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Fishery Bulletin 104(3) 



with one healed ocular cavity (D. W. Ker- 

 stetter, personal observ. ). 



We observed a high percentage of 

 hooked white marlin with associated eye 

 damage, specifically in conjunction with 

 circle hooks. In contrast, Horodysky and 

 Graves (2005) noted only one animal out 

 of 40 hooked through the eye with a circle 

 hook. The difference between studies may 

 be a factor of the hook sizes used in the 

 fisheries; the recreational fishery gener- 

 ally uses much smaller circle hooks than 

 the commercial pelagic longline fishery 

 (7/0 and 9/0 sizes versus 16/0 and 18/0). 

 Jolley^ observed that for 134 (15.8%) of 

 848 sailfish caught recreationally with 

 J-style hooks, the barbs exited near the 

 eyes, noting that the distal lateral regions 

 of the istiophorid mouth roof (those areas 

 underlying the eyes) are thinly-covered 

 muscle tissue rather than bone. A hook 

 would therefore presumably pass much 

 more easily through this tissue to the 

 eye than if it encountered the lower jaw. 

 Prince et al. (2002b) considered hooking 

 through the upper palate potentially le- 

 thal, not only because of the opportunity 

 for the hook to penetrate the occipital or- 

 bit, but also because of the tendency for 

 J-style hooks in that location to compro- 

 mise the integrity of the cranium, making 

 it more susceptible to infection. Two tags 

 that did not transmit data in our study 

 were attached to fish caught with J-style hooks in the 

 center of the upper palate. Borucinska et al. (2002) 

 noted that for blue sharks iPrionace glauca) wounded 

 by fishing hooks, an injury caused by a perforating hook 

 may lead to systemic debilitation over longer time inter- 

 vals than that typically measured with PSAT tags. 



The postrelease mortality rates obtained for white 

 marlin from Horodysky and Graves (2005) and this 

 study also allowed the estimation of total U.S. fishing 

 mortality for this species. For the U.S. directed recre- 

 ational fishery, the white marlin postrelease mortality 

 rate (35% for J-style hooks; Horodysky and Graves, 

 2005) was applied to estimated yearly catch data and 

 added to "best estimates" of the U.S. recreational land- 

 ings (Goodyear and Prince, 2003). For the pelagic long- 

 line fishery, catch and condition at release data were 

 obtained from the NMFS Pelagic Observer Program 

 database (Lee''). The 55.6% postrelease mortality rate 

 (J-style hooks, nontransmitting tags as mortalities; 

 present study) was applied to the number of white mar- 

 lin released alive to obtain an estimate of the number 

 of fish that died following release. Average underesti- 



n Recreational landings 



 Pelagic longline dead discards 



D Estimated recreational 

 postrelease mortality (35%) 



B Estimated pelagic longine 

 postrelease mortality (55 6° 



Figure 2 



Calculated white marlin (Tetrapturiis albidus) fishing mortality esti- 

 mates in metric tons (tl for the recreational and pelagic longline fisheries 

 of the United States. The bottom part of each bar represents the reported 

 mortality in each fishery (recreational landings and commercial dead 

 discards, respectively), while the top part of the bar represents the 

 possible additional fishing mortality based on conservative assumptions 

 of 359r postrelease mortality with J-style hooks for the recreational 

 fishery (Horodysky and Graves, 2005) and 55.6% postrelease mortality 

 with J-style hooks in the commercial pelagic longline fishery (present 

 study). The solid line is the three-year running average for estimated 

 total recreational mortality (reported and estimated postrelease mor- 

 tality), and the dashed line is the estimated total commercial pelagic 

 longline mortality. 



Lee, D. 2004. Personal commun. NOAA/NMFS Southeast 

 Fisheries Science Center, 75 Virginia Beach Dr., Miami, FL 

 33149. 



mates of the actual white marlin fishing mortality to 

 recreational fishery reported landings or to commercial 

 fishery dead discards during this ten-year period were 

 88.6% and 61.6%, respectively. 



Our analysis indicates that the directed U.S. rec- 

 reational fishery may generate higher levels of white 

 marlin fishing mortality than the U.S pelagic long- 

 line fishery in some years simply due to greater num- 

 bers of animals caught (Fig. 2). Because we chose the 

 postrelease mortality estimates based on the historic 

 terminal gear choices of J-style hooks, these results 

 do not account for the probable decrease in total white 

 marlin postrelease mortality resulting from mandated 

 (pelagic longline) and voluntary (recreational) changes 

 in the U.S. fisheries from J-style hooks to circle hooks. 

 However, even this estimated magnitude of actual mor- 

 tality incurred as the result of the U.S. recreational or 

 pelagic longline fisheries results in the international 

 pelagic longline fishery remaining the largest source 

 of total white marlin fishing mortality in the Atlantic 

 (ICCAT, 2005). 



The results of this study clearly demonstrate that 

 white marlin are capable of surviving the trauma as- 

 sociated with capture by pelagic longline fishing gear. 

 Short-term survival of released white marlin was rela- 

 tively high whether one discounted nontransmitting 

 tags (89.5% survival) or considered nontransmitting 



