487
12 Species Case Studies
luxury seafood status, consumers continue to seek it even when prices increase as
supplies decrease (YSM personal observation 2006).
For effective management more information is needed but a number of protective
measures are applicable. Since the humphead wrasse spawns at widely dispersed
sites in relatively small groups over much, if not all, of the year, closure of specifi c
sites, unless they are the only natural or the last remaining aggregation site, would
not be effective to protect the local population. Sites outside the closure area would
receive even more pressure and most could be overfi shed. There could be a seasonal
closure (or opening), but this would make little biological sense unless there was a
specifi c seasonality of aggregation and spawning. Ideally, large marine protected
areas could encompass a number of aggregation sites to ensure persistence of
spawning stock and activity. Management anywhere the species is exploited beyond
subsistence levels will almost certainly require size limits (upper and lower) to
ensure persistence of males and that juveniles survive to reproductive age. Annual
quotas could be applied (for methodology see Sadovy et al. 2007 ) , however, monitoring and management for effective implementation of such regulations is unlikely
to be fi nancially viable for such a limited fi shery.
Since the species is now partially protected due to the Appendix II CITES listing
which requires a sustainable management plan to be in place before exports are
permitted, efforts should be focused on stopping illegal trade, which is considerable
(YSM unpublished data; www.humpheadwrasse.info CITES page). There is also a
need to document recovery of populations in areas where fi shing has stopped. Other
threats that remain include spearfi shing at night, when fi sh are in their sleeping
holes, particularly using SCUBA gear. Many countries do not allow the species to
be exported and Malaysia and Indonesia have recently introduced annual export
quotas of zero and 5,400 fi sh (for 2010; down from 8,000 for the previous few
years). However, a recent review of the realities of sustainably managing this species, taking into account the costs of monitoring and enforcement concludes that
any exports are unlikely to be sustainable suggesting that the species is not suited to
the international export trade, in general, given its biology, the management necessary and the problems with successful enforcement of regulations (Gillett 2010 ) .
12.14 Bluehead Wrasse – Thalassoma bifasciatum
Robert R. Warner
University of California Santa Barbara , Santa Barbara, CA , USA
e-mail: warner@lifesci.ucsb.edu
12.14.1 General
Bluehead wrasse ( Thalassoma bifasciatum [Bloch, 1791]) is member of the
wrasse (Labridae) family. Bluehead wrasse live in relatively shallow water
over coral reefs and other hard-bottom substrates throughout the tropical
12 Species Case Studies
luxury seafood status, consumers continue to seek it even when prices increase as
supplies decrease (YSM personal observation 2006).
For effective management more information is needed but a number of protective
measures are applicable. Since the humphead wrasse spawns at widely dispersed
sites in relatively small groups over much, if not all, of the year, closure of specifi c
sites, unless they are the only natural or the last remaining aggregation site, would
not be effective to protect the local population. Sites outside the closure area would
receive even more pressure and most could be overfi shed. There could be a seasonal
closure (or opening), but this would make little biological sense unless there was a
specifi c seasonality of aggregation and spawning. Ideally, large marine protected
areas could encompass a number of aggregation sites to ensure persistence of
spawning stock and activity. Management anywhere the species is exploited beyond
subsistence levels will almost certainly require size limits (upper and lower) to
ensure persistence of males and that juveniles survive to reproductive age. Annual
quotas could be applied (for methodology see Sadovy et al. 2007 ) , however, monitoring and management for effective implementation of such regulations is unlikely
to be fi nancially viable for such a limited fi shery.
Since the species is now partially protected due to the Appendix II CITES listing
which requires a sustainable management plan to be in place before exports are
permitted, efforts should be focused on stopping illegal trade, which is considerable
(YSM unpublished data; www.humpheadwrasse.info CITES page). There is also a
need to document recovery of populations in areas where fi shing has stopped. Other
threats that remain include spearfi shing at night, when fi sh are in their sleeping
holes, particularly using SCUBA gear. Many countries do not allow the species to
be exported and Malaysia and Indonesia have recently introduced annual export
quotas of zero and 5,400 fi sh (for 2010; down from 8,000 for the previous few
years). However, a recent review of the realities of sustainably managing this species, taking into account the costs of monitoring and enforcement concludes that
any exports are unlikely to be sustainable suggesting that the species is not suited to
the international export trade, in general, given its biology, the management necessary and the problems with successful enforcement of regulations (Gillett 2010 ) .
12.14 Bluehead Wrasse – Thalassoma bifasciatum
Robert R. Warner
University of California Santa Barbara , Santa Barbara, CA , USA
e-mail: warner@lifesci.ucsb.edu
12.14.1 General
Bluehead wrasse ( Thalassoma bifasciatum [Bloch, 1791]) is member of the
wrasse (Labridae) family. Bluehead wrasse live in relatively shallow water
over coral reefs and other hard-bottom substrates throughout the tropical