NOTE Witzell: Distribution and abundance of sea turtles caught in the western Atlantic Ocean 



207 



head sea turtles were sporadically captured through- 

 out the entire fishing area in the winter and spring 

 and became abundant during the summer and fall 

 in fishing areas 5-7 (Fig. 4). September was the most 

 productive month with a combined total of 330 

 (24.7%) loggerhead sea turtle catches. Reported 

 catches varied annually (Table 2). The mean curved 

 carapace length (nuchal notch to tip of marginal) and 

 weights of these captured sea turtles from the north 

 east distant area (7) were 55.9 cm (SD=6.5 cm, n=98) 

 and 22.1 kg (SD=11.1 kg, /)=72). These turtles were 

 smaller than coastal loggerheads from the northeast- 

 ern United States (Lutcavage and Musick, 1985). 



CPUE values indicated that loggerhead capture 

 rates varied between areas (Table 3) and were high- 

 est for the northeast distant area (7). CPUE analy- 

 sis indicated that the overall loggerhead sea turtle 

 capture rates with light sticks were higher than the 

 CPUE without light sticks (Table 3). Unlike leather- 

 back sea turtles, loggerhead sea turtles readily con- 

 sumed baited hooks. The fate of such hooked turtles 

 is unknown, but they have been observed trailing 

 multiple gangions; therefore some turtles previously 

 hooked have remained actively feeding in the area. 



Pelagic longline data indicate that loggerhead 

 turtle distribution extends from coastal waters to the 

 edge of the continental shelf from Cape Hatteras, 

 North Carolina, to Georges Bank and the Grand 



Banks in the summer and fall months and also ex- 

 tends into deep waters off the shelf These turtles 

 are apparently able to move out of critically cold win- 

 ter slope water to more hospitable southern waters. 

 NMFS tagging data revealed that turtles hooked on 

 their flippers were tagged in the spring in areas 6 

 and 7 and recovered in warmer winter waters in ar- 

 eas 4 and 2, respectively (NMFS'^). 



Conclusions 



It is not surprising that pelagic longline fisheries 

 incidentally catch turtles because fishing effort is 

 concentrated either near the 200-m isobath or near 

 interactions between major current systems. In these 

 areas a variety of potential prey species (various nek- 

 tonic organisms associated with Sargassum, as well 

 as cephalopods, coelenterates, and schooling fish) 

 concentrate and consequently attract tunas, sword- 

 fish, and sharks (Laurs et al., 1984; Maul et al., 1984; 

 Kurowicki, 1987; Fiedler and Bernard, 1987; Podesta 

 et al., 1993; Lutcavage, 1996). Aerial survey data off 

 the eastern United States (Shoop and Kenney, 1992) 

 and pelagic longline data presented here indicate that 



■^ NMFS Cooperative Marine Turtle Tagging Program, Miami 

 Laboratory, 75 Virginia Beach Drive. Miami, PL 33149. 



