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Fishery Bulletin 100(3) 



Table 1 



Haplotype distribution among loggerhead sea turtle nesting groups compiled by Encalada et al. (1998). Haplotypes K and M were 

 identified previously in the Madeira and Azores foraging assemblages (Bolten et al., 1998). Haplotype N was identified previously 

 in a sample of stranded individuals from the Atlantic U.S. coast (Rankin-Baransky et al., 2001 ). 



Haplotype 



NWFL 



A 



B 



C 



D 



E 



F 



G 



H 



1 



J 



K 



M 



N 



34 



4 

 2 



SFL 



NEFL-NC 



22 



24 



2 



1 



1 



104 

 1 



Mexico 



11 

 2 



Greece 



Brazil 



St. Lucie, Florida 



19 



11 



40 



45 



7 



11 



by Amos and Hoelzel ( 1991). Samples were transferred to 

 the University of Florida for analysis. Standard phenol 

 and chloroform DNA isolation protocols were conducted 

 on the tissue samples (Hillis et al, 1996). A 380-bp frag- 

 ment of the mitochondrial DNA control region was ampli- 

 fied using primers 



TCR5 (5'-TTGTACATCTACTTAATTACCAC-3'), and 

 HDCM2 (5-GCAAGTAAAACTACCGTATGCCAGGTTA-3') 



designed for sea turtles (Encalada et al, 1996; Norman et 

 al., 1994). Cycling parameters were as follows: 94°C 1 min, 

 25 cycles of (94°C/45s -t- 52°C/30s + 72°C/4.5s) and 3-min 

 extension at 72°C. 



Individuals were compared to known loggerhead sea 

 turtle haplotypes and assigned a letter designation based 

 on Encalada et al. (1998) and Bolten et al. (1998). To test 

 for statistical differences among haplotype frequencies at 

 rookeries and the foraging location, chi-square analyses 

 were performed with the program CHIRXC (Zaykin and Pu- 

 dovkin, 1993) and probabilities were generated with a Monte 

 Carlo randomization procedure (Roff and Bentzen, 1989). 



Maximum likelihood (ML) analysis for mixed stock 

 identification (Grant et al., 1980) was used to estimate 

 the contributions of nesting populations to the foraging 

 habitat adjacent to the St. Lucie Power Plant on Hutchin- 

 son Island. This method estimates the most likely con- 

 tributions of source populations based on the haplotype 

 frequencies in the source populations and in the mixed 

 population. The source populations and frequencies of 

 associated haplotypes used in the analysis were those of 

 Encalada et al. (1998). It should be noted that the addition 

 of new nesting population data could change the results 

 presented in our study. The addition of new nesting data 

 will always be a problem when conducting these types of 



analyses but should not preclude the use of this technique 

 to determine potential contributors to a foraging popula- 

 tion. The maximum likelihood program GIRLSEM was 

 used (Masuda et al., 1991). As a starting point in ML 

 iterations with GIRLSEM, it was assumed that all source 

 populations had an equal probability of contributing (i.e. 

 population size, distance from the foraging location, etc. 

 did not have an impact on the percentage of animals re- 

 cruiting to a particular area). Standard errors and 95% 

 confidence intervals of the point estimates were generated 

 from 100 bootstraps of the stock and mixture data sets 

 with GIRLSEM (Pella et al., 1998). 



Results 



Mitochondrial DNA analysis 



Of the 109 tissue samples collected, 106 produced read- 

 able sequences (Table 1). Eighty five of the samples con- 

 sisted of the most common haplotypes A and B. Haplotype 

 C, another haplotype found in multiple rookeries at low 

 frequency, was found in seven individuals. One indi- 

 vidual was characterized by haplotype G, known only in 

 the northwest Florida (NWFL) and south Florida (SFL) 

 source populations. Two haplotypes "endemic" to Mexico 

 (Yucatan), I and J, were found in six of the individuals 

 sampled. The remaining seven individuals possessed hap- 

 lotypes (K, M, and N) observed previously, but only from 

 surveys of foraging or stranded individuals. 



The haplotype frequencies of the foraging juveniles 

 were significantly different from all nesting loggerhead 

 sea turtle populations except for the SFL nesting popula- 

 tion (x^=9-51,P=0. 40). Although the haplotype frequencies 

 were similar to that of the SFL nesting population, the 

 presence of haplotypes not associated with the SFL popu- 



