437
12 Species Case Studies
fi shes. This assessment was echoed by the American Fisheries Society (Coleman
et al . 2000 ) , which, in addition, advocated that no-take zones be accompanied by a
reduction in total allowable catch to reduce the shift of fi shing effort from these
areas to adjacent ones.
Especially worrisome for the recovery of the species is the fact that (1) the
number of aggregations has declined (Sadovy de Mitcheson et al. 2008 ) , (2) traditional spawning aggregations appear not to return, such as in the US Virgin Islands
(Beets and Friedlander 1992 ) , although there are indications of increased numbers
at one site (Rick Nemeth, personal communication 2007), and (3) Nassau grouper
numbers in extant spawning aggregations have also declined (Sadovy and Eklund
1999 ) . In Belize, for example, one of the last viable Nassau grouper spawning
aggregations decreased from 15,000 to fewer than 3,000 individuals (a decline of
over 80%) in the 25 years leading up to 2001 (Sala et al. 2001 ) .
To address the problem of overfi shing of Nassau grouper, at least six measures
should be considered: (1) prevent over-fi shing of spawning aggregations – overfi shing is a major factor in decline of the species; the most practical measure to reduce
overexploitation is to not fi sh aggregations; (2) protect sub-adult fi sh from capture – a
minimum size limit for Nassau grouper should be established at or above the size of
sexual maturation. This measure is in place in a number of countries (Bahamas,
Cuba, Belize, etc.) although enforcement is typically lacking; (3) protect remnant
populations from fi shing – this is necessary in locations where Nassau grouper populations are reduced to the point where there is no evidence of reproductive activity, or
where there may be refuges for spawning stock, or important life history areas, (4)
improve compliance with fi shery restrictions – enforcement of fi shery closures and
other existing controls on capture of Nassau grouper is needed. This includes addressing problems of illegal, unmonitored and unregulated trade in The Bahamas, and
elsewhere; (5) implement regional management strategies – given the possibly panmictic nature of the species and its extensive seasonal migrations, regional management is needed. The SPAW (Specially Protected Areas and Wildlife) protocol might
be applicable; (6) Decide on the best use of Nassau within countries – decisions may
be needed in countries with remaining viable populations of Nassau grouper as to
whether this species should be retained for local trade and food security, be part of a
signifi cant export trade, or conserved for tourism and reef health. It is very likely that
the most productive management approach in any situation is to protect spawning
aggregations for reproduction, without allowing any fi shing; the eggs and larvae produced can maintain the fi shery at other times of the year.
Finally, an ecosystem approach, based on expanding the network of marine protected areas (MPAs) throughout the Caribbean and addressing key aspects of the
species and the assemblage of which it forms a part will be key to its long-term
persistence as a viable fi shery, as a dive-tourism draw, and as a member of the reef
ecosystem in which it lives. For example, since Nassau grouper are often captured
as part of a multi-species snapper/grouper fi shery, and since returning undersize fi sh
is often not acceptable to fi shers, no-take zones prevent individuals from being taken
as unwanted bycatch, as well as provide a haven from spearfi shing. Given that
Nassau grouper make ontogenetic habitat shifts from nearshore to deeper reef areas,
12 Species Case Studies
fi shes. This assessment was echoed by the American Fisheries Society (Coleman
et al . 2000 ) , which, in addition, advocated that no-take zones be accompanied by a
reduction in total allowable catch to reduce the shift of fi shing effort from these
areas to adjacent ones.
Especially worrisome for the recovery of the species is the fact that (1) the
number of aggregations has declined (Sadovy de Mitcheson et al. 2008 ) , (2) traditional spawning aggregations appear not to return, such as in the US Virgin Islands
(Beets and Friedlander 1992 ) , although there are indications of increased numbers
at one site (Rick Nemeth, personal communication 2007), and (3) Nassau grouper
numbers in extant spawning aggregations have also declined (Sadovy and Eklund
1999 ) . In Belize, for example, one of the last viable Nassau grouper spawning
aggregations decreased from 15,000 to fewer than 3,000 individuals (a decline of
over 80%) in the 25 years leading up to 2001 (Sala et al. 2001 ) .
To address the problem of overfi shing of Nassau grouper, at least six measures
should be considered: (1) prevent over-fi shing of spawning aggregations – overfi shing is a major factor in decline of the species; the most practical measure to reduce
overexploitation is to not fi sh aggregations; (2) protect sub-adult fi sh from capture – a
minimum size limit for Nassau grouper should be established at or above the size of
sexual maturation. This measure is in place in a number of countries (Bahamas,
Cuba, Belize, etc.) although enforcement is typically lacking; (3) protect remnant
populations from fi shing – this is necessary in locations where Nassau grouper populations are reduced to the point where there is no evidence of reproductive activity, or
where there may be refuges for spawning stock, or important life history areas, (4)
improve compliance with fi shery restrictions – enforcement of fi shery closures and
other existing controls on capture of Nassau grouper is needed. This includes addressing problems of illegal, unmonitored and unregulated trade in The Bahamas, and
elsewhere; (5) implement regional management strategies – given the possibly panmictic nature of the species and its extensive seasonal migrations, regional management is needed. The SPAW (Specially Protected Areas and Wildlife) protocol might
be applicable; (6) Decide on the best use of Nassau within countries – decisions may
be needed in countries with remaining viable populations of Nassau grouper as to
whether this species should be retained for local trade and food security, be part of a
signifi cant export trade, or conserved for tourism and reef health. It is very likely that
the most productive management approach in any situation is to protect spawning
aggregations for reproduction, without allowing any fi shing; the eggs and larvae produced can maintain the fi shery at other times of the year.
Finally, an ecosystem approach, based on expanding the network of marine protected areas (MPAs) throughout the Caribbean and addressing key aspects of the
species and the assemblage of which it forms a part will be key to its long-term
persistence as a viable fi shery, as a dive-tourism draw, and as a member of the reef
ecosystem in which it lives. For example, since Nassau grouper are often captured
as part of a multi-species snapper/grouper fi shery, and since returning undersize fi sh
is often not acceptable to fi shers, no-take zones prevent individuals from being taken
as unwanted bycatch, as well as provide a haven from spearfi shing. Given that
Nassau grouper make ontogenetic habitat shifts from nearshore to deeper reef areas,