The Malabar grouper is one of the most important groupers in commercial and recreational fisheries in the Indo-Pacific region. Because of confusion with similar Epinephelus species, there is little data regarding the extent of its exploitation (3). However, it is believed that fishing has reduced the global population of this species (1). The Malabar grouper is also captured for the live fish trade, and juveniles are caught for “mariculture grow-out”, whereby the wild juveniles are put in cages and grown until they reach a saleable size (1). In addition, habitat loss places additional pressure on populations of the Malabar grouper. In south-east Asia, the area of mangrove swamps has declined drastically and a large proportion of reefs are threatened by human activities (1). These human impacts include poor land management practices that are releasing more sediment, nutrients and pollutants into the oceans and stressing the fragile reef ecosystem. Over fishing has ‘knock-on' effects that results in the increase of macro-algae that can out-compete and smother corals, and fishing using destructive methods physically devastates the reef. A further potential threat is the increase of coral bleaching events, as a result of global climate change (4).
|Scientific Name:||Epinephelus malabaricus (Bloch & Schneider, 1801)|
Epinephelus malabaricus (Bloch & Schneider, 1801)
|Taxonomic Notes:||There has been taxonomic confusion and misidentification with E. coioides, E. tauvina and E. malabaricus at least in Australia and probably elsewhere, and it may take some time to sort out the correct information for E. malabaricus. There is a lack of confidence that all the information currently available actually applies to malabaricus. This confusion over identity undermines efforts to review its status (B. Russell pers. comm.). However, E. tauvina apparently prefers clear reef areas of islands, and E. coioides and E. malabaricus less so (see distribution maps in Heemstra and Randall 1993). It is only the latter two species that overlap strongly in distribution (predominantly in Australia, the Red Sea and in East Africa), such that the major confusion is likely to be between these two. Much fishery activity for E. malabaricus/coioides is not heavily within the range of E. tauvina. |
A practiced eye can readily distinguish the two species (colour and body shape) and so the general trends are thought to be sufficient to allow this preliminary review. The ichthyologist Jack Randall has suggested that most identifications of E. tauvina in SE Asia, are likely to be one of the other two species (J. Randall pers. comm.). However, workers need to be alerted to this possible problem and work is needed to resolve the possible species identification problem for this species (Heemstra and Randall 1993 has a good summary of the differences between the three species).
Assessment Information [top]
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||Cornish, A. (Grouper & Wrasse Specialist Group)|
|Reviewer(s):||Sadovy, Y. & Kulbicki, M. (Grouper & Wrasse Red List Authority)|
Making a definitive assessment for this species is problematic at this time due to uncertainties in the data that arise from taxonomic confusion and misidentifications (see the taxonomic notes above).
E. malabaricus is targeted at all life history stages throughout its range, including for the live reef food fish trade and is undoubtedly heavily fished, and probably overfished in some countries, sometimes markedly. Available information from New Caledonia and from the fry fisheries in the Philippines demonstrate that fishing can greatly reduce populations. This is not surprising as this animal shows characteristics of large maximum size, late age of sexual maturity, at least in males that probably equates to > 5yrs, sex change, and correspondingly low resilience to fishing (see under Habitat and Ecology).
Although, fishing pressure on E. malabaricus has undoubtedly reduced the global population of this susceptible species, quantitative data on changes in population size could not be obtained from any location and the species does not seem to be regularly monitored in any fisheries: identification problems may further make trends difficult to identify in Australia, the Red Sea and East Africa (in these areas confusion with E. coioides and E. tauvina is possible although the trends in all three species might reasonably be expected to be similar, given their biology and value in fisheries). Furthermore, even anecdotal information is missing from large areas of the range of this grouper, such as Indonesia, most of SE Africa, the Red Sea, and New Guinea. Due to these substantial data gaps, it is not possible to estimate or even infer whether the size of population reductions over the last 10 years, or three generations, is > 30% (i.e., VU A2d) and the species is, therefore, classified as Near Threatened (almost qulaifies for a threatened listing under criteria A2bd.). As there is little substantial protection for this species outside Australia at this time, it is suspected that the global population will continue to decline over the next few years at least, given its value as a commercial fish and life history characteristics.
It is hoped that that this assessment can be revised in future years with better data as the large global capture fishery for E. malabaricus (adult and juveniles) and large loss of mangrove habitat is cause for real concern, even if the ability to breed this species in captivity means it is unlikely to go extinct out of the wild. The slow population doubling time and the fact that the species is fished at many different stages of its life history, makes it a naturally vulnerable species.
Fishery data is needed for this species and attention should be paid to distinguishing it clearly from E. coioides and, in some places, also from E. tauvina.
E. malabaricus is one of the more important groupers in fisheries and aquaculture of the Indo-Pacific region, and is also one of the most common. It is caught with trawls, longlines, traps, spear and hook-and-line (Heemstra and Randall 1993).
Information on abundance and fisheries in different countries is scarce but includes:
E. malabaricus is common within estuaries of tropical eastern Australia where, despite occurring to sizes of 400 mm fork length or more, the population consists almost entirely of pre-reproductive females, fork length range is 122-619 mm for individuals caught from estuaries, and 582-762 mm from offshore waters, while previous studies have classified estuary populations of E. malabaricus in the Indo- Pacific as being comprised of both juveniles and adults (Sheaves 1995).
It has been assessed as 'Lower Risk' in Australia using old IUCN Red List Categories and Criteria. Being highly territorial and growing to a large size (>1m), E. malabaricus is susceptible to fishing pressures and local abundances could readily decline at rates faster than which it could recover. However, catch data are lacking.
E. malabaricus occurs in a number of marine parks, notably the Great Barrier Reef Marine Park and World Heritage Area. There are also size limits in place in Queensland (see under Conservation).
E. malabaricus used to be found just about everywhere around New Caledonia. Nowadays this species is rather rare in shallow waters with some specimens remaining in deeper waters. This species is definitely overexploited in the southern lagoon and in bad shape along most of the west coast. On the east coast and in the Loyalty Islands the stock is probably still in reasonable shape, but is certainly much declined from its status 30-40 years ago, judging from pictures taken at that time. This species shares the same spawning site in Prony Bay as E. coioides and is probably more frequent in the catch there. This species is nearly 100% caught by handlines (the juveniles are not found in mangroves like E. coioides). The average size observed at Noumea market is around 5-10 kg and the maximum size around 25 kg. This species is regularly present, especially during the spawning season, but never in large quantities (M. Kulbicki pers. comm. 2004).
A commercial fish that is common in the market, but usually in very small numbers. Mainly caught by handlines, longlines, traps and sometimes bottom trawls. On coral and rocky reefs it has a common size of 25 cm but may reach 60 cm. Mariculture of this species was first started in Penang in 1973 and continues with fry usually imported from Thailand, the Philippines or caught in local coastal waters (Mohsin and Amba 1996).
E. malabaricus is a common species along the west coast of India and in the Gulf of Mannar. It is also one of the dominant species in the Andaman Islands, and is exploited there in large quantities for the live fish trade (J. Charles pers. comm. 2004).
Landings data are not available for this species alone in Kenya, but historical grouper landing data (1978-2001) from the Kenya coast reflect about 80% drop of the peak landings in 1980s. Some populations of groupers are conserved within the marine parks, even then the densities are very low; during a two year trapping project within two marine reserves, only one specimen of E.malabaricus (>60 cm) was taken (Boaz-Arara pers. comm. 2003).
The species was not seen during a rapid biodiversity assessment of the Calamianes Islands (Palawan Province, Philippines) (Werner and Allen 2000) or the Raja Ampat Islands, West Papua, Indonesia (McKenna et al. 2002), or the Togean and Banggai Islands, Sulawesi, Indonesia (Allen and McKenna 2001). It is reported to be rare in the wild in Hong Kong (Sadovy and Cornish 2000).
Fisheries for Fry/Fingerlings for Mariculture
Fry/fingerlings of E. malabaricus are caught from the wild for mariculture in Indonesia, Malaysia, Thailand, Vietnam, the Philippines, Sri Lanka and China. E. malabaricus is the most commonly taken species after E. coioides in many areas. Small individuals of both of these species are primarily taken from brackish water or mangroves (Sadovy 2000).
Sizes for all species wild-caught range from 1-25 cm, which are all below the size of sexual maturation (70-80 cm length, Van der Elst 1988) and most capture is aimed at fishes around 15 cm. The annual trade in the SE Asia region for fry/fingerlings, of which E. malabaricus is but one species, is estimated at hundreds of millions, many of which die before reaching a size where they can be sold to be eaten. There is a widely acknowledged shortage of wild-caught seed of grouper compared to seed demand for culture and strong indications that in many areas supplies are declining, particularly those that have been long and heavily harvested (Sadovy 2000). In the Philippines, for instance, E. coioides and E. malabaricus comprise most of the catch of juveniles for grow-out in the Philippines and, anecdotally, declines of up to 50% have been reported for some areas. Perceived reasons by those involved in the trade include habitat destruction, overfishing of adults, and overfishing of the fry (Sadovy 2000).
Trade in Adults for the Live Reef Food Fish Trade
Wild-caught, or raised from hatcheries E. malabaricus is sold in the Hong Kong live reef fish food market; the highest proportion at 35-55 cm length. Annual production from hatcheries in Thailand increased from 15,000 fish in 1991 to 265,200 in 1995 (Yashiro 1999). Maturity size range is 45-50 cm TL, common consuming size is 34-48 cm TL (Lau and Parry-Jones 1999). The species is also reared in Hong Kong via mariculture (Lee and Sadovy 1998). Although E. malabaricus is one of the 13 principal species in the trade which sources wild-caught and maricultured large reef fishes from the Indo-Pacific for export primarily to Hong Kong, China (Sadovy et al. 2003), import data are not available for this species alone (i.e., several grouper species are combined into one category).
Geographic Range [top]
|Range Description:||Epinephelus malabaricus is found in the Indo-Pacific: Red Sea and East Africa to Tonga, north to Japan, south to Australia. It is not known from the Persian Gulf.|
A spawning aggregation is known from Prony Bay, New Caledonia (M. Kulbiki pers. comm. 2004).
Area of occupancy equals that of spawning aggregations although the actual area is unknown as there are undoubtedly many spawning aggregations for this species that are presently unknown.
American Samoa; Australia; Cambodia; China; Comoros; Djibouti; Egypt; Eritrea; Fiji; Hong Kong; India (Andaman Is.); Indonesia; Iran, Islamic Republic of; Israel; Japan (Nansei-shoto); Jordan; Kenya; Madagascar; Malaysia; Mayotte; Micronesia, Federated States of ; Mozambique; New Caledonia; Oman; Pakistan; Palau; Papua New Guinea; Philippines; Samoa; Saudi Arabia; Seychelles; Singapore; Solomon Islands; Somalia; South Africa; Sri Lanka; Sudan; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Tonga; Viet Nam; Wallis and Futuna; Yemen
|FAO Marine Fishing Areas:|
Atlantic – southeast; Indian Ocean – western; Indian Ocean – eastern; Pacific – eastern central; Pacific – northwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||All available information on population has been covered above under the Red List justification.|
|Current Population Trend:||Decreasing|
Habitat and Ecology [top]
|Habitat and Ecology:||A common species found in a variety of habitats: coral and rocky reefs, tidepools, estuaries, mangrove swamps and sandy/mud bottom from the shore to depths of 150 m. Juveniles are found nearshore and in estuaries (Heemstra and Randall 1993). |
E. malabaricus is a protogynous hermaphrodite with sex change from female to male occurring. Sexual maturity in males does not occur until they are 114 cm length (Lau and Li 2000). This species has a very low resilience to fishing, with a minimum population doubling time more than 14 years (Froese and Pauly 2005).
|Major Threat(s):||Fishing pressure|
Fishing threats include commercial and recreational line fishing, and the live reef fish trade, involving the removal of many juveniles for mariculture grow-out.
Significant decreases in mangrove area are known to have occurred in SE Asia. In Malaysia, 12% was lost from 1980 to 1990, in the Philippines mangroves have decreased by 60% (4,000 km² originally to 1,600 km² in 1997), in Viet Nam mangroves decreased by 38% (4,000 km² to 2,525 km² in 1997) while in Thailand the loss has been 54% (5,500 km² in 1961 to 2,470 km² in 1997) (Spalding et al. 1997). These figures represent a loss of some 7,445 km² of mangrove, or about 9% of the SE Asian total. Other countries like Indonesia, which has the most mangroves in the world (42, 550 km²) are also known to have suffered losses (Spalding et al. 1997).
The primary area of occurrence is SE Asia where an estimated 56% of all reefs are at high risk due to a variety of human activities. In other areas where E. malabaricus occurs, the risk is not as high but still considerable, 15% in the Middle East and 25% in the Indian Ocean, also 10% in the Pacific where E. malabaricus is only known from a few locations (all figures from Bryant et al. 1998).
Conservation Actions [top]
|Conservation Actions:|| Under Queensland Fisheries Service (QFS) regulations the current size limits for the Greasy Grouper (E. tauvina) are 38 cm minimum and 100 cm maximum, whilst the current recreational in-possession limit is 5 for any Epinephelus species. In practice, this regulation may also apply to E. malabaricus since it looks similar. (See http://www.dpi.qld.gov.au/fishweb/11379.html for new regulations in Queensland). |
While many marine parks have been introduced in areas within the range of E. malabaricus e.g., Papua New Guinea, Indonesia and the Philippines, most of these are considered to be 'paper parks' and are poorly managed or legislation is poorly enforced. Only 8% of the 100,000 km² of coral reefs in SE Asia is included in marine protected areas (MPAs) and only 14% of the 646 MPAs are considered effective, hence the majority of these MPAs probably provide little protection to the species they house (Licuanan and Gomez 2000, Chou et al. 2002).
E. malabaricus can be maricultured and is considered as the easiest for culturing among the main species in the market in the Philippines (Anonymous 1998). Larval rearing of this species has been achieved in Thailand (Tookwinas 1989). Hatchery production of this species occurs in Taiwan. However, it is not known how much of the marketed fish in SE Asia comes from the wild (as adult or as juvenile for grow-out) and how much from hatchery-based culture.