Urolophus Orarius (Coastal Stingaree) (Last and Gomon, 1987)

The Minister decided this species was not eligible for listing as threatened on 21 December 2009

Advice to the Minister for the Environment, Heritage and the Arts from the Threatened Species Scientific Committee (the Committee) on Amendment to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)

1. Name

Urolophus orarius The species is commonly known as the Coastal Stingaree. It is in the Family Urolophidae.

2. Reason for Conservation Assessment by the Committee

This advice follows assessment of information provided by a public nomination to list the Coastal Stingaree. The nominator suggested listing in the vulnerable category of the list.

This is the Committee’s first consideration of the species under the EPBC Act.

3. Summary of Conclusion

The Committee judges that the species is not eligible for listing in any category.

4. Taxonomy

The species is conventionally accepted as Urolophus orarius (Coastal Stingaree) (Last and Gomon, 1987).

5. Description

The Coastal Stingaree is a small stingray that grows up to 34 cm in length (SARDI, unpubl. data, 2009). It has a subcircular, disk-shaped body, a stout tail about three-quarters the length of the body disk, a spear-shaped tail fin, and no dorsal fin. It bears a stout and prominent, serrated, poisonous spine on the middle reaches of its tail. Its upper side is coloured greyish to brown, with dark blotches across the eyes, body and base of the tail. Its underside is pale whitish-grey (Last and Gomon, 1987).

6. National Context

The Coastal Stingaree is endemic to inshore areas of the eastern half of South Australia’s coastlines, from Beachport to Ceduna. It is present in the southern areas of both Spencer Gulf and Gulf St Vincent but the northern areas of the gulfs are considered unsuitable habitat (Last, pers. comm., 2009). It is currently known to use habitats between the 14 and 50 metre depth range, with the majority of records of the species coming from the 20 to 50 metre depth range. The species may utilise shallower habitats as well, however there has been no sampling in shallow waters. Almost all records of the species are from prawn trawl by-catch, which is restricted to depths of more than 10 metres. Recreational divers have reported a few sightings of the species in water less than 10 metres deep (Last, pers. comm., 2009; SA DEH, unpubl. data, 2009).

Urolophus orarius (Coastal Stingaree) Listing Advice — Page 1 of 6 The Minister decided this species was not eligible for listing as threatened on 21 December 2009

The Coastal Stingaree’s distribution occurs in the Eyre Meso-scale Bioregion , the Murat Meso- scale Bioregion and the Great Australian Bight Transition of the Integrated Marine and Coastal Regionalisation of Australia (IMCRA v4.0) scheme.

The Coastal Stingaree’s distribution occurs in the Spencer Gulf Prawn Fishery, the Gulf St Vincent Prawn Fishery and the West Coast Prawn Fishery, which target the Western King Prawn (Melicertus latisulcatus) and are managed by Primary Industries and Resources South Australia (PIRSA).

7. Relevant Biology / Ecology

The Coastal Stingaree is a small stingray species that utilises inshore habitats with sand substrates and depth ranges of 14–50 metres, and possibly shallower depths. It is considered to be a sparsely distributed species with low abundance (Walker, 2004; Last et al., 2006).

Little is known about the Coastal Stingaree’s diet, but other Urolophus species feed primarily on small crustaceans (Trinnie, 2003).

Little is known about the species’ reproductive biology, however the biology of closely related species in the Urolophus genus has been studied. These studies show that Urolophus species become sexually mature at a relatively late stage in female fish, have a long 10–12 month gestation period and produce relatively few young (generally one to two, four or six, depending on the species) (Trinnie, 2003; White and Potter, 2005). The young are developed internally, feeding on their yolk sacs but also receive nourishment from nutrient-rich uterine fluids, a phenomenon termed matrotrophic viviparity (Dulvy and Reynolds, 1997). The young are very large relative to the size of adult fish (Trinnie, 2003; White and Potter, 2005). There is a fair probability that the Coastal Stingaree has a similar reproductive biology.

8. Description of Threats

The main threat to the Coastal Stingaree is mortality resulting from capture as by-catch in prawn trawl fisheries. The current known depth range for the species coincides with the depths prawn trawling is undertaken in Spencer Gulf and Gulf St Vincent and adjacent areas. Walker (2004) categorises the species as having a high risk of being encountered during trawl fishing, a high selectivity to trawl fishing gear and a medium risk of mortality during the by-catch sorting process.

In addition to direct mortality, by-catch is likely to reduce recruitment rates, as stingaree species tend to spontaneously abort their young while on sorting tables (White, pers. comm., 2009). Last et al. (2006) report similar observations. If present in the Coastal Stingaree, this behaviour, combined with the long gestation of stingaree species (10–12 months) and the risk of gravid Coastal Stingarees being caught in any 12 month period in the trawl zone, may significantly reduce recruitment rates.

Prawn trawling has also degraded or altered benthic habitats and ecological communities in areas of Gulf St Vincent, which is likely to impact on the Coastal Stingaree given the species’ habitat preferences (Tanner, 2003, 2005). Damage to coastal marine habitats as a result of dredging projects or other developments are a potential threat to the species.

The South Australia prawn trawl fisheries feature various gear restrictions, seasonal closures, depth restrictions and other management arrangements intended to reduce by-catch and environmental impact. Notably, the number of licences in the fisheries are fixed, and this along

Urolophus orarius (Coastal Stingaree) Listing Advice — Page 2 of 6 The Minister decided this species was not eligible for listing as threatened on 21 December 2009 with a biologically determined total allowable catch, means there is not expected to be any significant future increase in fishing effort in these fisheries.

9. Public Consultation

The nomination used in this assessment was made available for public exhibition and comment for 30 business days. No public comments were received.

10. How judged by the Committee in relation to the criteria of the EPBC Act and Regulations

The Committee judges that the species is not eligible for listing under any category under the EPBC Act. The assessment against the criteria is as follows:

Criterion 1: It has undergone, is suspected to have undergone or is likely to undergo in the immediate future a very severe, severe or substantial reduction in numbers.

While there have been no targeted surveys for the Coastal Stingaree, the species has been recorded in prawn trawling by-catch surveys in Spencer Gulf and Gulf St Vincent. No pattern of decline in numbers is indicated in by-catch data dating from the late 1990s to present (Carrick, 1997; PIRSA, 2003; Dixon et al., 2005; SARDI, unpubl. data, 2009). While data gathered in prawn trawling surveys do not indicate a past decline in species’ numbers, as there have been no targeted population surveys for the Coastal Stingaree, the impacts of commercial fishing are difficult to determine. Therefore the Committee considers that there are insufficient data to determine whether the Coastal Stingaree has undergone a substantial reduction in numbers.

The Coastal Stingaree is subject to the ongoing threat of prawn trawl fisheries which can cause mortality, abortion of young and degradation of suitable habitat. This threat may lead to reduced recruitment rates given the species’ biological characteristics of low fecundity and delayed sexual maturity. However, there are insufficient data available to determine whether this will result in a future decline in the species’ numbers.

There are insufficient data to establish whether the species has undergone or will undergo a decline in numbers in biologically relevant timeframes, therefore the species has not been demonstrated to have met the required elements of Criterion 1, and is not eligible for listing in any category under this Criterion.

Criterion 2: Its geographic distribution is precarious for the survival of the species and is very restricted, restricted or limited.

Based on prawn trawling by-catch and museum records, the Coastal Stingaree’s geographic distribution is considered to encompass inshore areas of the eastern half of South Australia’s coastline between Beachport and Ceduna, including all seabed between depths of 14–50 metres and including the eastern half of the Great Australian Bight, but excluding the northern areas of the gulfs. Based on this distribution, the species’ extent of occurrence is indicated to be up to 40,000 km2 (DEWHA, 2009), however this figure is not likely to be absolutely definitive. The Committee does not consider this distribution to be limited to any particular degree.

Urolophus orarius (Coastal Stingaree) Listing Advice — Page 3 of 6 The Minister decided this species was not eligible for listing as threatened on 21 December 2009

The Coastal Stingaree is subject to the ongoing threat of prawn trawl fisheries which can cause mortality, abortion of young and degradation of suitable habitat. However, the extent of impacts on the species from this threat is not known. No past or potential future declines, or fragmentation of populations, can be inferred from current data. Therefore the Committee does not consider the species’ geographic distribution to be precarious.

As the species’ geographic distribution is not limited or precarious, it does not meet sufficient elements of Criterion 2 and is therefore not eligible for listing in any category under this Criterion.

Criterion 3: The estimated total number of mature individuals is limited to a particular degree; and either (a) evidence suggests that the number will continue to decline at a particular rate; or (b) the number is likely to continue to decline and its geographic distribution is precarious for its survival.

While there have been no targeted surveys for the Coastal Stingaree, based on prawn trawling by- catch and by-catch surveys, the Coastal Stingaree appears to be a sparsely distributed species. A November 2001 to December 2002 prawn trawling by-catch survey, carried out by SARDI, recorded 40 stingarees identified as Coastal Stingarees from 515 trawl tows (0.08 animals per trawl tow) (Dixon et al., 2005). A 2007 prawn trawling by-catch survey carried out by SARDI, using different methodology and comprised of 120 thirty-minute trawl tows, recorded 14 specimens (0.12 animals per trawl) and an average density of 0.058 individuals per hectare (SARDI, unpubl. data, 2009). Given the species’ estimated extent of occurrence of up to 40,000 km2, at these densities, the total number of mature individuals is unlikely to be limited. However, there are insufficient data available to determine this figure.

There are insufficient data to establish whether the species’ numbers are likely to decline in the future in biologically relevant timeframes. Therefore the species has not been demonstrated to have met sufficient elements of Criterion 3, and is not eligible for listing in any category under this Criterion.

Criterion 4: The estimated total number of mature individuals is extremely low, very low or low.

Given the species’ estimated extent of occurrence of up to 40,000 km2 and a density estimate of 0.058 individuals per hectare, a coarse estimate suggests the total number of mature individuals is unlikely to be low. However, as there have been no targeted surveys to determine population numbers for the Coastal Stingaree, there are insufficient data available to accurately determine this figure. Therefore, the species has not been demonstrated to have met the required elements of Criterion 4, and is not eligible for listing in any category under this criterion.

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Criterion 5: Probability of extinction in the wild that is at least (a) 50% in the immediate future; or (b) 20% in the near future; or (c) 10% in the medium-term future.

No quantitative (statistical) analyses have been done to estimate a probability of extinction of the Coastal Stingaree in the wild over a relevant timeframe. Therefore, the species has not been demonstrated to have met the required elements of Criterion 5, and is not eligible for listing in any category under this criterion.

11. CONCLUSION

Urolophus orarius (Coastal Stingaree) was nominated for inclusion in the list of threatened species referred to in section 178 of the EPBC Act. The nominator suggested listing in the vulnerable category of the list.

The Committee considers there are insufficient data available to determine whether the Coastal Stingaree has undergone a past decline in numbers. While the species is subject to the ongoing threat of prawn trawling, there are insufficient data available to determine whether this will result in a future decline in numbers. The species’ geographic distribution is not limited and is not considered to be precarious for its survival. Based on the species’ extent of occurrence and density estimates, the total number of mature individuals of the Coastal Stingaree is unlikely to be limited or low. However, given the absence of targeted surveys for this species, there are no estimates of the species’ total population size. In addition, there are no data available to estimate a probability of extinction of the species in the wild over a relevant timeframe. Therefore the species is not eligible for listing against any of the criteria.

12. RECOMMENDATION

(i) The Committee recommends that Urolophus orarius (Coastal Stingaree) is not eligible for inclusion in the list referred to in section 178 of the EPBC Act:

Associate Professor Robert J.S. Beeton AM FEIANZ Chair Threatened Species Scientific Committee

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13. References cited in the advice

Carrick N (1997). A Preliminary Assessment of the By-Catch from the Spencer Gulf Prawn Fishery. South Australian Fisheries Assessment Series 97/02. SARDI Aquatic Sciences, South Australia.

DEWHA (2009). Unpublished data from Environmental Research and Information Branch. Australian Government Department of the Environment, Water, Heritage and the Arts.

Dixon C, Svane I and Ward T. (2005). Monitoring and assessment of by-catch and by-product in the Spencer Gulf Prawn Trawl Fishery. SARDI Research Report No. 102. SARDI Aquatic Sciences, South Australia.

Dulvy N and Reynolds J (1997). Evolutionary transitions among egg-laying, live-bearing and maternal inputs in sharks and rays. Proceedings of the Royal Society of London B 264: 1309–1315.

Last PR (2009). Personal communication. CSIRO Marine.

Last PR and Gomon MF (1987). New Australian fishes. Part 15. New species of Trygonoptera and Urolophus (Urolophidae). Memoirs of Museum Victoria 48: 63–72.

Last PR, Kyne PM and Marshall LJ (2006). Urolophus orarius. In: 2008 IUCN Red List of Threatened Species. . Downloaded on 13 April 2009.

PIRSA (Primary Industries and Resources South Australia) (2003). Ecological Assessment of the South Australian Spencer Gulf Prawn Fishery, Gulf St Vincent Prawn Fishery and West Coast Prawn Fishery. Assessment report prepared for Environment Australia, against the Guidelines for the Ecologically Sustainable Management of Fisheries for the purposes of Part 13 and 13(A) of the Environment Protection and Biodiversity Conservation Act 1999. Prepared by Primary Industries and Resources South Australia (PIRSA) — Fisheries, in association with the Prawn Fishery Management Committee and the South Australian Research and Development Institute (SARDI) Aquatic Sciences, September, 2003.

SARDI (South Australian Research and Development Institute) (2009). Unpublished data.

SA DEH (South Australian Department of Environment and Heritage) (2009). Unpublished data.

Roberts S (2009). Personal communication. SARDI.

Tanner JE (2003). The influence of prawn trawling on sessile benthic assemblages in Gulf St. Vincent, South Australia. Canadian Journal of Fisheries and Aquatic Sciences 60: 517–526.

Tanner J (2005). Three decades of habitat change in Gulf St Vincent, South Australia Transactions of the Royal Society of South Australia 129: 65–73.

Trinnie FI (2003). Demographic biology of Urolophus paucimaculatus, Trygonoptera sp. B, U. crutiatus and U. bucculentus in south eastern Australia. Honours thesis, Deakin University. Summarised in: Anonymous (2002d). Queenscliff Marine Station — Annual Report. Report on marine research by Deakin University, Marine and Freshwater Resources Institute, Monash University, Royal Melbourne Institute of Technology, The University of Melbourne, and Victoria University. Melbourne.

Walker TI (2004). Catch susceptibility of chondrichthyan animals to demersal fishing gear in the South East Scalefish and Shark Fishery. Draft 1. PIRVIC: Queenscliff.

White W (2009). Personal communication. CSIRO Marine.

White WT and Potter IC (2005). Reproductive biology, size and age compositions and growth of the batoid Urolophus paucimaculatus, including comparisons with other species of the Urolophidae. Marine and Freshwater Research 56: 101–110.

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