28
R.S. Nemeth
size of the insular shelf (Luckhurst 1998 ; Nemeth 2005 ; Nemeth et al. 2006a, 2007 ,
Chapter 12.3).
Different tagging methodologies will infl uence estimation of catchment areas
and can be used to answer different questions. For example tagging fi sh at spawning
aggregation sites can be used to identify migration distances and directions, location
of adult home range habitats and catchment areas (Nemeth 2005 ; Hutchinson and
Rhodes 2010 ) . Alternatively, adults tagged within their resident habitats can be tracked
to identify previously unknown spawning aggregation sites. For example, Zeller ( 1998 )
used both these approaches to track leopard coralgrouper ( Plectropomus leopardus )
movements from home ranges to spawning aggregation sites around Lizard Island,
Australia. Leopard coralgrouper tagged at home sites migrated from 0.2 to 5.2 km
to four different spawning aggregation sites. Movements of these fi sh were contained within the narrow 20 m depth contour surrounding the island shelf (Zeller
1997, 1998 ; Zeller and Russ 2000 ) , resulting in an estimated catchment area of
1.5 km
2 for fi shes from the largest spawning aggregation site (e.g. Granite Head)
(Nemeth 2009 ) . Several adults were also tagged at the Granite Head spawning site
and recaptured on isolated shoals up to 11 km away (Zeller 1998 ) . These individuals
increased the potential catchment area for the Granite Head FSA site from 1.5 km
2
to at least 80 km
2 , a substantial increase that may have implications for future
management decisions and potential MPA design for this species and shows the
importance of working on a large enough sample size.
2.2.2 Staging Area
Within the FMA different habitats along migration routes or surrounding the spawning aggregation site may provide different services to aggregating species. As migrating adults begin to converge on the spawning aggregation site fi sh densities increase.
For several groupers within the genera Epinephelus , Mycteroperca , and Plectropomus ,
all the adults do not pack into the spawning area for the entire spawning season but
instead occupy large staging areas (Fig. 2.3 ) where they may congregate in groups to
rest, feed or occupy cleaning stations (Samoilys 1997 ; Rhodes and Sadovy 2002 ;
Nemeth et al. 2006b ; Semmens et al. 2006 ; Robinson et al. 2008 ) . Fish within staging
areas maintain normal colouration and do not display spawning colour patterns typically found in the courtship arena or at spawning sites (see below). For example, in
the Seychelles Robinson et al. ( 2008 ) observed small groups of 3–20 normal coloured
brown-marbled grouper ( Epinephelus fuscoguttatus ) and camoufl age grouper
( Epinephelus polyphekadion ) occupying a staging area (6,900 m
2
) which surrounded
the spawning site (5,750 m
2
). Within the staging area grouper densities were highest
about 5 days before spawning but then declined as fi sh moved to the spawning site to
set up territories. While in staging areas, brown-marbled and camoufl age groupers
did not display spawning colouration, courtship behaviours or territoriality and thus
temporarily resided in these locations for some other purpose (Robinson et al. 2008 ) .
Similar movement and behavioural patterns were observed for leopard coralgrouper
R.S. Nemeth
size of the insular shelf (Luckhurst 1998 ; Nemeth 2005 ; Nemeth et al. 2006a, 2007 ,
Chapter 12.3).
Different tagging methodologies will infl uence estimation of catchment areas
and can be used to answer different questions. For example tagging fi sh at spawning
aggregation sites can be used to identify migration distances and directions, location
of adult home range habitats and catchment areas (Nemeth 2005 ; Hutchinson and
Rhodes 2010 ) . Alternatively, adults tagged within their resident habitats can be tracked
to identify previously unknown spawning aggregation sites. For example, Zeller ( 1998 )
used both these approaches to track leopard coralgrouper ( Plectropomus leopardus )
movements from home ranges to spawning aggregation sites around Lizard Island,
Australia. Leopard coralgrouper tagged at home sites migrated from 0.2 to 5.2 km
to four different spawning aggregation sites. Movements of these fi sh were contained within the narrow 20 m depth contour surrounding the island shelf (Zeller
1997, 1998 ; Zeller and Russ 2000 ) , resulting in an estimated catchment area of
1.5 km
2 for fi shes from the largest spawning aggregation site (e.g. Granite Head)
(Nemeth 2009 ) . Several adults were also tagged at the Granite Head spawning site
and recaptured on isolated shoals up to 11 km away (Zeller 1998 ) . These individuals
increased the potential catchment area for the Granite Head FSA site from 1.5 km
2
to at least 80 km
2 , a substantial increase that may have implications for future
management decisions and potential MPA design for this species and shows the
importance of working on a large enough sample size.
2.2.2 Staging Area
Within the FMA different habitats along migration routes or surrounding the spawning aggregation site may provide different services to aggregating species. As migrating adults begin to converge on the spawning aggregation site fi sh densities increase.
For several groupers within the genera Epinephelus , Mycteroperca , and Plectropomus ,
all the adults do not pack into the spawning area for the entire spawning season but
instead occupy large staging areas (Fig. 2.3 ) where they may congregate in groups to
rest, feed or occupy cleaning stations (Samoilys 1997 ; Rhodes and Sadovy 2002 ;
Nemeth et al. 2006b ; Semmens et al. 2006 ; Robinson et al. 2008 ) . Fish within staging
areas maintain normal colouration and do not display spawning colour patterns typically found in the courtship arena or at spawning sites (see below). For example, in
the Seychelles Robinson et al. ( 2008 ) observed small groups of 3–20 normal coloured
brown-marbled grouper ( Epinephelus fuscoguttatus ) and camoufl age grouper
( Epinephelus polyphekadion ) occupying a staging area (6,900 m
2
) which surrounded
the spawning site (5,750 m
2
). Within the staging area grouper densities were highest
about 5 days before spawning but then declined as fi sh moved to the spawning site to
set up territories. While in staging areas, brown-marbled and camoufl age groupers
did not display spawning colouration, courtship behaviours or territoriality and thus
temporarily resided in these locations for some other purpose (Robinson et al. 2008 ) .
Similar movement and behavioural patterns were observed for leopard coralgrouper