© 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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Yellow-eyed Red Snapper / Yelloweye Redfish / Yellow-eye Nannygai

Family Name:	Berycidae
Scientific Name:	Centroberyx australis Shimizu and Hutchins, 1987
Recommended Status	South Australia - Data Deficient; Western Australia - possibly Near Threatened; Commonwealth waters - Data Deficient
Rationale:  Yellow-eyed Red Snapper is included here because (i) like other related species in Berycidae, it is likely to be long-lived with high variability in size at age, probably with low natural mortality rate and delayed maturity / high age at first spawning; it is commonly accepted that populations of such species cannot tolerate high and sustained catches over space and time; (ii) it is an aggregating / schooling species that is highly vulnerable to capture, and is being caught in increasing tonnages by some commercial fisheries, particularly in Western Australia, and possibly also in the GAB, where quota is currently high for the closely related species C. gerrardi, with which the less abundant C. australis overlaps in distribution and habitat; (iii) in the closely related C. gerrardi, year class strength may be highly variable, and environmentally-driven, and that is also likely to be so for C. australis; (iv) despite poor knowledge of the population dynamics, and biomass, and inadequate regulation of catches from all fisheries combined, this species has been increasingly targeted in W.A. commercial fisheries in recent years (with no management cap on catches), and Yellow-eyed Red Snapper, along with other Redfish species, is also an increasingly popular recreational target in S.A. and W.A., particularly charter boat catches; (v) research on related species has indicated that abundance, and size and age structure of berycid fishes (e.g. Redfishes / Red Snappers) can be rapidly fished down in commercial fisheries, and such species are susceptible to both growth- and recruitment-overfishing; (vi) C. australis catches are not separated from other Redfish catches in the commercial fishery in the GAB, nor in the commercial catch in South Australian waters; therefore trends in catch, effort and CPUE over space and timer are not recorded; additionally, recreational and charter boat catches are grouped with other Redfishes, hence there are few recreational catch statistics; and (vii) there is little information about this species across the range, including reliable measures of relative abundance and biomass over space and time; age and growth; distribution and connectivity between populations (in SA and WA); habitat preferences of adults and juveniles; reproduction; larval movement; population dynamics and ecology.

Page Contents

Current Conservation Status

No listings known

Distribution

Southern Australia

The Yellow-eyed Red Snapper occurs only in western South Australia and Western Australia, as far north as Shark Bay (Hutchins and Swainston, 1986; Kuiter, in Gomon et al., 1994).
The holotype is from Ocean Reef on the west coast of W.A. (W.A. Museum data, 1986).

South Australia

Examples of locations in S.A. where this species has been recorded include the central Great Australian Bight (Brown and Knuckey, 2002; Museum of Victoria records, cited in OZCAM database, 2009).

Habitat

The species is found near the bottom, in deeper offshore waters of the continental shelf and upper slope, usually from 80m to around 300m (Hutchins and Swainston, 1986; Kuiter, in Gomon et al., 1994), although there are isolated records, reported to be this species, from as deep as 560m (CSIRO et al., 2001; Gomon et al., 2008).
In the Great Australian Bight, this is a reef-associated species on the mid and outer continental shelf (AFMA, 2008c). Off the lower central coast of W.A. (e.g. Kalbarri area), this species has been recorded around silt- covered high relief reef outcrops in uppermost slope waters (e.g. 293m deep) (DEWHA, 2009).

Notes on Biology

Maximum length is around 51cm (Kuiter, in Gomon et al., 1994). One of the maximum sizes recorded is 0.9kg, being a specimen caught at Rottnest Island in 1993 (Australian Anglers Association record).
C. australis of up to 51cm and more than 2.5kg form schools on the outer shelf / upper slope (Daley et al., 1998). The species forms large schools in south-western Australia (Hutchins and Swainston, 2001).

Fisheries Information

Commercial

C. australis is a commercial species (CSIRO, 2003), taken by hand-line and bottom trawl (Kuiter, in Gomon et al., 1994). It is marketed as “Yelloweye Redfish” (Seafood Services Australia, 2003).

C. australis is recorded as part of the bycatch in the Southern and Eastern Scalefish and Shark Fisheries (SESSF) (AFMA, 2002a), and is occasionally sold in the eastern States (e.g. Sydney fish market) (Daley et al., 1998). Bromhead and Bolton (2005) reported C. australis to be part of discarded bycatch in the South East Trawl fishery component of the SESSF; however, the species was not listed in the bycatch as part of an Integrated Scientific Monitoring Program for that fishery (Wayte et al., 2004), nor does the main part of the distribution overlap with the geographical range of that fishery.

Most catches of this species are taken in the Great Australian Bight Trawl fishery (GABTF). Although a single stock of Bight Redfish (C. gerrardi) is assumed for fishery management purposes, C. australis may be one of the two other Centroberyx species in addition to C. gerrardi that form part of the catch in the west of the GABTF (AFMA, 2002h). The GABTF is discussed in a corresponding synopsis, in relation to C. gerrardi, the main Redfish species taken in the fishery. Sampling of the GAB Trawl fishery during 2000 and 2001, showed that during the survey period, Centroberyx australis was recorded in 11 of the 209 trawl shots, and the average quantity retained was 3.5kg per shot, with 2kg per shot discarded (Brown and Knuckey, 2002). In the GABTF, an Integrated Scientific Monitoring Program (ISMP) estimated that about 1.8t per annum are caught, with about 36% discarded. In that fishery, almost all catches are taken from depths shallower than 200m (AFMA, 2008c).

C. australis is an important commercial fish species in W.A. State fisheries, where previously (up to 2003/04) it was incorrectly recorded as C. affinis, the latter of which does not occur in W.A. (see Hutchins and Swainston, 1986; Kuiter, in Gomon et al., 1994). The combined catch of Yellow-eyed Red Snapper (called “Redfish” in W.A.) from all commercial fisheries in W.A. is provided below. A small proportion of C. australis is likely to also be present in the reported catch for Bight Redfish (C. gerrardi – see synopsis) (M. Cliff, W.A. Fisheries Research Centre, pers comm., 2006).

Reported Catches of C. australis from W.A. waters, 1994-95 to 2006-07 (may also include quantities of C. gerrardi and C. lineatus)
Year	Live Weight (kg)
1994/95	19,704
1995/96	18,531
1996/97	25,657
1997/98	49,651
1998/99	43,707
1999/00	48,755
2000/01	77,329
2001/02	76,402
2002/03	87,912
2003/04	69,734
2004/05	79,054
2005/06	62,224 (+ 773)
2006/07	29,725
(W.A. Fisheries Research Services Division statistics 1994-2001; W.A. State of the Fisheries reports, 2000/01 – 2007/08).

In 2000 / 2001, 20t of the total W.A. catch of Redfish was taken in the South Coast Bioregion of W.A. (i.e. east of Black Point, to the S.A. border) (Fisheries Research Division, 2002).

It is probable that C. australis forms a portion of the “Redfish” catch taken commercially in South Australia. Information on State-recorded catches of Redfish is provided in the synopsis on Bight Redfish C. gerrardi.

In the South Australian Rock Lobster fishery, bycatch of Redfish is retained for sale (Sloan, 2003a), or used as bait (Ward et al., 2003). During a bycatch survey from 2001 to 2003 in the South Australian Rock Lobster Fishery (Brock et al., 2004), the numbers of C. australis (incorrectly listed as C. affinis) caught in the Northern Zone, may be in the order of 40 - 150 specimens per year, according to catches recorded in fishers’ logbooks (see below). Lower numbers were recorded in logbooks in the Southern Zone during that period, and the catch in the Southern Zone might be in the order of less than 15 specimens per year, if logbook data are representative.

Proportional Catch of C. australis in S.A. Rock Lobster Fishery from Log Book Monitoring 2001-03 (Brock et al. 2004)
Northern Zone	No. Pot Lifts (& % of Total)	Catch of Yellow-eyed Red Snapper
2001/02	545,886 (60%)	84
2002/03	486,155 (57%)	17
Southern Zone
2001/02	545,886 (60%)	7
2002/03	486,155 (57%)	0

Recreational

The species is also taken by sports fishers, and some organisations keep records of the maximum sizes caught (e.g. Australian Anglers Association, W.A. Division).

Centroberyx species are significant for recreational boat fishers in southern W.A. (Fisheries Research Division, W.A. Fisheries, 2002). Boat fishing is concentrated near major population centres, with Centroberyx species being amongst approximately 6 major target species taken by recreational fishers in the South Coast Bioregion (Fisheries Research Division, W.A. Fisheries, 2002).

Centroberyx species, including C. australis, are taken by some angling clubs and associations in W.A. (e.g. Victoria Park Angling Club, W.A.; Quinns Rock Fishing Club Inc; Australian Anglers Association, W.A. Division, 2005).

The species is taken in the South Australian charter boat fishery, but numbers are combined with the more commonly caught Bight Redfish C. gerrardi. The proportion of the “Red Snapper / Nannygai” catches that constituted C. australis (compared with C. gerrardi) is not known for this report, but it is noted that Yellow-eyed Red Snapper is commonly called “Nannygai” by fishers in South Australia. During two monitoring periods in the South Australian Charter Boat fishery (Period 1 = September 2005 to June 2006, and Period 2 = July 2006 to June 2007) a total of 5,613 “Red Snapper / Nannygai” (= approx. 8,391kg) were caught and retained during Period 1, and 9,477 (= approx. 14,263kg) were caught and retained during Period 2. During Period 1 and Period 2, the numbers of legal sized specimens that were caught and released were 239 and 1,015 respectively. The numbers of undersized specimens caught and released were 351 and 845 respectively. Recorded catches were highest during the summer and early autumn, particularly during the second sampling period, when more than half of the catch was taken during this December – April period (Knight et al., 2007).

Vulnerable Characteristics of the Species

Although the biology and population dynamics of this species have not been studied in detail, it is possible that Yellow-eyed Red Snapper is similar to related Centroberyx species in southern Australia, which are long-lived, schooling species associated with particular habitat features / structures, and may have a high age at maturity, and a low rate of natural mortality (see synopsis on C. gerrardi). These characteristics make populations susceptible to over-exploitation. This species is also easy to find, easy to catch, and there are few controls over catches.

In W.A., Centroberyx species are defined for fisheries management purposes as a “Category 1” species. Fish in this category are generally long-lived, slow-growing, mature at four years-plus, form semi-resident populations, are vulnerable to localised depletion due to their life history, and are of low abundance and/or highly targeted. Category 1 fish have low catch rates, and are highly valued for their fishing and eating qualities. For these reasons, Category 1 fish are considered to have a high risk of overexploitation, and require a high degree of protection (Harrison, 2001; W.A. Department of Fisheries, 2004a).

Based upon age and growth data, C. australis is reported to have a low resilience to exploitation, in terms of population doubling time, and high vulnerability to fishing-induced population decline (Cheung et al., 2005, cited in Froese and Pauly, 2009).

Threatening Processes

Fishing may be the major threatening process for populations of this species, and there is increasing fishing pressure on the population, from commercial fishing in W.A., coupled with an uncertain level of fishing pressure from commercial fishing in South Australia, and from the Commonwealth-managed GAB fishery (in which Yellow-eye Red Snapper catches are not separated from Bight Redfish catches, hence there are no fishery-based catch data, and also, there are very few fishery-independent estimates of annual catch). Additionally, all Redfish species (including Yellow-eye Red Snapper are increasingly being targeted by recreational fishers (especially charter boats) in both S.A. and W.A., as capacity to fish deeper waters continues to improve. It is possible that large commercial catches over several years result from a particularly successful year class (or series of year classes) moving through the fishery, and if catch quotas are not set conservatively or responsively as those abundant year classes are exhausted, population structure and biomass may be adversely affected if weak year classes (resulting in lower total abundance and biomass) are targetted at the same high levels over time.

In the GAB, the increasing catches of the related species Bight Redfish C. gerrardi (see synopsis), coupled with increased activity of the fishing industry in that region, may affect the abundance of Yellow-eyed Redfish over time, particularly if the current level of quota remains high, yet C. australis may not be as abundant as C. gerrardi in that region, but still be caught due to overlap in distribution and habitat.

The relative proportion of the related species Bight Redfish in continental shelf landings of the GAB Trawl Fishery has varied over time, and is considered likely to be environmentally-driven (Caton and McLoughlin, 2005). Similar variation in catch rates between cold and warm periods has been observed in eastern Australia, for the related species C. affinis (Rowling, 2001, cited by Bruce et al., 2002). If so, then environmentally-driven variations over time in availability of Yellow-eyed Red Snapper would increase the vulnerability of this species to over-exploitation.

In 2006, an Ecological Risk Assessment (ERA) for species in the Great Australian Bight Trawl Fishery (Daley et al., 2006), ranked Centroberyx australis as a “high risk” species, in terms of population impacts from capture in the GAB trawl fishery, noting also the “endemic” nature of the stock in the GAB. In a “Level 2 Residual risk assessment” for species in the GABTF, this species was again ranked as being at “high risk”, with the assessment noting that: “ISMP estimates 1.8t caught, 36% discarded, almost all caught shallower than 200m. Mainly distributed in the inshore boundary of the fishery and is generally associated with reefs ........ the species has a higher productivity risk than the target species. Given the relatively low catch, susceptibility may be scored too high” (AFMA, 2008c). However, in a “rapid quantitative Level 3 assessment”, or “Sustainability Assessment of Fishing Effects (SAFE) assessment” undertaken by AFMA, a supplement to the ecological risk assessment (by CSIRO) for the GABTF, this species was ranked as “low risk” of impact from operation of the fishery. According to AFMA (2008d), the Level 3 assessment process considers the mitigating effects of management arrangements that were not explicitly included in the ERAs, or introduced after the process commenced. It is noted that the Level 3 assessment is made proportional to the spatial area in which the fishery operates, compared with the spatial area of distribution of the species, but this does not account for aggregation or uneven area of occupancy, rather than even distribution throughout space (the latter of which is unrealistic, for site-associated benthic species in a heterogeneous benthic environment).

In W.A., Centroberyx species are defined for fisheries management purposes as a “Category 1” species. Fish in this category are generally long-lived, slow-growing, mature at four years-plus (i.e. generally have a high age at maturity), form semi-resident populations, are vulnerable to localised depletion due to their life history, and are of low abundance and/or highly targeted. Category 1 fish have low catch rates, and are highly valued for their fishing and eating qualities, and there is usually significant pressure on stocks. For these reasons, Category 1 fish in W.A. are considered to have a high risk of over-exploitation, and require a high degree of protection (Harrison, 2001; W.A. Department of Fisheries, 2004a, 2004d).

Research Notes

In W.A., previously there has been considerable confusion in catch reports of Centroberyx species received from commercial fishers. Up till the mid 2000s, the Department of Fisheries did not have on-board sampling programs to verify species identifications (M. Cliff, W.A. Fisheries Research Centre, pers comm., 2006). Therefore, a research program was planned from 2007 onwards, in an effort to better understand the finfish stocks of the south coast of Western Australia, and Yellow-eyed Red Snapper and other species are being covered in this program (M. Cliff, W.A. Fisheries Research Centre, pers. comm., 2006). Current research on Bight Redfish C. gerrardi (see synopsis) may assist C. australis, and the latter species should be included in current fishery-management oriented research programs.

Research Recommendations

Where possible, catches of Yellow-eyed Red Snapper and Bight Redfish should be separated in reporting, in both State- and Commonwealth-managed fisheries, and in recreational and charter boat catch statistics.

More information is required on the habitat requirements and location of juvenile Yellow-eye Red Snapper, particularly the location of “nursery areas”.

There is insufficient information on many aspects of the biology, including age and growth, and reproduction (particularly size and age at maturity; fecundity at size and age; and also recruitment strength over space and time). Spawning dynamics should also be investigated, so that the fishery (e.g. in W.A.) can avoid capturing adults during peak spawning periods, which could jeopardise the sustainability of the stock and the fishery if it occurs over time.

There is a possibility of ontogenetic patterns of movement in this and other related Centroberyx species, which should be investigated.

Given that C. australis is a fish in Berycidae, closely related to Redfishes C. gerrardi and C. affinis, it is likely to be a relatively long-lived species, and therefore collection of information on the size- and age-composition of the stock (particularly in W.A. waters, where the main commercial fishery exists) would be important for the proper management of the fishery, and the sustainability of the population.

The stock-recruitment relationship could be important for this species (as is the case with other abundant schooling species in Berycidae), and requires further investigation (including modelling work).

More information is required on aggregation and migration over space and time, and the relation between Yellow-eyed Red Snapper in S.A. and W.A., in terms of stock structure etc. Research to reduce the uncertainty of the stock structure is a priority. Current research on Bight Redfish C. gerrardi in W.A. (see synopsis) may assist this requirement for C. australis.

Research is required on the relation of C. australis movements, aggregations, variations in relative abundance (and therefore variations in availability to the fishery) with environmental variables, such as the Southern Oscillation Index, and El Niño and La Niña cycles.

Notes on Management

Previously, prior to introduction of Redfish quota in 2006, the Great Australian Bight Trawl fishery, in which Centroberyx australis is taken, was managed through input controls, including limited entry of vessels, limited cod-end mesh size, and area restrictions for boats in excess of 40 m in length. There were 10 operators in the fishery in 2001-2002 (AFMA, 2003i). There is now a quota for Bight Redfish (see synopsis on C. gerrardi), but the proportion of the catch that constitutes C. australis is not specified in quota, nor in catch statistics.

In April 1998, Environment Australia declared the Great Australian Bight Marine Park (Commonwealth waters) under the National Parks and Wildlife Conservation Act 1975. The Park was designated to ensure the long term protection and maintenance of biological diversity within the area. The Park is divided into a marine mammal protection area and a benthic protection strip. Seasonal closures have been implemented within the marine mammal protection area, and demersal trawling has been prohibited within the benthic protection strip area (AFMA, 2003i). It is possible that a small portion of the stock is protected in the region of the GABMP. It is noted, however, that (i) at the depths at which Yellow-eyed Red Snapper are likely to be fished, the GABMP benthic protection “strip” covers a very small proportion of the fishable area in the GAB; and (ii) total allowable catches in the Great Australian Bight have continued to increase since the declaration of this protected area.

In South Australia, for recreational fishing of all Centroberyx species, there is a legal minimum length of 30cm, a bag limit of 10 fish, and a boat limit of 30 fish (PIRSA, 2006). In the charter boat fishery in S.A., there is a legal minimum size of 30cm, and a passenger limit of 10 Yellow-eye Red Snapper (for charters up to 3 people) or 5 Yellow-eye Red Snapper (for charters up to 6 people), equivalent to a charter boat limit of 30 Yellow-eye Red Snapper (Presser and Mavrakis, 2005; PIRSA, 2005b).

In W.A., during the mid to late 2000s, the legal minimum size of any Centroberyx species taken in the West Coast Bioregion (between Augusta and Kalbarri) was 30cm (previously 23cm), and there was a daily bag limit of 4 fish, for all Centroberyx species combined (Department of Fisheries, W.A., 2004a, 2008c). In the South Coast Bioregion of W.A., there is a legal minimum size of 30cm, and a bag limit of 8 Centroberyx species (Department of Fisheries, W.A., 2006b, 2009a).

Management Recommendations

All catches of Centroberyx species, including discards, should be recorded at species level when caught in the Great Australian Bight Trawl fishery. Monitoring of catches of Centroberyx australis over space and time in the GAB Trawl Fishery is required. There is a single estimate of yearly catch from shelf waters (1.8 tonnes per annum, 36% discarded: AFMA, 2008c), and catches should be monitored over space and time.

Centroberyx species caught in State-based commercial fisheries should be identified to species level, and catches should be monitored over space and time if possible.

Assessments of Centroberyx australis catches in the GAB Trawl fishery and in the W.A. state-managed fishery should be undertaken, given the reported high vulnerability to depletion of Centroberyx species.

Data should be collected with a view to undertaking a population assessment in future, which would integrate data from both State-managed and Commonwealth-managed fisheries.

Measures (such as barotrauma reduction methods) should be undertaken to try to ensure the survival of hooked undersized specimens taken by charter boat fishers.

Measures to reduce bycatch of Centroberyx species in rock lobster pots (particularly in the Northern Zone in the S.A. fishery) should be implemented where possible.

Where possible, compliance with recreational (including charter boat) catch limits for Centroberyx species should be checked.

Other Information

The Yellow-eyed Red Snapper has been frequently misidentified as Centroberyx affinis (the Nannygai, or Redfish, from south-eastern Australia) (Kuiter, in Gomon et al., 1994).