Dipturus wengi 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Rajiformes Rajidae

Scientific Name: Dipturus wengi
Species Authority: Séret & Last, 2008
Common Name(s):
English Weng's Skate
Taxonomic Notes: Weng’s Skate (Dipturus wengi) appears to belong to a complex of closely related skate species that differ only slightly in their morphology (Last and Stevens 2009). Records of this species from off Indonesia and the Philippines are likely a different species.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2015-04-25
Assessor(s): Bigman, J.S., Ebert, D.A. & Kyne, P.M.
Reviewer(s): Walls, R.H.L. & Dulvy, N.K.
Facilitator/Compiler(s): Kyne, P.M. & Walls, R.H.L.

Weng’s Skate (Dipturus wengi) is a poorly-known deepwater skate that is endemic to eastern and southeast Australia, although the full extent of it's range is uncertain. It occurs on the continental slope at depths of 485–1,165 m (primarily 600–1,000 m). Its range overlaps with a number of commercial fisheries along the east coast of Australia. Most notably, fishing pressure has been historically high on the upper continental slope off southeast Australia, where declines have been demonstrated in the upper slope skate community. However, the species is naturally less common in this region, and is more abundant in the north of its range in deep tropical waters off Queensland. Fishing pressure is much lower in this region, and in fact there has been no demersal trawling recently in the Commonwealth managed Coral Sea Fishery, the management area of which overlaps with this skate. As such, the species has refuge in unfished or only lightly fished areas in the north of its range and in the deeper parts of its bathymetric occurrence. Despite the lack of information concerning its population size and structure, life history and ecology, an assessment of Least Concern is warranted. Bycatch levels and any changes or expansion in deepwater fisheries need to be monitored.

Previously published Red List assessments:
2011 Least Concern (LC)

Geographic Range [top]

Range Description:Weng’s Skate is distributed along the continental slope off eastern Australia from west of Lihou Reef and Cays, Queensland (16º54’S, 151º30’E) and southward to Bicheno, Tasmania (~42ºS, 148ºE). It has been found off Queensland, New South Wales, and eastern Tasmania, but has not been confirmed in the Great Australian Bight or off Western Australia. It likely occurs off western Tasmania, but populations off Western Australia (between Albany and Rowley Shoals) may in fact be a closely-related species (Séret and Last 2008, Last and Stevens 2009).
Countries occurrence:
Australia (New South Wales, Queensland, Tasmania, Victoria)
FAO Marine Fishing Areas:
Indian Ocean – eastern; Pacific – western central; Pacific – southwest
Lower depth limit (metres):1165
Upper depth limit (metres):485
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Weng's Skate is most common in deep tropical waters and rarer in cool temperate waters (Last and Stevens 2009). There are no population estimates for this species.
Current Population Trend:Unknown
Additional data:

Habitat and Ecology [top]

Habitat and Ecology:This skate occurs most commonly along the continental slope in the tropical waters of Queensland and more rarely in cool temperate waters, at depths of 485–1,165 m, but mostly between 600–1,000 m (Séret and Last 2008, Last and Stevens 2009). It reaches at least 128 cm total length (TL) with a size-at-birth of about 20 cm TL (Last and Stevens 2009), but its biology is poorly known.

Use and Trade [top]

Use and Trade: There is no known use or trade of this species.

Threats [top]

Major Threat(s): The range of this skate overlaps with a number of commercial fisheries along the east coast of Australia. Most notably, fishing pressure has been historically high on the upper continental slope off southeast Australia. The Commonwealth Trawl Sector of the Commonwealth managed Southern and Eastern Scalefish and Shark Fishery (SESSF) operates in the southern portion of the species' range. In trawl surveys within this region at depths of 200–650 m over a 20 year period, Graham et al. (2001) demonstrated a decline in slope skate species of >83%. Weng's Skate (as Raja sp. I) was a small component of catches in the deeper depth zone and has no doubt been effected by the level of fishing pressure on the slope off southeast Australia. The closure of most areas below 700 m now provide refuge for this species in deeper waters (Georgeson et al. 2014).

The northern part of the species' range, where it is apparently more common (Last and Stevens 2009), overlaps with the Commonwealth managed Coral Sea Fishery. This is a relatively small-scale fishery with few active vessels and no trawl effort since the 2006-07 fishing season (Noriega et al. 2014). This fishery is not likely to be having any significant effect on this skate.

Conservation Actions [top]

Conservation Actions: This species has refuge at depth in areas closed to trawling off southeast Australia (Georgeson et al. 2014) and in some marine protected areas of the Commonwealth Marine Reserve, including the Coral Sea Commonwealth Marine Reserve. Bycatch levels should be monitored in commercial fisheries that overlap with its range. Furthermore, research is required into its life history and ecology.

Classifications [top]

In-Place Research, Monitoring and Planning
  Action Recovery plan:No
  Systematic monitoring scheme:No
In-Place Land/Water Protection and Management
  Conservation sites identified:No
  Occur in at least one PA:Yes
  Area based regional management plan:No
  Invasive species control or prevention:Not Applicable
In-Place Species Management
  Harvest management plan:No
  Successfully reintroduced or introduced beningly:No
  Subject to ex-situ conservation:No
In-Place Education
  Subject to recent education and awareness programmes:No
  Included in international legislation:No
  Subject to any international management/trade controls:No
5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.4. Unintentional effects: (large scale)
♦ timing: Ongoing ♦ scope: Minority (<50%) ♦ severity: Unknown ⇒ Impact score: Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
3. Monitoring -> 3.1. Population trends

Bibliography [top]

Georgeson, L., Stobutzki, I. and Curtotti, R. (eds). 2014. Fishery Status Reports 2013-14. Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.

Graham, K.J., Andrew, N.L. and Hodgson, K.E. 2001. Changes in the relative abundances of sharks and rays on Australian South East Fishery trawl grounds after twenty years of fishing. Journal of Marine and Freshwater Research 52: 549-561.

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015-4. Available at: www.iucnredlist.org. (Accessed: 19 November 2015).

IUCN SSC Shark Specialist Group. Specialist Group website. Available at: http://www.iucnssg.org/.

Last, P.R. and Stevens, J.D. 2009. Sharks and Rays of Australia. Second Edition. CSIRO Publishing, Collingwood, Australia.

Noriega, R., Hansen, S. and Mazur, K. 2014. Coral Sea Fishery. In: Georgeson, L., Stobutzki, I. and Curtotti, R. (eds), Fishery status reports 2013-14, pp. 48-60. Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.

Séret, B. and Last, P.R. 2008. A new Australian skate of the genus Dipturus (Rajoidei: Rajidae). In: Last, P.R., White, W.T., Pogonoski, J.J., and Gledhill, D.C (eds), Descriptions of New Australian Skates, CSIRO Marine and Atmospheric Research Paper No. 021.

Citation: Bigman, J.S., Ebert, D.A. & Kyne, P.M. 2015. Dipturus wengi. In: The IUCN Red List of Threatened Species 2015: e.T195453A68621850. . Downloaded on 29 November 2015.
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