© 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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Common Gurnard Perch / Ruddy Gurnard Perch

Family Name:	Neosebastidae
Scientific Name:	Neosebastes scorpaenoides Guichenot, 1867
Recommended Status in S.A:	Data Deficient in South Australia Possibly Near Threatened in Commonwealth waters
Rationale:  Although the Common Gurnard Perch is found throughout south-eastern Australia, and has a broad depth range on the continental shelf and upper 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 Commonwealth-managed trawl and hook fisheries (where it is recorded in large numbers, and is classified in the SETF and GABTF as being at “medium risk” of population impacts), various State-managed fisheries (but apparently low bycatch in S.A.), and it is also taken by some recreational fishers, but there are few requirements to try to minimise bycatch of benthic, site-associated fish species;  (iv) given the strong site association and limited dispersal ability of gurnard perches, dredging and other physical damage to shallow, soft bottom habitats may adversely affect populations in the shallow part of the range, but there are no specific data, 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). Data are insufficient for an assessment of conservation status in S.A. waters. However, given the seemingly large, unregulated bycatch in Commonwealth-managed waters (despite no information on abundance of the population and sustainability of fishing it), the species may qualify for classification as Near Threatened in Commonwealth-managed waters of southern and south-eastern Australia.

Page Contents

Current Conservation Status

no listings known

Distribution

Southern Australia

The Common Gurnard Perch occurs in south-eastern and southern Australia, ranging from southern New South Wales, to the eastern edge of the Great Australian Bight, and including Tasmania (Poss, in Gomon et al., 1994) and the Bass Strait islands (Edgar, 1984, cited by RPDC Marine, 2002).
The species is considered to be particularly numerous in Tasmania (Hutchins and Swainston, 1986) particularly Bass Strait (Motomura and McGrouther, in Australian Museum, 2006n), and is considered typical of the Tasmanian Province, in bioregional classification (Edgar et al., 1997).

South Australia

Examples of locations in which the Common Gurnard Perch has been recorded in S.A. include the eastern Great Australian Bight (e.g. Ceduna); various parts of Spencer Gulf (e.g. northern, central and south-western, including the Port Lincoln area); western and south-western Gulf St Vincent (e.g. Port Giles; Edithburgh); metropolitan Gulf St Vincent (e.g. Port Willunga, Moana, Christies Beach, Seaford, shipwrecks off Glenelg, and a record from Port Wakefield, purported to be this species); Investigator Strait; north-eastern Kangaroo I. (e.g. Kangaroo Head, Snapper Point and other locations) and the Encounter Bay / Murray Mouth area (Hutchins and Swainston, 1986, 2001; Carrick et al., 1997; record by D. Muirhead, cited by MLSSA, 1999a; Fairhead et al., 2002a; K. Smith, unpubl. data, 2003; P. Jennings, SARDI, unpubl. data, 2003; Australian Anglers Association, 2005; Edgar et al., 2006; Museum of Victoria record, South Australian Museum records, cited in OZCAM database, 2005, 2007; photograph by A. Cooper, University of Tasmania, 2008).
The species is considered to be uncommon in the Great Australian Bight, which is the western edge of the geographic range (Motomura and McGrouther, in Australian Museum, 2006n).

Habitat

The Common Gurnard Perch is a demersal, reef-dwelling species on the continental shelf (May and Maxwell, 1986; Motomura, 2003, cited in Froese and Pauly, 2007). In the shallower part of the depth range, a number of records have come from macroalgae-covered reefs. In addition to reefs, the species has also been reported from drainage channels and subtidal soft sediment areas in Victoria (Parry et al., 1990; Plummer et al., 2003), and estuaries (e.g. King I. area of Tasmania - Edgar et al., 1999).
The depth range is commonly reported to be between 2m and 140m (150m) (May and Maxwell, 1986; Daley et al., 1998; Edgar, 2000), but Poss (in Gomon et al., 1994) reported that the species is more commonly found in the range 130m – 230m. It is noted that there are records from less than 130m (e.g. 74m, and within the range 20m – 48m), and also from deeper waters on the continental slope (e.g. 405m) (Bird and Watson, 1993, cited by Plummer et al., 2003; CSIRO Marine Research records, S.A. Museum records, W.A. Museum records, cited in OZCAM database, 2005, 2007).
There are some unusual, shallow water records reported to be this species, from the estuarine area of the Murray Mouth, and in even shallower water, from Port Wakefield in northern GSV (South Australian Museum records F 06228, F 02038, and F 01624, cited in OZCAM database, 2005). In estuarine areas, the Common Gurnard Perch has been described as a “marine straggler”, according to Whitfield’s classification (1999, cited by Higham et al., 2002). Young fish generally occur in shallower water than adults (Motomura and McGrouther, in Australian Museum, 2006n).

Notes on the Biology

Growth

The species grows to a maximum length of about 39cm or 40cm (May and Maxwell, 1986; Hutchins and Swainston, 1986).
The record weight of a specimen is 0.82 kg, being a specimen taken from Seaford in S.A., in 1987 (Hutchins and Swainston, 2001; Australian Anglers Association, 2005).

Diet

The diet of Gurnard Perch consists of small fish, squid, crabs and other small crustaceans, and marine worms (Bulman et al., 2001; DPIWE Tasmania, 2004i).

Other Information

In Bass Strait, gurnard perches have been recorded in the diet of the Australian Fur Seal Arctocephalus pusillus doriferus (Gales and Pemberton, 1994; Hume et al., 2004). 

Fisheries Information

Commercial – Commonwealth Fisheries

The Common Gurnard Perch has been marketed as “Coral Perch”, as have other Neosebastes species (Seafood Services Australia, 2003). However, as discussed below, the species is reported to be discarded when caught in a number of Commonwealth-managed fisheries in southern Australia. BRS (2004, 2006) included this species in commercial fisheries databases for Australia, but no catch statistics were listed for the periods 1990-1999 or 2000-2002 (the years for which commercial data are available via that means).
Poss (in Gomon et al., 1994) reported that the species is frequently taken as bycatch by commercial trawlers in southern Australia. The species is part of the bycatch in some Commonwealth-managed fisheries (AFMA, 2002a; Bromhead and Bolton, 2005), as discussed below.
Gurnard Perch is a discarded bycatch species in the Commonwealth-managed Southern Shark Fishery (AFMA, 2001d). Walker et al. (2003) showed that the Common Gurnard Perch is vulnerable to both shark long-line hooks and shark gillnets, and during various experiments and fishery observations of the SSF in 1973-76 and 1998-2001, Neosebastes scorpaenoides was reported to be the second most prevalent bony fish species caught by long-line and the third most prevalent species caught by gillnet. In the experiments with various hook sizes, hundreds of Common Gurnard Perch specimens were caught using all hook sizes, with larger numbers caught (i.e. approximately 450 – 650 specimens per 1000,000 hook-hours) using the largest hook sizes (5/O and 7/O). However, for the gillnet catch, it is noted that the majority of the catch of Common Gurnard Perch during those experiments was from mesh sizes that are not currently used in the fishery. Catches from 5-inch and 6-inch gillnets were lower (i.e. about 35-40 animals per 1000 km- hours) than those from 2-inch to 4-inch nets (Walker et al., 2003).  During Southern Shark Fishery bycatch surveys in Bass Strait, 57 (SE = 19) Common Gurnard Perch were caught with hooks during the period 1973-76, and 15 (SE = 11) were caught using 6-inch nets, but no specimens were caught with 6-inch nets during a repeat of the survey in 1998-2001 (Walker et al., 2003).
In the otter trawl sub-fishery of the South East Trawl Fishery (SETF), an Integrated Scientific Monitoring Program (ISMP) reported that in 80 shots, 14kg were retained, but about 8.3 tonnes of N. scorpaenoides specimens were discarded, which is about 104kg per trawl shot (Wayte et al., 2004). In the Danish seine sub-fishery of the SETF, the ISMP reported that in 316 shots, about 5.7 tonnes of N. scorpaenoides specimens were discarded (Wayte et al., 2004), which is an average of 18kg per shot.
Neosebastes scorpaenoides is a common component of the bycatch in the Great Australian Bight Trawl Fishery. During a bycatch sampling program in 2000 and 2001, Common Gurnard Perch was recorded in 51 of the 209 trawl shots in the GAB Trawl Fishery, none was retained, and an average of 3.9kg per trawl shot was discarded (Brown and Knuckey, 2002).
In the Commonwealth-managed Small Pelagic Fishery, an observer program during 2002-2003 showed that Neosebastes scorpaenoides is a very minor part of the bycatch (AFMA, 2004c).

Commercial – State Fisheries

The species is part of the bycatch in the N.S.W. Ocean Trawl Fishery (N.S.W. Department of Primary Industries, 2004). In New South Wales, fishery-independent surveys to assess bycatch composition in the N.S.W. Ocean Trawl Fishery have been undertaken, using ocean fish trawl and prawn trawl gear. Results showed that the percentage frequency of occurrence of across all trawls was 35.9% in the “Wreck Bay and Tathra inshore grounds of the ocean fish trawl shelf sector” (N.S.W. Department of Primary Industries, 2004).
Common Gurnard Perch is listed as a commercial species in Tasmania (Jordan and Lyle, 2000), and is taken by gillnet (Murphy and Lyle, 1999). Examples of reported scalefish fishery catches (incorrectly listed as Thetis fish) include 1.1t in 1995/96, and none in other years of the 1990s (Lyle and Jordan, 1999). The species is a bycatch in the commercial fishery for Banded Morwong. For example, during commercial bycatch sampling for the Banded Morwong fishery from 1994-97, gurnard perch (incorrectly listed as Thetis Fish) were recorded as an incidental, low quantity bycatch on the Tasman Peninsula (Murphy and Lyle, 1999).
There are museum records of specimens that were taken by commercial fishing in the Port Phillip Bay and Bass Strait area (Anonymous, 2002b, cited in Froese and Pauly, 2007).
The Common Gurnard Perch has been recorded as a minor part of the bycatch in the Spencer Gulf prawn trawl fishery (e.g. 7 specimens recorded in 32 trawl tows, during a survey in the mid-1990s) (Carrick, 1997).
N. scorpaenoides is collected in Tasmania for the aquarium industry. The permitted annual catch limit is 300 individuals, with a fishing block limit (6 x 6 nautical miles) of 50 individuals (DPIWE Tasmania, 2005b; Australian Government DEH, 2005b). In 2006, specimens were being advertised for sale through a Tasmanian aquarium supply company.

Recreational

The Gulf Gurnard Perch is taken by anglers, and some clubs and associations keep records of the maximum sizes caught (e.g. Australian Anglers Association, 2005).
The species is caught incidentally by recreational fishers in southern Australia, including South Australia, although it is not generally targeted. Poss (in Gomon et al., 1994) reported that the species is occasionally taken by hook and line in bays and estuaries. Museum of Victoria (2005b) reported that the species is “frequently” taken on hook and line by anglers, and the poisonous spines can cause injury.
In Tasmania, Common Gurnard Perch is caught over sand and hard bottom by recreational fishers, reportedly from 2m to over 100m depth, and the species is promoted as “good eating” (DPIWE Tasmania, 2004i). In Tasmania, gurnard perches (incorrectly listed as Thetis Fish) are reported to be often caught over seagrass, sand and mud, by recreational fishers (Lyle and Campbell, 1999; DPIWE Tasmania, 2004i). In a study of recreational gillnetting practices, gurnard perches (incorrectly listed as Thetis Fish) were caught over both reef and soft bottom habitat in south-western Tasmania, using both 1008mm and 114mm mesh (Lyle et al., 2000).
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.
Gurnard Perches in the Neosebastes genus are taken by spear fishers (e.g. Australian Underwater Federation Inc., 2003), and although no records of this species could be found for this report, it is likely that N. scorpaenoides would be targeted, as it is one of the larger, edible gurnard perches. More recently, gurnards (unspecified, with specimens over 0.4kg) were listed as target species in the 54^th Australian Spearfishing Titles 2006, held on northern Kangaroo Island (Australian Underwater Federation Inc., 2006.

Vulnerable Characteristics of the Species and Threatening Processes

Like other members of the Scorpaenidae, the Common 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.
Fishing may be a threatening process to N. scorpaenoides populations. The species is reported to suffer barotrauma when caught in bycatch, and in New South Wales, is classified as a species of “high fisheries impact potential”, with moderate resilience, but overall at “high risk” of population impacts from trawl fishing (N.S.W. Department of Primary Industries, 2004). In a draft ecological risk assessment of the South East Trawl and Danish Seine Fishery (Wayte et al., 2004), 3 “productivity attributes” and 6 “attributes of susceptibility” for the N. scorpaenoides were used to categorise it as a “medium risk” species; i.e. susceptible to population impacts from trawling.  In 2006, an Ecological Risk Assessment (ERA) for species in the Great Australian Bight Trawl Fishery (Daley et al., 2006), ranked N. scorpaenoides as a “medium risk” species, in terms of population impacts from capture in the GAB Trawl Fishery. Apart from trawl fishing, populations may be at risk from fishing impacts due to shark hooks and gillnets, in south-eastern Australia.

Research Requirements

More information is required on the distribution and abundance within the range, and the biology of this species.
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 bycatch of this species in otter trawls, Danish seines, long-line hooks and gillnets in Commonwealth-managed fisheries, as well as in State-managed trawl fisheries. Although there are no estimates of population size, N. scorpaenoides is caught in seemingly large number (tonnes per annum) in some fisheries, with no regulations over catch, and few requirements to minimise bycatch of benthic, site-associated fish species. 
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.

Other Information

N. scorpaenoides is very similar in appearance to a number of other gurnard perch species, including the Gulf Gurnard Perch N. bougainvillii and the Black-spotted Gurnard Perch N. nigropunctatus, both from southern W.A. and S.A.. Gurnard perch species are differentiated on the basis of characters such as the spines and ridges on the head, pectoral fin rays and lateral line scales (Australian Museum, 2005d and 2005f). 
The Common Gurnard Perch occurs in a number of marine protected areas in Victoria, such as the Point Hicks Marine National Park (MNP), Yaringa MNP, French Island MNP, Churchill MNP, Ninety Mile Beach MNP, Point Hicks MNP, Port Phillip Heads MNP, Beware Reef Marine Sanctuary and Jawbone Marine Sanctuary (Parry et al., 1990; Bird and Watson, 1993, cited by Plummer et al., 2003; Plummer et al., 2003; Edmunds et al., 2003).