© 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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Western Orange Perch

Family Name:	Serranidae
Scientific Name:	Lepidoperca filamenta Roberts, 1987
Recommended Status in S.A:	Data Deficient
Rationale:  The Western Orange Perch is included here because it (i) has a limited geographic distribution within S.A., with the Great Australian Bight being the eastern edge of the species range; (ii) is known from a relatively narrow depth range, in outer continental shelf waters; (iii) is a member of the Serranidae, whose life history characteristics make them susceptible to over-exploitation and population decline; (iv) is taken as by-product or is discarded as bycatch in a number of fisheries in deeper waters of the continental shelf; and (iv) there is a paucity of information about relative abundance / population sizes, habitat requirements, biology, and population dynamics.

Page Contents

Current Conservation Status

No listings known

Distribution

General

The species occurs in western South Australia and southern Western Australia (Kuiter, in Gomon et al., 1994). Western Orange Perch L. filamenta has been recorded between the central western coast of W.A. and Eyre Peninsula in S.A. (Kuiter, in Gomon et al., 1994), and the type locality is west of Eucla in the Great Australian Bight (Eschmeyer, 2004).

South Australia

Other than the published eastern limit of the range (Port Lincoln, according to Kuiter, in Gomon et al., 1994), and catch data from the Great Australian Bight (see below), no other examples of Western Orange Perch L. filamenta in S.A. could be found for this report; however there are 5 old records (1912) from the W.A. / S.A. border, including the holotype and paratypes (Australian Museum records, cited in OZCAM database, 2006).

Habitat

The species is demersal in deeper waters of the continental shelf (Kuiter, in Gomon et al., 1994; Froese and Pauly, 2004). A relatively narrower depth range (128m – 220m) has been reported for Western Orange L. filamenta (Kuiter, in Gomon et al., 1994).

Notes on the Biology

Growth

L. filamenta grows to about 18cm (Kuiter, in Gomon et al., 1994).

Diet

No specific information on the diet is available, however it is noted that smaller Serranids usually eat zooplankton (Heemstra and Randall, 1999).

Reproduction

Most species in the Serranidae are protogynous hermaphrodites, as are most members of the sub-family Anthiinae (P. Heemstra, South African Institute for Aquatic Biodiversity, pers. comm., 2006) to which species in Lepidoperca belong. Protogynous hermaphrodites first mature as females and, after spawning one or more times, they will then change sex, spawning thereafter as males (Heemstra and Randall, 1999).

Fisheries Information

In the Great Australian Bight Trawl Fishery, fisher’s logbooks recorded a small catch (200kg) of “Orange Perch” in 2000/01, but the species was not specified.
The species is known mainly from trawling records in Western Australia. For example, one or both of the western Lepidoperca species is taken in the Western Trawl Fisheries (which, for reporting purposes, comprises the North West Slope Trawl Fishery and the Western Deepwater Trawl Fishery). During the period 1992/93 to 2003/04, at least 2,287 Orange Perch were taken in the Western Trawl Fisheries, comprising a range of 0 – 735 individuals per annum, and a catch of several hundred specimens per year in some of those years (AFMA, 2004f). Catch data were not included for 5 of the years in the ‘forementioned period, hence the total catch of Lepidoperca would be higher than that specified. It is noted that the logbook data specified above (AFMA, 2004f), incorrectly reported the Orange Perch catch as being the eastern species L. pulchella, which does not occur in W.A.. Ward et al. (2003) reiterated the taxonomic error, listing L. pulchella as the Orange Perch species caught in the Great Australian Bight trawl fishery.  Similarly, Bromhead and Bolton (2005), listed L. pulchella as the single species of Orange Perch caught in 7 fisheries managed by the Commonwealth, including those in the south-western region. Within the range of L. filamenta, those fisheries for which L. pulchella (the eastern species) was listed include the Gillnet, Hook and Trap Fishery (by-product species), South East Trawl Fishery (discarded), Great Australian Bight Trawl fishery (possibly by-product, but uncertain), and Western Deepwater Trawl (by-product).

Vulnerable Characteristics of the Species

To date, L. filamenta is known mainly from trawl specimens, over a relatively narrow depth range of less than 100m, on the outer continental shelf and upper slope. The full depth distribution is not recorded, however if it is as narrow as the data from trawling suggest, that may increase the vulnerability of populations to impact (particularly from trawling at those depths). 
The species is a member of the Serranidae, a family of fish that have life history characteristics that increase the vulnerability of populations to decline. For example, Serranids are generally slow moving, benthic, site-associated fish with distinct population structure, which makes them vulnerable to fishing-induced population impacts (see section above, on Serranidae family).
Virtually nothing is known of the distribution within the range, relative abundance, habitat requirements, biology, ecology, or population dynamics of this species.

Threatening Processes

Capture in benthic trawls may be the main threatening process for populations Lepidoperca species in south-central and south-western Australia. Although there are no species-specific data for Western Orange Perch, the closely related south-eastern Australian species Lepidoperca pulchella (Orange Perch) has been listed as one of the bycatch species in the N.S.W. Ocean Trawl Fishery that has a “high” fishery impact profile (New South Wales Department of Primary Industries, 2004). Studies in New South Wales showed that the species suffers barotrauma when hauled in trawls, also has a low probability of survival when caught, and L. pulchella was classified overall as an “intermediate to high risk” species in terms of population impacts from trawl fishing. A very similar assessment was given for the N.S.W. species, Lepidoperca brochata (see NSW Department of Primary Industries, 2004). In a recent draft ecological risk assessment of the South East Trawl and Danish Seine Fishery (Wayte et al., 2004), 5 “productivity attributes” and 6 “attributes of susceptibility” for the eastern species L. pulchella were used to categorise it as a “medium risk” species; i.e. susceptible to population impacts from trawling. Given that, it is likely that L. filamenta would be similarly susceptible to population impacts due to trawling.   

Research Requirements

For both species of Lepidoperca, data are required on the distribution (within the geographic range and depth range), relative abundance, habitat requirements, biology, ecology, and population dynamics.

Management Requirements

Target catch, by-product and bycatch of this species in trawl fisheries should be better quantified, and monitored over time. Measures are required to reduce the bycatch of this species, particularly in trawl fisheries.
Given that there is virtually no knowledge of the species relative abundance, biology, habitats, or resilience to exploitation, methods to reduce the bycatch of this species should be investigated.