Necropsy ﬁndings in sea turtles taken as bycatch in the North Paciﬁc longline ﬁshery
Thierry M. Work
Hawaii Field Station
National Wildlife Health Center
U.S. Geological Survey
300 Ala Moana Blvd., Room 5-231
Honolulu, Hawaii 96850.
E-mail address: email@example.com
George H. Balazs
Southwest Fisheries Science Center
National Marine FisheriesService, NOAA
2570 Dole St.
Honolulu, Hawaii 96822.
Concern about interactions between turtles caught in longline ﬁsheries are
ﬁsheries and marine turtles has in- released alive (McCracken1; Kleiber2).
creased in recent years, particularly The few dead turtles that area recov
since East Paciﬁc leatherback turtles ered can be returned to shore legally
(Dermochelys coriacea) maybecome only by observers (who are present in
extinct (Spotila et al., 2000). However, only ~5% of the Hawaii-based North
relatively little published information Paciﬁc ﬁshing ﬂeet) (Balazs et al.,
exists on interactions between sea 1995). Nevertheless, examining freshly
turtles and North Paciﬁc longline ﬁsh- dead turtles caught in longline ﬁsher
eries. The most available literature onies provides a unique opportunity to
the topic focuses on modeling data from gain insight into the health status and
ﬁsheries observers for estimating the diet of pelagic sea turtles. Our objec
probability of animals dying and ﬁsh- tive was to systematically evaluate all
ery-induced mortality (McCracken1; available carcasses of fresh-frozen sea
Kleiber2). A more recent study wasturtles that had been caught in the
undertaken with satellite telemetry Hawaii-based longline ﬁshery for an
and remote sensing to evaluate the evaluation of their health and to docu
probability of interaction between ment their diet.
1 McCracken, M. L. 2000. Estimation of longline ﬁsheries and loggerhead
sea turtle take and mortality in the Ha sea turtles (Caretta caretta) and thewaiian longline ﬁsheries. Administra effects of hooking (Polovina et al., Methods
tive Report H-00-06, 29 p. Southwest 2000; Parker, in press).
Fisheries Science Center, Nat. Mar. Fish. Necropsies on turtles caught by Free-ranging marine turtles acciden
Service, NOAA, 2570 Dole St., Honolulu, longline ﬁsheries may provide ad- tally taken as bycatch by the North
HI 96822. ditionalobjective data on the causes Paciﬁc longline ﬁshery were landed
2 Kleiber, P. 1998. Estimating annual takes of mortality and the health of pelagic on the ﬁshing vessel and evaluated
and kills of sea turtles by the Hawaiian longline ﬁshery, 1991–97, from observer turtles. Although ample literature ex- for signs of life by ﬁshery observers
program and logbook data. Administra ists on evaluatingthe health of benthic employed by the National Marine
tive Report H-98-08, 21 p. Southwest coastal-residing immature sea turtles Fisheries Service. Sea turtles that
Fisheries Science Center, Nat. Mar. Fish. Serv., NOAA, 2570 Dole St., Honolulu, HI in Hawaiian waters (Aguirre et al., were judged to be dead by speciﬁc cri-
96822. 1994; Work and Balazs, 1999), noth- teria (Balazs et al., 1995)were stored
ing is known about the health status frozen and returned to Honolulu,
of pelagic sea turtles because of the Hawaii, where we recorded weight (kg)
difﬁculty in locating animals (Bolten and body morphometrics (cm).
and Balazs, 1983) and the unavailabilGross necropsies entailed a complete
Manuscript accepted 28 May 2002. ity of specimens for diagnosis. Most external andinternal exam of all organ
Fish. Bull. 100:876–880 (2002).
systems. We also recorded any identiﬁ able stomach contents. Body condition of turtles was subjectively classiﬁed as good, fair or poor if coelomic and mesen teric fat reserves appeared ample, mod erate, or sparse, respectively. Postmor tem condition was classiﬁed as good, fair, or poor depending on the gross ap pearance of organs...