© 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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Bastard Trumpeter / Silver Trumpeter / Copper Moki

Family Name:	Latridae
Scientific Name:	Latridopsis forsteri (Castelnau, 1872)
Recommended Status	South Australia: Data Deficient; South-Eastern Australia (including Commonwealth waters): Data Deficient; Commonwealth Waters: possibly Near Threatened
Rationale:  Although Bastard Trumpeter is a common reef species in south-eastern Australia and Tasmania, it is included here because (i) it is a large, relatively long-lived, site-associated fish species found for part of its life in nearshore reef habitats, and species with such population dynamics and habits are vulnerable to decline from over-exploitation; (ii) schools of Bastard Trumpeter appear to move freely over home reefs, making them particularly susceptible to capture (e.g. by gill-nets and hooks); (iii) Bastard Trumpeter exhibit strong recruitment variability, which increases the susceptibility of populations to gradual decline if fishing remains high during years of poor recruitment; (iv) the species is highly prized by both recreational and commercial fishers, so is caught wherever it is accessible; (v) Bastard Trumpeter is reported to have a moderate to high vulnerability to fishing-induced population decline; (vi) population size is unknown in any area, and little is known of the life history (other than growth, and variable recruitment strength), particularly the details of offshore migration with size / age. Catch and effort are highest in Tasmania, where there are no biomass estimates; catch rates are considered to be a poor indicator of stock abundance, and stock status is reported to be uncertain. However, in Tasmania, concern has been raised by industry representatives, recreational fishers and scientists about depletion due to the effects of fishing, coupled with apparent poor recruitment during the past decade (and this has also occurred during periods of the 19th and 20th centuries). Recent summaries indicate that current inshore populations in Tasmania are at low levels, and continuing to decline. Additional issues include the relatively high catches of individuals that are under legal minimum size, and also reproductively immature (i.e. growth- and recruitment-overfishing may be occurring in Tasmania). Catch and release mortality may also be an issue. Management is hindered by the multi-sector and multi-gear nature of the catches, and the fact that this species is often taken as a by-catch, rather than a target catch. South Australia is at the edge of the geographic range of Bastard Trumpeter. In South Australia, this species has been taken in small tonnages per annum during the past decade, and the catch by recreational fishers and charter boats is unknown, but potentially low. There is no knowledge of the population size of Bastard Trumpeter in South Australia; however, given its geographically limited distribution in the State (i.e. South-East), it is likely that the population size is small, compared with populations in the main part of the range (such as Tasmania) where Bastard Trumpeter is more abundant and common. If the population in south-eastern South Australia is separated from that in Tasmania or Victoria, it is noted that even a small amount of fishing may have an adverse impact on a small, local population of a large, site-associated, relatively long-lived fish of limited spatial distribution. However, there are no data over space and time in South Australia to indicate status of the population in this State.

Page Contents

Current Conservation Status

There are no formal listings, but it is noted that in Tasmania at the turn of this century, Smith and Heran (2001) reported that the species is probably fully fished.

Distribution

General

The Bastard Trumpeter occurs in south-eastern and southern Australia, and around New Zealand (May and Maxwell, 1986; Paulin et al., 1989; Francis, 1996; Kuiter, in Gomon et al., 1994; Smith et al., 2003).

Southern Australia

Within Australia, the Bastard Trumpeter is common in Tasmania, and is found in smaller numbers in NSW (from approximately Sydney southwards), Victoria, and south-eastern South Australia (Hutchins and Swainston, 1986; Kuiter, in Gomon et al., 2004).

Elias and Hart (2004) reported that the species was commonly observed during visual censuses of reef fishes in Victoria. Bastard Trumpeter is considered to be one of the characteristic species that comprise the fish community in east Wilsons Promontory (Edmunds et al., 2000).

The species has also been recorded around islands in Bass Strait (e.g. Edgar, 1984), and right around Tasmania (Edgar, 1999).

Kuiter (in Gomon et al., 1994) reported that central N.S.W. is the northern limit, and South Australia is the western limit of the distribution.

South Australia

Examples of locations in South Australia where Bastard Trumpeter occur include deeper waters off south-western and south-eastern Kangaroo Island; deeper waters south-east of the Dudley Peninsula (Kangaroo Island) and west of the southern Coorong / Lacepede Bay area; and deeper waters off south-eastern S.A. (e.g. between Kingston and the Victorian border) (SARDI catch and effort database records, 1995-1997).

Sub-adults have been recorded in low numbers at a shallow subtidal reef near Beachport, in the lower south east of South Australia (J. Baker, pers. obs. 2009).

There are also old records from southern Fleurieu Peninsula (South Australian Museum records 1954 and 1965; West Australian Museum record, 1954); and the Encounter Bay / Murray Mouth area (South Australian Museum records, 1915 and 1965).

There is a recent, unverified record from Port Stanvac, in shallow water (3-5m), reported during a fish survey by a government agency (Theil and Tanner, 2009).

Habitat

Generally, Bastard Trumpeter is found on the continental shelf, from the shallow subtidal down to about 160m (May and Maxwell, 1986; Morton et al., 2005). Juveniles and sub-adult fish inhabit shallow inshore reefs, whereas larger fish apparently move offshore onto deep (>50 m) reefs of rough topography (Bax et al., 1999; Morton et al., 2005). Fishers report Bastard Trumpeter from “deep offshore reefs”, and on top of underwater pinnacles (FishNet, 2005).

In northern Tasmania, the species has been recorded on reefs with cover of large macroalgae, such as Ecklonia radiata, and Phyllospora comosa, interspersed with barren areas caused by grazing of the urchin Centrostephanus rodgersii (Barrett and Wilcox, 2001). In Victoria, the Bastard Trumpeter has been recorded on sheltered reefs amongst the string kelp Macrocystis angustifolia (Parks Victoria, 2003), and also on deeper reefs with significant vertical structure (e.g. overhangs and caves) and dense cover of sessile invertebrates (Elias et al., 2004). Similarly in south-eastern South Australia, sub-adults of Bastard Trumpeter have been recorded in channels of a nearshore reef, where giant kelp Phyllospora comosa and bull kelp Durvillaea potatorum were dominant cover (J. Baker, pers. obs., 2009). During a survey of fish-habitat relations in south-eastern Australia, Bastard Trumpeter was reported to be closely associated with rocky reefs (Williams and Bax, 2001).

The species occurs in the vicinity of rocky reefs, and over sand near reefs. Bastard Trumpeter is usually seen in small numbers, although large schools in the thousands have also been observed (Kuiter, in Gomon et al., 1994; Australian Museum, 2004v).

Juveniles and sub-adults often occur in shallow water; larger, mature adults occur in deeper waters of the continental shelf (Edgar, 2000; Smith and Heran, 2001).

Juveniles (“paper fish” – see below) occur in schools and settle on reefs in spring. In Tasmania, fish as small as 16cm fork length (FL) have been sampled from inshore reefs in January (Murphy and Lyle 1999, cited by Morton et al., 2005). In Tasmania, juveniles have reportedly been recorded in Heterozostera tasmanica seagrass habitat (e.g. Georges Bay and Prosser Bay), and over mud habitat (Georges Bay) in the shallow subtidal (Jordan et al., 1998). There are also records from estuaries (e.g. on Flinders Island in Bass Strait, and Swanport in eastern Tasmania) (Edgar et al., 1999).

Notes on Biology and Behaviour

Growth and Age

L. forsteri grows to around 65cm (Last et al., 1983; Kuiter, in Gomon et al., 1994; Hutchins and Swainston, 2001). Tag-recapture and length-frequency analysis studies in Tasmania have shown that Bastard Trumpeter reach about 33-34cm by age 3 (Murphy and Lyle, 1999). Growth rates may begin to slow after approximately 2 to 2 ½ years of age (Murphy and Lyle, 1999). In Tasmania, Murphy and Lyle (1999, cited by Morton et al., 2005) described the pattern of juvenile growth. During that study, the majority of juvenile fish resident on inshore reefs were aged less than 5 years old, and almost all during that study were aged at less than 10 years (Murphy and Lyle, 1999). Juveniles reach an average length of around 28 cm after two years and 42 cm after four years, with most growth occurring during summer and autumn (Murphy and Lyle, 1999). Older fish grow significantly more slowly, with a large range in size-at-age in fish over approximately 50cm (Murphy and Lyle, 1999).

The maximum weight recorded is about 4.25kg (Last et al., 1983, cited by Morton et al., 2005; Hutchins and Swainston, 2001; Australian Underwater Federation Inc., 2003). The largest Bastard Trumpeter are recorded rarely in New South Wales, and they appear to be significantly larger than those in shallow waters in Tasmania (G. Edgar, TAFI, pers. com., 2009).

Few adult fish have been examined, but indications are that maximum ages are in excess of 17 years (Murphy and Lyle 1999, cited by Morton and Lye, 2005). Edgar (2000) reported that mature adults can live for up to 30 years.

Diet and Feeding behaviour

Bastard Trumpeter are benthic feeders, taking various small invertebrates (Paulin et al., 1989, cited by Morton et al., 2005), particularly amphipods and isopods (Harries and Lake, 1985; cited by Morton et al., 2005). Adults are likely to be opportunistic carnivores (Morton et al., 2005).

A dietary analysis study in Tasmania indicated that there is significant trophic overlap between Banded Morwong Cheilodactylus spectabilis and Bastard Trumpeter (Metcalf et al., 2008).

Reproduction

In Tasmania, sexual maturity may occur at sizes greater than 45cm and ages greater than 4 years (Harries and Lake, 1985; Murphy and Lyle, 1999). Johnston (1882, in Harries and Lake, 1985, cited by Morton et al., 2005) reported that mature Bastard Trumpeter are only found near offshore, rocky reefs greater than 20m depth (up to about 130m deep).

Spawning apparently occurs in late winter, although little is known as only a small number of sexually mature fish have been observed (Lyle, 1994, cited by Morton et al., 2005).

Fishers report that Bastard Trumpeter from offshore come close inshore to reef areas when spawning (FishNet, 2005). Bastard Trumpeter may spawn in winter (DPIPWE, 2009).

Recruitment is highly variable over time, with strong (e.g. 1993) and weak year classes (Murphy and Lyle, 1999).

Recruitment to reefs is episodic, and likely follows oceanographic patterns (e.g. Thresher, 2002). In the mid to late 1990s, during a study of the inshore gill-net fishery in Tasmania, a large number of juvenile Bastard Trumpeter were observed to recruit to inshore rocky reefs in southern Tasmania. The strong cohort during that period was considered to be based on the 1993 spawning season (Murphy and Lyle, 1999). In another Tasmanian example, a recruitment of Bastard Trumpeter onto a reef at Tinderbox resulted in a small resident population that was observed during 2000-01 (Barrett et al., 2002).

There may be some offshore movement with growth to adulthood (DPIPWE, 2009), because the few reports of large adult Bastard Trumpeter have been from deep water reefs (such as in eastern Bass Strait) (Jeremy Lyle, unpubl. data, cited by Murphy and Lyle, 1999).

Behaviour

Juveniles tend to school, and adults are usually solitary (Morton et al., 2005).

L. forsteri is a reef resident, and juveniles recruit to particular reefs. Barrett and Edgar (1998) and Edgar and Barrett (1999), reported that Bastard Trumpeter showed a great degree of site fidelity at the Maria Island Marine Reserve in eastern Tasmania, and during bi-annual surveys from 1992 to 1997, individuals rarely moved between reefs. In another Tasmanian study, during the late 1990s, tag-recapture data showed that juvenile Bastard Trumpeter remained in the vicinity of local reefs for several years, with 88% of recaptures occurring within 5 km of the tagging location (Murphy and Lyle, 2000). During that study, only a small number of individuals moved away from the reef system where they were tagged (and a single fish moved 143.5km, and another 62km). During another survey, at Swanport in eastern Tasmania, one individual was re-sighted in the same area several times during a 12 month period (Edgar et al., 2004).

Other Information

Small individuals are extremely compressed and nearly transparent, hence the common name “paper fish” (Kuiter, in Gomon et al., 1994; Edgar, 2000). The pelagic juvenile “paper fish”, are also recognised from adults by their silvery dorsal surface, and deepness below the pectoral fins (Neira et al., 1998, cited by Morton et al., 2005).

Little is known of the stock structure or potential migrations of Bastard Trumpeter (Lyle, 1994; Morton et al., 2005). Although not conclusive, the lack of mature fish in shallow waters may indicate structuring within the population, with immature fish inshore and adult fish offshore in deeper water (Harries and Lake, 1985, cited by Morton et al., 2005). If so, Bastard Trumpeter would share a similar life history to Striped Trumpeter Latris lineata and Blue Moki (Latridopsis ciliaris), a closely related New Zealand species (Morton et al., 2005).

Fisheries Information

Commercial – Commonwealth

Although there is no major fishery for this species in Commonwealth waters, larger adult Bastard Trumpeter are a minor bycatch of off-shore gill-netting for Warehou – e.g. in eastern Bass Strait (Murphy and Lyle, 1999; Smith and Heran, 2001). The species is therefore part of the bycatch in the Commonwealth-managed Southern and Eastern Scalefish and Shark Fisheries (SESSF) (AFMA, 2002a). In these fisheries (e.g. South East Trawl fishery – SETF; Gill-net, Hook and Trap fishery – GHAT; Great Australian Bight Trawl fishery - GABTF), there is a stated bycatch possession limit of 20kg of Bastard Trumpeter, because it is a State-managed species, in Tasmania and South Australia (AFMA, 2002a, 2004e). Despite this bycatch limitation, Bromhead and Bolton (2005) reported that Latridopsis forsteri is a bycatch species in numerous Commonwealth-managed fisheries across Australia, including a retained by-product in most of those. Some of the reported examples include Eastern Tuna and Billfish Fishery (purportedly discarded bycatch); GHAT (retained by-product); SETF (retained by-product), Norfolk Island Offshore Demersal Finfish Fishery (retained by-product), and GABTF and Western Deepwater Trawl Fishery (reportedly retained by-product in both) (Bromhead and Bolton, 2005).

In the Southern Shark Fishery (= part of the GHAT), Walker et al. (2003) reported the species as part of the bycatch from 6-inch (15cm) shark nets in the Bass Strait region, and previously, also bycatch in other net sizes no longer used in the shark fishery in south-eastern Australia. In the South East Non-Trawl fishery (also part of the GHAT), during a monitoring program from 1999 to 2000, Bastard Trumpeter was reported as a very minor by-catch of mesh nets (approximately 8kg, 6 specimens) (Knuckey et al., 2001).

Commercial – Tasmania

Most of the catch in southern Australia is taken from Tasmanian waters. Small catches (usually less than 3t per year) have been recorded throughout the 1990s from N.S.W., Victoria and South Australia (BRS, 2004a).

Traditionally in Tasmania, Bastard Trumpeter was the primary scalefish species targeted by both commercial and recreational gill-net fishers, and this species has been exploited since European settlement. Concerns were first expressed about the status of species as a resource, as early as the 1880s, resulting in a Royal Commission to investigate the problem (Murphy and Lyle, 1999). The commercial catch history suggests at least two periods of major declines in abundance, in the late-1910s, and again in mid-1970s (Harries and Croome, 1989, cited by Murphy and Lyle, 1999). L. forsteri is still taken in the Inshore Scalefish Fishery in Tasmania, using “grab-all nets”, a type of gill-net (Murphy and Lyle, 1999; Morton et al., 2005), and minor quantities are taken by beach seine. The Tasmanian fishery is based almost entirely on juveniles (Ziegler et al., 2006). Most catches are taken off the east, south, south-east and west coasts. Much of the catch is immature fish (Harries and Lake, 1985, cited by Morton et al., 2005). In Tasmania, catches prior to the mid 1980s were generally below 20t per annum, but rose to around 60 tonnes by the mid 1990s, then declined again to levels of around 20 tonnes (Morton et al., 2005) From 1995/96 - 1999/00, highest catches (more than 20t) were taken from two fishing blocks in SE Tasmania, and one block on the lower mid west coast, but catches from all three areas were lower during the period 2000/01 to 04/05. Grab-all net effort (in number of days fished) has also declined consistently since the mid 1990s (Lyle et al., 2004). During the past decade of decline in both catch and effort, grab-all catch per unit effort (CPUE, in kg per gear unit, and kg per day) has remained stable (Lyle and Hodgson, 2002; Lyle et al., 2004). In Tasmania, Bastard Trumpeter is also a bycatch of the specific gill-net fishery for live Banded Morwong. In the Banded Morwong fishery, surveys indicated that Bastard Trumpeter comprised about 1% of the catch (by numbers) in north-eastern and eastern Tasmania, and about 4% of the catch in the south-east (Murphy and Lyle, 1999). There are licence restrictions for the commercial fishery in State waters. In 2004-2005, the commercial catch of Bastard Trumpeter in Tasmania was at about 17t (Ziegler et al., 2006), the lowest catch since the mid 1980s. Catches from Tasmania are taken by State fishers, and also by dual-endorsed fishers, who hold Commonwealth and Tasmanian fishing permits.

Bastard Trumpeter: Reported Catch from Tasmania, 1969-2005

(from Lyle and Jordan, 1999; Lyle and Hodgson, 2002; Lyle et al., 2004; Ziegler et al., 2006)

Commercial – Victoria

L. forsteri is taken in small quantities in Victoria, with about 1 to 2 tonnes per annum during the late 1960s and early 1970s, and no catches were reported during most years of the 1980s, other than 1.8t in 1983/84 (e.g. BRR, 1991). Maps in BRS (2004) indicate that more than 5t per annum may have been taken in Victorian waters in 2001, 2001 and 2002. Trumpeter is sometimes a bycatch of fishing for other species, such as Rock Lobster Jasus edwardsii and Pink Snapper Chrysophrys auratus (DPI Victoria, 2008a,b).

Commercial – New South Wales

The species is also recorded in fisheries in New South Wales, with reported catches between 1 and 4 tonnes in most years of the 1990s, but none recorded between 1997 and 1999 (BRS, 2004). Pease (1999) recorded the commercial catches from 53 estuaries in NSW during the period 1991 to 1995, and reported that the mean annual catch of L. forsteri from all regions combined was about 2.7 tonnes (SD = 1.3 tonnes). During 2000/01, the total commercial catch of trumpeters (reportedly Latris lineata and Latridopsis forsteri combined) in NSW was reported to be about 11 tonnes, with 25% of this taken by the NSW Ocean Trawl Fishery (see below) (NSW Department of Primary Industries, 2004). The species is also recorded in the bycatch (reportedly discarded) of the Ocean Trap and Line fishery. During 2000/01, 93kg of Bastard trumpeter were recorded, plus an additional 1.17 tonnes of unspecified trumpeter (mixed species, but not including Tasmanian Trumpeter). Catches of unspecified “Trumpeter” in New South Wales amounted to 7.6 tonnes in 2000/01, but not all of this would have been Latris or Latridopsis species. The catches of “Trumpeter” comprised 1.3t from Ocean Fish Trawl (but see below), 1t from Ocean Prawn Trawl, and 1.17t from Ocean Trap and Line fishery (New South Wales Department of Primary Industries, 2006). The 3.4t of “Trumpeter” caught in the Estuary General fishery and 0.6t from the Estuary Prawn fishery would have been a species of Pelates, not Latris or Latridopsis (G. Edgar, TAFI, pers. comm., 2009). A previous estimate of the catch of Trumpeters (reported to be Latris lineata and Latridopsis forsteri) in the N.S.W. Ocean Trawl Fishery during the same year (2000/01) was higher, amounting to 2.6 tonnes of trumpeters in the ocean fish trawl sector, but only 65kg was taken in the ocean prawn trawl sector (N.S.W. Department of Primary Industries, 2004).

Commercial – South Australia

L. forsteri is taken in small quantities in the Marine Scalefish Fishery in South Australia, from fishing areas in south-eastern S.A., between southern Kangaroo Island and the Victorian border. Data for the 1980s are shown below (from BRR, 1991). During 1995 – 1997, South Australian records show that about 450kg of Bastard Trumpeter were recorded as being taken in one year in deep waters seaward of the Coorong, and in 3 other fishing blocks (of 1 degree square), less than 100kg was recorded (SARDI data, 1995-1997). Recent data from South Australian waters are not available for this report.

Bastard Trumpeter: Total Reported Catch in South Australian Waters
Year	Catch (t)
1984/85	<0.5
1985/86	~ 0
1986/87	2
1987/88	3.2
1988/89	1.5
1989/90	2
1990/91 - 1998/99	(no data lodged with BRS)
2000	<1
2001	<1
2002	<1
(from BRR, 1991; BRS, 2004)

Recreational

Traditionally in Tasmania, Bastard Trumpeter was the primary scalefish species targeted by recreational gill-net fishers, and the species has been exploited since European settlement (Murphy and Lyle, 1999). Bastard Trumpeter (as well as Striped Trumpeter L. lineata) are “iconic” species in Tasmania, and there is inter-sector competition between commercial and recreational fisheries for these fish (Morton et al., 2005). L. forsteri is still one of the more popular species taken by graball nets (gill-nets) (Lyle et al., 2000) and spearfishing in Tasmania (Barrett et al., 2002), and most of the specimens caught in shallow waters are less than 5 years old, and about 1kg in weight (Edgar, 2000). In Tasmania, the annual recreational gill-net catch was reported to be as high as 42 tonnes over the period December 1996 – April 1998 (Lyle and Hodgson, 2002). The National Recreational and Indigenous Fishing Survey (Henry and Lyle, 2003; Morton et al., 2005) reported that, during the survey time period (May 2000 to April 2001), approximately 31,000- 34,000 Bastard Trumpeter specimens were caught and kept by recreational fishers in Tasmania, out of a total catch of approximately 39,000. The total recreational catch of Bastard Trumpeter was estimated to be approximately 43t in 2000/01, which is double the commercial catch (Ziegler et al., 2006). During the 2000/01 survey period, almost all of the catch was taken by inshore boat fishers, using gill-nets. Very small quantities were taken by other methods (line and spear). About 36% of the retained catch was taken from south-east Tasmania (Tasman Peninsula), 25% from the west coast; 13% from Derwent Channel; 12% from the central east coast; 5% from Frederick Henry-Norfolk Bay regions, and 6% from off the north coast (Morton et al., 2005). Recreationally-caught Bastard Trumpeter sampled during 2000/01, ranged between 29-52 cm FL, with the majority of the catch between 35 and 45cm, and an average length of 40cm FL (1.2 kg) (Morton et al., 2005). Several years previous to those results, surveys during 1997/98 indicated greater representation of fish under 30cm, resulting in a mean length of about 30cm FL (Lyle and Campbell, 1999).

Bastard Trumpeter is listed as the 4th highest species (in terms of quantities) taken by gill-netting in Tasmania (Smith and Heran, 2001). During a survey in Tasmania from December 1997 to April 1998, 215 specimens were recorded in the grab-all catch, 10 from fishing using SCUBA, and 10 from line fishing (Lyle and Campbell, 1999). During that survey, in which 63 recreational catches of Bastard Trumpeter were sampled, 97% of fishers surveyed could identify this species, with only 3% mistaking Bastard Trumpeter for another fish (e.g. Warehou) (Lyle and Campbell, 1999). During gill-net fishing trials in Tasmania in 1999, Bastard Trumpeter was one of 3 species that collectively comprised 60% of the total catch of 2,500 fish, and was also the most frequently caught reef species, representing around 30% of the total catch from the reef sets (Lyle et al., 2000). During that study, the size range of Bastard Trumpeter in the catches was 28–44cm FL, the majority of which were legal size, captured in the 108 and 114mm gill-nets (Lyle et al., 2000). In contrast, mullet nets catch undersized Bastard Trumpeter (Lyle et al., 2000).

The species is taken by spearfishing. The Australian Underwater Federation has reported that the record size of L. forsteri taken by spearfishing was 4.25kg, a specimen taken from Broughton Island in N.S.W., in 1972 (Australian Underwater Federation, Inc., 2003). It is noted that L. forsteri was one of the species included in the list of fish taken in spearfishing competitions during the 1980s (e.g. 32nd Australian Skindiving Convention) (Johnson, 1985b). More recently, Bastard Trumpeter (specimens over 0.4kg) was listed as target species in the 54th Australian Spearfishing Titles 2006, held on northern Kangaroo Island (Australian Underwater Federation Inc., 2006).

Anglers in Victoria and New South Wales also take this species. The record-sized specimen reported for Victoria was taken at Apollo Bay, in 1985 (Australian Anglers Association – Victorian Division, 2003). The New South Wales record is 3.26kg, a specimen taken in 1973 (New South Wales Fishing Clubs Association record).

During the National Recreational and Indigenous Fishing Survey (Henry and Lyle, 2003), Bastard Trumpeter catches by recreational fishers in southern Australian States other than Tasmania were not reported at species level during that survey.

Vulnerable Characteristics of the Species

Bastard Trumpeter is a large, relatively long-lived, site-associated fish species found for part of its life in nearshore reef habitats, and species with such population dynamics and habits are vulnerable to decline from over-exploitation.

Schools of Bastard Trumpeter appear to move freely over home reefs, making them particularly susceptible to capture in gill-nets. Such nets are widely used by both recreational and commercial fishers in Tasmanian waters and L. forsteri is actively targeted by both user groups (Murphy and Lyle 1999, cited by Buxton et al., 2006).

Bastard Trumpeter exhibit strong recruitment variability, which increases the susceptibility of populations to gradual decline if fishing remains high during years of poor recruitment. For example, a strong year class was recorded in Tasmania during the mid 1990s, reportedly based on the 1993 spawning season (Murphy and Lyle, 1999), but years can elapse before such recruitment events are repeated. The influence of the strong variability in recruitment has been a feature of the Tasmanian fishery for this species over the past century (Harries and Croome, 1989, cited by Ziegler et al., 2006).

Bastard Trumpeter is reported to have a medium resilience to exploitation, in terms of minimum population doubling time (based on growth or reproductive parameters), but a moderate to high vulnerability to fishing-induced population decline (Cheung et al., 2005, cited in Froese and Pauly, 2009).

South Australia is at the edge of the geographic range of this species, and the species is found in comparatively low abundance in South Australia, compared with the eastern part of the range.

Threatening Processes

Fishing is considered to be one of the main threatening processes, particularly in Tasmania, where Bastard Trumpeter is taken commercially, and is also a popular species for recreational anglers. This species has been exploited commercially in Tasmania since European settlement, and concerns were expressed about the status of the resource as early as the 1880’s (Lyle, 1994, cited by Morton et al., 2005). During the turn of this century, Smith and Heran (2001) reported that the species is probably fully fished, with no recent assessment. Although stock status is uncertain in Tasmania, and no stock biomass estimates are available, concern has been raised by industry representatives and recreational fishers about depletion, due to the effects of fishing, coupled with apparent poor recruitment in recent years (Lyle et al., 2004; Morton et al., 2005; Ziegler et al., 2006), and this has also occurred during periods of the 19th and 20th centuries. In Tasmania, years of poor recruitment have presumably contributed to the downturn in commercial catches and the under-representation of small individuals during most years of the 2000s, compared with the 1990s (Morton et al., 2005). During the past decade of decline in both catch and effort in Tasmania, grab-all catch per unit effort (CPUE, in kg per gear unit, and kg per day) has remained stable (Lyle and Hodgson, 2002). Although part of this may be due to the fact that the species is generally taken as a by-product rather that a target species (Lyle et al., 2004; Ziegler et al., 2006), it may also be an example of serial depletion of reef-associated aggregations of Bastard Trumpeter in shallow water. Because the species is largely taken as by-product, total catch rather than catch rates may be a better indicator of abundance/availability for Bastard Trumpeter. As such, the trend in commercial production suggests that current inshore populations are at low levels, and continuing to decline (Lyle et al., 2004; Ziegler et al., 2006).

During a survey in Tasmania from December 1997 to April 1998, 28% of the catch of Bastard Trumpeter from grab-all nets was under legal minimum size (35cm) (Lyle and Campbell, 1999). The minimum size limit of 35cm TL is well below the size at maturity (Morton et al., 2005).

It is noted that Bastard Trumpeter was ranked as one of the top 10 finfish species in Tasmania that is subject to catch and release mortality (McLeay et al., 2002), yet Lyle et al. (2000) reported the species to be very robust, other than when caught in gill-nets for long periods (e.g. overnight).

Mesh selectivity trials and tag recapture data in Tasmania have shown that Bastard Trumpeter caught and retained from gill-net fishing in inshore waters are sexually immature (Murphy and Lyle, 1999). The majority of fishing for this species occurs in these inshore waters, hence it can be inferred that a significant proportion of Bastard Trumpeter caught in Tasmania have not had the opportunity to spawn. Both growth- and recruitment-overfishing is likely, given the fact that the fishery in Tasmania is based on juveniles (Ziegler et al., 2006).

During a survey in Tasmania, in which size of fish in the catch was compared with distance from boat ramp, Bastard Trumpeter showed a pattern indicative of fishing impacts that are related to the proximity to the nearest boat ramp. The greatest mean size and the greatest numbers of legal-sized individuals occurred at more isolated sites (Stuart-Smith et al., 2008).

It is noted that the species is reported to be at “medium risk” of population impacts from operation of the otter trawl sub-fishery of the South East trawl component of the SESSF (Wayte et al., 2004), but catches in this fishery are likely to be low relative to State-based fisheries, due to the depth range.

In South Australia, the species has been taken in small tonnages per annum during the past decade, in the Marine Scalefish Fishery. There is no knowledge of the population size of Bastard Trumpeter in South Australia; however, given its geographically limited distribution in S.A. (i.e. South-East), it is likely that the population size is small, compared with populations in the main part of the range (such as Tasmania) where Bastard Trumpeter is more abundant and common. If the population in south-eastern South Australia is separated from that in Tasmania or Victoria, it is noted that even a small amount of fishing may have an adverse impact on a small, local population of a large, site-associated, relatively long-lived fish of limited spatial distribution. However, there are no data over space and time in South Australia to indicate status of the population in this State.

Another major threatening process for this species may be climate change. Bastard Trumpeter is a cool water species, adversely affected by rising water temperatures. It is currently uncertain to what extent the historic decline in the Tasmanian populations is due to rising water temperatures, comparing with over-fishing (G. Edgar, TAFI, pers. comm., 2009).

Research Notes

In Tasmania, acoustic tagging of various reef fishes species (including L. forsteri) has been undertaken. One of the aims is to assess movement information for this species, to determine if spatial closures are needed to ensure a significant proportion of fish reach maturity before becoming vulnerable to fishing (Semmens et al., 2008).

Research Recommendations

More information is needed on the relation between populations in Tasmania, New South Wales, Victoria and south-eastern South Australia. Particularly, information is required to determine whether any of these populations are linked.

Related to the above, ontogenetic patterns of movement and migration need to be determined (see Research Notes, above).

In all parts of the range, including South Australia, there is a paucity of information regarding the offshore populations, and offshore fisheries for Bastard Trumpeter.

Species-specific catch and effort data are required over space and time, in fisheries where Bastard Trumpeter are caught and retained as by-product, or discarded as bycatch.

In Tasmania, continued collection of data on age and size composition will assist in determining fishing strategies appropriate for the species (Murphy and Lyle, 1999).

In Tasmania, researchers have recommended that a monitoring program be set up, to provide a pre-recruit index of Trumpeter abundance that would assist interpretation of catch and effort information obtained from logbook data (Murphy and Lyle, 1999).

In Tasmania, TAFI (2005) indicated that priority areas of research for Bastard Trumpeter are stock status, stock structure, recruitment processes and reproductive dynamics; age and growth; movement and migration.

More information is required about biomass of adult Bastard Trumpeter on offshore reefs (Ziegler et al., 2006).

Management Notes

In Tasmania, the size limit was changed from 33cm TL to 35cm TL in 1998, the new size limit being equivalent to 30cm FL (Lyle and Campbell, 1999). A survey of the catch composition indicated that, based on the old and new size limits, 17% and 28% of the grab-all catch numbers, respectively, were undersized. The significant proportion of undersized fish at the new size limit suggested that grab-all mesh sizes used to fish Bastard Trumpeter may be inappropriate (Lyle and Campbell, 1999).

In Tasmania, there was previously a daily bag limit of 30, and a possession limit of 45 (Smith and Heran, 2001), but this has now been replaced by a personal possession limit of 15 (DPIPWE web site, August, 2009).

Fisheries management in Tasmania discourages the use of highly valued species such as trumpeter for bait. For example, only the heads and frames of Bastard Trumpeter may legally be used for baiting rock lobster pots and rings, unless a receipt for purchasing the fish is available (DPIPWE web site, 2009).

Management Recommendations

Legal minimum sizes (above the size at first maturity) should be in place in all States in which this species is caught commercially and recreationally. It is noted that an increase of minimum size limit to above the size at maturity (which appears to be greater than 45cm), would be beneficial to the population, but would significantly inhibit the current commercial and recreational fisheries for the species in Tasmania, which are based on juveniles (Ziegler et al 2006).

There is some evidence that depleted populations of this reef-associated fish can benefit from the protection offered by marine reserves. In Tasmania, Barrett and Edgar (1998) and Edgar and Barrett (1999, also cited by Ward et al., 2001) showed that after 6 years of protection from fishing, the Bastard Trumpeter increased significantly in number (i.e. 2 orders of magnitude increase in abundance) and density inside the Maria Island Marine Reserve, compared with fished reference sites outside, where Trumpeter were not recorded. According to the Tasmania State of the Environment report (RPDC, 2003), the numbers of Bastard Trumpeter increased 100 times over a 10 year period in that reserve, partially due to a large recruitment event in 1994, which the reserve protected and maintained. Barrett and Buxton (2002) also reported increases in abundance between 1992 and 1996, including increases in the number of larger-sized individuals (e.g. 38cm and over). Individuals reached reproductive size inside the reserve and such protected areas are suggested as a management alternative to protect spawning stock biomass (Haddon et al., 2007). Over a longer time scale, studies of this species in marine reserves in Tasmania indicated intermittent peaks of abundance as a consequence of episodic recruitment. Between 1992 and 2002, consistently higher numbers of Bastard Trumpeter were recorded at Maria Island reserve, relative to a control (fished) site, particularly during the mid 1990s to early 2000s (data by G. Edgar and N. Barrett, cited in Buxton et al., 2006). Bastard Trumpeter recruited to coastal Tasmanian reefs in large numbers at intervals of 1-4 years, with population decline over subsequent years as animals matured and emigrated to offshore sites, or were affected by natural mortality (Edgar et al., 2007). The study of this species at Maria Island (Edgar and Barrett, 1999), and also another study on Bastard Trumpeter in the Banded Morwong gill-net fishery in Tasmania (Murphy and Lyle, 1999), indicated that short-term movements (up to two years) of Bastard Trumpeter are mainly limited to within 5 km or so, and longer term movements may not be much greater, which suggests that marine that reserves of 5 to 10 km in length could offer a reasonable level of protection for Trumpeters (prior to any longer distance migration with age).

During gill-net mesh size trials in Tasmania, Bastard Trumpeter were captured in significant numbers at approximately 26cm FL (i.e. under legal minimum size) using 105mm mesh, and 30cm FL in 114mm mesh (Murphy and Lyle, 1999). These results suggested that a move by the gill-net fishery to 115mm mesh as a minimum mesh size is clearly justified, if minimum mesh sizes are to be consistent with minimum size limits for Bastard Trumpeter (at least in relation to size at first capture) (Murphy and Lyle, 1999).

In New South Wales, species-specific data should be collected from fisheries which take Bastard Trumpeter, rather than catch records being aggregated as mixed species “trumpeter”.

Catches of Bastard Trumpeter in Commonwealth-managed fisheries should be better quantified over space and time, given the reported offshore migration of older individuals. Measures to reduce bycatch of this species in fisheries targeting other scalefish (and sharks) should be implemented where possible.

Catches of this species by commercial and recreational fishers in south-eastern South Australia and Victoria should be better quantified.

This is a distinctly south-eastern Australian species, and both fisheries data and biological information from Tasmania, Victoria, New South Wales and south-eastern South Australia should be considered in stock assessments. In particular, given that there is some evidence for movement away from shallows into deeper water with age / size, Tasmanian assessments may need to also consider the Bastard Trumpeter in other locations (e.g. outer shelf waters on the eastern side of Tasmania, and also on the other side of Bass Strait, in Victorian waters).

Other Information

Trumpeter species are reported to be at low risk of population impacts from the operation of the New South Wales Ocean trawl fishery (N.S.W. Department of Primary Industries, 2004).

The species has been recorded in marine reserves in Tasmania, such as Maria Island (Edgar and Barrett, 1999; Barrett and Buxton, 2002), Governor Island (Murphy and Lyle, 1999) and Tinderbox (Barrett et al., 2002), and also at proposed reserve sites, including sites at St Helens, Low Point, Table Cape and Waterhouse Island (Barrett and Wilcox, 2001).

In Victoria, Bastard Trumpeter has been recorded at Wilsons Promontory Marine National Park (MNP) (Edmunds et al., 2003; Plummer et al., 2003); Twelve Apostles MNP (Parks Victoria, 2003) Port Phillip Heads MNP and Phillip Island (Edmunds et al., 2003, 2006), Marengo Reefs Marine Sanctuary (Tsernjavski, 1995, cited by Plummer et al., 2003), and the Bunurong Marine and Coastal Park (Ferns and Hough, 2002).