-1 as did two juvenile of ~57 cm TL. Five individuals of ~66 cm TL grew ~0.85 cm month-1 (Huveneers et al. 2013).
|Use and Trade:||
Historically, the attractive skin has been used as decorative leather (Last and Stevens 2009). However, it is unknown if this practice is still occurring. In Australia, wobbegong flesh is sold locally for human consumption through ‘fish and chip’ and fresh fish retail outlets. Wobbegong fins have no known commercial value.
Commercial fishing is probably the main threats to this species in eastern Australia. Observed site fidelity is likely to increase wobbegong susceptibility to fishing pressure. On an Australia-wide basis, wobbegongs are commonly caught in trawls, beach seines, gillnets, lobster pots and traps, by hook-and-line, and also by spearfishing.
In New South Wales, three wobbegong species (the Spotted Wobbegong, the Ornate Wobbegong, and the Banded Wobbegong) are taken in the Ocean Trap and Line Fishery (OTL), in the fish and prawn sectors of the Ocean Trawl Fishery, and very few in the Estuary General Fishery. The majority of commercial wobbegong catches occur in the OTL fisheries, where they have historically been taken as both a target species by setline methods and as byproduct by other methods (NSW Department of Primary Industries, unpubl. data). The New South Wales total catch of wobbegongs, combining all fishing methods and fisheries, has declined from about 120 tonnes in 1990-91 to about seven tonnes in 2008-09, after which catches stabilized and have remained around 20 tonnes up to 2013-14. As a result, the previous assessment in 2007 listed the three wobbegong species caught in New South Wales as Vulnerable regionally (for New South Wales) because of a 55% decline in catches in less than a decade (Pease and Grinberg 1995, NSW Department of Primary Industries, unpubl. data). However, fishing effort reported as the number of days fished also declined between 1990-91 and 2008-09, resulting in catch rate being relatively constant around 15 kg per fishing days from 1990-91 until 2009. Catch rates after 2009 increased to about 70 kg per day, but are not directly comparable to values prior to 2009 as catch reporting changed from monthly to daily summaries in July 2009. Prior to July 1997, catches from other jurisdictions landed into New South Wales were also included. Fishing effort and ensuing catch rate should, however, be used with caution because it is coarsely reported as the number of days fished and does not account for the number of hooks used or soak times. Additionally, the historical aggregation of the wobbegong species in catch data until July 2009 is a further complicating factor. Based on species-specific reporting from July 2009, catches of the Spotted Wobbegong ranged from 51-65 kg per fishing days (mean 58.4 kg) and 4.9-9.9 tonnes per year (mean 6.5 tonnes) and showed no declines.
Wobbegongs are not targeted in Queensland, but have been recorded in low numbers in the bycatch of prawn trawl fisheries (Kyne et al. 2002). Small wobbegongs are sometimes caught by crab pots in Southeast Queensland and Moreton Bay, but are usually discarded (J. Stead, pers. comm., 2007).
In South Australia, wobbegongs are infrequently sold at the Adelaide Fish Market. Commercial catches of wobbegong (unspecified species) are small ranging ~0.5–4 tonnes, with the highest yearly catch being in the mid 1980s (A. Tsolos, pers. comm., March 2015). In southern Australia, a small number of wobbegongs are taken within the Southern and Eastern Scalefish and Shark Fishery (SESSF). Estimates of mean annual catch mass of the Spotted Wobbegong in the SESSF during 2000–06 was 24.5 tonnes (Walker and Gason 2007).
The Spotted Wobbegong is a small component of the bycatch 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. Fisheries-dependent surveys of southwest Western Australia fisheries reported that the Spotted Wobbegong constituted 0.7% and 0.4% of total elsamobranch catches from gillnet and longline gear, respectively (Jones et al. 2010). The Western Australian temperate demersal gillnet and demersal longline fisheries mean annual wobbegong catch is about 40 tonnes year-1 (range 28-68 tonnes) between 1999 and 2014 and does not show any sign of decline (Department of Fisheries Western Australia 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, pers. comm.) due to low flesh recovery rates from smaller individual. Thus, the Spotted Wobbegong and the Banded Wobbegong are believed to be a major component of those aggregated catches. If discarded, 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 National Recreational and Indigenous Fishing Survey (Henry and Lyle 2003) reported that 5,174 wobbegongs (all species combined) were caught and kept by recreational fishers in southern Australian states during the survey time period (May 2000 to April 2001), comprising 1,944 from New South Wales, 999 from Queensland, 252 from South Australia, and 1,978 from Western Australia. 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), while the estimated annual catch during 2011–12 by Western Australian recreational fishing from boat licence holders was 1,535 wobbegongs, with 20% or 304 individuals retained (Ryan et al. 2013).
Until late 2006, there were no management strategies specifically regulating the wobbegong commercial fishery in New South Wales. The only regulation in place was a recreational bag limit of two wobbegongs per day (later reduced to zero in September 2007) and a commercial gear limit of no more than ten lines each with a maximum of six hooks when setlining within three nautical miles of the coast. There were no gear limits outside three nautical miles, but as of 2008, amendments to the share management plans instated a maximum of 1,200 hooks and 30 traps per endorsement holder. Since September 2006, wobbegongs have been included in the daily trip limit for a specific list of shark species to one tonne for a 24 hour period and two tonnes for 48 hours or greater. New South Wales Department of Primary Industries also recommended that fishers in the Ocean Trap and Line (OTL) and Lobster fisheries have in their codes of practice to release wobbegongs less than 130 cm TL caught in fish traps. Since July 2007, the use of wire trace, or other trace made of metal type materials, is prohibited to decrease instances of gut-hooking.
As a result of the observed decline in New South Wales wobbegong catches and following a study of the biology and ecology of orectolobids in New South Wales (Huveneers 2007), new management regulations were introduced in May 2008 for the three species of wobbegongs for the Lobster and OTL fisheries, including a daily limit of six wobbegongs and a minimum size limit of 180 cm for the Ornate Wobbegong and the Banded Wobbegong, and 130 cm for the Spotted Wobbegong. The similar minimum size limit for the Ornate Wobbegong and the Banded Wobbegong was selected due to potential difficulties for fishers to differentiate the two species and was based on the size-at-maturity of the Banded Wobbegong. In April 2010, amendments to the Lobster and OTL Share Management Plans provided for the six carcass trip limit to remain in place, but the minimum size limit lapsed with the fishing closure in May 2013. In March 2011, amendments to the Ocean Trawl Share Management Plan provided for the same six carcass trip limit than the Lobster and OTL fisheries (V. Silberschneider, pers. comm., February 2015).
In Western Australia, 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 the Spotted Wobbegong, shark fishing effort (mainly demersal gillnet) is sparsely distributed and managed 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 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).
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). Some protection may be offered by those protected areas already being implemented for the Grey Nurse Shark (Carcharias taurus) in New South Wales. This species is potentially protected in the following Australian marine protected areas, marine parks and nature reserves:Great Sandy Marine Park, Qld
Moreton Bay Marine Park, Qld
Cape Byron Marine Park, Byron Bay, northern NSW
Julian Rocks Aquatic Reserve, off Byron Bay, northern NSW
Solitary Islands Marine Park, north of Coffs Harbour, NSW
Port Stephens-Great Lakes Marine Park, north of Sydney, central NSW
Jervis Bay Marine Park, south of Sydney, NSW
Batemans Marine Park, south of Sydney, NSW
Shark Bay Marine Park, WA
Ningaloo Marine Park, WA
Jurien Bay Marine Park, WA
All Victorian marine parks
All South Australian marine parks
Possibly also occurs in the following areas:
Hamelin Pool Marine Nature Reserve, WA
Shoalwater Islands Marine Park, WA
Marmion Marine Park , WA
Muiron Islands Marine Management Area, WA
Recreational fishers may also have had a negative effect on this species in the past. An in-possession limit of two wobbegongs per person was introduced for recreational fishers in New South Wales and reduced to zero in September 2007. This new regulation may help to alleviate any adverse affects caused by recreational fishing practices. In Western Australia, recreational fishers are subject to a daily bag limit of two sharks per person, and in Queensland, one shark per person.
|Citation:||Huveneers, C., Pollard, D.A., Gordon, I., Flaherty, A.A. & Pogonoski, J. 2015. Orectolobus maculatus. The IUCN Red List of Threatened Species 2015: e.T41837A68638559.Downloaded on 20 March 2018.|