Appendix B. Life history pattern classification method.

Life history pattern classification method

Appendix A. Turtle and prey stable isotope analyses.

Turtle and prey stable isotope analyses

δ¹⁵N values (‰) of source and trophic amino acids in leatherback turtles known from satellite tracking to migrate to the western and eastern Pacific Ocean.

<p>*</p

Definitions of four models used to estimate the underlying isotopic signatures of the Eastern and Western Pacific Ocean and to assign each individual to one of the two foraging grounds.

<p>Definitions of four models used to estimate the underlying isotopic signatures of the Eastern and Western Pacific Ocean and to assign each individual to one of the two foraging grounds.</p

Summary of leatherback tissue sampling and δ¹³C and δ¹⁵N values for turtles nesting in Jamursba Medi, Papua Barat, Indonesia.

<p>Satellite tags were applied to 12 of 14 turtles sampled 2007 and one of four sampled in 2010.</p

Map of satellite-tracked post-nesting movements of 13 leatherback turtles from Jamursba-Medi, Papua Barat Province Indonesia, overlaid with stable nitrogen isotopic values for skin tissue of nesting females from the same population.

<p>Satellite-tracked turtles were studied in 2007 and 2010; non-tracked turtles (<i>n</i> = 65) were skin sampled in 2005–2007 and 2010. Blue and red track lines depict turtles within the ‘high δ¹⁵N’ and ‘low δ¹⁵N’ groups, respectively. Tracks with numbered termini depict movements of leatherbacks that were analysed for CSIA-AA (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037403#pone-0037403-t002" target="_blank">Table 2</a>).</p

Scatterplot of stable carbon vs. stable nitrogen values for 78 leatherback turtles sampled at the Jamursba-Medi nesting beach in Papua Barat Indonesia.

<p>Scatterplot of stable carbon vs. stable nitrogen values for 78 leatherback turtles sampled at the Jamursba-Medi nesting beach in Papua Barat Indonesia.</p

Leatherback turtle skin nitrogen stable isotopic compositions.

<p><b>a</b>, nitrogen isotopic composition of skin from leatherback turtles known to feed in the eastern and western Pacific; <b>b</b>, nitrogen isotopic composition of glutamic acid and phenylalanine in skin tissue from leatherback turtles feeding in the eastern and western Pacific; <b>c</b>, trophic position calculated using the isotopic compositions of glutamic acid and phenylalanine <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037403#pone.0037403-Faure1" target="_blank">[17]</a>, presented as a weighted average based on AA measurement error. Error bars represent weighted standard deviation of trophic position means; <i>n</i> = 3 each. While there was a significant difference in skin δ¹⁵N between eastern and western Pacific foragers (t-test: <i>p</i><0001), there was no significant difference in trophic position between these two groups (t-test: <i>p</i> = 0.682).</p

Marginal posterior distributions of δ¹⁵N values for the two assumed foraging grounds (bell-shaped curves) and individual assignments to one of the two foraging grounds (filled circles in horizontal arrangement) with color-coded probabilities of belonging to the eastern Pacific foraging area.

<p>Panel A is from Model 4, whereas the Panel B is from Model 6. For both models, posterior distributions depicted in red are from the ‘low δ¹⁵N’ (i.e. putative western Pacific foragers), whereas those in blue represent the ‘high δ¹⁵N’ group (i.e., putative eastern Pacific foragers).</p

First Assessment of the Sex Ratio for an East Pacific Green Sea Turtle Foraging Aggregation: Validation and Application of a Testosterone ELISA

<div><p>Determining sex ratios of endangered populations is important for wildlife management, particularly species subject to sex-specific threats or that exhibit temperature-dependent sex determination. Sea turtle sex is determined by incubation temperature and individuals lack external sex-based traits until sexual maturity. Previous research utilized serum/plasma testosterone radioimmunoassays (RIA) to determine sex in immature/juvenile sea turtles. However, there has been a growing application of enzyme-linked immunosorbent assay (ELISA) for wildlife endocrinology studies, but no study on sea turtles has compared the results of ELISA and RIA. This study provides the first sex ratio for a threatened East Pacific green sea turtle (<i>Chelonia mydas</i>) foraging aggregation, a critical step for future management of this species. Here, we validate a testosterone ELISA and compare results between RIA and ELISA of duplicate samples. The ELISA demonstrated excellent correspondence with the RIA for providing testosterone concentrations for sex determination. Neither assay proved reliable for predicting the sex of reproductively active females with increased testosterone production. We then applied ELISA to examine the sex ratio of 69 green turtles foraging in San Diego Bay, California. Of 45 immature turtles sampled, sex could not be determined for three turtles because testosterone concentrations fell between the ranges for either sex (females: 4.1–113.1 pg/mL, males: 198.4–2,613.0 pg/mL) and these turtles were not subsequently recaptured to enable sex determination; using a Bayesian model to predict probabilities of turtle sex we predicted all three ‘unknowns’ were female (> 0.86). Additionally, the model assigned all turtles with their correct sex (if determined at recapture) with 100% accuracy. Results indicated a female bias (2.83F:1M) among all turtles in the aggregation; when focusing only on putative immature turtles the sex ratio was 3.5F:1M. With appropriate validation, ELISA sexing could be applied to other sea turtle species, and serve as a crucial conservation tool.</p></div