148
P.L. Colin
for the TWA. In the 1990’s conservation entities began trumpeting the “discovery”
of multi-species use of sites as a means to publicize the need for conservation
protection for such sites. However, virtually all known large TA sites worldwide are
used by multiple TA species; exceptions to this generality may refl ect nothing more
than a lack of adequate study to detect other species using the site (some red hind
sites, Colin et al. 1987 ; Nemeth et al. 2007 ) or local extirpation of some species. Sites
where goliath grouper may be aggregating to spawn (spawning has never been seen)
are not yet known to be sites shared with other TA species; again this may simply be
a lack of study on a year-round basis since most aggregation sites are only studied
during aggregation periods.
Multi-species use of a site can be simultaneous, sequential, or in most cases both.
Often there are slight differences in the locations where different species aggregate
at sites (Heyman and Kjerfve 2008 ; Nemeth et al. 2007 , PLC unpublished data) and
in the timing of their reproduction; ample reason to support the detailed mapping of
sites (Chap. 9 ). In the IWP the camouflage grouper, brown-marbled grouper
and squaretail coralgrouper use the same sites across a wide geographic range, often
simultaneously, despite some inter- and intra-specifi c aggression (also see Rhodes
and Sadovy 2002 ) . At Ulong Channel, Palau, a relatively narrow and shallow channel,
the three species have simultaneous, largely overlapping, distributions while in
another much wider and deeper channel mouth 30 km away, the three species overlap
much less (Fig. 2.6). In Fiji, at a reef channel aggregation site for the three species,
the camoufl age grouper is more concentrated on one side of the channel than the
other, while the brown-marbled grouper only occurs on the opposite side of the
channel and close to a fourth species, the blacksaddle coralgrouper, Plectropomus
laevis , aggregation (Yvonne Sadovy de Mitcheson unpublished data).
Less attention has been directed toward multi-species use of RA sites. Reef tops,
particularly seaward margins of barrier reefs, are locations for spawning by both
resident IWP aggregators (typically brown surgeonfi sh, striated surgeonfi sh, bullethead parrotfi sh) and non-aggregating fi shes with spawning occurring on daytime
falling tides, often in a sequence (Robertson 1983 , PLC unpublished data). In the TWA,
several examples of RA multi-species use are known, including for the redfi n
parrotfi sh, Sparisoma rubripinne and spotted goatfi sh, Pseudupeneus maculatus,
(US Virgin Islands – Randall and Randall 1963 ; Colin and Clavijo 1978 ) and two
surgeonfi shes in Puerto Rico (Colin and Clavijo 1988 ) .
5.8.6 Predation on Spawning Adults and Eggs
Predation attempts by piscivores on spawning reef fi shes, including those forming
aggregations, appear to be uncommon, despite limited quantitative data. Chapter
2 details many of these (Table 2.1) and suggests that reports of attacks are more
common for RA than TA and more common in the IWP than TWA. In general
reports for tropical reefs indicate roughly one attack (often not successful) per
P.L. Colin
for the TWA. In the 1990’s conservation entities began trumpeting the “discovery”
of multi-species use of sites as a means to publicize the need for conservation
protection for such sites. However, virtually all known large TA sites worldwide are
used by multiple TA species; exceptions to this generality may refl ect nothing more
than a lack of adequate study to detect other species using the site (some red hind
sites, Colin et al. 1987 ; Nemeth et al. 2007 ) or local extirpation of some species. Sites
where goliath grouper may be aggregating to spawn (spawning has never been seen)
are not yet known to be sites shared with other TA species; again this may simply be
a lack of study on a year-round basis since most aggregation sites are only studied
during aggregation periods.
Multi-species use of a site can be simultaneous, sequential, or in most cases both.
Often there are slight differences in the locations where different species aggregate
at sites (Heyman and Kjerfve 2008 ; Nemeth et al. 2007 , PLC unpublished data) and
in the timing of their reproduction; ample reason to support the detailed mapping of
sites (Chap. 9 ). In the IWP the camouflage grouper, brown-marbled grouper
and squaretail coralgrouper use the same sites across a wide geographic range, often
simultaneously, despite some inter- and intra-specifi c aggression (also see Rhodes
and Sadovy 2002 ) . At Ulong Channel, Palau, a relatively narrow and shallow channel,
the three species have simultaneous, largely overlapping, distributions while in
another much wider and deeper channel mouth 30 km away, the three species overlap
much less (Fig. 2.6). In Fiji, at a reef channel aggregation site for the three species,
the camoufl age grouper is more concentrated on one side of the channel than the
other, while the brown-marbled grouper only occurs on the opposite side of the
channel and close to a fourth species, the blacksaddle coralgrouper, Plectropomus
laevis , aggregation (Yvonne Sadovy de Mitcheson unpublished data).
Less attention has been directed toward multi-species use of RA sites. Reef tops,
particularly seaward margins of barrier reefs, are locations for spawning by both
resident IWP aggregators (typically brown surgeonfi sh, striated surgeonfi sh, bullethead parrotfi sh) and non-aggregating fi shes with spawning occurring on daytime
falling tides, often in a sequence (Robertson 1983 , PLC unpublished data). In the TWA,
several examples of RA multi-species use are known, including for the redfi n
parrotfi sh, Sparisoma rubripinne and spotted goatfi sh, Pseudupeneus maculatus,
(US Virgin Islands – Randall and Randall 1963 ; Colin and Clavijo 1978 ) and two
surgeonfi shes in Puerto Rico (Colin and Clavijo 1988 ) .
5.8.6 Predation on Spawning Adults and Eggs
Predation attempts by piscivores on spawning reef fi shes, including those forming
aggregations, appear to be uncommon, despite limited quantitative data. Chapter
2 details many of these (Table 2.1) and suggests that reports of attacks are more
common for RA than TA and more common in the IWP than TWA. In general
reports for tropical reefs indicate roughly one attack (often not successful) per