|Scientific Name:||Epinephelus polyphekadion (Bleeker, 1849)|
Epinephelus polyphekadion (Bleeker, 1849)
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||Russell, B., Situ, A. & Cornish, A. (Grouper & Wrasse Specialist Group)|
|Reviewer(s):||Sadovy, Y. & Kulbicki, M. (Grouper & Wrasse Red List Authority)|
Although E. polyphekadion is widely distributed, it may be particularly susceptible to overfishing, especially spearfishing, as it is easy to approach underwater. Also, it is easy to target in its spawning aggregations which are particularly easy to find in their outer reef channel pass habitat. Declines from aggregation-fishing have been reported in fisher interviews from a range of countries. Habitat degradation of coral reefs also has the potential to affect its numbers and a high proportion of coral reefs have been degraded in a significant part of its range in SE Asia. On the other hand, it remains one of the more common species of live fish imported into the Hong Kong restaurant market, although the ever shifting sources of these fish could obscure any localized depletions (Sadovy et al. 2003).
Given its susceptibility to fishing, both because of its aggregations (of the 34 spawning aggregations known for this species, the status of 14 is unknown, 16 are in decline, 1 has gone and 3 are increasing in response to protection (see www.scrfa.org database) and because of its general biology (long life, late sexual maturation), and its desireability in the live fish trade with prospects that the trade could well increase in the future, a listing of Near Threatened is considered appropriate (almost qualifies for listing under criteria A2d+3d). This species needs to be monitored in the future to determine trends in the fishery; in particular it needs to be determined whether the species spawns outside of spawning aggregations.
|Range Description:||Found in the Indo-Pacific: Red Sea and east coast of Africa to French Polynesia. In the western Pacific it ranges from southern Japan to southern Queensland and Lord Howe Island (Heemstra and Randall 1993). |
Spawning aggregations are known from Palau, Pohnpei (Micronesia), Mauritius, Cook Islands, Solomon Islands, Seychelles, Fiji, Papua New Guinea, French Polynesia, New Caledonia, and also outside Great Barrier Reef Marine Park (Australia). Aggregations probably also occur off Malaysia.
For this species, which aggregates to spawn, area of occupancy could be taken as the area of all aggregation sites. This area, which will occupy < 10% extent of occurrence, is not known.
Native:American Samoa; Australia (Lord Howe Is.); British Indian Ocean Territory (Chagos Archipelago); Brunei Darussalam; China; Cocos (Keeling) Islands; Comoros; Cook Islands; Djibouti; Egypt; Eritrea; Fiji; French Polynesia (Marquesas, Tuamotu); Guam; India; Indonesia; Israel; Japan (Nansei-shoto, Ogasawara-shoto); Jordan; Kenya; Kiribati (Kiribati Line Is.); Madagascar; Malaysia; Maldives; Marshall Islands; Mauritius; Micronesia, Federated States of ; Mozambique; Nauru; New Caledonia; Niue; Northern Mariana Islands; Palau; Papua New Guinea; Philippines; Pitcairn; Samoa; Saudi Arabia; Seychelles; Solomon Islands; Somalia; Sudan; Taiwan, Province of China; Tanzania, United Republic of; Tokelau; Tonga; Tuvalu; United States Minor Outlying Islands (Wake Is.); Vanuatu; Wallis and Futuna; Yemen
|FAO Marine Fishing Areas:|
Indian Ocean – western; Indian Ocean – eastern; Pacific – eastern central; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Regional Status |
Camouflage Grouper has been targeted annually during aggregation periods since pre-recorded history. In 1999, local fishermen were observed to remove an estimated 4,000 pre-spawning Camouflage Grouper from the Kehpara Marine Sanctuary, Pohnpei, site within 7 days, about 20–30% of the estimated size of the total number of aggregated fish (Rhodes and Sadovy 2002a and b). Three years of monitoring E. polyphekadion at one aggregation site in Pohnpei revealed a decrease from about 20,000 fish in 1998 and 1999 to only about 1,000 fish in 2001. Gonadosomatic index of Camouflage grouper showed that the spawning season in 1998 included the months February, March and April, whereas in 1999 the season was a little different, extending from January to March, inclusive: this indicates that temporal closure for commercial catches of grouper from March 1 to April 30 will not necessarily cover the full aggregating period of this species. A total of 620 individuals were recorded during monitoring in three days of March 2001 at the full moon at that site (Pet et al. 2001).
Plectropomus areolatus, Epinephelus fuscoguttatus and E. polyphekadion dominate the commercial catch of groupers in Palau (Kitalong and Dalzell 1994). At least five grouper spawning aggregations have possibly disappeared since the 1970s in Palau according to Noah Idechong, maybe due to overfishing: one of these is mostly of E. polyphekadion and E. fuscoguttatus, lost in the 1990s. P. areolatus, E. polyphekadion and E. fuscoguttatus used to aggregate on either side of Ebiil (Johannes et al. 1999). Aggregations of this species were also identified during fisher surveys by the Society for the Conservation of Reef Fish Aggregations with indications from fishers of declines (see newsletters on www.scrfa.org) from surveys taken in early 2000s.
Of the eight spawning aggregations identified during fishery surveys by the Society for the Conservation of Reef Fish Aggregations (SCRFA), one is stable and the rest in decline according to falling CPUE (see SCRFA database on www.scrfa.org).
The species has been assessed using IUCN criteria as 'Lower Risk' in Australia. It is caught with hook-and-line, spears and traps. There are size restrictions on this species in Queensland waters (Queensland Government 2003). It comprises 0.4% of the inspected catch of traditional Indonesian fishing vessels fishing around Scott and Ashmore Reefs in West Australia (Russell and Vail 1988; also see report by Nowara and Newman (2001) at http://www.fish.wa.gov.au/docs/frr/frr125/frr125.pdf).
British Indian Ocean Territory
Recorded to form spawning aggregations in Peros Banhos. In a nine day fishing program during the aggregation period in 2000, a total of 24,751 kg of E. polyphekadion was taken, during which the highest catch rate was observed in a trip returning with 747 kg of fish (consisting of 85% E. polyphekadion) with a CPUE of 36.4 kg/man hour. Sex ratio in spawning aggregations changes in different locations, sometimes suggesting a dramatic decrease in the number of males caught, maybe due to depletion of aggregating males (MRAG [Marine Resource and Fisheries Consultants – office London UK] observer, pers. comm.).
E. polyphekadion aggregates in reef passes with E. fuscoguttatus in southern Seychelles (see Marine Conservation News Volume 2 no. 2, July 2004).
One of most important species in the Maldivean live fish trade (Johannes and Riepen 1995); heavily targeted in Maldives (Sluka 2001). At least one spawning aggregation site exists but its current status is unknown (Sluka 2000).
Aggregates to spawn. Historical live reef fish trade operations have predominantly been pulse fishing events that target seasonal spawning aggregations of serranids. Existing interviews reveal that historical fishing pressure on reef fish resources has been light, catch rates of Epinephelus show no decline or only slight decline over the past few decades (Hamilton 2003). See also www.scrfa.org fisher survey for PNG and Solomon Is. (For the volume of exports in 1997 see Table 1 in the Supplementary Material).
Papua New Guinea
Targeted in Papua New Guinea. Taken by hook and line, spears, traps (Heemstra and Randall 1993). In coral reefs of Milne Bay Province, occasionally recorded at depth 2–45m (Werner and Allen 1998). See also www.scrfa.org fisher survey for PNG and Solomon Is. in early 2000s.
The one spawning aggregation reported is in decline according to declining CPUE noted in fisher surveys in the early 2000s (see SCRFA database and Malaysia report on www.scrfa.org).
Groupers are among the most intensively fished taxa around Kavadu Island in Fiji, in two of the fishing grounds studied, groupers accounted for 66% and 55% of yield from three families: groupers, snappers and parrotfishes, but its contribution to the biomass was 21% and 23%, indicating that groupers were heavily fished. Abundance of Camouflage Grouper (mean biomass gm-2) recorded ranged from 0.15 to 1.84 in 10 fishing grounds around Kavadu Island (Jennings et al. 1999). A recent survey by Secretariat for the Pacific Community indicates very low densities (0.0004 fish/m²) for this species over six locations. The average size was 33 cm FL. Of the nine aggregations for this species identified, seven are in decline judging by declining CPUE in SCRFA fisher interviews (see database www.scrfa.org, and newsletter). When one aggregation was first fished in 1985, four fishers got about 300 kg and by mid 1990s, four fishers got about 100 kg and by 2002–3, four fishers got about 12–20 fish between them from the aggregations, as their best catches (this CPUE is catch per trip).
Density of E. polyphekadion was recorded as 0.0006 per m² and biomass of 0.1795 gm-2 in UVC counts of shallow water reef fishes in Tongatapu Reefs in 1996 (the Secretariat of Pacific Community, pers. comm. 2003). A larger survey in 2002–2003 on Haapai, Vavau and Tongatapu indicated average sizes of 32 cm FL and densities approximatively ten times lower (0.000063 fish/m²) than in 1996.
Fishermen target an annual spawning aggregation, with females dominating. About 15 aluminum skiffs regularly fish Taruia Passage in Cook Islands, catch rates are usually in the vicinity of 10 to 12 fish per man hour, fish average around 1.5 kg, and generally range from 1 to 2 kg. Fishermen in general only fish for local consumption, with some minor exports from national urban centers. Anecdotal information does not suggest significant reduction in stocks caused by these fisheries to date (Passfield 1996).
Reported to form spawning aggregation on some atolls. Fishermen in general only fish for local consumption, with some minor exports from national urban centers. Anecdotal information does not reveal any perceived significant reduction in stocks caused by these fisheries to date (Passfield 1996).
Extensive visual census of transects throughout American Samoa in 2002 recorded no E. polyphekadion (Rob Schroeder, Coral Reef Ecosystem Investigation, pers. comm), although the species has been reported to occur here.
E. polyphekadion is usually not kept by fishermen because it is too often ciguatoxic, but it is often found on the Noumea fish market despite this (M. Kulbicki pers. comm. 2003). Surveys (2,000 transects) indicate that this species is not common in the 0–10 m depth range (0.00009 fish/m²), but that sizes are large (41 cm FL). This species is known to aggregate for spawning in Dumbea Pass (November–December), mixed with other species of groupers, in particular Epinephelus cyanopodus (M. Kulbicki, pers. comm.). This species is known to spawn just before full moon with several other grouper species in reef passages; at the end of the spawning period, fish (particularly males) can be quite skinny and weak from not eating (Claude Chauvet pers. comm. 2005). Numbers of fish have dropped from around 4,500 in 1992 to 2,000 in 2002 at the Dumbea Pass site (C. Chauvet and E. Clua unpublished manuscript).
A survey (510 transects) in 1996 of 10 atolls indicate that this species had a density of 0.02fish/m² and a biomass of 1.6 g/m² and an average size of 34 cm FL. However, a recent survey of Tikehau atoll (350 km²) shows that this species, which was a major component of the commercial catch in the 1980s, could no longer be observed. The fish used to group for spawning at the entrance of the pass of this atoll. The fish were caught using traditional fishing fences ("parc à poissons"; "aua" in Tahitian) (M. Kulbicki pers. comm.).
One of the commercially important species frequently occurring along the nearest coral reef area on the southern part of the Red Sea coast of Saudi Arabia (Rasem et al. 1997).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Usually found in coral-rich areas of lagoon and outer reefs. Most abundant around islands, particularly atolls. Usually in small schools (Heemstra and Randall 1993). It occurs at depths of 2 to 46 m (Myers 1999). |
In one study in Palau, mature females were between 301 and 470 mm fork length, mature males between 340 and 500 mm and immature fish between 239 and 286 mm, indicating sexual maturation occurred between about 290 and 300 mm fork length in Palau (Johannes et al. 1999). Tamaru et al. (1996) reported a female to male (f:m) sex ratio of 1:4 in Palau, while the female to male ratio was 2.9 in a New Caledonia lagoon (Loubens 1980). Spawning occurs between June and August.
A study based in Pohnpei on reproductive biology, spawning and genetic structure of E. polyphekadion showed that spawning occurred at night, for several nights during the full moon period during each of several months between February and April (Rhodes and Sadovy 2002a, b). Males entered spawning sites before females and a significant proportion of the fish can be removed during one aggregation period (despite some protection, not all aggregation months are protected). Sexual maturation in 50% of females was about 270 mm SL in Pohnpei and there was no evidence for sex change in the species (Rhodes and Sadovy 2002a, b). It is possible that, in Pohnpei, there is population sub-structuring of this species (Rhodes et al. 2003).
Saudi Arabia has succeeded in cross breeding two species of groupers, with good grow-out potential for aquaculture: Epinephelus polyphekadion x E. fuscoguttatus (James et al. 1998).
Commercial and recreational fishing, including the life reef fish trade, and also habitat degradation of coral reefs.
E. polyphekadion is one of the most commonly consumed live reef food fish in Hong Kong, the main countries of origin were the Philippines and Indonesia. A survey of the imports of 39 of the 114 companies that trade live fish with Hong Kong (Lau and Parry-Jones 1999), revealed that E. polyphekadion made up 5% (approx. 1,200 t) of the total annual volume of fish imported into Hong Kong for this trade. Sold in the Hong Kong live reef fish food market, the highest proportion at 35–45 cm length (Lee and Sadovy 1998). In Hong Kong, maturity size range is 31–35cm TL, and common consuming size is 33.57–52.41 cm TL (Lau and Parry- Jones 1999). The amount imported between 1999–2002 into Hong Kong is shown in Table 2 in the Supplementary Material.
From the 1980s, the Pohnpei State Government began implementing measures to reduce fishing effort on groupers, including a partial sales ban during spawning season (March to April), but subsistence fishing on aggregations continued during the closed season, with fish being frozen until the end of the ban. Also the ban may have little overall effect since aggregation sites in close proximity to population centers can be targeted outside the ban period. In 1995, the Kehpara Marine Sanctuary was established, but the northwest boundary fell short of covering Camouflage Grouper or Brown-marbled Grouper aggregation, so fishing continued. No foreign fishing vessels are allowed and there are entry restrictions for divers at one site, but aggregations extend at least one month beyond protection (Reef Fish Spawning Aggregations Working Group 2002).
The Marine Protection Act of 1994 prohibits sale or purchase of E. polyphekadion from April 1 through July 31 each year, which is intended to protect spawning aggregations. In 1995 the Act was amended to prohibit any capture of these groupers even for subsistence purposes in the closed period (Johannes 1999). A four-month 'bul' (traditional taboo) is enforced in the state of Ngeremlengui, but this is not completely effective in preventing fishing on the spawning aggregations, which are said by fishermen to be much smaller than they were 10 years ago (Johannes 1999). No foreign fishing vessels are allowed and entry restriction is in place for divers at one site. The species is probably still in fair condition, but aggregations extend at least one month beyond protection (Reef Fish Spawning Aggregations Working Group 2002).
A slot size of 50–100 cm has been in place since December 2003 – see website below for Coral Reef Fin Fish Management Plan in Queensland; minimum size limits proposed for coral reef fin fish are set at a point which allows at least half of the fish in a population to reach reproductive maturity and spawn before they are available for harvest (Queensland Government 2003).
A management plan for the live reef fish trade was drafted in Honiara, seeking to totally protect the spawning aggregations of E. polyphekadion by placing a ban on aggregation fishing for five days either side of the new moon during the three months of the year when aggregations are known to form (Donnelly 2001). The LRFFT (live reef food-fish trade) interim licence conditions were revised in 2002 (E. Oreihaka pers. comm. 2003), and a recent article in the SPC Live Reef Fish Information Bulletin (Samoilys 2002) stated that the management plan drafted in 2001 was yet to be implemented. The most recent update is that many of the main recommendatoins of the draft plan were incorporated into a 2002 revised version of the LRFFT interim licence conditions (E. Oreihaka pers. comm. 2003): Article 22 of Law – fishing of spawning aggregations is not permitted under the licence to buy and export live fish.
Saudi Arabia has succeeded in cross breeding two species of groupers, with good grow-out potential for aquaculture: Epinephelus polyphekadion x E.fuscoguttatus (James et al. 1998).
New Caledonia has restricted fishing during the spawning months in the area of the known spawning aggregation. This measure aims more Epinephelus cyanopodus than E. polyphekadion which is not at present a target species for most fishermen due to its local toxicity (M. Kulbicki pers. comm).
The species has been spawned in captivity in Palau (Tamaru et al. 1996) but there has been no published follow-up work.
|Citation:||Russell, B., Situ, A. & Cornish, A. (Grouper & Wrasse Specialist Group). 2006. Epinephelus polyphekadion. The IUCN Red List of Threatened Species 2006: e.T61339A12464342.Downloaded on 24 May 2018.|
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