808 



Fishery Bulletin 90(4). 1992 



January 1991 starting at lat. 27°01.720'N, long. 

 168°56.153'W, in the vicinity of an unnamed seamount 

 some 940 km east of Midway Is. and 150 km north- 

 northeast of Raita Bank, Northwestern Hawaiian Is. 

 The gear was hauled on 25 January beginning at lat. 

 26°59.094'N, long. 168°57.810'W. The turtle was 

 taken on the first hook of a 3-hook basket located about 

 mid-set. This hook was set at 1818h and hauled at 

 0907 h the next day, for a soak time of 14 h 49 min. 

 Because the hook timer (a 7.5x3 cm cylinder of clear 

 plastic resin with an embedded clock chip; Somerton 

 et al. 1988) on that line was lost, an estimate of the 

 time of hooking is not available. The hook timer on the 

 second hook-line, with full bait remaining, was set off 

 at 051 Ih; the hook timer on the first hook of the 

 previous basket, with the bait missing, was set off at 

 0159 h. The float lines, made of polypropylene rope, 

 were 9m long. The hook droppers, made of 2.1mm 

 monofilament, were 13 m long with a 60g weighted 

 swivel 4 m from the hook. Thus, the depth of hook 1 

 was nominally ~22m, unless altered by currents, since 

 the first hook-line of each basket was attached within 

 3 m of the float. Green, 12 h chemical light sticks were 

 placed ~2m above each of the 206 hooks (the light 

 sticks still glowed weakly at the time of hauling). Each 

 hook was baited with a whole, previously-frozen Argen- 

 tinean squid {Illex sp.), weighing ~0.34kg. 



While entanglement of leatherbacks in pelagic long- 

 line and other gears has been described, ours is ap- 

 parently the first report of a hook and bait being eaten. 

 Chemical light sticks used on swordfish longline may 

 impose an added hazard for leatherbacks by simulating 

 natural prey. The magnitude of the take, the level of 

 mortality or serious injury, and the impact on the 

 leatherback stock are unknown. Additional data on the 

 take by pelagic fisheries as well as information on 

 leatherback feeding habits, stock structure, and popula- 

 tion dynamics would be needed to evaluate the impact 

 of the take. 



Citations 



Bacon, P.R. 



1970 Studies on the leatherback turtle Dermochelys coriacea 

 (L.), in Trinidad, West Indies. Biol. Conserv. 2:213-217. 

 Balazs, G.H. 



1982 Driftnets catch leatherback turtles. Oryx 16:428-430. 



1985 Impact of ocean debris on marine turtles: Entanglement 

 and ingestion. In Shomura. R.S., and H.O. Yoshida (eds.), 

 Proceedings, Workshop on the fate and impact of marine 

 debris, 27-29 November 1984, Honolulu, p. 387-429. NCAA 

 Tech. Memo. NMFS-SWFC-54, NMFS Honolulu Lab. 



Bleakney, J.S. 



1965 Reports of marine turtles from New England and eastern 

 Canada. Can. Field-Nat. 19:120-128. 

 Brongersma, L.D. 



1969 Miscellaneous notes on turtles, IIB. Proceedings, K. 

 Ned. Akad. Wet. Ser. C. Biol. Med. Sci. 72:90-102. 

 Davenport, J. 



1988 Do diving leatherbacks pursue glowing jelly? Br. 

 Herpetol. Soc. Bull. 24:20-21. 

 Davenport, J., and G.H. Balazs 



1991 'Fiery bodies'— Are pyrosomas an important component 

 of the diet of leatherback turtles? Br. Herpetol. Soc. Bull. 

 37:33-38. 

 Dollar, Robert A. 



1991 Summary of swordfish longline observations in Hawaii, 

 July 1990-March 1991. Admin. Rep. H-91-09, NMFS Hono- 

 lulu Lab.. 13 p. 

 Eckert, K.L.. and C. Luginbuhl 



1988 Death of a giant. Mar. Turtle Newsl. 43:2-3. 

 Eckert, S.A., D.W. Nellis, K.L. Eckert, and G.L. Kooyman 

 1986 Diving patterns of two leatherback sea turtles {Dermo- 

 chelys coriacea) during internesting intervals at Sandy Point, 

 St. Croix, U.S. Virgin Islands. Herpetologica 42(3):3'81-388. 

 Frazier, J.G., and J.L. Brito Montero 



1990 Incidental capture of marine turtles by the swordfish 

 fishery at San Antonio, Chile. Mar. Turtle Newsl. 49:8-13. 

 Honolulu Star-Bulletin 



1935 [Photograph with a caption indicating a 200 kg leather- 

 back turtle was found entangled in the line and hooks of a sam- 

 pan, a Japanese-style fishing boat probably using longline 

 gear.] Honolulu Star-Bulletin, 8 April 1935, p. 3. 

 Lazell, J.D. Jr. 



1976 This broken archipelago. Cape Cod and the islands, am- 

 phibians and reptiles. Demeter Press Book, Grafelfing, Ger- 

 many, p. 191. 

 Margaritoulis, D.N. 



1986 Captures and strandings of the leatherback sea turtle, 

 Dermochelys coriacea, in Greece (1982-1984). J. Herpetol. 

 20(3):471-474. 

 Nishemura, W.. and S. Nakahigashi 



1990 Incidental capture of sea turtles by Japanese research 

 and training vessels: Results of a questionnaire. Mar. Turtle 

 Newsl. 51:1-4. 



Somerton, D.A., B.S. Kikkawa. and CD. Wilson 



1988 Hook timers to measure the capture of individual 

 fish. Mar. Fish. Rev. 50(2): 1-5. 

 Tobias, W. 



1991 Incidental catch a continuing problem in the Mediterra- 

 nean. Mar. Turtle Newsl. 51:10-12. 



USFWS (U.S. Fish & Wildlife Service) 



1969 Cruise report, USFWS ship Townsend Cromwell, cruise 

 44. USFWS Hawaii Area Biol. Lab., 4 p. [Avail. NMFS 

 Honolulu Lab.] 

 Wetherall, J. A.. G.H. Balazs. R.A. Tokunaga. and M.Y.Y.Yong 

 In press Bycatch of marine turtles in North Pacific high-seas 

 driftnet fisheries and impacts on the stocks. In Proc, Int. 

 North Pac. Fish. Comm., Nov. 4-6, 1991, Tokyo. 

 Witzell. W.N. 



1984 The incidental capture of sea turtles in the Atlantic U.S. 

 Fi.shery Conservation Zone by the Japanese tuna longline fleet, 

 1978-81. Mar. Fish. Rev. 46(3):56-58. 



