|Scientific Name:||Orectolobus ornatus (de Vis, 1883)|
|Taxonomic Notes:||Orectolobus ornatus was previously synonimised with O. halei and was believed to be the juvenile form of O. halei. Taxonomic revision of New South Wales species showed that O. ornatus differs from O. halei in color pattern (more freckled in O. ornatus), an adult size smaller than 120 cm TL, fewer dermal lobes at the posterior preorbital group (3-4), precaudal vertebrae count (<106), spiral valve count (<25), and the absence of supraorbital knob. Morphometrically, O. ornatus has a longer pelvic fin to anal fin interspace, smaller pectoral fins, smaller head dimensions, and relatively smaller claspers in mature specimens (Huveneers 2006).
Assessment is complicated by taxonomic uncertainties based on the identification of the Papua New Guinea specimen. This species should at present be considered as an Australian endemic (L.J.V. Compagno, pers. comm.).
|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 Ornate Wobbegong (Orectolobus ornatus) is an Australian endemic species. Previous records from Papua New Guinea, Indonesia, and Japan could be different undescribed species of wobbegongs. A biologically sensitive species, site-attached within its relatively shallow water range and previously 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 1997-98 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 Ornate Wobbegong, to be 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 days 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 180 cm for the Ornate Wobbegong and the Banded Wobbegong (O. halei) implemented between 2008 and 2013 effectively protected the Ornate Wobbegong since its maximum size is about 120 cm total length. 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. As a result, there is no evidence to infer or suspect population decline of the Ornate Wobbegong, and current catches are relatively low and not spread across the species' distribution, resulting in the species being listed as Least Concern.
|Previously published Red List assessments:|
|Range Description:||The Ornate Wobbegong is an eastern Australian endemic that has been recorded from the Whitsunday Islands (20°20'S 148°54'E, Australian Museum specimen IA 3831) southwards with confirmed reports from Port Stephens (32°43'S, 152°11'E, Australian Museum specimen I 43621-001-5) (Huveneers 2006) and likely reports in Sydney (Huveneers 2007).|
Other sources (Last and Stevens 2009, Compagno 2001) show the global distribution of the Ornate Wobbegong as including Indonesia, Papua New Guinea, and Japan. However, wobbegongs from these areas could be misidentified specimens or different undescribed species of wobbegongs.
Native:Australia (New South Wales, Queensland)
|FAO Marine Fishing Areas:|
Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There is currently no information available on population size or trend of this species. A phylogeographic study showed no evidence of subpopulations (Corrigan 2009), but the Ornate Wobbegong population was previously considered the juvenile of the Banded Wobbegong (O. halei) (Huveneers 2007).|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The Ornate Wobbegong is a common inshore bottom-dwelling shark of continental waters that is found in bays, on macroalgal rocky reef areas, coral reefs (including lagoons and reef flats, reef faces, and reef channels), and around offshore islands (Compagno 2001). In a study in Port Stephens, New South Wales, the Ornate Wobbegong 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 species 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 Ornate Wobbegong occurs inshore on the continental shelf to at least 100 m depth (Last and Stevens 2009, Compagno 2001) and is also known from around offshore islands such as Heron Island (P. Hallam, pers. comm., 2007). It is often found in clearer water than the closely related Spotted Wobbegong (O. maculatus) (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). Furthermore, the Ornate Wobbegong has been re-sighted within a 75 hectare area for a period of over 211 days (Carraro and Gladstone 2006), whereas a sympatric species, the Banded Wobbegong, has been recorded within the same area for over 2.5 years suggesting site fidelity for wobbegongs (Huveneers et al. 2006, Huveneers, unpubl. data).
Compagno (2001) describes this shark as a nocturnal species that rests on the bottom during the day in caves, under ledges on reefs, and in trenches and that undertakes nocturnal excursions away from resting areas.
Although the Ornate Wobbegong was previously believed to mature at about 175 cm total length (TL), further studies revealed that the Banded Wobbegong actually matures at about 175 cm TL, whereas the Ornate Wobbegong matures at about 80 cm TL (Huveneers 2007, Huveneers et al. 2007). Similar to the Banded Wobbegong and the Spotted Wobbegong, the Ornate 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. 2007). The Ornate Wobbegong is lecithotrophic viviparous with a litter size ranging from 4-18 (mean 9) and a size at birth of about 20 cm TL (Huveneers et al. 2007, Huveneers et al. 2011). Maximum length is about 120 cm TL (Huveneers 2006).
Growth parameters were estimated from 275 Ornate Wobbegong vertebrae 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 logistic growth function, and estimated growth parameters were: 99.9 cm total length for L∞ and 0.19 for k. The maximum number of growth bands was 20 (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 wobbegongs is more likely to be linked to somatic growth than seasonality (Huveneers et al. 2013). Newborn captive Ornate Wobbegong grew about 20 cm TL year-1 (Huveneers et al. 2013).
|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. 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.
Commercial fishing is probably the main threat 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 (Spotted Wobbegong, Ornate Wobbegong, and 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 orectolobid 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 Ornate Wobbegong ranged from 38-89 kg per fishing days (mean 60 kg) and 1.7-4.3 tonnes per year (mean 2.7 tonnes) and showed no declines.
Wobbegongs are not targeted in Queensland. The Banded Wobbegong has been recorded in low numbers in the bycatch of prawn trawl fisheries (Kyne et al. 2002), whereas small wobbegongs, such as the Ornate Wobbegong, are sometimes caught by crab pots in Southeast Queensland and Moreton Bay, but are usually discarded (J. Stead, pers. comm., 2007).
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.
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. Since the Ornate Wobbegong does not grow larger than 120 cm, the minimum size limit effectively prohibited the landing of this species. 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).
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.
Australian marine protected areas in which the species occurs:
Moreton Bay Marine Park, Qld
Great Sandy 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
Recreational fishers may also have had a negative effect on this species in the past. An in-possession limit of two wobbegong sharks 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 effects caused by recreational fishing practices. A possession limit for recreational fishers of one shark applies in Queensland.
|Citation:||Huveneers, C., Pollard, D.A., Gordon, I., Flaherty, A.A. & Pogonoski, J. 2015. Orectolobus ornatus. The IUCN Red List of Threatened Species 2015: e.T41838A68638906.Downloaded on 19 June 2018.|
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