472
12 Species Case Studies
the night time aggregation at one site was discovered by a spearfi sher in 2003
(Hamilton et al. 2004 ) ; fi shers can remove up to 60 fi sh from an aggregation in less
than 2 h. The species is used for subsistence and artisanal purposes and catches
appear to be stable.
The species has not been assessed for its conservation status. While it is typically
not managed, at one site in PNG a ban was placed in May 2004 on day and nighttime spearfi shing at this site in the 10 days leading up to and including the new
moon. This lunar ban is in force for every month of the year. Only subsistence hook
and line fi shing is allowed here during this lunar period (Hamilton et al. 2004 ) .
12.12 Silver Seabream (‘Snapper’) – Pagrus auratus
Gary Jackson
Department of Fisheries , Western Australian Fisheries & Marine Research
Laboratories , P.O. Box 20, North Beach, Western Australia , 6920 Australia
e-mail: Gary.jackson@fi sh.wa.gov.au
12.12.1 General
The silver seabream or ‘snapper’, Pagrus auratus, is a large and long-lived member
of the family Sparidae (seabreams and porgies, referenced as ‘silver seabream’ in
www.fi shbase.org ) (Fig. 12.28 ). The species is widely distributed throughout warm
temperate and subtropical waters of the western Indo-Pacifi c from China and Japan
across to India and down to Indonesia, Australia and New Zealand (Paulin 1990 ) .
Populations in the northern and southern hemispheres are independent and isolated
but similar enough to be considered the same species ( www.fi shbase.org ). Snapper
support important commercial and recreational fi sheries throughout their distribution and are of some interest to the aquaculture sector (Kailola et al. 1993 ) .
Juveniles typically inhabit sheltered marine waters such as bays and inlets, often
over mud and seagrass (Kailola et al. 1993 ) . Adults may be associated with reefs but
are also found over mud and sand out to depths of more than 300 m (Kailola et al.
1993 ) . Snapper can attain 130+ cm total length (TL) and 20+ kg in weight (Gomon
et al. 2008 ) . Fish commonly reach 40+ cm TL and mature at 20–30 cm TL ( www.
fi shbase.org ). The species is an opportunistic demersal predator with a broad-ranging
diet that can include crustaceans, bivalves, cephalopods, marine worms, starfi sh, sea
urchins and fi shes (Coutin et al. 2003 ) . Snapper can live to 40+ years in Australia
(Norriss and Crisafulli 2010 ) and 50–60 years in New Zealand (Francis et al. 1992 ) .
Snapper in Shark Bay, Western Australia, have been extensively studied since the
1980s, greatly enhancing our understanding of the species biology and management
of its exploitation (Moran et al. 2005 ; Jackson 2007 ) . Stock structure in the region is
complex. Genetics, tagging, otolith chemistry and other techniques have shown little
12 Species Case Studies
the night time aggregation at one site was discovered by a spearfi sher in 2003
(Hamilton et al. 2004 ) ; fi shers can remove up to 60 fi sh from an aggregation in less
than 2 h. The species is used for subsistence and artisanal purposes and catches
appear to be stable.
The species has not been assessed for its conservation status. While it is typically
not managed, at one site in PNG a ban was placed in May 2004 on day and nighttime spearfi shing at this site in the 10 days leading up to and including the new
moon. This lunar ban is in force for every month of the year. Only subsistence hook
and line fi shing is allowed here during this lunar period (Hamilton et al. 2004 ) .
12.12 Silver Seabream (‘Snapper’) – Pagrus auratus
Gary Jackson
Department of Fisheries , Western Australian Fisheries & Marine Research
Laboratories , P.O. Box 20, North Beach, Western Australia , 6920 Australia
e-mail: Gary.jackson@fi sh.wa.gov.au
12.12.1 General
The silver seabream or ‘snapper’, Pagrus auratus, is a large and long-lived member
of the family Sparidae (seabreams and porgies, referenced as ‘silver seabream’ in
www.fi shbase.org ) (Fig. 12.28 ). The species is widely distributed throughout warm
temperate and subtropical waters of the western Indo-Pacifi c from China and Japan
across to India and down to Indonesia, Australia and New Zealand (Paulin 1990 ) .
Populations in the northern and southern hemispheres are independent and isolated
but similar enough to be considered the same species ( www.fi shbase.org ). Snapper
support important commercial and recreational fi sheries throughout their distribution and are of some interest to the aquaculture sector (Kailola et al. 1993 ) .
Juveniles typically inhabit sheltered marine waters such as bays and inlets, often
over mud and seagrass (Kailola et al. 1993 ) . Adults may be associated with reefs but
are also found over mud and sand out to depths of more than 300 m (Kailola et al.
1993 ) . Snapper can attain 130+ cm total length (TL) and 20+ kg in weight (Gomon
et al. 2008 ) . Fish commonly reach 40+ cm TL and mature at 20–30 cm TL ( www.
fi shbase.org ). The species is an opportunistic demersal predator with a broad-ranging
diet that can include crustaceans, bivalves, cephalopods, marine worms, starfi sh, sea
urchins and fi shes (Coutin et al. 2003 ) . Snapper can live to 40+ years in Australia
(Norriss and Crisafulli 2010 ) and 50–60 years in New Zealand (Francis et al. 1992 ) .
Snapper in Shark Bay, Western Australia, have been extensively studied since the
1980s, greatly enhancing our understanding of the species biology and management
of its exploitation (Moran et al. 2005 ; Jackson 2007 ) . Stock structure in the region is
complex. Genetics, tagging, otolith chemistry and other techniques have shown little