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Home , Coral grouper, Leopard coral grouper, Trout

Leopard Coral ( leopardus)

Regional Status and Catch Statistics

Australia P. leopardus is the main in the commercial and recreational on the , comprising 60% of the demersal reef fish catches landed by commercial fishers (Turnbull 1996), and contributing up to around 1,500 tonnes per annum (Mapstone et al. 1996). The increase in the demand for the fish in since 1995 led to an increase in effort of almost 30% in the Townsville Mid Shelf and Southern regions (Ayling et al. 2000): on Cairns Mid Shelf reefs, catch rates have dropped from 3.5 in 1992 to 0.85 kg/boat/day in 1997–1998 (76% decline) while fishing effort has increased from 150 boat days to 350 boat days over the same period. Similarly, on Cairns Outer Shelf reefs, catch rates have dropped from 2.02 in 1992 to 0.65 kg/boat/day in 1997 (68% decline). On Townsville Mid Shelf reefs, catch rates have dropped from 1.45 in 1992 to 0.40 kg/boat/day (72% decline) in 1997. With a 75% increase in fishing effort (boat days), the catch rates on Townsville Outer Shelf reefs declined from 6.82 in 1992 to 1.31 kg/boat/day (80% decline) in 1997. On Southern Mid Shelf reefs, catch rates decreased from 1.65 in 1992 to 0.68 in 1997 (59% decline). Considering Queensland fisheries production as a whole, the harvest of coral trout has been increasing since 1999 due to the increase in fishing effort: 1,643 tonnes (1999), 1,927 tonnes (2000) and 2,086 tonnes (2001)(ABARE 2003). The increase in effort is in part due to the export of live fish for the live reef food fish trade. According to a report on P. leopardus populations by Ayling et al. (2000), there are significant differences in trends in density of P. leopardus between time periods (Early: 1982 to 1990; Mid:1991 to 1994; Recent: 1995 to 1999) in two regions of the Great Barrier Reef (GBR), and the differences are consistent between reefs. The trends were stable through the 1980s, then they became positive in the early 1990s; however, they changed became negative in the 1995 to 1999 period. The same report indicates that the mean densities are significantly lower (p<0.001) in recent times compared with those in the 1980s and mid 1990s in one region of the GBR. It also shows a significant reduction in both mean length (p=0.007) and length range (p<0.001) between the early (1982 to 1990) and recent (1995 to 1999) time periods and between early and middle (1991 to 1994) periods. Mean length was 37.9 cm in the early time period, 35.8 cm in the middle time period and 34.7 cm in the recent time period; and the percentage of fish over 50 cm TL reduced from 7.2% to 2.3% over the period, suggesting growth of P. leopardus. The length range (measured by standard

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deviation) decreased from 10.3 cm in the early time period to 6.5 cm in the recent time period, implying a reduction of fish in the small and/or large size classes. It is shown by length frequency plots that this reduction can be attributed mainly to a decline in the number of large fish.

The legal size restriction for P. leopardus on the Great Barrier Reef (GBR) is set at 38 cm TL (QDMA, 1999), above the size at first maturity, which presumably allows females opportunity to before being caught (Ferreira 1994). However, a decline in average size and age of females (Adams et al. 2000), apparently in response to fishing pressure caused by gear selectivity, has been observed. This implies that the overall fecundity in the population may be reduced, all else being equal, as fecundity is positively correlated with fish size (Roff 1992). The sex ratio is evidently affected as a result of earlier sex change from female to male. Female biased ratios have been recorded everywhere on the GBR (Samoilys 2000), whereas male biased sex ratios have been recorded in the southern Swains region of the GBR (Adams et al. 2000).

The highest catch and effort of the coral trout fishery on the GBR occurs during the spawning season (September–November), probably due to favourable weather during this time. There is no evidence of increased fishing effort during the new moon periods when spawning aggregations form (Turnbull and Samoilys 1997). However, an increase in catchability of P. leopardus on mid-shelf reefs in the Cairns Section of the Great Barrier Reef Marine Park during September has been attributed to fish aggregating to spawn (Davies 2000). Further, within the period of 1990 to 1999, one of two main spawning aggregations of P. leopardus on reefs near Cairns n the northern part of the GBR disappeared from 1996 to 1998, very probably due to targeted fishing. There is evidence this aggregation has now recovered in the absence of fishing (Samoilys, Squire and Roelofs 2001, unpublished data).

In Abrolhos Island of (the only area coral trout occurs in WA), the harvest of the sp. has doubled over the period of 1990 to 1995 and 1996 to 2001: the total catch increased from 6.4 tonnes (1990) to 12.5 tonnes (1995); and the CPUE increased from 6.79 kg per day (1996) to 15.9 kg per day (J. St John pers. comm. 2001). The latter is an extremely high catch rate compared with the GBR and Philippines, suggesting the Abrolhos Island population may still be healthy.

Japan In Japan, a large population of coral trout occurred around Ishigaki Island ten years ago (Akinobu Nakazono pers. comm. 2003); however, fishermen have changed the fishing sites from Ishigaki Island to Iriomote Island, implying that the population in Ishigaki Island has been decreasing due to overfishing.

Hong Kong In Hong Kong, P. leopardus was once common; however, it is rare today, very probably because of overfishing (Sadovy and Cornish 2000).

Malaysia Regarding the landings in Sabah of east Malaysia, 97.26% decline was observed over the period of 1998 to 2000 (TRACC 2000).

Philippines Only juveniles are now moderately common in Calamianes Islands, which are located at Palawan waters – the biggest supplier of fish in Philippines (Werner and Allen 2000). In the past, adult sized fish were caught. Once the live reef food fish traders became active in the area, large numbers of fish

2 were purchased, fishers had to travel longer to maintain catches and now mainly juveniles are caught – these are often placed in floating net cages and grown-out until they meet market size for live export in the . This practice is likely to be unsustainable because it represents a juvenile fishery and is likely to result in severe recruitment overfishing (SCRFA 2003, Padilla et al. 2003).

Papua New Guinea In Papua New Guinea, Leopard Coral Trout is moderately abundant (Werner and Allen 1998), though occurs in notably lower densities than those seen on Australia’s GBR (Samoilys et al. 1995).

Fiji, Solomon Islands and Western Samoa Plectropomus leopardus appears to be a moderately uncommon species in Fiji, Solomon Islands, and Western Samoa, even on reefs that are subjected to low levels of fishing pressure; it appears that P. maculatus is the more common coral trout in these islands (Samoilys et al. 1995, Samoilys and Carlos 2000). P. leopardus is therefore likely to be more vulnerable to increased fishing pressure (e.g., from the LRFFT) on these Pacific islands than the Australian populations (Samoilys and Donnelly 1998).

Indonesia The species is popular with the live reef food fish trade and extensively sourced in many areas. Interviews of fishers in SW Sulawesi and in the Kei Islands (Moluka) strongly suggested that in areas where this species has been heavily targeted for a long period (i.e. introduction of the live reef food fish trade in the early to mid 1990s) catch rates have been declining (SCRFA 2004).

Trade statistics of imports to Hong Kong As Hong Kong is one of the biggest importers of live food fish in the world (Sadovy and Lee 1998), its import data may reflect the harvest of the fish in other countries. Recently, the import of coral trout has increased greatly (58% increase): 1,420,582 kg (1999), 2,060,617 kg (2000), 1,991,353 kg (2001) and 2,237,650 kg (2002). P. leopardus is a very important and preferred species in the live reef food fish trade and fetches a high price (approx. USD70 at retail per kg. (Sadovy et al. 2003). Generally, the major suppliers are: Indonesia, Philippines, Malaysia and Australia, with Australia becoming the major supplier. The import into Hong Kong (in kg) from the major suppliers is as follows:

1999 2000 2001 2002 Indonesia 342,872 488,974 262,508 274,327 Philippines 352,817 515,774 404,413 597,778 Malaysia 225,988 239,226 203,725 186,579 Thailand 13,240 792 37,393 5,614 Singapore 7,428 817 140 437 Vietnam 56,227 55,763 28,764 34,548 Taiwan 5,077 3,348 651 0 Cambodia 0 17,669 9,996 4,007 Fiji 200 14,056 9,214 0 Australia 406,960 721,021 1,025,435 1,132,597 (Data Source: International Maritime Alliance – from HK Govt. Census and Statistics data)

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Apparent declining trends of imports (between 1999 and 2002) are observed in Indonesia (20% decline), Malaysia (15% decline), Vietnam (39% decline) and Cambodia (77% decline, using data from 2000 to 2002), whereas increasing trends are found in Philippines (69% increase) and Australia (178% increase). Other countries such as Thailand, Taiwan, Fiji and Singapore showed fluctuation.

Note: References mentioned above are cited in full under the detailed results page for the species on the IUCN Red List of Threatened Species.

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