Burke et al.: Diet of Lepidochelys kempii 



29 



and its first appearance in the feces was determined. 



All fecal samples collected for dietary analysis 

 were immediately placed in preservative. For fecal 

 samples obtained during 1989, animal components 

 were preserved as described by Zinn ( 1984) and al- 

 gae were preserved in Transeau's solution ( 10 parts 

 formalin/30 parts ethanol/60 parts distilled H. 2 0/25 

 mg CuS0 4 /L). Feces obtained prior to 1989 were pre- 

 served in 10% formalin. 



Analysis of the fecal samples was conducted in 

 January 1990, after all the samples were collected. 

 The samples were removed from the preservative 

 and air dried for 24 hours on wire mesh in an en- 

 closed hood. The samples were then placed in a U.S. 

 standard number-5 mesh (4 mm) sieve and pieces 

 smaller than 4 mm were separated out by shaking 

 the sample in a Tyler RO-TAP testing sieve shaker 

 for three minutes. Pieces smaller than 4 mm were 

 not identified because of the difficulty of assigning 

 them to a meaningful category. The amount of 

 sample lost because of this constraint was never 

 greater than 5% for any given sample. 



Each fecal sample was examined under a dissect- 

 ing microscope and each fragment of the sample was 

 identified to the lowest taxon possible. Fragments 

 belonging to the same taxonomic level were grouped. 

 A list of components (e.g., one species of crab is one 

 component) was compiled for each sample and the 

 data were analyzed to determine the percentage of 

 turtles in which each component occurred. Less than 

 1% of the fragments could not be assigned to a taxo- 

 nomic category. 



For the 1989 samples only, the relative amount of 

 each dietary component was determined by oven 

 drying each component from each sample for 48 

 hours at 60°C and weighing it. The dry weights were 

 then used to determine the relative importance of 

 the different dietary components in each turtle's 

 fecal sample. Dry weight analysis was conducted by 

 finding the percentage of each sample weight rep- 

 resented by each component and then determining 

 the mean for that component. This technique of 

 analyzing dry weights as a percentage eliminated 

 over- or under-representation of large or small fe- 

 cal samples. 



A second method of determining dietary compo- 

 nents was analysis of gastrointestinal contents from 

 stranded, dead turtles. Stranded Kemp's ridleys died 

 from a number of causes: cold-stunning, boat colli- 

 sions, entanglement in a gill net, and natural and 

 unknown causes. Whenever possible, each stranded 

 turtle was weighed, measured (straight-line cara- 

 pace length) and dissected. Following removal, in- 

 testinal contents were placed in 95% ethanol (1985), 

 10% formalin (1986-1988), or treated in the same 



manner as the fecal samples (1989). Identification 

 of intestinal tract contents was performed during 

 1990. All components of each sample were identified 

 to the lowest taxon possible, generally to species. 

 These data were used to determine the percentage 

 of turtles in which the components occurred. 



Results 



The food passage rate analysis indicated that lob- 

 ster was retained within the digestive tracts of the 

 two Kemp's ridleys for seven and eight days. Be- 

 cause fecal samples were obtained within 48 hours 

 of receiving a turtle from a fisherman, we believe 

 the possibility of samples having been "contami- 

 nated" by items eaten while the turtles were in the 

 fishermen's nets is minimal. 



Mean straight-line carapace length for the 19 

 turtles in the fecal analysis study was 32.3 cm 

 (range=24.7 to 42.7 cm, SD=4.87). Eighteen of the 

 19 turtles consumed crabs (Fig. 2). Mollusc species 

 were found in 26% of the fecal samples and algae 

 were found in 11%> of the Kemp's ridley feces. Natu- 

 ral and synthetic debris were present in 21% and 

 11% of the feces respectively. 



Crab species that were identified included nine- 

 spined spider crabs, Atlantic rock crabs, and lady 

 crabs (Ovalipes ocellatus). Further examination of 

 only the crab portion of the feces revealed that 58% 

 of the turtles had consumed spider crabs, 36% had 

 eaten rock crabs, and 16% had consumed lady crabs. 



100 



60 



w 40 

 O 



CRAB MOLLUSK ALGAE NATURAL SYNTHETIC 



DEBRIS DEBRIS 



Figure 2 



Percent occurrence of various prey items identified 

 in the feces of 19 Kemp's ridley sea turtles 

 (Lepidochelys kempii) that were live-captured in 

 Long Island waters. Each bar indicates the percent 

 of turtles in which the prey items occurred. 



