457
12 Species Case Studies
whether biological population parameters obtained from exploited populations
refl ect “normal” populations. The difference in densities of leopard coralgrouper on
reefs closed to fi shing between WA and the GBR (Table 12.2 ) is revealing and may
indicate severely depleted populations on the GBR.
The species is considered to be near threatened on the IUCN Red List based on
declining populations in different countries ( www.iucnredlist.org ).
12.9.5 Lessons Learned, Specifi c Management Challenges
Despite a signifi cant amount of research and management of leopard coralgrouper
on Australia’s GBR there remain concerns and diffi culties:
As one of a group of coral trout species, some of which are hard to distinguish,
•
disaggregating accurate information on leopard coralgrouper is diffi cult.
The live fi sh trade represents a market demand for small (“plate-size” = 25–40 cm
•
TL) fi sh increasing fi shing pressure on fi sh entering the fi shery (38 cm TL legal
size), and fi shing inshore in shallow reef areas (<20 m) where fi shers perceive
young fi sh occur.
Understanding the impacts of the GBR spawning closures on leopard coralgrou•
per is diffi cult because no monitoring system was established when the closures
were introduced, and only two spawning aggregations have been monitored for
any length of time on the entire GBR.
Only four reefs have been specifi cally protected for their leopard coralgrouper
•
spawning sites (Russell and Pears 2007 ) .
The status of leopard coralgrouper populations in Asian and Pacifi c Island countries, the extent to which leopard coralgrouper contributes to the live fi sh export
fi shery, and whether aggregation-fi shing is involved in this fi shery are all largely
unknown. The species is very highly valued at the retail end of the trade so there is
high interest in sourcing wild fi sh. This fi shery is typifi ed by declining catches of
high value groupers in some areas of Indonesia, Malaysia, Philippines and Vietnam,
though imports to Hong Kong appear to be stable (Sadovy et al. 2003 ) . The
Philippines continues to be a major source of leopard coralgrouper for the Hong
Kong–based trade in live reef fi sh. Fish are either caught and exported or caught, if
below the preferred marketable size, and placed in cages to grow to a more profi table size. This has led to a heavy fi shery in juvenile leopard coralgrouper which has
had severe negative effects in Palawan where they are trying to bring the export of
the species under control (e.g. Padilla et al. 2003 ; Yvonne Sadovy de Mitcheson,
personal communication 2010).
Management and conservation of leopard coralgrouper should employ a range of
measures to limit total catch and protect spawning stock biomass, including size limits, effort controls, area controls and seasonal spawning closures. Spawning closures
alone are not likely to be adequate because aggregation spawning may only partially
contribute to the total reproductive output of the species (at least on the GBR).
12 Species Case Studies
whether biological population parameters obtained from exploited populations
refl ect “normal” populations. The difference in densities of leopard coralgrouper on
reefs closed to fi shing between WA and the GBR (Table 12.2 ) is revealing and may
indicate severely depleted populations on the GBR.
The species is considered to be near threatened on the IUCN Red List based on
declining populations in different countries ( www.iucnredlist.org ).
12.9.5 Lessons Learned, Specifi c Management Challenges
Despite a signifi cant amount of research and management of leopard coralgrouper
on Australia’s GBR there remain concerns and diffi culties:
As one of a group of coral trout species, some of which are hard to distinguish,
•
disaggregating accurate information on leopard coralgrouper is diffi cult.
The live fi sh trade represents a market demand for small (“plate-size” = 25–40 cm
•
TL) fi sh increasing fi shing pressure on fi sh entering the fi shery (38 cm TL legal
size), and fi shing inshore in shallow reef areas (<20 m) where fi shers perceive
young fi sh occur.
Understanding the impacts of the GBR spawning closures on leopard coralgrou•
per is diffi cult because no monitoring system was established when the closures
were introduced, and only two spawning aggregations have been monitored for
any length of time on the entire GBR.
Only four reefs have been specifi cally protected for their leopard coralgrouper
•
spawning sites (Russell and Pears 2007 ) .
The status of leopard coralgrouper populations in Asian and Pacifi c Island countries, the extent to which leopard coralgrouper contributes to the live fi sh export
fi shery, and whether aggregation-fi shing is involved in this fi shery are all largely
unknown. The species is very highly valued at the retail end of the trade so there is
high interest in sourcing wild fi sh. This fi shery is typifi ed by declining catches of
high value groupers in some areas of Indonesia, Malaysia, Philippines and Vietnam,
though imports to Hong Kong appear to be stable (Sadovy et al. 2003 ) . The
Philippines continues to be a major source of leopard coralgrouper for the Hong
Kong–based trade in live reef fi sh. Fish are either caught and exported or caught, if
below the preferred marketable size, and placed in cages to grow to a more profi table size. This has led to a heavy fi shery in juvenile leopard coralgrouper which has
had severe negative effects in Palawan where they are trying to bring the export of
the species under control (e.g. Padilla et al. 2003 ; Yvonne Sadovy de Mitcheson,
personal communication 2010).
Management and conservation of leopard coralgrouper should employ a range of
measures to limit total catch and protect spawning stock biomass, including size limits, effort controls, area controls and seasonal spawning closures. Spawning closures
alone are not likely to be adequate because aggregation spawning may only partially
contribute to the total reproductive output of the species (at least on the GBR).