© Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia Full citation Baker, J.L. (2009) Marine Species of Conservation Concern in South Australia: Volume 1 - Bony and Cartilaginous Fishes. Report for the South Australian Working Group for Marine Species of Conservation Concern. J. Baker (consultant); Science and Conservation Division, and Coast and Marine Conservation branches of S.A. Department for Environment and Heritage (DEH); Marine and Coastal Community Network of S.A. (MCCN), and Threatened Species Network (TSN). Web version published by Reef Watch, South Australia.

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Deepwater Stargazer / Blackbanded Stargazer

Family Name:	Uranoscopidae
Scientific Name:	Kathetostoma nigrofasciatum Waite and McCulloch, 1915
Recommended Status in S.A:	Data Deficient, possibly Near Threatened
Rationale:  Although the Deepwater Stargazer has a broad depth range, it is included here because  (i) it has a limited geographic distribution in southern Australia, being found in southern W.A. and western S.A., the latter of which may be the eastern edge of the range; (ii) it is a benthic, site-associated, and probably long-lived fish species, with limited mobility and possibly limited dispersal ability, and thus may be vulnerable to site-specific benthic impacts; (iii) it is a frequently recorded, discarded bycatch species in the Great Australian Bight Trawl Fishery, and might also be part of the discarded bycatch in other trawl fisheries, but there are no restrictions on capture, and little assessment of population impacts has been undertaken to date; (iv) the broad depth range (from upper shelf to deep upper slope waters) may indicate the presence of more than one species, with differing vulnerability to impact; (v) there is little information on the nature and extent of threatening processes, but the species may be at high risk of population impact from trawl capture in the GAB; and (vi) it is one of the species in Uranoscopidae for which there is little information on the habitat requirements, relative abundance, biology (particularly reproduction, and longevity), or population dynamics.

Page Contents

Current Conservation Status

No listings known

Distribution

Southern Australia

The Deepwater Stargazer is found in western S.A. and southern W.A., with the reported distribution ranging from the eastern end of the Great Australian Bight (GAB), through to Rottnest Island (Gomon, in Gomon et al., 1994).
Williams et al. (2001) characterised K. nigrofasciatum as one of the indicator species in “a southern community of the well-defined (continental) shelf break community” in south-western Australia, which contains a number of Flindersian (warm temperate southern Australian) species that occur mainly between 200m and 400m depth, and extend northwards to about 28° S latitude.

South Australia

In S.A., the species has been recorded mainly in the deeper mid and outer continental shelf waters and slope waters across the GAB, from the western side of Eyre Peninsula, through to the W.A. border, and there is also a record from deeper waters off western Kangaroo Island (Brown and Knuckey, 2002; CSIRO Marine Research records, SA Museum records, Museum of Victoria records, cited in CSIRO, 2007 and OZCAM database, 2007). There are isolated and unverified museum records from other parts of S.A. reported to be K. nigrofasciatum, all in shallower waters, including one from 2 nautical miles off Outer Harbour in north-eastern Gulf St Vincent (1953), and two records from near Wallaroo in eastern Spencer Gulf, collected in 1894 and identified in 1932 (S.A. Museum records F02783, F01742 and F01743, cited in OZCAM database, 2007). There is also one unverified record from off Rapid Bay (Australian Anglers Association, 2005).

Habitat

The Deepwater Stargazer is a benthic species in deeper waters, on the mid to outer continental shelf, and upper slope. The depth range commonly cited in publications is 130m to 270m or 320m deep, presumably based on trawl records (May and Maxwell, 1986, cited in Froese and Pauly, 2009; Gomon, in Gomon et al., 1994; Gomon et al., 2008). However, there are records reported to be this species, from continental slope waters of the Great Australian Bight (as deep as 700m: CSIRO Marine Research data), and also from shelf waters shallower than 130m. Examples from shallow waters include a specimen collected at 20 fathoms (36.6m) (Waite and McCulloch, 1915, cited by Eschmeyer, 2003); records from 42m (CSIRO Soela trawl survey record, 1981, and Courageous trawl survey record, 1978); 70m (CSIRO Marine Research - Ichthyology record CA 3683, and S.A. Museum record F08073), and less than 40m (S.A. Museum records F02783, F01742 and F01743, unverified). There are also records from deeper than 270m (e.g. CSIRO Marine Research - Ichthyology record T 1393-2).

Notes on Biology and Behaviour

Growth

Deepwater Stargazer grows to at least 28cm (May and Maxwell, 1986, cited in Froese and Pauly, 2006; Gomon, in Gomon et al., 1994). One of the maximum sizes (reported to be this species) is 0.285kg, a specimen taken off Rapid Bay in S.A., in 1976 (Australian Anglers Association, 2005).

Diet

Stargazer species are ambush feeders that lie camouflaged in benthic sand and wait for prey.

Fisheries Information

Commercial

The Deepwater Stargazer is not targeted, but has been recorded as a component of the bycatch of fisheries, such as the Commonwealth-managed SESSF (AFMA, 2002a). Bromhead and Bolton (2005) reported that K. nigrofasciatum is a discarded bycatch species in both the South East Trawl Fishery and the Great Australian Bight Trawl Fishery (GABTF).
In terms of frequency of capture, Deepwater Stargazer is a significant bycatch species in the GABTF. Bycatch sampling in 2000 - 2001 (Brown and Knuckey, 2002) showed that during that period, Deepwater Stargazers were observed in 85 of the 209 trawl shots, none were retained, and the average quantity discarded was 4.2kg per trawl shot (Brown and Knuckey, 2002).

Recreational

The species occurs in waters deeper than the most recreational fishers operate; however it is noted that the Australian Anglers Association (AAA) has a fishing record, reportedly Kathetostoma nigrofasciatum, taken from Rapid Bay (Gulf St Vincent), in 1976. It is noted that the species mostly occurs in deeper continental shelf and upper slope waters; hence the GSV record is unusual. The validity of the GSV record could not be determined for this report.

Vulnerable Characteristics of the Species

The Deepwater Stargazer has a limited geographic distribution in southern Australia, being found only in western S.A. and southern W.A.
Deepwater Stargazer is a member of the Uranoscopidae, a family of strongly site-associated, benthic fishes of limited mobility, and probably limited dispersal ability. The strong site association of Uranoscopidae fish makes them vulnerable to site-specific benthic impacts, such as trawling and dredging.
As is the case with other members of the family, populations of the Deepwater Stargazer are likely to have a fairly low level of resilience to exploitation.  This species may be relatively long-lived (as is a related species in New Zealand, Kathetostoma giganteum).
The broad depth range of specimens reported to be Deepwater Stargazer, might indicate separate speces in shelf and slope waters, and vulnerability is higher in deeper waters where this species is caught by commercial trawls.

Threatening Processes

Bycatch monitoring has shown that Deepwater Stargazer is frequently recorded in bycatch of the GAB Trawl Fishery. Trawling may be a threatening process, both directly (mortality of stargazers caught in the by-catch) and indirectly (due to benthic habitat damage), but more information is required. No data are available about the change over time in abundance of this species in the bycatch, nor are there other indirect (or direct) measures of potential impact on populations, but it is noted that in 2006, an Ecological Risk Assessment (ERA) for species in the Great Australian Bight Trawl Fishery (Daley et al., 2006), ranked K. nigrofasciatum as a “high risk” species, in terms of population impacts from capture in the GAB trawl fishery.

Research Requirements

There is some discrepancy between the depth range cited in fish identification texts, and the recorded depths at which various museum specimens of Kathetostoma nigrofasciatum were captured. The presence or absence of this species in shallow waters should be determined, including an expert check of the species identity of SA Museum specimens F02783, F01742 and F01743.
The taxonomy of specimens from different depth ranges should be investigated. Given the broad depth distribution of specimens reported to be this species (i.e. from upper continental shelf waters to deep waters of the upper continental slope), it is possible that separate species exist, or at least separate populations with different conservation requirements.
There is little information on the habitat requirements, biology (particularly reproduction, and longevity), relative abundance or population dynamics of this species.

Management Requirements

Quantification of stargazer bycatch (to species’ level) in the SET and GAB trawl fisheries over space and time is recommended, and measures to reduce the bycatch of benthic species such as stargazers are required, where possible.