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Juvenile green turtles occupy coastal marine habitats important for their ontogeny; however, the details of their movement, connectivity, and space use in these developmental habitats are still poorly understood. Given that these areas are often threatened by human disturbance, additional information on green turtle spatial ecology is needed to meet conservation endpoints for this endangered species. For this study, we used fixed passive acoustic telemetry to (1) describe movement patterns and connectivity of immature green turtles within, outside, and across 2 bays, Manglar and Tortuga bays, on Culebra and Culebrita islands, Puerto Rico; and (2) determine spatio-temporal drivers of the presence and absence of turtles within Manglar Bay. Network analysis used to quantify movement patterns showed that turtles in our study exhibited differential space use with little to no connectivity across the 2 bays. In addition, turtles exhibited high site fidelity, with larger turtles leaving on brief trips. We applied a presence-absence Bayesian binomial model on a subset of 9 turtles at an hourly temporal scale and showed that turtles within Manglar Bay occupied areas of lagoon and seagrass habitats at night and were rarely using areas of macroalgae habitat. The parameter estimates from the model enabled us to predict the space use of turtles across Manglar Bay, and the hourly probability distributions highlighted predictive diel movement patterns across the bay. Considering the importance of juvenile and subadult life stages for population viability, we recommend continued protection of these critical juvenile turtle developmental habitats to ensure recruitment into the adult life stage.

Somatic growth is an integrated, individual-based response to environmental conditions, especially in ectotherms. Growth dynamics of large, mobile animals are particularly useful as bio-indicators of environmental change at regional scales. We assembled growth rate data from throughout the West Atlantic for green turtles, Chelonia mydas, which are long-lived, highly migratory, primarily herbivorous mega-consumers that may migrate over hundreds to thousands of kilometers. Our dataset, the largest ever compiled for sea turtles, has 9690 growth increments from 30 sites from Bermuda to Uruguay from 1973 to 2015. Using generalized additive mixed models, we evaluated covariates that could affect growth rates; body size, diet, and year have significant effects on growth. Growth increases in early years until 1999, then declines by 26% to 2015. The temporal (year) effect is of particular interest because two carnivorous species of sea turtles-hawksbills, Eretmochelys imbricata, and loggerheads, Caretta caretta-exhibited similar significant declines in growth rates starting in 1997 in the West Atlantic, based on previous studies. These synchronous declines in productivity among three sea turtle species across a trophic spectrum provide strong evidence that an ecological regime shift (ERS) in the Atlantic is driving growth dynamics. The ERS resulted from a synergy of the 1997/1998 El Niño Southern Oscillation (ENSO)-the strongest on record-combined with an unprecedented warming rate over the last two to three decades. Further support is provided by the strong correlations between annualized mean growth rates of green turtles and both sea surface temperatures (SST) in the West Atlantic for years of declining growth rates (r = -.94) and the Multivariate ENSO Index (MEI) for all years (r = .74). Granger-causality analysis also supports the latter finding. We discuss multiple stressors that could reinforce and prolong the effect of the ERS. This study demonstrates the importance of region-wide collaborations.

Outbreaks of fibropapillomatosis (FP), a neoplastic infectious disease of marine turtles, have occurred worldwide since the 1980s. Its most likely aetiological agent is a virus, but disease expression depends on external factors, typically associated with altered environments. The scarcity of robust long-term data on disease prevalence has limited interpretations on the impacts of FP on turtle populations. Here we model the dynamics of FP at 2 green turtle foraging aggregations in Puerto Rico, through 18 yr of capture-mark-recapture data (1997−2014). We observed spatiotemporal variation in FP prevalence, potentially modulated via individual site-fidelity. FP ex pression was residency dependent, and FP-free individuals developed tumours after 1.8 ± 0.8 yr (mean ± SD) in the infected area. Recovery from the disease was likely, with complete tumour regression occurring in 2.7 ± 0.7 yr (mean ± SD). FP does not currently seem to be a major threat to marine turtle populations; however, disease prevalence is yet unknown in many areas. Systematic monitoring is highly advisable as human-induced stressors can lead to deviations in host− pathogen relationships and disease virulence. Finally, data collection should be standardized for a global assessment of FP dynamics and impacts. Natural and Environmental Resources of Puerto Rico (DNER); US National Marine Fisheries Service (NMFSNOAA Section 6); US Fish and Wildlife Service, Chelonia; WIDECAST; Fundação para a Ciência e a Tecnologia (FCT) info:eu-repo/semantics/publishedVersion

Marine turtles are challenging species to protect because they occur over large geographic scales. Tagging individual turtles at nesting beaches and foraging areas, and the resulting mark-recapture data sets have gradually enabled us to understand marine turtle migratory behaviour and dispersal. Within the Caribbean region, several turtle tagging projects have led to longer-term evaluations and assessments of connectivity. Thus, marine turtle mark-recapture data is important for developing conservation strategies at regional-scale. In this study, we analyse turtle tagging data from the Gulf of Venezuela to determine regional (Caribbean and Atlantic geographic level) and local (within the Gulf of Venezuela) links. To achieve this, we retrieved, compiled, and analysed multiple databases with records of marine turtles that were tagged and then recaptured in the Gulf of Venezuela. Sixty-six tag return records were evaluated, 43 from animals initially tagged outside of the Gulf of Venezuela and then recaptured inside, plus 23 records retrieved from turtles that were tagged and recaptured within the Gulf of Venezuela. We found evidence of connectivity between 12 different locations where initial tagging events occurred, eight from other feeding areas and four from nesting beaches. We described four different movement patterns for 23 turtles tagged and re-captured within the Gulf of Venezuela. Most of the recapture records we obtained occurred after the turtles were known, or presumed, to have been killed by local fishers. Hence, knowing patterns of dispersal and connectivity are crucial to improving local and regional conservation and threat mitigation.

Marine migratory species encounter a range of threats as they move through coastal and oceanic zones. Understanding the connectivity and dispersal patterns of such species is critical to their effective conservation. Here we analyzed the temporal genetic composition and the most likely origin of juvenile green turtles foraging at Puerto Manglar and Tortuga Bay, Culebra, Puerto Rico, using mitochondrial DNA control region sequences. We identified 17 haplotypes, of which CM-A3 (51.5%), CM-A5 (19.4%) and CM-A1 (13.6%) were the most common. Haplotype (h) and nucleotide (π) diversities were 0.680 and 0.008, respectively. There was no evidence of significant variation in the genetic composition of these aggregations throughout seven years (2000-2006), suggesting that relative contributions from source populations did not significantly change during this period. Mixed Stock Analysis (MSA), incorporating 14 Atlantic nesting populations as possible sources, indicated four main contributing stocks to the Culebra foraging grounds: Costa Rica (34.9%), Mexico (29.2%), East Central Florida (13.2%), and Suriname (12.0%). The regional pattern of connectivity among Wider Caribbean rookeries and Culebra was further evidenced by a second MSA using Atlantic Regional Management Units (RMUs) as sources, with 94.1% of the mixed stock attributed to this area. This study addresses the information gap on the connectivity of the green turtle in the North Atlantic, and establishes an important baseline that can be used to determine future changes in stock composition. Department of Natural and Environ-mental Resources of Puerto Rico; US National Marine Fisheries Service (NMFS-NOAA, Section 6, grant NA08NMF4720436); US Fish and Wildlife Service, Chelonia Inc, and WIDECAST. Work was conducted under permits by NMFS-NOAA (permit nos. 1253, 1518, 14949) and DNER (06-EPE-016). ARP had the support of the Portuguese Foundation for Science and Technology info:eu-repo/semantics/publishedVersion

In Puerto Rico, green sea turtles (Chelonia mydas) appear to congregate in certain areas that constitute neritic developmental habitats for juvenile green turtles and foraging habitats for migrating larger immature and adult green turtles. The objective of this study was to establish baseline blood health indices in free-ranging green sea turtles occupying such habitats in Puerto Rico. We analyzed packed cell volume, morphometrics, and plasma biochemistry and protein electrophoresis parameters for free-ranging green sea turtles in the Culebra archipelago of Puerto Rico. The general health of turtles included in this study was rated as good based on body condition, physical examination, and molecular diagnostics. We report packed cell volume, plasma biochemistry, and protein electrophoresis reference interval values for juvenile and subadult green sea turtles. Development of site-specific baseline blood health parameters for wild, healthy sea turtle populations is an important factor in creating effective management protocols and enhances our ability to understand the effects of anthropogenic and environmental changes on sea turtle health.

Understanding conservation needs relies on robust estimates of key population parameters, such as survival, abundance and somatic growth. We investigated the somatic growth and abundance dynamics of 2 aggregations of immature green turtles, at Tortuga Bay and Puerto Manglar (Culebra, Puerto Rico), throughout 15 yr of capture-mark-recaptures. We used nonlinear models to investigate the effects of carapace length, sampling year, growth interval and the pres- ence of fibropapillomas on growth rates, and used the size-specific growth rate function to esti- mate how long turtles remain at each bay. Abundances were estimated and compared with time- specific growth rate functions, to infer density-dependency effects on somatic growth rates, and trends in abundance were evaluated by fitting generalized linear models. We found foraging site specific growth rates and report the highest mean somatic growth rate for green turtles in the wild (6.1 ± 1.7 cm yr �1 , at Puerto Manglar). The size-specific growth rate function was monotonic at both sites, with growth rates declining continuously with increasing carapace length. We inferred minimum ages at maturity of 14 and 22 yr, for Puerto Manglar and Tortuga Bay turtles, respec- tively. Throughout the 15 yr of this study there was a positive trend in aggregation size at Puerto Manglar (mean annual increase of 10.9%), which was not observed at Tortuga Bay. Our study highlights the influence of geography and habitat quality on somatic growth rates, and delivers robust demographic estimates valuable for local and regional assessments of the conservation sta- tus of the green turtle.

Somatic growth dynamics are an integrated response to environmental conditions. Hawksbill sea turtles (Eretmochelys imbricata) are long‐lived, major consumers in coral reef habitats that move over broad geographic areas (hundreds to thousands of kilometers). We evaluated spatio‐temporal effects on hawksbill growth dynamics over a 33‐yr period and 24 study sites throughout the West Atlantic and explored relationships between growth dynamics and climate indices. We compiled the largest ever data set on somatic growth rates for hawksbills – 3541 growth increments from 1980 to 2013. Using generalized additive mixed model analyses, we evaluated 10 covariates, including spatial and temporal variation, that could affect growth rates. Growth rates throughout the region responded similarly over space and time. The lack of a spatial effect or spatio‐temporal interaction and the very strong temporal effect reveal that growth rates in West Atlantic hawksbills are likely driven by region‐wide forces. Between 1997 and 2013, mean growth rates declined significantly and steadily by 18%. Regional climate indices have significant relationships with annual growth rates with 0‐ or 1‐yr lags: positive with the Multivariate El Niño Southern Oscillation Index (correlation = 0.99) and negative with Caribbean sea surface temperature (correlation = −0.85). Declines in growth rates between 1997 and 2013 throughout the West Atlantic most likely resulted from warming waters through indirect negative effects on foraging resources of hawksbills. These climatic influences are complex. With increasing temperatures, trajectories of decline of coral cover and availability in reef habitats of major prey species of hawksbills are not parallel. Knowledge of how choice of foraging habitats, prey selection, and prey abundance are affected by warming water temperatures is needed to understand how climate change will affect productivity of consumers that live in association with coral reefs.

Habitat features influence the distribution and abundance of marine animals and are used to identify critical areas to protect threatened marine species. In this study, we surveyed juvenile hawksbill turtles in 5 localities of the Culebra Archipelago, Puerto Rico; described the habitats using cover of benthic features; and related relative abundance of turtles among localities with food availability. We tested the hypothesis that variability in turtle abundance among study sites was related to spatial variability in the availability of diet items. Our results point out that spatial variability in turtle abundance is not related to food availability by itself; rather, the structural complexity and types of benthic structure played a more important role in explaining the turtles' local abundance. The importance of structural complexity is most likely related to sheltering.

Inshore bays are key foraging grounds for immature green turtles Chelonia mydas. At these confined areas, capturemarkrecapture (CMR) programs generate valuable informa- tion that can be used to estimate vital rates, essential for the effective conservation of this endan- gered species. We compiled the CMR history profiles of 273 individuals from 13 yr of in-water sur- veys and employed the Cormack-Jolly-Seber model to estimate the survival probabilities of green turtles in 2 neritic bays at Culebra municipality, Puerto Rico. The CMR profiles were grouped into 2 size classes: juvenile and subadult. No adults were captured during the study. We found no sig- nificant differences in survival probability between the green turtles occupying each bay. We also assessed the survival probability of fibropapillomatosis (FP)-afflicted turtles versus FP-free turtles and found no significant differences among these groups. However, there was a significant differ- ence in survival between the 2 size classes. Juveniles showed a higher survival probability (0.8322, 95% CI = 0.7875 to 0.8690) than subadults (0.5290, 95% CI = 0.3851 to 0.6682). The low survival of subadults is potentially biased by the permanent emigration of some of these individu- als. Previous studies have shown that larger immatures leave shallow protected bays and occupy deeper open waters, sometimes associated with adults. Juveniles seem to be resident, and their survival rate can serve as a reference value for viability analysis. This is the first study on the survival of green turtles in the West Indies.

Recent literature on foraging in Hawksbill Sea Turtles in the Caribbean region concludes that prey selectivity is a combination of preference for certain prey species and their local abundance. In this study, prey selectivity patterns were measured in five juvenile Hawksbill Sea Turtle (Eretmochelys imbricata) aggregations in the Culebra Archipelago, Puerto Rico, and the hypothesis that juvenile Hawksbill Sea Turtles exhibit selectivity for certain prey items independent of their environmental availability was tested. Hawksbill Sea Turtles showed positive selection for the corallimorph Ricordea florida, which was rare in all four study sites, and for the alga Lobophora variegata, that was abundant in one site. Turtles exhibited low preference for the sponge Chondrilla nucula, the most common prey item in both diet samples and the environment at all study sites. Low preference for this sponge corresponds to its high availability in the environment. Turtles also exhibited low preference for the spo...

Detailed post-breeding movement data is presented for hawksbill turtles tracked by satellite telemetry from Mona Island, Puerto Rico. Seven nesting females and 8 breeding males were tracked. Females traveled for 3 to 53 d to reach their foraging grounds, swimming distances of 84 to 2051 km (mean 867 km, n = 7) at average speeds of 23.5 to 38.7 km d -1 (n = 7). Males traveled for

We investigated the dispersal, recruitment and migratory behaviour of the hawksbill sea turtle (Eretmochelys imbricata), among different life-history stages and demographic segments of the large hawksbill turtle aggregation at Mona Island, Puerto Rico. There were significant differences in both mitochondrial DNA (mtDNA) haplotype diversity and haplotype frequencies among the adult males, females and juveniles examined, but little evidence for temporal heterogeneity within these same groups sampled across years. Consistent with previous studies and the hypothesis of strong natal homing, there were striking mtDNA haplotype differences between nesting females on Mona Island and nesting females in other major Caribbean rookeries. Breeding males also showed strong, albeit weaker, genetic evidence of natal homing. Overall, Bayesian mixed-stock analysis suggests that Mona Island was the natal rookery for 79% (65-94%) of males in the aggregation. In contrast, the Mona Island rookery accounted for only a small subset of the new juvenile recruits to the foraging grounds or in the population of older juvenile hawksbills turtles on Mona. Instead, both new recruits and the older juvenile hawksbill turtles on Mona more likely recruited from other Caribbean rookeries, suggesting that a mechanism besides natal homing must be influencing recruitment to feeding habitats. The difference in the apparent degree of natal homing behaviour among the different life-history stages of hawksbill turtles at Mona Island underscores the complexity of the species' life-history dynamics and highlights the need for both local and regional conservation efforts.

We document three examples of fibropapillomatosis by histology, quantitative polymerase chain reaction (qPCR), and sequence analysis from three different geographic areas. Tumors compatible in morphology with fibropapillomatosis were seen in green turtles from Puerto Rico and San Diego (California) and in a hybrid loggerhead/ hawksbill turtle from Florida Bay (Florida). Tumors were confirmed as fibropapillomas on histology, although severity of disease varied between cases. Polymerase chain reaction (PCR) analyses revealed infection with the fibropapilloma-associated turtle herpesvirus (FPTHV) in all cases, albeit at highly variable copy numbers per cell. Alignment of a portion of the polymerase gene from each fibropapilloma-associated turtle herpesvirus isolate demonstrated geographic variation in sequence. These cases illustrate geographic variation in both the pathology and the virology of fibropapillomatosis.

With nest incubation temperature determining sex in marine turtle hatchlings, sex ratios among populations and intermediate aggregations are likely to exhibit more geographic and temporal variability than for vertebrates with genotypic sex determination. In this study, we examined the sex ratio of an immature Hawksbill Seaturtle (Eretmochelys imbricata) aggregation at Mona Island, Puerto Rico, using serum testosterone level criteria that were validated through laparoscopy in a subset of turtles. Measured serum testosterone for female turtles ranged between 0.32 and 17 pg/ml and for males between 18.2 and 262 pg/ml. Of 120 turtles sampled, 53 individuals were classified as females and 66 as males, with one individual undetermined. The resulting F:M ratio of 0.80:1 is not significantly different from 1:1. This result contrasts with the highly female-biased sex ratios reported from surrounding Caribbean immature hawksbill aggregations, suggesting that the Mona near shore habitat recruits male turtles from a source uncommon to other aggregations.

Hawksbill Seaturtles have temperature-dependent sex determination. As such, the resulting sex ratios are of conservational and ecological significance. Buck Island Reef is an interesting location for sex ratio studies since it represents a natural and unexploited foraging ground for hawksbills in the Caribbean. To examine sex ratios, blood samples were obtained from juvenile Hawksbill Seaturtles captured on Buck Island Reef over a four-year period. We used a radioimmunoassay to determine testosterone levels in those samples and compared those values to testosterone levels of juvenile hawksbills from the Caribbean whose sex has been verified by laparoscopy. The results of this study reveal a significantly female-biased sex ratio (approximately 80% female) occurs in this juvenile aggregation inhabiting Buck Island Reef.

Carapace length growth data were obtained from 197 hawksbill turtles Eretmochelys imbricata which were marked and recaptured from 1992 to 2000 at feeding grounds of Mona and Monito Islands, Puerto Rico. Straight-line carapace length (SCL) upon initial capture ranged from 20.0 to 84.5 cm. SCL growth rates ranged from -0.59 to 9.08 cm yr -1 , were non-monotonic, and aver- aged highest in turtles measuring 34 to 35 cm. Somatic growth rates varied by site within the study area, with turtles from the aggregation at Monito Island growing on average 2.1 times faster than res- idents of Mona Island habitats. Aggregation density and body condition index (body mass SCL -3 ) were also highest at Monito Island. Hawksbills recruiting to Monito Island at 23 cm SCL are expected to reach maturity less than 14.7 yr later. Growth rates in the turtles studied are similar to those reported for other Caribbean localities, but faster than hawksbills of the southern Great Barrier Reef, Australia. Hawksbills appear capable of utilizing habitats of widely varying quality, with prey abun- dance exerting a strong effect on somatic growth rates.

Distances between capture and recapture locations of tagged immature hawksbill turtles Eretmochelys imbricata (Linnaeus) are analyzed for four near-shore survey sites at Mona and Monito Islands, Puerto Rico. Data were obtained for 87 turtles ranging in size from 20.0 to 56.7 cm straight-line carapace length. Net displacements by individual turtles averaged 0.45 km (S.D.=0.66, range 0.00–5.22) for mean inter-capture intervals of 465 days (S.D.=331, range 9–1118). Measured displacements were not correlated with turtle size and did not differ significantly between survey sites. Movements of three immature turtles fitted with sonic tags were monitored by acoustical tracking in reef habitats along the southwestern coast of Mona Island. The area utilized by the turtles during the 11–16 days of tracking measured 0.07–0.21 km2. It is concluded that immature hawksbill turtles maintain a limited home range area and appear resident at the feeding grounds of Mona and Monito Islands for periods of at least several years.

Hawksbill turtles move between nesting colonies and feeding grounds, but in most cases it is not known which reproductive populations occupy a particular feeding habitat. In this study, genetic markers derived from mitochondrial DNA sequences are used to estimate the contribution of Caribbean nesting colonies to a feeding ground at Mona Island, Puerto Rico (n = 41). Maximum likelihood analysis indicates that this feeding population is not composed primarily of turtles from the neighboring nesting colony (also on Mona Island), but is drawn from nesting populations throughout the Caribbean region. A sampled nesting colony in the southern hemisphere (Bahia, Brazil) did not contribute, at detectable levels, to the Mona Island feeding ground. From this evidence, we concluded that hawksbill turtles recruitment to feeding grounds over a scale of hundreds of kilometres, but not over the scale of 7000 km that separate Mona Island from Bahia, Brazil. These data indicate that a hawskbill turtle harvest on feeding grounds will reduce nesting populations throughout the Caribbean region.

Over the past 3 decades, the status of sea turtles and the need for their protection to aid population recovery have increasingly captured the interest of government agencies, non-governmental organisations (NGOs) and the general public worldwide. This interest has been matched by increased research attention, focusing on a wide variety of topics relating to sea turtle biology and ecology, together with the interrelations of sea turtles with the physical and natural environments. Although sea turtles have been better studied than most other marine fauna, management actions and their evaluation are often hindered by the lack of data on turtle biology, human-turtle interactions, turtle population status and threats. In an effort to inform effective sea turtle conservation a list of priority research questions was assembled based on the opinions of 35 sea turtle researchers from 13 nations working in fields related to turtle biology and/or conservation. The combined experience of the contributing researchers spanned the globe as well as many relevant disciplines involved in conservation research. An initial list of more than 200 questions gathered from respondents was condensed into 20 metaquestions and classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies. © Inter-Research 2010.

We investigated the dispersal, recruitment and migratory behaviour of the hawksbill sea turtle (Eretmochelys imbricata), among different life-history stages and demographic segments of the large hawksbill turtle aggregation at Mona Island, Puerto Rico. There were significant differences in both mitochondrial DNA (mtDNA) haplotype diversity and haplotype frequencies among the adult males, females and juveniles examined, but little evidence for temporal heterogeneity within these same groups sampled across years. Consistent with previous studies and the hypothesis of strong natal homing, there were striking mtDNA haplotype differences between nesting females on Mona Island and nesting females in other major Caribbean rookeries. Breeding males also showed strong, albeit weaker, genetic evidence of natal homing. Overall, Bayesian mixed-stock analysis suggests that Mona Island was the natal rookery for 79% (65-94%) of males in the aggregation. In contrast, the Mona Island rookery accounted for only a small subset of the new juvenile recruits to the foraging grounds or in the population of older juvenile hawksbills turtles on Mona. Instead, both new recruits and the older juvenile hawksbill turtles on Mona more likely recruited from other Caribbean rookeries, suggesting that a mechanism besides natal homing must be influencing recruitment to feeding habitats. The difference in the apparent degree of natal homing behaviour among the different life-history stages of hawksbill turtles at Mona Island underscores the complexity of the species' life-history dynamics and highlights the need for both local and regional conservation efforts.

Marine turtles are accomplished divers capable of making extended breath-hold dives (Berkson, 1966) and frequenting great depths (Landis, 1965; Eckert et al., 1986). Because aquatic respiration in non-hibernating turtles is minimal (Lutz and Bentley, 1985), the animals are obliged to periodically rise to the surface to breathe. Adaptations in lung structure (Lutz and Bentley, 1985) and blood properties (Friedman et al., 1985) facilitate a rapid gas exchange in marine turtles. Ventilation in large turtles is completed after taking only a few deep breaths (Tenney et al., 1974), allowing these animals to resume benthic activities with min