© 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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Red Cod

Family Name:	Moridae
Scientific Name:	Pseudophycis bachus (Bloch and Schneider, 1801)
Recommended Status:	Data Deficient in South Australia; possibly Near Threatened in SE Australia and NZ
Rationale:  Although Pseudophycis bachus has a broad geographic range and depth distribution across southern Australia, it is included here because (i) it is a strongly site-associated fish from continental shelf and upper slope waters, and may thus be susceptible to site-specific impacts in some areas; (ii) S.A. is the edge of the geographic range, and although it is occasionally recorded, the relative abundance of Red Cod in S.A. is poorly known; (iii) it is a highly fecund, relatively short-lived species, that is a significant food source for fur seals and other pinnipeds, as well as a variety of sea birds and predatory fish, and some dolphin species, and thus has an important ecological role in food webs (particularly in south-eastern Australia and New Zealand, where it is most abundant); (iv) environmentally-driven variations in recruitment strength from year to year appear to be large, and thus Red Cod may be vulnerable to over-exploitation, particularly if fisheries’ effort levels and/or catch quotas do not consider variations in population abundance over time; (v) it is caught in small numbers in several commercial fisheries in S.A., but is more commercially significant in south-eastern Australia (e.g. Bass Strait) and N.Z.; (vi) considering the high variability in abundance, there are inadequate catch restrictions in commercial fisheries in southern Australia, and monitoring of  population abundance (e.g. using an index of recruitment strength) is also required; (vii) recreational catches are poorly known, and there are no catch restrictions in most States (other than Tasmania).

Page Contents

Current Conservation Status

No listings known in Australia
In N.Z., Red Cod is categorised as a fished species of moderate conservation concern (category D), due to “the destructive impact of bottom trawling on deepwater benthic habitats; the bycatch of globally threatened Hector’s dolphins, the unknown sustainability of current catch limits and recent catch levels in two areas; the doubtful sustainability of two other current catch limits, and the lack of a management plan” (Weeber and Szabo, 2005).

Distribution

General

Red Cod is found throughout New Zealand (Roberts, 1987; Paulin et al., 1989; Francis, 1996), including the Chatham Islands (Roberts, 1991), and in southern Australia (Hutchins and Swainston, 1986; Cohen et al., 1990).
In New Zealand, Red Cod is more abundant around the South Island (Armitage et al., 1994, cited in Froese and Pauly, 2007), particularly continental shelf waters of the East Coast of the South Island (Keller et al., 2003). Red Cod is considered to be one of the three most abundant demersal fish species on continental shelf and upper slope of the South Island’s east coast (Beentjes et al., 2002).
There are distinct differences between the populations of P. bachus in New Zealand and southern Australia, and the two are likely to be sub-species (Gomon, in Gomon et al., 1994).

Southern Australia

The Red Cod is known from the southern coast of N.S.W., through to South Australia, and the distribution includes Tasmania (Cohen et al., 1990; Hutchins and Swainston, 1986; Edgar, 1984 and 1991, cited by RPDC Marine, 2002; Barrett and Wilcox, 2001).

South Australia

Examples of locations in South Australia where the species has been recorded include deeper waters off the western, central and eastern Great Australian Bight; Investigator group islands (e.g. Ward I.) and other locations off western Eyre Peninsula / eastern Great Australian Bight; south-western Eyre Peninsula area (e.g. off Coffin Bay); southern Spencer Gulf (e.g. Port Lincoln area); northern Gulf St Vincent, and various locations in the south East (with examples including Blackfellows Caves, Livingstons Bay, Beachport, Kingston, Cape Jaffa) (Kuiter, 1983; Gomon, in Gomon et al., 1994; M. Hoare, SARDI, pers. comm., 2007; CSIRO Marine Research records, cited by CSIRO, 2007; South Australian Museum records, cited in OZCAM database, 2007).
A number of records have come from trawl surveys across the mid and outer continental shelf of the Great Australian Bight, during the 1960s and 1970s (CSIRO Marine Research data, cited in CSIRO, 2007).

Habitat

The Red Cod is found in a variety of habitats in estuaries, bays and on the continental shelf, including sheltered and moderately exposed sand habitats, silt / mud bottoms, seagrass beds, and on reefs (May and Maxwell, 1986; Gomon, in Gomon et al., 1994; Jordan et al., 1998; Edgar, 2000; FAO, 2004). In SE South Australia, Red Cod have been commonly recorded in lobster pots, and also observed in rocky limestone reefs, under ledges/overhangs (usually hiding in the dark), and also under jetties (M. Hoare, SARDI, pers. comm., 2007).
In New Zealand, the habitat of Red Cod ranges from crevices and caves in shallow-water rocky areas at depths less than 50m (Cohen et al., 1990; FAO, 2004), to soft sandy or muddy bottoms in deeper waters of the continental shelf and slope (Cohen et al., 1990).
Hutchins and Swainston (1986) reported the species to be “reasonably common” on protected reefs in coastal bays and estuaries, in south-eastern Australia.
During a survey of the Investigator Group isles (eastern GAB) in 1982, one specimen of Red Cod was recorded, in a cave at 5m depth (Kuiter, 1983).
In Tasmania, juveniles have been found in Heterozostera tasmanica (= H. nigricaulis) seagrass beds, and also over un-vegetated muddy habitats, in a number of shallow bays around that State (Jordan et al., 1998). On the north coast of Tasmania, the species was recorded in higher number on reefs with crevices, compared with non-creviced reefs (Barrett and Wilcox, 2001). The species has also been recorded in the Tamar Estuary (but does not spawn there – see Notes on the Biology) (Lara and Neira, 2003).
In southern Australia, the reported depth range is from the shallow subtidal to the continental slope (0m – 375m) (Edgar, 2000). In south-eastern South Australia, juveniles have been commonly recorded in water less than 10m, and adults to more than 60m (M. Hoare, SARDI, pers. comm., 2007). In New Zealand, Red Cod is considered to be most abundant below 80m (Keller et al., 2003), particularly between 200m and 300m along the edge of the continental shelf and upper slope (Cohen et al., 1990), but can be occur uncommonly at depths exceeding 700m (Armitage et al., 1994, cited in Froese and Pauly, 2007). Off southern New Zealand, Jacob et al. (1998) recorded the species mainly within the depth range 80m – 300m.

Notes on the Biology

Age and Growth

In southern Australia, Red Cod grows to between 60cm (Hutchins and Swainston, 1986, 2001) and 80cm (Gomon, in Gomon et al., 1994; Edgar, 2000). In New Zealand, the maximum size is estimated to be about 80cm for females and 70cm for males (Horn, 1995; Beentjes, 2000), although it is noted that Cohen et al. (1990, cited in Froese and Pauly, 2007) reported a maximum size as large as 90cm. The young grow to 22cm after year one, 30 to 35cm after year two, and about 50cm after year four, when they become sexually mature (Cohen et al., 1990).
The record size in southern Australia is 2.085kg, being a specimen taken by angling (Hutchins and Swainston, 2001).
Off the South Island of New Zealand, a validated ageing study has shown that few Red Cod appear to live longer than 4 years (Horn, 1996). It is noted that this study was based on commercial catch data, which was assumed to be representative of all age classes. In a previous ageing study reported by Beentjes (1992), about 6% of fish were aged older than 5 years. Weeber and Szabo (2005, citing Annala et al., 1994) reported that the species might live as long as 7 years. Generally, the species is considered to be fast growing and short lived, with a high natural mortality rate (Annala, 1995, cited by Horn, 1996).

Diet and Feeding Behaviour

Red Cod eats small fish, such as Hyperlophus vittatus and Engraulis australis (Edgar and Shaw, 1995b, cited in Froese and Pauly, 2007), cephalopods, small crabs (including Ovalipes swimming crabs, and  Leptomithrax spider crabs – McLay et al., 1995); other benthic crustaceans (Ayling and Cox, 1982, cited by Cohen et al., 1990; Armitage et al., 1994, cited in Froese and Pauly, 2007), and gastropods (such as Maoricolpus roseus, in New Zealand) (Allmon et al., 1994, cited by Bax et al., 2003).
The species feeds nocturnally. For example, recreational fishers in some parts of New Zealand have noted that Red Cod do not take baits during the day, but take baits commonly throughout the night, and are thus caught in large numbers after dark.
In New Zealand, feeding aggregations appear in late spring to summer, and move into deeper water in winter (Annala et al., 2003; New Zealand Ministry of Fisheries, 2005b).

Reproduction

Studies in New Zealand have shown that P. bachus matures at about 45cm – 55cm, or 2-3 years of age (Annala, 1994; New Zealand Ministry of fisheries, 2005b). The species spawns once per year, mainly during the winter months (July – August) over the outer continental shelf. Spawning varies with latitude, and occurs later at higher latitudes. For example, in the Canterbury Bight, Red Cod spawn from August to October. On the southeast coast of New Zealand, there is some evidence that Red Cod spawn in waters as deep as 300+m - 750m during winter, as juvenile fish are found in offshore waters after the spawning period (Annala et al. 2003; New Zealand Ministry of Fisheries, 2005b).
Large females are highly fecund, and can produce up to 30 million eggs (Cohen et al., 1990).
In New Zealand (Horn, 1996) and Tasmania (Jordan et al., 1998), noticeable differences in recruitment strength from year to year have been observed. Specifically, a study by Beentjes and Renwick (2001) in New Zealand indicated that fluctuations in Red Cod landings are dependent on sea surface temperature, controlled largely by climatic variability, including El Niño and La Niña events. Catch per unit effort data from young fish in the commercial fishery were used as an indirect index of recruitment strength of Pseudophycis bachus, and there was an apparent and consistent correlation with sea surface temperature (rather than any other explanatory variable) over a wide range of time lags, followed by frequencies of southwest and northeast flow patterns. The correlations were negative with sea surface temperature, positive with the occurrence of cool southwest weather types, and negative with the occurrence of warm northeast weather types. It therefore appears that Red Cod have poor recruitment in La Niña years, and good recruitment in El Niño years (Beentjes and Renwick, 2001).

Other Information

Juvenile Red Cod are one of the food items consumed by the Little Penguin Eudyptula minor in New Zealand (Perriman et al., 2000) and Australia (Montague and Cullen, 1988; Gales and Pemberton, 1990; Cullen et al., 1992), particularly when preferred foods such as pilchards and anchovies are in low abundance (Chiaradia et al., 2003). The species is also a significant part of the diet of the Yellow-eyed Penguin Megadyptes antipodes in New Zealand (Moore and Wakelin, 1997; Moore, 1999). Red Cod are also a part of the diet of seabirds such as cormorants (e.g. Butler, 2003), Australasian Gannet Morus serrator (Robertson, 1992), and various species of albatross (e.g. Imber, 1999; James and Stahl, 2000; Hedd and Gales, 2001), the latter of which feed on fishery discards of Red Cod when fishing vessel personnel process the catch at sea (James and Stahl, 2000).
In southern Australia, Red Cod is eaten by Australian Fur Seal Arctocephalus pusillus doriferus (Gales and Pemberton, 1994), and New Zealand Fur Seal A. forsteri. In Tasmania, a study of the diet of Australian Fur Seal showed that Red Cod was one of the 5 main types of fish consumed, and formed at least 10% of the diet (Hume et al., 2004). Similarly, a study in southern Australia by Page et al. (2005) showed that P. bachus forms up to 8% of the diet of adult male Australian Fur Seals, or 9 – 16% on a seasonal basis, but formed a lower proportion of the diet of New Zealand Fur Seals. In New Zealand, a study during 1994 and 1995 showed that the proportion of Red Cod in the diet of A. forsteri ranged between 0% and 7%, varying with year and season (Harcourt et al., 2002). A previous study (Fea et al., 1999) reported juvenile Red cod to be one of the 5 dominant prey items consumed by New Zealand Fur Seals at a rookery on the Otago Peninsula. Red Cod is also a minor component of the diet of the New Zealand Sea Lion Phocarctos hookeri (Childerhouse et al., 2001).
Red Cod is also consumed by cetaceans such as the Dusky Dolphin Lagenorhynchus obscurus (Kastelein et al., 2002) and the Bottlenose Dolphin (Tursiops sp.) (Lusseau and Wing, 2006).
Red Cod are preyed upon by bentho-pelagic fish such as Blue Grenadier Macruronus novaezelandiae (Clark, 1985, cited in Froese and Pauly, 2006), Ling Genypterus blacodes (Mitchell, 1984), and the introduced species Chinook Salmon Oncorhynchus tshawytscha (James and Unwin, 1996).
Various behaviours have been observed in different parts of the range. For example, in Tasmania, some site association has been observed: at Lobster Point, a tagged individual of P. bachus was re-sighted at various intervals up to 3 months after tagging, and it moved less than 20m between re-sightings (Edgar et al., 2004). In contrast, in parts of New Zealand, Red Cod move in schools (seasonal feeding aggregations), and are seasonally abundant in some areas during spring and summer, before moving into deeper water (New Zealand Ministry of Fisheries, 2005b). During the winter, fishers along the east coast of New Zealand have observed that Red Cod come close inshore, into the lagoons at the mouths of the major rivers.

Fisheries Information

Commercial – Southern Australia

P. bachus is a commercial species in southern Australia, and the marketing name is “Southern Rock Cod” (Seafood Services Australia, 2005). Red Cod is taken in considerable numbers by commercial shallow water trawlers in the Bass Strait region (Gomon, in Gomon et al., 1994).
It is part of the bycatch in the Commonwealth-managed Southern and Eastern Scalefish and Shark Fisheries (SESSF) (AFMA, 2002a). In the South East Trawl Fishery (SETF), Wayte et al. (2004) reported that in the otter trawl sub-fishery of the Commonwealth-managed SETF, an Integrated Scientific Monitoring Program (ISMP) recorded, in 78 trawl shots: 715kg of P. bachus retained, and 383kg discarded.
P. bachus is a component of the bycatch in the Great Australian Bight Trawl Fishery (GABTF) (Bromhead and Bolton, 2005; Daley et al., 2006), but it was not recorded in catches during a bycatch monitoring program in 2001-02 (e.g. Brown and Knuckey, 2002). Bromhead and Bolton (2005) reported that P. bachus is discarded in the GABTF, and the proportion retained in that fishery is not known for this report.
Bromhead and Bolton (2005) reported that P. bachus is a retained by-product species in the Commonwealth-managed Gillnet, Hook and Trap fishery. The species has also been recorded in a bycatch monitoring program for the South East Non-Trawl Fishery (Knuckey et al., 2001).
P. bachus is a commercial species in Tasmania (Lyle and Jordan, 1999). Smith and Heran (2001) reported that the combined commercial catch of species in Pseudophycis ranged between 10t and 20t in almost all years between 1990 and 2000, but declined to 4t in 2001. The proportion of the catch that was P. bachus is not known for this report.

Commercial - South Australia

Pseudophycis bachus is a very minor component of the bycatch in the prawn trawl fishery in Spencer Gulf, South Australia. For example, 1 Red Cod, reported to be P. bachus, was recorded from 32 trawl tows, in a sampling program during the mid 1990s (Carrick, 1997).
Red Cod is reported to be part of the bycatch in the South Australian Rock Lobster Fishery (Sloan, 2003a). In 2002/03, during bycatch sampling of 1% of the annual number of pot lifts in the Northern Zone, 1 specimen was recorded in the Northern Zone, and 19 were recorded in the Southern Zone (Brock et al., 2004). If the 1% sample was representative (as assumed in Brock et al., 2004), then the maximum annual catch of Red Cod could therefore be in the order of 100 specimens in the Northern Zone and 1900 specimens in the Southern Zone. Juveniles of Red Cod are commonly caught in rock lobster puerulus collectors (for lobster population monitoring), and adults caught in lobster pots (M. Hoare, SARDI, pers. comm., 2007). It is not known what proportion of the bycatch may be P. breviuscula, P. barbata, or L. rhacina (see synopses), rather than P. bachus.

Commercial – New Zealand

Globally, the largest catches of P. bachus are from New Zealand (Cohen et al., 1990; FAO, 2004). In that country, the species is now taken by domestic vessels only, but significant catches during the 1970s and 1980s were taken by vessels from Japan, Korea and Russia. The species is trawled, mainly in offshore waters, but there is also some targeting in shallow water (Blezard, 2002), including inshore areas in the south (Weeber and Szabo, 2005). Red cod are targeted primarily in continental shelf waters (i.e. less than 200m), and are also a bycatch of deepwater fisheries off the southeast and southwest coasts of the South Island. The domestic Red Cod fishery is seasonal, usually beginning in November and continuing to May or June, with peak catches around January and May. During spring and summer, red cod are caught inshore before moving into deeper water during winter (N.Z. Ministry of Fisheries, 2005b). In New Zealand, Canterbury Bight and off Westland are the main fishing grounds for Red Cod. Annual total landings from N.Z. waters (taken by domestic and foreign vessels combined) have fluctuated widely, i.e. between 4,000 and 18,000 t annually since the late 1970s. Apart from changes to domestic and foreign fishing arrangements during the 1980s, catch variations are thought to be linked to real variation in yearly biomass of this species, which has fast growth, high mortality, and variable recruitment (Annala, 1995; Beentjes and Renwick, 2001). Red Cod are first caught at age 2, and the fishery largely comprises 2 and 3 year old fish (Beentjes and Renwick, 2001). The total annual allowable catch (TAAC) was set at 15, 290t in 1986/87, 15, 840t in 1990, and 16,066 tonnes in 1995, and remained at 16,066t into the early 2000s (N.Z. Ministry of Fisheries, 2005b). The catch during that period has been highly variable (Figure 5).

Figure 5 Total catches of Red Cod (Pseudophycis bachus) from New Zealand, 1986 – 2006

(from New Zealand Ministry of Fisheries, 2005b, 2007).

Previously, during the 1970s and 1980s, P. bachus was recorded as a very minor part of the bycatch of US and NZ purse seine vessels operating in the New Zealand Exclusive Economic Zone (Bailey et al., 1996). Catches are also very minor in New Zealand’s domestic tuna fisheries (Murray et al., 2002).

Recreational

Red Cod is taken by recreational fishers in Tasmania (Lyle and Campbell, 1999), by gillnets and lines. Smith and Heran (2001) reported that the recreational gillnet catch of species in Pseudophycis is about 9.1t per annum, but the total catch (all fishing methods combined) is not recorded, nor are species-specific catch statistics. There is a possession limit of 30 cod, all species combined (Department of Primary Industries and Water web site, October, 2006).
In New Zealand, recreational fishers take Red Cod mainly on the east coast of the South Island. Various surveys throughout the 1990s indicated that about 100t - 200t per year are taken (and possibly up to 300t in 1999/2000) (New Zealand Ministry of Fisheries, 2005b). There is seasonal variation in availability, and recreational anglers report that Red Cod are sometimes relatively common in shallow water off beaches during the cooler months of the year. Red cod is one of the most abundant species caught by surf casting
The species is taken by spear fishers in some areas. One of the record sized specimens was taken by spear fishing, in Victoria (Australian Underwater Federation Inc., 2003).

Other

In New Zealand, P. bachus is a traditional Maori food (Anonymous, 2004).

Vulnerable Characteristics of the Species

The Red Cod is a site-associated benthic fish species that may be vulnerable to site-specific impacts in some areas.
Early life stages of Red Cod may be sensitive to environmental conditions, resulting in variations in recruitment strength (and consequent juvenile abundance) from year to year. For example, in New Zealand, commercial catch per unit effort data for young Pseudophycis bachus have been used as an indirect index of recruitment strength. Fluctuations in landings of young Red Cod are dependent on sea surface temperature, controlled largely by climatic variability, including El Niño and La Niña events (Beentjes and Renwick, 2001). Similarly in Tasmania, over an 11 year period of monitoring at the Maria I. Marine Reserve, Pseudophycis bachus exhibited cyclical changes of abundance that were unrelated to reserve protection (Barrett et al., in press). This variation in abundance can increase the susceptibility of populations to over-exploitation, if fishing effort and/or catch quotas do not account for the changes in abundance from year to year (e.g. remain static, or increase in years of “poor” recruitment strength).

Threatening Processes

Fishing is likely to be the main threatening process. For example, due to environmentally driven variations in recruitment strength (Beentjes and Renwick, 2001), in various parts of New Zealand where P. bachus is fished, it is possible that constant catch at the level of the current TACC is unlikely to be attainable or sustainable in most years (Annala et al., 2003, cited by Weeber and Szabo, 2005). In southern Australia, there has been little assessment of the effects of fishing on this species; however a draft ecological risk assessment report for the South East Trawl Fishery, listed P. bachus as being a “high risk” species, in terms of population impacts from trawling (Wayte et al. 2004). A similar report also ranked the species as being of “medium risk” of impact from capture in the Great Australian Bight Trawl Fishery (Daley et al., 2006).
Degradation of estuarine areas may have some adverse effects on P. bachus populations. For example, during the early 1980s, an ulcer disease was reported from Red Cod in the Tamar River, northern Tasmania (Munday, 1985), possibly related to contamination from discharges. Munday (pers. comm. cited in Lilley et al., 1998) reported that the disease is no longer reported in the area, now that Launceston’s sewage system has been improved. More recently, a study in Atlantic Salmon farm pens in southern Tasmania showed that wild P. bachus that had entered the cages developed significantly higher loads of Trichodina gill parasites than Red Cod at reference sites away from the cages. Other parasites observed to infest wild fish entering the cages included digenean trematodes, epitheliocystis and cysts of unknown origin (Nowak et al., 2004).

Research Notes

During the early 2000s, work was undertaken in south-eastern Australia to (i) understand more about the increase in the proportion of P. bachus that has been observed in the diets of Australian Fur Seal and Little Penguin at Phillip Island in Victoria (Kemp, 2002); and (ii) determine the proportion of each Pseudophycis species (P. bachus, P. barbata and P. breviuscula) in the diet of these species, using analyses of otolith shape and otolith microchemistry (e.g. Kemp et al., 2005).

Research Requirements

There is a paucity of information on the habitat requirements of this benthic species in the mid and outer continental shelf and upper slope, and the effects of trawling such habitats.
More information is required on the ecological effects of exploiting Red Cod populations at current levels in south-eastern Australia and New Zealand.
Much of the information on biology and population dynamics comes from New Zealand populations. In southern Australia, more information is required on aspects of the life history, such as age and growth, reproduction, migration, and recruitment strength.

Management Requirements

Commercial catch statistics should be separated to species level. For example, BRS (2004) reported catches from Tasmania in the dozens of tonnes during the 1990s (e.g. 64t in 1995/96) of “cods – unspecified, in the Melanonidae and Moridae”. It is impossible to determine the proportion of P. barbata in such aggregated catches of “cods”, and therefore such data would be of little use in population and fisheries assessments.
Invariable TACCs based on catch history may be unsuitable for species such as Red Cod, due to apparent environmentally-driven variations in recruitment strength. Analysis of environmental data (e.g. see Beentjes and Renwick, 2001) and population modelling may assist in predicting catches, so that annual quotas can be adjusted to account for “good” and “poor” year classes of Red Cod.
Measures to reduce the bycatch of Pseudophycis species in rock lobster pots (e.g. fitting escape gaps) should be encouraged.
Recreational fishing limits (for anglers and spear fishers) are required in some States, including South Australia. It is noted that there are fishing limits for Morid cods in Tasmania.

Management Notes

In New Zealand, indices of biomass and recruitment are determined from trawl surveys, and a stock reduction model has been used in stock assessment (Cordue, 1998a, 1998b, cited in New Zealand Ministry of Fisheries, 2005b).

Other Information

P. bachus is found in a number of protected areas in Victoria (such as Gabo I. - Plummer et al., 2003; Port Philip Heads, and Wilsons Promontory - Edmunds et al., 2003), and in Tasmania (e.g. Lobster Point – Edgar et al., 2004, and Maria I. - G. Edgar, pers. comm., 2006). It has also been recorded at a number of sites along the northern and north-eastern Tasmania coast that have been proposed as marine reserves (Barrett and Wilcox, 2001).
P. bachus is also found in a number of marine reserves in New Zealand, such as Long Island – Kokomohua (Davidson, 2004).
P. bachus is often confused with P. barbata, particularly in popular literature on temperate fishes, and in fisheries statistics.