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Fishery Bulletin 108(3) 
and pelagic stingray), as well as sailfish, were alive 
upon retrieval. Among commercially important spe- 
cies, 49% of the bigeye tuna were alive upon retrieval, 
whereas only 3 of 79 albacore were alive. Swordfish 
survival was also low (20%) and no relationship was 
evident between fish size and mortality. Bigeye tuna 
and two shark species exhibited the highest survival 
when the longline was at a settled depth. Six species 
(represented by sample sizes >30 individuals) exhibited 
long survival times of up to 14 hours after capture 
(Table 4). 
Discussion 
Lunar illumination and sensory abilities 
of large pelagic fish 
At a broad scale, our results indicate that the phases of 
the moon, which presumably affect ambient light levels, 
have a significant but limited influence on the night 
catch rates of albacore and swordfish in the Reunion 
Island-based swordfish longline fishery, whereas such a 
lunar influence was not found for other species. We found 
that the highest swordfish CPUE occurred 
during the first and last quarters of the 
lunar cycle — a finding that is consistent 
with the results obtained for the same 
fishery in the Indian Ocean (Guyomard 
et ah, 2004). 
Other studies conducted in various geo- 
graphical areas with distinctive oceanic 
features, have indicated that lunar influ- 
ences on swordfish CPUE are not consist- 
ent. The highest swordfish CPUE occurred 
during the full moon phase in the Hawaii- 
based swordfish fishery (Bigelow et al., 
1999) and in the central Atlantic sword- 
fish fishery (Draganik and Cholyst, 1988). 
In the U.S. longline fishery in the west- 
ern Atlantic, more hooks were deployed 
in the 2-week period around full moon, 
but Podesta et ah (1993) could not dem- 
onstrate a significant correlation between 
CPUE and lunar illumination, whereas 
Hazin et ah (2002) and Damalas et ah 
(2007) showed positive effects of other lu- 
nar phases on swordfish CPUE. No sig- 
nificant relationship between lunar phase 
and swordfish abundance could be dem- 
onstrated in artisanal swordfish fisheries 
off the Cuban coast (Moreno et ah, 1991). 
In the case of a swordfish gillnet fishery 
operating in the Mediterranean Sea, Di 
Natale and Mangano (1995) showed that 
the lowest catch rate occurred during 
the full moon. Lastly, it is apparent that 
swordfish size and maturity may confound 
catch rates during different lunar phases 
(Draganik and Cholyst, 1988; Neves Dos 
Santos and Garcia, 2005). 
One possible explanation for the ab- 
sence of a consistent pattern in associa- 
tion with lunar phase could be attributed 
to prey availability. In the Atlantic Ocean, 
swordfish appear to exhibit feeding plas- 
ticity (i.e., are opportunistic feeders and 
exhibit various search strategies for prey) 
based on forage abundance and prey size; 
larger swordfish tend to eat larger prey 
than smaller swordfish (Chancollon et 
ah, 2006). In the Pacific Ocean, Young et 
ah (2006) showed no significant relation- 
