210 



Fishery Bulletin 97(1), 1999 



leatherback and loggerhead sea turtles use the en- 

 tire continental shelf, as well as the thermally dy- 

 namic waters off the continental edge. 



The northeast distant fishing area (7) is particu- 

 larly productive. The circulation and thermodynam- 

 ics of fishing area 7 are very complex and provide a 

 unique pelagic habitat. The Gulf Stream begins to 

 meander northeastward off Cape Hatteras, and the 

 western edge of the Gulf Stream eventually passes 

 south of the Grand Banks as it turns eastward to- 

 ward Europe. The thermodynamics of north Atlan- 

 tic circulatory process near the Grand Banks is com- 

 plicated (Schmitz and McCartney, 1993), and it is 

 this interaction of cold slope water and warm Gulf 

 Stream water that is productive for large pelagic fish 

 and sea turtles. Moreover, the Gulf Stream spins off 

 warm-core rings on the cooler northeastern slope 

 water (Auer, 1987), where pelagic longline fishing is 

 heaviest. These warm-core rings have been well stud- 

 ied, resulting in a plethora of published literature 

 (Wiebe and McDougall, 1986). Unfortunately, these 

 biological studies have concentrated on planktonic 

 productivity and mesopelagic fishes rather than on 

 larger pelagic apex predators; however, these rings 

 affect the distribution and abundance of large pe- 

 lagic fish, marine mammals, and sea turtles. 



Fishery managers and sea turtle researchers need 

 to develop conservation strategies that mitigate sea 

 turtle and longline interactions. The high numbers 

 of potentially lethal loggerhead sea turtle captures 

 in the northeast distant area (7) during the summer 

 and fall swordfish fishery particularly need to be 

 addressed by fishery managers. 



Acknowledgments 



I thank J. Cramer, for providing turtle data and back- 

 ground information on the U.S. longline fleet and the 

 NMFS pelagic logbook database, and H. Huang, for 

 providing the tables and graphics. The manuscript 

 was improved by comments fi-om D. Lee, M. Lutcavage, 

 W. Richards, and two anonymous reviewers. 



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