30 



Fishery Bulletin 92(1). 1994 



a. 

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CRAB MOLLUSK ALGAE NATURAL SYNTHETIC 



DEBRIS DEBRIS 



Figure 3 



Mean percent of the fecal dry weight of general 

 catergories of Kemp's ridley sea turtles 

 (Lepidochelys kempii) prey items. Each area repre- 

 sents the mean percent of dry weight for that com- 

 ponent of the feces (n=14). Crabs composed the pre- 

 dominant portion of the feces. 



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 \- 



z 



CRAB 



MOLLUSK 



NATURAL 

 DEBRIS 



Figure 4 



The percent of Kemp's ridley sea turtles 

 (Lepidochelys kempii) from the digestive tract analy- 

 sis that had consumed various types of ingesta. 

 Most of the turtles had consumed crabs. Synthet- 

 ics and algae were not present in the digestive 

 tracts. 



Included in three fecal samples were crab parts from 

 which the fragments could not be identified to genus. 



Mollusc species in the samples included blue 

 mussels (Mytilus edulis) and bay scallops 

 (Argopectin irradians). Two Kemp's ridley fecal 

 samples contained mollusc fragments that could not 

 be identified beyond phylum. Algal species in the 

 samples included Sargassum natans, Fucus sp., and 

 Ulua sp. A few turtles had small pieces of the mac- 

 rophyte Zostera marina as well. Natural debris in- 

 cluded such things as pebbles, small rocks, and bird 

 feathers. Synthetic debris included only small pieces 

 of polystyrene and latex. 



Analysis of fecal components with dry weights 

 (mean of percent per sample) revealed that crabs 

 were the predominant component of all but one of 

 the 14 fecal samples from 1989. The mean percent 

 of crab dry weight for the samples was 80% (Fig. 3). 

 The mean percent dry weight for each crab species 

 revealed that spider crabs composed 60% of the 

 identifiable crab parts. The remainder was com- 

 posed of 22% rock crabs and 18% lady crabs. Thus, 

 most of the Kemp's ridleys had consumed spider 

 crabs, which represented a large portion of the bulk. 

 Although more turtles consumed rock crabs than 

 lady crabs, Kemp's ridleys that consumed lady crabs 

 had feces composed exclusively of them. 



For the period 1985 througn 1989, 87 dead Kemp's 

 ridleys were recovered from Long Island's waters. 

 Gastrointestinal tracts were removed from 40 of the 



87 turtles. Eighteen of the 40 stranded Kemp's rid- 

 leys contained identifiable diet components in the 

 gut. All 18 turtles were juveniles. Mean straight-line 

 carapace length for the 18 stranded turtles was 30.5 

 cm (range=24.8 cm to 39.7 cm, SD=3.5 cm). Thirteen 

 of the 18 gastrointestinal tracks contained crab 

 parts and seven contained mollusc shells (Fig. 4). 



The most frequently encountered crabs in the gut 

 content samples were spider crabs and rock crabs. 

 Spider crab fragments were found in five of the 18 

 samples; rock crabs were found in four of the 18 

 samples. Lady crabs were found in two of the 

 samples and the blue crab (C. sapidus) was found 

 in the digestive tract of one Kemp's ridley. Two of 

 the turtles had crab parts in their digestive tracts 

 that could not be assigned reliably to any genus. 



An additional 14 of the 40 Kemp's ridleys that 

 were dissected had completely empty digestive 

 tracts. All of these turtles had stranded from cold- 

 stunning. Upon further review of necropsy data 

 sheets from all of the Kemp's ridleys that had 

 stranded during the study period, but from which 

 samples were not preserved, it was noted that al- 

 most all of the cold-stunned individuals had empty 

 or almost empty gastrointestinal tracts. 



The remaining eight turtles had been collected in 

 1985 and 1986, and gut contents were unidentifiable 

 because of improper preservation. These samples 

 had been preserved for as long as five years prior 

 to examination. 



