© 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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Brown-spotted Boarfish (“Yellow-spotted” Boarfish) and Giant Boarfish

Family Name:	Pentacerotidae
Scientific Name:	Brown-spotted: Paristiopterus gallipavo Whitley, 1944 Giant: Paristiopterus labiosus (Günther, 1872)
Recommended Status in S.A:	Data Deficient, possibly Near Threatened
Rationale:  The Brown-spotted Boarfish and the Giant Boarfish are included here because (i) central South Australia is at the end of the geographic range ofP. gallipavo, and the species therefore has a limited distribution in this State; (ii) both are demersal, site-associated species, that are vulnerable to capture by commercial trawls and gillnets; (iii) Paristiopterus species have a strong social structure (i.e. males and females are reported to form life-long pairs, and seasonal aggregations may also occur), they reach a large maximum size, and they may be slow growing and relatively long lived (i.e. more than 11 years), characteristics that increase the vulnerability of exploited populations to decline; (iv) Paristiopterus boarfish are taken in the dozens of tonnes per annum, and there are no controls over the capture of these species in trawl and gillnet fisheries, yet a number of studies have indicated that Paristiopterus species have low resilience to fishing and/or may be at high risk of population impacts from fishing;  (v) to a lesser extent than in commercial fisheries, both species are taken by recreational anglers and spear fishers,, with inadequate regulations in southern Australian States; and (vi) like other members of the Pentacerotidae, Paristiopterus species are likely to be bottom feeders, and have a strong habitat association; therefore, habitat damage in continental shelf waters due to processes such as trawling, dredging, nutrient pollution and sedimentation (in shallower parts of the range), may have a consequent negative impact on boarfish populations; however no specific studies have been undertaken. Given these factors, the status of the populations of the two Paristiopterus species should be investigated. There is a possibility that these two species may be Near Threatened in deeper waters off South Australia and other southern States, particularly in areas where the species are taken by commercial fishing.

Page Contents

Current Conservation Status

No listings known

Distribution

General

The Brown-spotted Boarfish P. gallipavo is closely related to the Giant Boarfish P. labiosus, and the two species may form a species pair of non-overlapping distribution (Gomon et al., 1994).
The Giant Boarfish P. labiosus occurs in New Zealand (being more numerous off the North Island), and southern Australia. There is some discrepancy between authorities regarding the southern Australian distribution. May and Maxwell (1986, cited in Froese and Pauly, 2007) and Hutchins and Swainston (2001) reported that the Giant Boarfish P. labiosus occurs in N.S.W., Victoria, Tasmania and South Australia. There are numerous records from the Great Australian Bight in South Australia, reported to be this species (e.g. CSIRO Marine Research data, cited in CSIRO, 2007). It is noted that Gomon (1994) and Australian Museum (2003t) did not include S.A. in the distribution.
The Brown-spotted Boarfish P. gallipavo ranges from central S.A. (Investigator Strait / Kangaroo Island area) through to W.A. (Hutchins and Swainston, 1986, 2001; Gomon et al., 1994).

South Australia

Examples of locations in S.A. where the Brown-spotted Boarfish P. gallipavo has been recorded include the metropolitan waters (e.g. artificial reefs and shipwrecks off Glenelg, and Seacliff Reef); southern Fleurieu Peninsula (e.g. Wirrina Reef, and Cape Jervis); Kangaroo Island; Investigator Strait; and the numerous locations in the Great Australian Bight (Kuiter, 1983; Australian Anglers Association record, 1993; MLSSA, 1999; MLSSA dive records, undated; Hutchins and Swainston, 2001; K. Smith, unpublished data, 2001; Brown and Knuckey, 2002; J. Brook, unpublished data, 2005; Australian Museum, 2005b; CSIRO Marine Research data, cited in CSIRO, 2005; Australian Museum records; Museum of Victoria records, cited in OZCAM database, 2007). D. Muirhead (Marine Life Society of South Australia, 1998c) reported that P. gallipavo is common in South Australian waters.
Examples of locations in South Australia where the Giant Boarfish P. labiosus has reportedly been recorded include the western, central and eastern Great Australian Bight (from the S.A. / W.A. border area, through to western Eyre Peninsula); the western side of southern Eyre Peninsula, in the south-eastern GAB (e.g. off Coffin Bay), and Kangaroo Island / Investigator Strait (CSIRO Marine Research data, cited in CSIRO, 2007; Museum of Victoria records, South Australian Museum records, cited in OZCAM database, 2007).

Habitat

Both Paristiopterus species are demersal in continental shelf waters.
The Brown-spotted Boarfish P. gallipavo occurs mainly on the continental shelf, and has been recorded to approximately 260m deep, but more frequently in the range 75m – 200m (CSIRO et al., 2001). For P. gallipavo, there is some discrepancy between authorities regarding the upper depth limit. CSIRO et al. (2001) reported an upper depth limit of 36m, based upon Soela trawl survey data from 1981 (see CSIRO, 2007); Robins et al. (1991, cited in Froese and Pauly, 2007) reported 60m as the upper limit, and Gomon et al. (1994) reported 96m. However, if diver’s records from South Australia are correct, the upper depth limit would be less than 30m, possibly as shallow as 10m.
Giant Boarfish P. labiosus occurs in similar habitats and at similar depths to P. gallipavo, and is reported to range from the shallows to at least 165m or 200m deep (Gomon et al., 1994; CSIRO et al., 2001; Australian Museum, 2003t), with many records coming from the range 40m – 150m (CSIRO et al., 2001). The species is known from reef areas, and Giant Boarfish also hide within artificial reef habitats, such as shipwrecks etc (where divers in N.S.W. and N.Z. occasionally record the species). Giant Boarfish are site-associated, and may remain in the same area for long periods, as resident fish (Ayling and Cox, 1982; Doak, 2003).
Young Giant Boarfish may aggregate in small groups near reefs (as occurs in New Zealand), in shallower water than the adults. Giant Boarfish are frequently found over sand near reef “drop-offs”, including areas that fishers call “the weedline” (i.e. reef edge / interface between the kelp and the sand). Young Giant Boarfish are also observed swimming over sandy or muddy bottom areas, in relatively shallow water (e.g. 15m) (Australian Museum, 2003t).
The upper depth limit of P. labiosus is reported to be about 10m or 20m (Robins et al., 1991, cited in Froese and Pauly, 2007; CSIRO, 2001).

Notes on Biology and Behaviour

Age and Growth

P. gallipavo grows to at least 74cm (Hutchins and Swainston, 2001), and P. labiosus grows to around 100cm (Robins et al., 1991, cited in Froese and Pauly, 2007; Australian Museum, 2003t). The typical size observed is 45cm – 60cm (Master Fish Merchants Association of Australia, 2002).
Based on national spearfishing records (Australian Underwater Federation, 2003), the maximum sizes recorded are 5kg for Brown-spotted Boarfish, and 12kg for Giant Boarfish (Hutchins and Swainston, 2001). The Master Fish Merchants’ Association of Australia (2002) reported that although Giant Boarfish reaches around 12kg, the typical size range observed is 1.0kg - 2.5 kg. The 12.25kg specimen was taken in New South Wales, in 1961.
Froese and Kesner-Reyes (2002) reported that Giant Boarfish, which grows to a large maximum size, is relatively long-lived (more than 11 years).

Diet and Feeding Behaviour

A study in New Zealand showed that P. gallipavo feeds on benthic organisms such as sea cucumbers, echiuroid worms, polychaete worms, brittle stars, bivalves and other invertebrates (Russell, 1983).

Other Information

When young, Giant Boarfish form small peer groups and swim in small schools, but adult males and females are reported to form life-long pairs, and adult pairs are often seen swimming together (Australian Museum, 2003t; Seafriends Marine Conservation and Education Centre, 2004).
The seasonality of catches of boarfish in the Great Australian Bight Trawl Fishery (e.g. Brown and Knuckey, 2002), may indicate that boarfishes aggregate at certain times of the year (e.g. winter).

Fisheries Information

Australia – Commercial

The Australian Government Department of Agriculture, Fisheries and Forestry (AFFA), as well as the Master Fish Merchants’ Association of Australia, and some of Australia’s largest seafood supply companies, use the name “Giant Boarfish” for both Paristiopterus gallipavo and P. labiosus. Giant Boarfish is the official marketing name for both of these species, which are promoted as excellent eating fish that are sporadic in supply, little known amongst consumers, and therefore undervalued. Giant Boarfish is one of the 8 major seafood products sold by one of Australia’s largest seafood supply companies, based in South Australia.
Boarfish are caught in demersal otter trawls and gillnet fisheries in southern Australia (Sea-Ex Australia, 2004). The Museum of Victoria (2000) reported that both P. gallipavo and P. labiosus are taken by commercial trawlers.
Giant Boarfish P. labiosus and Brown-spotted Boarfish P. gallipavo are listed as two of the species taken in the combined Southern and Eastern Scalefish and Shark Fisheries (SESSF) (AFMA, 2002a).
Knuckey et al. (2001) listed P. labiosus as one of the species taken in the South East Non-Trawl Fishery (SENT). In 2000/2001, fishers’ logbooks recorded 10.7t of unspecified “boarfish” in the bycatch of the SENT Fishery, and 7.4t of boarfish were recorded in the bycatch of the Southern Shark Fishery (AFMA, 2002a), and these catch may have included a proportion of Giant Boarfish, amongst other boarfish species (see section above, on Pentacerotidae).
According to Bromhead and Bolton (2005), P. gallipavo is a retained by-product in the Commonwealth-managed Gillnet, Hook and Trap (GHAT) Fishery, Great Australian Bight Trawl (GABT) Fishery, and the Western Deepwater Trawl (WDT) fishery.
Total catches of Brown-spotted Boarfish P. gallipavo from Commonwealth-managed waters in Australia during the 1990s are listed below, according to statistics from BRS’s National Fisheries Production Database (NFPD) (BRS, 2004a). The majority of the catch comes from the Great Australian Bight (Table 30).

Table 30 Examples of Total Reported Annual Catch of P. gallipavo from Australian Waters
Year	Catch (t)
1994/95	40
1995/96	71
1996/97	119
1997/98	100
1998/99	64
(from BRS, 2004a)

In the Great Australian Bight Trawl Fishery (GABTF), “Giant Boarfish” or “Yellow-spotted Boarfish” is a target species, and very little is discarded (see AFMA, 2001c).  Four data sources (AFMA, 2001c; Lynch and Garvey, 2003; AFFA, 2002b and 2004b, and Ward et al., 2003) reported that the species taken in the GAB Trawl fishery is “Yellow-spotted Boarfish” P. gallipavo; however Brown and Knuckey (2002), who researched species composition and bycatch in the fishery, and Bromhead and Bolton (2005) reported that the species is Giant Boarfish P. labiosus. It is possible that the species in question is the yellow-spotted form of the Giant Boarfish, which, according to Hardy (in Gomon et al., 1994) is often incorrectly called “Yellow-spotted Boarfish”. Irrespective of the taxonomy, “Giant Boarfish” / “Yellow-spotted Boarfish” is one of the 7 target species retained in the part of the GABTF that operates in continental shelf waters (mainly between 120m and 160m depth) for “market fishing” of mixed species (AFMA, 2002a; Brown and Knuckey, 2002). Catches are seasonal, and the species is ranked 6^th of the “top 40” fish and shark species taken in the GABTF, in terms of weight (Lynch and Garvey, 2003). In 2001/02, 135 demersal trawls directed at market fishing in the Western Zone of the GAB Trawl Fishery, were monitored during 44 observer sea-days. Of the 203t of catch landed, 61% (by weight) was retained, and the retained catch was dominated by Deepwater Flathead (44%), Chinaman Leatherjacket (12%), “Giant Boarfish” (12%), Ornate Angelshark (6%), Bight Redfish (5%) and Western Gemfish (5%) (Brown and Knuckey, 2002). In the Western Zone of the GAB Trawl Fishery, large catches (e.g. 145kg per shot) of “Giant Boarfish” are occasionally made (Brown and Knuckey, 2002). Fishers’ logbooks in the GABTF recorded 36t of “Yellow-spotted Boarfish” in the catch, during 2000/2001, and 3.1t of unspecified boarfish species (AFMA, 2002a). Sampling of the catch composition in 2001 and 2002 showed that “Yellow-spotted Boarfish” accounted for 3% of the total catch in the GABTF during that period (Lynch and Garvey, 2003). During a bycatch sampling program in 2001 and 2002, “Giant Boarfish” were observed in 120 of the 209 trawl shots; the average quantity retained was 129kg per trawl shot, with only 0.3kg per trawl shot discarded (Brown and Knuckey, 2002). Boarfish are taken mainly in the Central and Western Zones of the GABTF, and specimens taken in the fishery range between 30cm and 83cm LCF (Brown and Knuckey, 2002). During the bycatch sampling program mentioned above, size composition of specimens reported to be P. labiosus, ranged from about 30cm to 52cm in the GAB Central Zone, and from about 30cm to 70cm in the GAB Western Zone (Brown and Knuckey, 2002).
ABARE and FRDC (2004) reported that the total commercial catch of boarfish in the GABTF was 39t in 2000/01; 104t in 2001/02 and 80t in 2002/2003. Reported landings from the GAB Trawl Fishery, according to 3 other sources, are shown (Table 31).

Table 31 “Yellow-spotted Boarfish”: Reported Commercial Catch in the GABTF
Year	Catch (t) (Source A)	Catch (t) (Source B)	Catch (t) (Source C)
1995	69
1996	119
1997	101
1998	64
1999	57		57
2000	33		30
2001	102		119
2002	70	77	91
2003			141
Source A: Lynch and Garvey (2003); Source B: AFFA (2003b, 2004b); Source C: AFFA (2002b, 2004c, 2005a)

 “Giant Boarfish” is reported to be commonly caught in the Commonwealth-managed South East Trawl fishery (Master Fish Merchants’ Association of Australia, 2002). Although they are not quota species (see Daley et al., 1998), boarfish are recorded in daily logbooks, because they are usually retained as by-product when caught (Wayte et al., 2004). In a scientific monitoring program of the bycatch in the SETF, both P. labiosus and P. gallipavo were recorded in minor quantities, less than 1t each, and all of the catch was retained (ISMP data, cited by AFMA, 2002a). Similarly, Wayte et al. (2004) reported that in the otter trawl sub-fishery of the South East Trawl Fishery, an Integrated Scientific Monitoring Program (ISMP) recorded in 2 trawl shots, about 130kg of P. gallipavo, all of which was retained. During that monitoring program, 92kg of P. labiosus were retained and 19kg were discarded, from 42 trawl shots (Wayte et al., 2004). Given that both Paristiopterus species are reported to be taken mainly in the SETF (although sporadically), it is possible that the bycatch monitoring results during the early 2000s were not typical of the per annum catch of these boarfish species in that fishery.
The Brown-spotted Boarfish and the Giant Boarfish have been recorded as very minor components of the Commonwealth-managed Southern Shark Fishery. For example, a study by Walker et al. (2003) of the bycatch from South Australia in the Southern Shark Fishery, showed that an average of 3 (SE = 2) P. gallipavo and 2 (SE = 1) P. labiosus are caught per 100,000 hook-hours (= 1000km hours), using 6 ½ inch and 6 inch mesh nets respectively. The total catch over the 1998-2001 sampling period was reported to be 6 specimens of P. gallipavo and 4 of P. labiosus.
Boarfish species taken by commercial fishing in southern Australian States are not recorded to species level. For each State, examples of catch data for boarfish species as a group are provided above, in the section on the family Pentacerotidae. Catches of boarfish that are taken more than 3 nautical miles (NM) from the coast are managed by the Commonwealth, and the States manage catches of boarfish species within 3 NM (AFMA, 2002a).
In New South Wales, P. labiosus is described as a “key secondary species” the Ocean Trawl Fishery (N.S.W. Department of Primary Industries, 2004).
In Tasmania, P. labiosus is taken by commercial fishers, in offshore waters.

Australia – Recreational

Both species are taken recreationally by anglers. The Australian Anglers Association (AAA), and State recreational fishing clubs and associations, keep records of the maximum sizes of both Paristiopterus species caught by recreational fishers. According to the AAA, the maximum size of a P. gallipavo specimen taken by angling is 1.71kg, (caught off Cape Jervis in S.A., in 1993), and the record size for a P. labiosus specimen taken by angling is 3.76kg (caught off Bass Point in N.S.W., in 1987). For both species, the national angling records are well below the maximum size to which the species grow.
Recreational catch statistics for each species are not available for this report; however examples of the recreational catch of boarfish species (unspecified) are provided above, in the section on the Pentacerotidae.
In Tasmania, boarfishes are taken recreationally using gillnets (Smith and Heran, 2001) and lines.
Spear fishers also take both boarfish species, in some of the shallow parts of the range. Boarfish are highly regarded as a table fish, and are thus significant targets for spear fishers. The Australian record sizes of both P. labiosus (12.25kg) and P. gallipavo (5kg) were specimens taken by spear fishers in N.S.W. and W.A. respectively (Hutchins and Swainston, 2001; Australian Underwater Federation , 2003). “Yellow-spotted Boarfish” P. gallipavo was one of the species eligible for weighing-in, in Australian and South Australian spearfishing competitions during the early 1980s (see Johnson, 1985a and 1985b). More recently, “Yellow-spotted Boarfish” (specimens over 0.7kg) was listed as one of the targets in the 54th Australian Spearfishing Titles 2006, held on northern Kangaroo Island (Australian Underwater Federation Inc., 2006).

New Zealand

P. labiosus is called Sowfish in New Zealand, and is one of the approved species that can be taken commercially in the High Seas fisheries. Giant Boarfish is also a bycatch in other fisheries, such as the target fishery for snapper (New Zealand Ministry of Fisheries web site, 2004).
In N.Z., Giant Boarfish is also taken by spear fishers, and in spearfishing competitions (Quinlan, 2003), and is highly regarded as a fish for eating. A recent spearfishing publication (DVD) in New Zealand provided advice from experts about hunting and catching Giant Boarfish, including schooling boarfish. There is an anecdotal report of the species being a “reasonably common catch” of spear fishers in New Zealand, and a number of spear fishers publish on internet forums, the details and photos of their catches of large Giant Boarfish specimens from various locations around New Zealand.

Vulnerable Characteristics of the Species, and Threatening Processes

Commercial fishing is likely to be the main threatening process. Both species are also taken by recreational fishers, but the recreational catch is likely to be much lower, given the depths at which both species occur. Some commercial fisheries in southern Australia take dozens of tonnes per annum, despite no studies having been undertaken to determine the size of the Giant Boarfish and Brown-spotted Boarfish populations, or the sustainability of fishing them. In a recent 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 P. gallipavo were used to categorise it as a “high risk” species; i.e. highly susceptible to population impacts from trawling. In an ecological risk assessment for the effects of fishing (ERAEF) in the Western Deepwater Trawl Fishery, P. gallipavo has been ranked as a high risk species (AFMA, 2008b). A study in New South Wales reported that species in the Pentacerotidae have an “intermediate impact profile” in terms of fisheries impact, and fishing poses an “intermediate” level of risk to populations.
Froese and Kesner-Reyes (2002) reported that Giant Boarfish reached 'fully exploited' status in FAO production statistics in 1998-1999. This little-studied demersal species grows to a large maximum size, is relatively long-lived (more than 11 years), and is reported to have a low resilience to exploitation, in terms of minimum doubling time for populations (Froese and Kesner-Reyes, 2002).
Generally, Boarfish are site-associated reef fish species that feed on the bottom. In some areas, damage to the benthos (e.g. by trawling) may have a negative impact on boarfish populations; however no specific studies have been undertaken.
Due to the protection afforded by the venomous spines, Boarfish individuals are not shy, and are consequently vulnerable to spear fishing (Museum of Victoria, 2000). However, it is noted that both the Brown-spotted Boarfish and the Giant Boarfish occur in deep waters as well as shallow reef areas, and hence would not be vulnerable to spear fishers over a large part of the depth range.

Research Requirements

A research program is required to determine the population sizes of Paristiopterus boarfish across southern Australia. Also currently lacking is knowledge of the population structure, age and growth, reproduction, diet, and habitat requirements, of boarfish species that inhabit deeper waters of the continental shelf and upper slope.
Boarfish species taken in trawl fisheries and gillnet fisheries in southern Australia should be identified to species level. This will assist accurate reporting of the total annual catch of Giant Boarfish and Brown-spotted Boarfish.

Management Requirements

There should be a national standard in reporting the names of these two species in the catches of Commonwealth fisheries, to avoid, for example, the discrepancies that are evident in the reporting of the boarfish species caught in the GABTF.
Reporting of annual catches should be consistent within and between documents from various Commonwealth government departments.
A global quota should be introduced for boarfish species taken in Commonwealth fisheries, including the Paristiopterus species. This measure would also require a research program to determine the size of boarfish populations, and the sustainability of fishing them.
Measures to reduce the bycatch of this, and other, boarfish species in trawl and gillnet fisheries should be investigated.

Other Information

According to Hutchins and Swainston, the Brown-spotted Boarfish Paristiopterus gallipavo is often confused with the yellow-spotted form of the Giant Boarfish P. labiosus, resulting in the common name “Yellow-spotted Boarfish” for P. gallipavo.
Although these boarfish species are not commonly seen by divers in southern Australia, and are mostly known from commercial trawl catches (Museum of Victoria, 2000), they are of interest to the diving community. Various dive clubs and associations, particularly in eastern Australia and New Zealand, document sightings of Giant Boarfish in dive reports, dive forums etc.
In New Zealand, Paristiopterus boarfish are found in some marine reserves, such as the Goat Island area of Cape Rodney- Okakari Point (Leigh); Poor Knights Islands, and Three Kings Island Nature Reserve, amongst others (Denny et al., 2003; Seafriends Marine Conservation and Education Centre, 2004).
The Brown-spotted Boarfish and the Giant Boarfish have venomous spines (Museum of Victoria, 2000).