© 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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Bighead Gurnard Perch / Gurnard Perch

Family Name:	Neosebastidae
Scientific Name:	Neosebastes pandus (Richardson, 1842)
Recommended Status in S.A:	Data Deficient
Rationale:  Although the Bighead Gurnard Perch has a broad depth range on the continental shelf and slope, it is included here because (i) like other members of the Neosebastidae, it is a benthic, site-associated reef fish of limited mobility, and these characteristics increase the species’ vulnerability to site-specific impacts; (ii) although the species appears to be widespread in South Australia, this State is at the edge of the geographic range; (iii) the species is part of the bycatch in various fisheries, including the S.A. rock lobster fishery (in which it appears to be a significant bycatch species), Commonwealth-managed trawl fisheries (such as the South East Trawl Fishery, in which it is classified as being at “medium risk” of population impacts) and possibly non-trawl fisheries, but there are few requirements to try to minimise bycatch of benthic, site-associated fish species; (iv) it is taken by some recreational anglers and spear fishers, with no species-specific data collected, and no regulations over catch; and (v) there is no knowledge of population sizes or population dynamics, and little information on the biology (particularly fecundity, annual recruitment strength, and longevity).

Page Contents

Current Conservation Status

no listings known

Distribution

Southern Australia

N. pandus is found along the central and southern W.A. coast, and across South Australia (Hutchins and Swainston, 1986; Poss, in Gomon et al., 1994; OZCAM database records, 2007).
There are unconfirmed reports from northern Tasmania (Queen Victoria and Albert Museum record, cited by Warman and Bryan, 2004), and Victoria (Australian Anglers Association, 2003).

South Australia

Many of the records from South Australia are from the Gulfs region, and from the Great Australian Bight. Examples of locations in S.A. where the species has been recorded include deeper continental shelf waters across eastern, central and western GAB (numerous records from CSIRO trawl surveys); eastern Spencer Gulf (e.g. Port Hughes and Wallaroo) and southern Spencer Gulf (e.g. Boston Bay and other locations in the Port Lincoln area); Troubridge Island off lower Yorke Peninsula; Kangaroo Island; and various parts of eastern Gulf St Vincent (such as Somerton Park, Noarlunga and Second Valley) (CSIRO Marine Research records, 1966 – 1980s, cited in CSIRO, 2007; South Australian Museum records, Museum of Victoria records, cited in OZCAM database, 2007).

Habitat

The Bighead Gurnard Perch lives around coastal reefs (particularly “broken bottom” / mixed reef patches near sand); “weedy” areas (Hutchins and Swainston, 1986); in sandy habitats (e.g. Hyndes et al., 1999), and in sponge beds (Motomura, 2003, cited in Froese and Pauly, 2007). At the Recherche Archipelago in south-western Australia, N. pandus has been recorded in reef habitat, and in soft bottom habitats worked by trawl / dredge (Hutchins, 2005).
The species occurs over a broad depth range on the continental shelf (Poss, in Gomon et al., 1994), and most of the CSIRO trawl records from the 1960s to 1980s were taken within the depth range 40m – 150m (CSIRO Marine Research data, cited in CSIRO, 2007). Bighead Gurnard Perch is also found in continental slope waters, to about 600m (Motomura, 2003; Motomura and McGrouther, in Australian Museum, 2006).

Notes on the Biology

Growth

The Bighead Gurnard Perch grows to around 50cm (Hutchins and Swainston, 1986; May and Maxwell, 1986), and over 1.8kg (Australian Anglers Association W.A. Division record, 1979; Hutchins and Swainston, 1986).

Diet

No species-specific information on the diet could be found for this report, but it is noted that related species of gurnard perch in southern Australia eat small fish, squid, crabs and other small crustaceans, and marine worms (Bulman et al., 2001; DPIWE Tasmania, 2004i).

Other Information

The species is not often seen (Edgar, 2000), despite being reasonably common (Hutchins and Swainston, 2001).

Fisheries Information

Commercial – Commonwealth Fisheries

Bighead Gurnard Perch is taken as bycatch in some Commonwealth-managed fisheries in southern Australia AFMA, 2002a).
In the otter trawl sub-fishery of the South East Trawl Fishery (SETF), an Integrated Scientific Monitoring Program (ISMP) reported the species in only 1 trawl shot, with 3kg retained, and 10kg discarded (Wayte et al., 2004).
The species is vulnerable to capture in the Commonwealth-managed Southern Shark Fishery (Walker et al., 2003), now part of the Gillnet, Hook and Trap Fishery. Walker et al. (2003) showed that the Bighead Gurnard Perch is vulnerable to gillnets of 2-inch and 3-inch mesh sizes. During gillnet bycatch experiments in south-eastern Australia, from 1973 to 1976, an average of 24 and 58 specimens of N. pandus were caught per 1000 km hours, in 2-inch and 3-inch nets respectively. It is noted, however, that these small mesh sizes are not currently used in the Southern Shark Fishery sector of the Commonwealth-managed Gillnet, Hook and Trap Fishery.
The species has been recorded in the bycatch in the Great Australian Bight Trawl Fishery (Ward et al., 2003). It is noted that, despite the common recording of this species in the Great Australian Bight during CSIRO trawl surveys from the 1960s to the 1980s, bycatch sampling in the GABTF in 2001-02 (Brown and Knuckey, 2002) recorded three other Neosebastes species, but N. pandus was not listed. It is not known for this report whether or not a proportion of the Neosebastes catch was N. pandus.

Commercial – State Fisheries

Bighead Gurnard Perch has been recorded as a minor part of the bycatch in the Spencer Gulf Prawn Trawl Fishery in South Australia (Museum of Victoria record, cited in OZCAM database, 2007).
Bighead Gurnard Perch is reported to be a significant part of the bycatch in the South Australian Rock Lobster Fishery. Bycatch sampling in 1991 – 92 showed that “gurnard perch” (unidentified) were caught in low numbers in both the Northern and Southern Zone of the fishery (Prescott and Xiao, 2001). A more recent bycatch monitoring program in the S.A. Rock Lobster Fishery showed that a Neosebastes species (reported to be N. pandus)is one of the most commonly taken bycatch species (in terms of numbers caught) in the Southern Zone of that fishery, and is also caught in lesser quantities in the northern Zone (Brock et al., 2004). The catches in each zone are shown below. Based on the logbook results, the total annual catch of Bighead Gurnard Perch may be in the vicinity of 300 - 350 individuals per annum in the Northern Zone, and 3,000 – 4,000 individuals in the Southern Zone. It is noted that the species was not recorded during a by-catch sampling program, in which a 1% sub-sample of the total number of pot lifts was monitored in 2002/03 (Table 6).

Table 6 Proportional catch of Bighead Gurnard Perch in the S.A. Rock Lobster Fishery, from log book monitoring 2001-2003
Northern Zone	No. pot lifts (and percentage of total)	No. N. pandus specimens caught
2001/02	320,003 (51%)	159
2002/03	265,843 (47%)	167
Southern Zone	No. pot lifts (and percentage of total)	No. N. pandus specimens caught
2001/02	545,886 (60%)	1,989
2002/03	486,155 (57%)	1,549
(Brock et al., 2004)

Recreational

The species is reported to be caught by anglers in deeper offshore waters (Hutchins and Swainston, 1986). In Western Australia, the species has been included in the section on “offshore, bottom-dwelling fishes”, in a recreational fishing species identification guide (Department of Fisheries, W.A., 2006d).
Some recreational fishing clubs and associations keep records of the maximum sizes caught by angling (e.g. Australian Anglers Association, WA Division Inc., 2002a). A record-sized specimen from Victoria, taken in Port Phillip Bay in 1985 (AAA, Victorian Division, 2003) is out of the geographic range, and needs to be verified.
The species is also taken by spearfishing, with a 1.3kg specimen from W.A. being a national record size from spearfishing (Australian Underwater Federation Inc., 2003).
It is noted that in the National Recreational and Indigenous Fishing Survey (Henry and Lyle, 2003, and associated data), results for all species in the Neosebastidae were aggregated, hence it is difficult to determine species-specific catches. Aggregated catches of gurnard perches are listed above, in the synopsis for Neosebastes bougainvillii.

Vulnerable Characteristics of the Species and Threatening Processes

Although the species appears to be widespread in South Australia, this State is at the edge of the geographic range.
Like other members of the Neosebastidae, Bighead Gurnard Perch is a benthic, site-associated reef fish of limited mobility, and these characteristics increase the species’ vulnerability to site-specific impacts, and to capture by a number of fishing methods.
Bycatch in Commonwealth-managed fisheries (particularly trawl, but possibly also non-trawl), and also in State-managed lobster pot fisheries may be a threatening process to N. pandus populations. For example, related species of gurnard perch (in eastern Australia) are reported to suffer barotrauma when caught in bycatch (N.S.W. Department of Primary Industries, 2004), and it is likely that Bighead Gurnard Perch would suffer similar trawl-induced mortality when caught. In 2004, an Ecological Risk Assessment (ERA) for species in the South East Trawl Fishery (Wayte et al., 2004), ranked N. pandus as a “medium risk” species, in terms of population impacts from capture in the SETF. Apart from trawl fishing, N. pandus may be vulnerable to capture in gillnets in south-eastern Australia, but there are insufficient species-specific data.

Research Requirements

More information is required on distribution and abundance within the range, and biology and population dynamics of this species (particularly fecundity, annual recruitment strength, and longevity).
Data are required on the numbers taken by commercial and recreational fishers across the range, in relation to required studies of abundance.

Management Requirements

Measures are required to reduce the number of bycatch specimens captured in rock lobster pots.
Where possible, measures are required to reduce the bycatch of benthic fishes (such as those in Neosebastidae and Scorpaenidae) in Commonwealth-managed (particularly) and State-managed trawl fisheries.
Recreational fishing regulations (e.g. size limits and bag limits) are recommended to regulate the capture of benthic, site-associated fishes such as members of the Neosebastidae and Scorpaenidae.