© 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.

---

Speckled Stargazer / Western Stargazer

Family Name:	Uranoscopidae
Scientific Name:	Kathetostoma canaster Gomon and Last, 1987
Recommended Status in S.A:	Data Deficient in South Australia; Near Threatened or possibly VU A2(d) in south-eastern Australia
Rationale:  Although the Speckled Stargazer has a wide geographic distribution across southern Australia, and broad depth range, it is included here because (i) the species is a benthic, site-associated, and probably long-lived fish, with limited mobility and possibly limited dispersal ability; (ii) it may be vulnerable to site-specific benthic impacts, and may have a relatively low resilience to exploitation; (iii) it is taken in seemingly very large quantities in Commonwealth-managed fisheries in southern Australia, particularly the South East Trawl Fishery, with no controls over the numbers taken, and no assessment of the sustainability of the catch over space and time; (iv) the species has been categorised as one at high risk of population impacts from trawl fishing in the SETF; (v) there has been inadequate assessment of population impacts of fishing, despite large quantities having been taken commercially (as by-product) every year since at least the early 1990s; and (iv) Speckled Stargazer is one of the species in Uranoscopidae for which there is little information on the habitat requirements, relative abundance, biology (particularly the reproduction, and longevity) or population dynamics.

Page Contents

Current Conservation Status

No listings known

Distribution

Southern Australia

The Speckled Stargazer ranges from the Sydney area in N.S.W., through to the western Great Australian Bight / south-western W.A., and Tasmania is part of the distribution (Gomon and Last, 1987; Gomon, in Gomon et al., 1994, Hutchins and Swainston, 2001).
The species is considered common in the South East Marine Region, and has been listed as an indicator species for that region (CSIRO et al., 2001).

South Australia

In S.A., examples of locations where the species has been recorded include Cape Jervis, near Investigator Strait (national angling record from 1997, cited by Australian Anglers Association, 2005); deeper waters (i.e. edge of continental shelf) off central and western Great Australian Bight (CSIRO Marine Research records 1965 and 1966, cited in CSIRO, 2007), and continental slope waters off the lower South East (e.g. south-west of Beachport, and further south-east, near the S.A. / Victorian border) (Museum of Victoria records, cited in OZCAM database, 2007).

Habitat

Speckled Stargazer is a benthic species found in sandy habitats (Hutchins and Swainston, 2001) over a broad depth range, from ~ 30m deep to more than 700m (Gomon, in Gomon et al., 1994); however the species is mostly found within the depth range 40m – 450m (CSIRO et al., 2001).

Notes on Biology and Behaviour

Growth

The Speckled Stargazer grows to between 65cm (Gomon, in Gomon et al., 1994) and 75cm (Hutchins and Swainston, 2001). One of the maximum sizes recorded is 2.81kg, being a specimen taken off Cape Jervis in S.A., in 1997 (Australian Anglers Association, 2005).
There is no information on the age of the species, but is it noted that a related species in New Zealand, K. giganteum, which grows to a similar size, reportedly reaches a maximum age of about 23 years (Sutton, 1999, 2004; Manning and Sutton, 2004).

Other Information

Stargazer species are ambush feeders, which lie camouflaged in benthic sediments, and wait for prey.

Fisheries Information

Commercial

The Speckled Stargazer is considered to have “better than average quality” flesh, and is marketed in small quantities (Gomon, in Gomon et al., 1994). In southern Australia, several species of stargazer from deeper waters, are usually taken as a bycatch of deepwater trawling operations, and are marketed either as whole fish or fillets of “monkfish” (Sea-Ex Australia, 2004).
The Speckled Stargazer is part of the bycatch of fisheries such as the Commonwealth-managed SESSF (Southern and Eastern Scalefish and Shark Fisheries), which includes the South East Trawl Fishery (AFMA, 2002a). Bromhead and Bolton (2005) reported that K. canaster is a retained byproduct species in the Gillnet, Hook and Trap Fishery; the South East Trawl fishery, and the Great Australian Bight Trawl Fishery.  In the Commonwealth-managed Gillnet, Hook and Trap fishery, Speckled Stargazer is a by-product species of the Scalefish Demersal Long-line sub-fishery and the Scalefish Automatic Long-line sub-fishery (Webb et al., 2004).
In an assessment of bycatch in the Southern Shark Fishery, Walker et al. (2003) showed that the species is vulnerable to capture in small mesh gill nets, and also by 10 / OSS shark hooks.
A scientific monitoring program in 2001 recorded 5.15 tonnes of Speckled Stargazer in the bycatch of the South East Trawl Fishery (SETF), 95% of which was retained (AFMA, 2002a). In the otter trawl sub-fishery of the SETF, an Integrated Scientific Monitoring Program (ISMP) reported that in 652 trawl shots, about 20.3 tonnes of Speckled Stargazer were retained (equivalent to 31kg per trawl shot retained), and about 963kg were discarded (Wayte et al., 2004). Large quantities of unspecified stargazer species (which may include Speckled Stargazer, amongst others) are recorded in fishers’ logbooks as bycatch. For example, in 2000/01, fishers’ logbooks recorded about 86 tonnes of stargazers in the bycatch of the SETF (AFMA, 2002a); however it is not known what proportion of the catch comprised K. canaster. In the Danish seine sub-fishery of the SETF, the ISMP recorded that in 11 shots, 4kg were retained, and 8.2kg were discarded (Wayte et al., 2004).
The species might also be taken in the so-called High Seas Trawl Fishery, but it is uncertain whether the species is retained (Bromhead and Bolton, 2005).
There are museum records of the Speckled Stargazer being taken by commercial fishing in the Port Phillip Bay / Bass Strait area (Anon., 2002b), and the species is also taken in New South Wales (Andrew et al., 1997).
During the past decade, K. canaster has been sold in large quantities in some fish markets in southern Australia. An example is shown in the table below. During the 1990s, the largest annual quantity sold through the Melbourne Wholesale Fish Market was approximately 133t, in 1997. An average of 75t per year of Speckled Stargazer was sold in this market over a 8 year period during the mid 1990s to early 2000s (see table below). The species is also marketed in New South Wales (e.g. Andrew et al., 1997, Table 2.4).
 

Table 13 Annual Quantities of K. canaster Sold, & Maximum & Minimum Quantities Sold per Month, at Melbourne Wholesale Fish Market, 1993-2001
Year	Minimum monthly  quantity sold	Maximum monthly Quantity sold	Total quantity sold per annum (t)
1993	0kg (Jan - May)	19,200kg (Sep)	68.1t
1994	0kg (Jul, Aug, Dec)	16,890kg (Sep)	69.4t
1995	0kg (Jan – Mar; May – Nov)	11,070kg (Dec)	14.25t
1996	0kg (Feb, Oct)	13,410kg (Aug)	86.1t
1997	4,980kg (Aug)	21,810kg (Sep)	132.8t
1998	3,150kg (Jun)	13,770kg (Apr)	74.5t
1999	0kg (Sep)	7,530kg (Mar)	57.9t
2000	3,270kg (Jan)	17,970kg (Nov)	93.9t
2001	3,000kg (Jul)	13,920kg (Feb)	49t *
*N.B. data in 2001 for January - July only, (Adapted from C.H. Smith Marine, 2004)

Recreational

The species is not targeted, but is incidentally taken by recreational fishers in some areas. Some clubs and associations keep records of the maximum sizes recorded (e.g. Australian Anglers Association, 2005).
Species-specific data on the recreational catch of stargazers is not available for this report; however it is noted that the recent National Recreational and Indigenous Fishing Survey (Henry and Lyle, 2003) reported that 1,782 Stargazer specimens were caught and kept by recreational fishers during the survey time period (May 2000 to April 2001), comprising 932 from Queensland, and 850 from New South Wales. The number discarded was not recorded, nor were statistics from the southern Australian States.

Vulnerable Characteristics of the Species

Speckled Stargazer is reported to have a low resilience to exploitation, in terms of minimum population doubling time (based on preliminary age and growth estimates) (Froese and Pauly, 2007). This species may be relatively long-lived (as is a related species in New Zealand, Kathetostoma giganteum).
Speckled 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.

Threatening Processes

Fishing is likely to be the main threatening process. It is possible that ongoing commercial exploitation of this species at the current level may have a negative impact on populations. Based on estimates of likely maximum age and growth rate, the species is reported to have a low resilience to exploitation. There appears to be no information on population sizes or population dynamics of Speckled Stargazer, yet this benthic species continues to be taken in seemingly large quantities by trawls (see above), with no quota on the number taken.
A recent draft ecological risk assessment of the South East Trawl and Danish Seine Fishery (Wayte et al., 2004), listed Speckled Stargazer as a “high risk” species, i.e. one of the species that is highly susceptible to population impacts from trawling. The species has also been listed as being at moderate risk from trawl impacts in the Great Australian Bight Trawl Fishery (Daley et al., 2006).

Research and Management Recommendations

Population and fishery assessments should be undertaken as a priority for commercial species such as Speckled Stargazer. This species has been taken in large quantities for more than a decade, with no knowledge of population impacts, or the sustainability of the catch over space and time. As a precautionary measure, controls are required (where possible) over the numbers of Speckled Stargazer taken as by-product in trawl fisheries, pending population assessments.
In addition to the trawl fisheries in which Speckled stargazer is taken as by-product, quantification of Stargazer bycatch (to species’ level) is required in other fisheries in which this species might be caught.
There is little information on the habitat requirements, biology (particularly reproduction, and longevity), relative abundance or population dynamics of this species.
Species-specific recreational catch statistics are lacking, and stargazer species are generally not targeted by recreational fishers. Nevertheless, given the potential for populations of Uranoscopid fishes to be affected by fishing, catch limits are required for recreational fishing of stargazer species, even deepwater species such as Speckled Stargazer, for which there are recreational catch records in the shallow part of the range.

Other Information

Thomson (1985) reported the mercury concentrations of a sample of Speckled Stargazers in Tasmanian waters.