|Scientific Name:||Epinephelus daemelii|
|Species Authority:||(Günther, 1876)|
Epinephelus daemelii (Günther, 1876)
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||Shuk Man, C. & Ng Wai Chuen (Grouper & Wrasse Specialist Group)|
|Reviewer(s):||Sadovy, Y. & Russell, B. (Grouper & Wrasse Red List Authority)|
E. daemelii grows to a large size and is considered to be a quality eating fish. It is territorial and curious by nature, making it susceptible to overfishing by line and spearfishers. Stocks have been quickly reduced by recreational as well as commercial fishing (Pogonoski et al. 2002).
Averaging 2.4 kg per fish, individuals were speared in NSW spearfishing competitions in 1976 (Pogonoski et al. 2002). Roughley (1916) reported of E. daemelii, "at one time it was fairly plentiful in the vicinity of Port Jackson", McCulloch (1922) reported that it was once quite common in that state but has become very scarce in recent years.
Historical evidence (pre 1908) is that a decline in abundance and possibly size occurred around the turn of the 20th century especially near large towns or cities. Anecdotal evidence from the 1960s and 1970s documented, in various fishing magazines, that overfishing by recreational line fishers and spearfishers had occurred, as large specimens were considered a prized catch. Despite protection in NSW waters since 1983, there is no evidence of an increase in abundance (The Fisheries Scientific Committee website).
Significant population decline is suggested but since limited biological information currently exists for E. daemelii (Pogonoski et al. 2002), further studies on the biology of this species are recommended.
A Near Threatened assessment is considered relevant to this species, given its declines in the past and its naturally vulnerable life history characteristic, as a grouper. Nearly qualifies as threatened under criterion A2bd. More information is needed and studies on the species in terms of biology and fishery are encouraged.
|Range Description:||Black Cod are known to occur in warm temperate and subtropical waters of the South-western Pacific Ocean. In Australia, the species' range extends from south Queensland to Kangaroo Island off South Australia (however, the South Australian record probably represents only a straggler or expatriate fish from the east coast). The species has been reported from northern Bass Strait waters but has not been sighted along the coast of Tasmania. Black Cod are found along the entire New South Wales coast and are most common in waters off northern New South Wales. A few individuals have been recorded from southern Queensland waters (e.g., off Flinders Reed), however, they are considered to be uncommon in the waters of Queensland (Harasti et al. 2004).
Black Cod were found to be common around Elizabeth and Middleton Reefs (near Lord Howe Island), two offshore reefs in Australian Commonwealth waters in the northern Tasman Sea (Leadbitter 1992, cited in Harasti et al. 2004; Oxley et al. 2004). Black Cod are also found in the northern parts of New Zealand, and Francis (1993) noted this species to be particularly common around Kermadec Island and also common at Three Kings Island, though it is generally rare elsewhere in New Zealand (Harasti et al. 2004).
Juvenile specimens have been collected as far south as Hawka Bay in Australia, at 0 to10 or 30 m depth. Although immature specimens occasionally range as far south as Cook Strait and one has been recorded from off Westland, they are rare south of East Cape. Juveniles are also known from New South Wales in Australia and Norfolk, Lord Howe and the Kermadec Islands (Paulin and Roberts 1992).
Native:Australia (Lord Howe Is., New South Wales, Queensland, Victoria); New Zealand (Kermadec Is., North Is.); Norfolk Island
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Pacific – southwest; Pacific – western central
|Lower depth limit (metres):||100|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Black Cod abundance at Elizabeth Reef was estimated at 4 cod/hectare, with no evidence of an increase or decrease in population size between surveys in 1987 and 2003, but mean size of fish showed an increase, possibly due to reduced catch effort since the 1980s. Maximum size recorded in 2003 was 150 cm.
Pogonoski et al. (2002) report that Black Cod is rarely encountered.
Minimum population doubling time is more than 14 years (Froese and Pauly 2005).
The population status cannot be inferred from the data currently available.The species is a target of both sport and commercial fishing. But how the population is affected is not clear and natural abundance, fishing effort and catch data are lacking. Biological studies are also needed.
|Current Population Trend:||Unknown|
|Habitat and Ecology:||
Black Cod are known to occur in caves, gutters and on rocky reefs from near shore to depths of as least 50 metres. In 2003, a commercial fisher incidentally caught a Black Cod at a depth of 100+ metres. Smaller individuals are encountered in estuaries (Hutchins and Swainston 1986, cited in Harasti et al. 2004), and recently settled juveniles can be commonly found in coastal rock pools along the NSW coastline (Hutchins and Swainston 1986, cited in Harasti et al. 2004; Griffiths 2003). The Black Cod is considered to be a territorial species because each adult individual generally has its own 'hole' (Harasti et al. 2004). Its cave usually has several alternative exits and the grouper hovers just off the bottom at the entrance, often just the snout and eyes protruding. Usually it shares its quarters with several other reef fishes like Red Moki (Doak 1978).
Observations by fishermen and divers suggest that this species is slow growing and slow moving (Leadbitter 1992). Ayling and Cox (1982) noted E. daemelii in New Zealand "a single fish can change from one extreme of colour to the other in just a few seconds, depending on its mood and the colour of the background" (McCulloch 1922).
It is hypothesized that habitat complexity may play a role in habitat selection, presenting a wide variety of structure in which Black Cod both seek refuge from danger and utilize for seeking and ambushing prey. Larger Black Cod were sighted further offshore, with smaller fish appearing to prefer the shallower waters of inshore reefs and islands (Harasti et al. 2004).
Life history and ecology
Kuiter (1993) suggested that the species is most active at dusk and during the night, and moves out of its shelter to hunt for prey. Observations by spearfishers and divers suggest that it is an opportunistic carnivore. It is generally considered to be an aggressive territorial species that may occupy a particular cave for life (Heemstra and Randall 1993).
Black Cod has maximum 200 cm (TL) and the maximum published weight is 68.0 kg (Froese and Pauly 2005).
Protogynous hermaphrodite, changing sex from female to male as it gets older (Heemstra and Randall 1993). Female change sex to become males at around 100–110 cm total length (Paulin and Roberts 1992). Very little research has been conducted on the reproductive biology of the Black Cod in Australian waters (Harasti et al. 2004).
E. daemelii is not known to form breeding aggregations in the North Island waters of New Zealand (Stewart 1999). Observations of up to twelve fish, with reproductive status unknown in one location at a time could suggest that the Black Cod may be a relatively social fish at particular times of the year. However, it is not known whether it forms spawning aggregations at any point in its range (Harasti et al. 2004).
Age, Growth and Longevity
In Australia large adults are known to attain at least 1.5 m in total length and 81 kg (Hutchins and Swainston 1986, cited in Harasti et al. 2004). They have been recorded as large as 1.8 m in New Zealand, but are more usually seen there at lengths of between 40–80 cm At the Kermadec Islands, north of New Zealand, where the population has not been fished commercially, E. daemelii may reach 2 m in length (Paulin and Roberts 1992). There is no information available on the growth rate or longevity of the Black Cod, though it is thought to be a slow growing species typical of groupers of its size (Harasti et al. 2004).
E. daemelii is an opportunistic carnivore (Leadbitter 1992). It is believed that adult black cod probably prey on fishes and crustaceans (McCullich 1922, cited in Harasti et al. 2004), whilst juveniles feed on smaller crabs and smaller fish species (Heemstra and Randall 1993). Black Cod have been known to take live bait such as small scombrids and carangids where fishers are fishing in their habitats (Harasti et al. 2004).
The main threat to this species appears to be that of illegal fishing activities. Additionally, the Black Cod is likely to be taken in small numbers as a bycatch of commercial and recreational fishing activities in rocky shore and island habitats along the southern Qld, NSW and northern Victorian coastlines (Pogonoski et al. 2002).
Impacts on juvenile Black Cod may occur due to the loss or degradation of estuarine nursery habitats (Fishnote 2002).
There is some evidence that E. daemelii caught in deeper (50–100 m) waters of northern NSW by commercial fishers do not survive after being released at the surface, suffering severely from swim-bladder decompression or "bloat" (Pogonoski et al. 2002).
Grant (1982) stated that fishermen in Australia regard this grouper as "top-grade table-fish" (cited in Randall and Heemstra 1991).
Protection measures taken:
1). Totally Protected Species in NSW waters (since 1983) (Australia).
2). Listed as a Vulnerable Species in NSW under the NSW Fisheries Management Act 1994 since 1999 (Australia).
3). Listed under section 15 of the Commonwealth Fisheries Management Act 1991, making its take in fishing operations under that Act illegal unless covered by a scientific permit (Australia).
4). Totally Protected Species in the Kermadec Islands Marine Reserve (New Zealand).
5). Australian Society for Fish Biology Threatened Fishes Committee Listings: 1988–1989 - Requiring investigation of its status;1990–1999 - Potentially Threatened (Pogonoski et al. 2002).
Australian and New Zealand Marine Protected Areas in Which the Species Occurs (Pogonoski et al. 2002):
Great Barrier Reef Marine Park (southern section Qld, Australia)
Cook Island Aquatic Reserve (off Tweed Heads, northern NSW, Australia)
Julian Rocks Aquatic Reserve (off Byron Bay, northern NSW, Australia)
Solitary Islands Marine Park (northern NSW, Australia)
Middleton and Elizabeth Reefs Marine National Nature Reserve (Tasman Sea, Australia)
Lord Howe Island Marine Park (Tasman Sea, Australia)
Kermadec Islands and Poor Knights Islands Marine Reserves (New Zealand)
Reserves within its range where E. daemelii probably occurs:
Norfolk Island Marine Reserve/Park (Tasman Sea) (Pogonoski et al. 2002).
|Citation:||Shuk Man, C. & Ng Wai Chuen (Grouper & Wrasse Specialist Group). 2006. Epinephelus daemelii. The IUCN Red List of Threatened Species 2006: e.T61337A12463721. . Downloaded on 28 June 2016.|