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Genetic monitoring of highly migratory endangered species is fundamental for effective management, particularly when they are shared internationally, and their populations need to be identified. A prime example is the green turtle, Chelonia mydas, whose genetic structure has been extensively studied in the Western Atlantic. Nevertheless, the identification of Cuban management units has remained uncertain, despite representing regionally significant nesting assemblages and occurring within a strategically central position. Compared to previous work, the current study used 800 bp mtDNA control region sequences and larger sample sizes (n = 189 from four nesting sites in SW Cuba). Of the 23 resolved haplotypes, nine were novel, fourteen were reported in Cuba for the first time, and eleven were endemic. Even though the distribution of nesting grounds barely spans 300 km, three management units were identified: Guanahacabibes-San Felipe (GUCB; with most of the endemic haplotypes), Isla de la Juventud (IJCB; with a predominance of haplotype CM-A13.1), and Cayo Largo (CLCB; with a haplotype profile closely related to Southern Caribbean rookeries). We discuss how the geographic distribution of mtDNA variation has likely been shaped by local and regional oceanic current patterns or derived from formerly hyperabundant regional populations. Genetic characterization of Cuban management units represents a significant contribution, filling critical knowledge gaps that have hampered the comprehensive mixed-stock analyses required to guide effective regional conservation strategies. [ABSTRACT FROM AUTHOR]

Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a "middle of the road" scenario (SSP2‐4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26–43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present‐day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from −20 to −191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming. [ABSTRACT FROM AUTHOR]

Abstract: Long-distance dispersal and ontogenetic shifts in habitat use are characteristic of numerous marine species and have important ecological, evolutionary, and management implications. These processes, however, are often challenging to study due to the vast areas involved. We used genetic markers and simulations of physical transport within an ocean circulation model to gain understanding into the origin of juvenile hawksbill sea turtles (Eretmochelys imbricata) found at Ascension Island, a foraging ground that is thousands of kilometers from known nesting beaches. Regional origin of genetic markers suggests that turtles are from Western Atlantic (86%) and Eastern Atlantic (14%) rookeries. In contrast, numerical simulations of transport by ocean currents suggest that passive dispersal from the western sources would be negligible and instead would primarily be from the East, involving rookeries along Western Africa (i.e., Principe Island) and, potentially, from as far as the Indian Ocean (e.g., Mayotte and the Seychelles). Given that genetic analysis identified the presence of a haplotype endemic to Brazilian hawksbill rookeries at Ascension, we examined the possible role of swimming behavior by juvenile hawksbills from NE Brazil on their current-borne transport to Ascension Island by performing numerical experiments in which swimming behavior was simulated for virtual particles (simulated turtles). We found that oriented swimming substantially influenced the distribution of particles, greatly altering the proportion of particles dispersing into the North Atlantic and South Atlantic. Assigning location-dependent orientation behavior to particles allowed them to reach Ascension Island, remain in favorable temperatures, encounter productive foraging areas, and return to the vicinity of their natal site. The age at first arrival to Ascension (4.5–5.5years) of these particles corresponded well to estimates of hawksbill age based on their size. Our findings suggest that ocean currents and swimming behavior play an important role in the oceanic ecology of sea turtles and other marine animals. [Copyright &y& Elsevier]

Mitochondrial DNA analyses have been useful for resolving maternal lineages and migratory behavior to foraging grounds (FG) in sea turtles. However, little is known about source rookeries and haplotype composition of foraging green turtle aggregations in the southeastern Pacific. We used mitochondrial DNA control region sequences to identify the haplotype composition of 55 green turtles, Chelonia mydas, captured in foraging grounds of Gorgona National Park in the Colombian Pacific. Amplified fragments of the control region (457 bp) revealed the presence of seven haplotypes, with haplotype (h) and nucleotide (p) diversities of h = 0.300±0.080 and p = π.009±0.005 respectively. The most common haplotype was CMP4 observed in 83% of individuals, followed by CMP22 (5%). The genetic composition of the Gorgona foraging population primarily comprised haplotypes that have been found at eastern Pacific rookeries including Mexico and the Galapagos, as well as haplotypes of unknown stock origin that likely originated from more distant western Pacific rookeries. Mixed stock analysis suggests that the Gorgona FG population is comprised mostly of animals from the Galapagos rookery (80%). Lagrangian drifter data showed that movement of turtles along the eastern Pacific coast and eastward from distant western and central Pacific sites was possible through passive drift. Our results highlight the importance of this protected area for conservation management of green turtles recruited from distant sites along the eastern Pacific Ocean. [ABSTRACT FROM AUTHOR]

While little is known about hawksbill turtles Eretmochelys imbricata in the eastern Pacific Ocean, available information suggests that the population has declined substantially in recent decades and could be near extirpation in the region. To evaluate the current status of the population more effectively and to determine the feasibility of recovery efforts, a workshop of regional marine turtle specialists was held in June 2008 in Los Cóbanos, El Salvador. An international working group, Iniciativa Carey del Pacífico Oriental (ICAPO; Eastern Pacific Hawksbill Initiative in English), was established to consolidate information, promote conservation projects and raise awareness about the species. We present information derived from the workshop and compiled by the ICAPO working group since that time. Considering only records from 1 January 2007 to 31 May 2009 it appears that El Salvador hosts the majority of known hawksbill turtle nesting activity in the eastern Pacific, with 79.6% (n = 430) of all nesting observation records, and Mexico hosts the majority of records of hawksbill turtles at sea, with 60.3% (n = 44) of all in-water observation records. Although current abundance is very low, the pervasiveness of the species in the region suggests potential for conservation and recovery. Despite a historical paucity of research focusing on this population, the relatively large and steadily increasing number of records as a result of concerted efforts demonstrates the viability of the ICAPO network as an instrument to promote conservation of this species in the eastern Pacific. [ABSTRACT FROM AUTHOR]

Despite intense interest in conservation of marine turtles, spatial ecology during the oceanic juvenile phase remains relatively unknown. Here, we used mixed stock analysis and examination of oceanic drift to elucidate movements of hawksbill turtles ( Eretmochelys imbricata) and address management implications within the Caribbean. Among samples collected from 92 neritic juvenile hawksbills in the Cayman Islands we detected 11 mtDNA control region haplotypes. To estimate contributions to the aggregation, we performed ‘many-to-many’ mixed stock analysis, incorporating published hawksbill genetic and population data. The Cayman Islands aggregation represents a diverse mixed stock: potentially contributing source rookeries spanned the Caribbean basin, delineating a scale of recruitment of 200–2500 km. As hawksbills undergo an extended phase of oceanic dispersal, ocean currents may drive patterns of genetic diversity observed on foraging aggregations. Therefore, using high-resolution Aviso ocean current data, we modelled movement of particles representing passively drifting oceanic juvenile hawksbills. Putative distribution patterns varied markedly by origin: particles from many rookeries were broadly distributed across the region, while others would appear to become entrained in local gyres. Overall, we detected a significant correlation between genetic profiles of foraging aggregations and patterns of particle distribution produced by a hatchling drift model (Mantel test, r = 0.77, P < 0.001; linear regression, r = 0.83, P < 0.001). Our results indicate that although there is a high degree of mixing across the Caribbean (a ‘turtle soup’), current patterns play a substantial role in determining genetic structure of foraging aggregations (forming turtle groups). Thus, for marine turtles and other widely distributed marine species, integration of genetic and oceanographic data may enhance understanding of population connectivity and management requirements. [ABSTRACT FROM AUTHOR]

Molecular studies of sea turtles have shown that the frequency of multiple paternity (MP) varies between species, and between rookeries of the same species. This study uses nuclear microsatellite markers to compare the incidence of MP in two neighbouring olive ridley rookeries on the Pacific coast of Costa Rica, with contrasting nesting behaviours — the ‘arribada’ population nesting at Ostional and the solitary nesters of Playa Hermosa. Using two highly polymorphic microsatellite markers, we tested 13 nests from each location and found a significant difference ( P<0.001) between the level of MP of the arribada rookery (92%— the highest found for marine turtles) and that of the solitary nesting rookery (30%). Additional analyses based on six microsatellite loci revealed no genetic differentiation between nesting females from the two locations, or between nesting females and attendant males from the Ostional breeding area. Sixty-nine per cent of the nests with MP were fathered by a minimum of three different males, and three nests showed evidence of at least four fathers. The results suggest that the differences observed in levels of MP between arribada and solitary rookeries are due to an effect of abundance of individuals on the mating system. This is supported by a regression analysis combining other paternity studies on sea turtles which shows that levels of MP increase with increasing abundance of nesting females. [ABSTRACT FROM AUTHOR]

To study the movement patterns of Green Seaturtle (Chelonia mydas) populations in the Caribbean region using Cuban habitats, tag-recapture data from local (Cuban National Tagging Program 1989–2002) and international programs (1959–2002) were compiled and compared. Of the 742 turtles tagged in Cuba at fishing areas, nesting beaches and head-start facilities, 5.5% were recaptured, mostly outside of Cuban waters and with a majority of these (76.9%) off the coast of Nicaragua. Green Seaturtles tagged elsewhere and recaptured in Cuba included head-started juveniles from Grand Cayman (45% of the total), Mexico (2.3%), and Florida (1.8%); wild juveniles from the Bahamas (14.1%), Bermuda (5.4%), and Florida (1.5%); and adults from Tortuguero (26%), Florida, USA (1.3%), Mexico (1%), Venezuela (1.3%), and U.S. Virgin Islands (0.3%). Recaptures of tags placed at sites north of Cuba (Bermuda and the Bahamas) clustered in the northeast region of Cuba, whereas those from the south (Grand Cayman) were recaptured in southern areas. Recaptures from Tortuguero tags were concentrated in the southeast and westward regions of Cuba. Turtles from the Bahamas, Grand Cayman, and Bermuda showed the highest recapture rates in Cuban habitats, with 3.2, 1.9, and 1.0% of the total number of tags applied, respectively. These results for a broad range of populations and across life stages underscore the regionwide significance of Cuban sites as critical habitats or migratory corridors. [ABSTRACT FROM AUTHOR]

The olive ridley sea turtle is predominantly an epipelagic species with no apparent migration corridors. Research in feeding areas in other sea turtle species has identified aggregations of individuals from diverse backgrounds; however, no specific feeding areas have been identified for the olive ridley. We used mtDNA control region sequencing to identify the haplotype composition of 85 olive ridley turtles (adult and immature turtles from both sexes) captured and released in Central Mexican Pacific waters. Amplified fragments of the control region (751 bp) revealed the presence of 17 haplotypes (h = 0.5877 ± 0.0622 and π = 0.001698 ± 0.001185), and 16 of them were phylogenetically grouped within the lineage of the Eastern Pacific, but the haplotype Lo37 showed close evolutionary relationships with the lineage of the East Coast of India. Lagrangian drifter data showed that West–East transport from the Indo-Pacific to the tropical Eastern Pacific might be possible through passive drift. These results highlight the importance of more genetic studies offshore and the role of the ocean currents in the migratory behavior of olive ridleys, as well as the need to establish multinational strategies for the conservation and management of the species in international waters. [ABSTRACT FROM AUTHOR]

Successful conservation of long‐lived species requires reliable understanding of long‐term trends and historical baselines. We present a framework for evaluating abundance trends and conservation outcomes for long‐lived marine species by integrating local ecological knowledge (LEK), ecological monitoring, and computer simulation, tested on a case‐study of long‐lived and heavily exploited green turtles (Chelonia mydas) in the Eastern Pacific. Models fit to LEK and monitoring data indicate that turtle abundance is increasing, but only after ∼40 years of safeguarding the species' nesting and foraging habitats in Mexico. However, current abundance is at ∼60% of baseline levels and historic population structure has not been reestablished, indicating the need for sustained, long‐term conservation actions. We demonstrate the potential of linking LEK and ecological science to provide critical information for conservation, by establishing reference baselines and gauging population status with a long‐term historical perspective, while promoting equitable and sustainable futures. [ABSTRACT FROM AUTHOR]

Reproductive seasonality is present across species and phyla. Many species retain seasonal patterns even in tropical regions where climatic variations may be less apparent. Environmental features and large-scale environmental cues play a role in species seasonality and can have major effects on reproductive success. In organisms that present environmental sex determination, the season in which individuals reproduce has consequences for their primary sex ratio. Here we looked at the possible effects on fitness and primary sex ratio for the olive ridley sea turtle (Lepidochelys olivacea) when nesting during peak and low nesting seasons. In the eastern Pacific, peak olive ridley sea turtle nesting occurs during the warmest months, which coincide with the rainy season. Yet, as nesting takes place year-round, a small proportion of the nests laid during the dry part of the season are exposed to contrasting environmental conditions. Most of the studies on Pacific coast sea turtles have estimated sex ratios produced during the rainy, high abundance period when most conservation activities are focused. Thus, dry-low season nests have on the whole, been overlooked. Here we compared sex ratios and hatchling fitness for offspring produced during the dry and rainy seasons in 2015. We found that olive ridley clutches incubated during the dry-low season were exposed to lower temperatures, yielded higher hatchling success, mainly produced male offspring and larger, heavier hatchlings with better locomotor abilities. This highlights that, for sea turtles, protecting nests outside of the peak nesting season may help future population viability by yielding higher proportions of males with greater locomotor capacities and, thus, survival. Our results highlight the critical value of monitoring and protecting species during their entire reproductive period and not concentrating all resources on the peak season to collect more data and protect a greater number of organisms. Our results suggest that monitoring low-season reproductive effort (nests in this case), albeit at much lower densities, would be critical for understanding and possibly ensuring population viability and adaptation to contemporary climate change and anthropogenic threats. [ABSTRACT FROM AUTHOR]

Understanding the population genetic structure of the species is essential for determining the possible management units (UM) and their conservation and/or sustainable exploitation with it. Chelonia mydas is recognized as an endangered philopatric turtle. This work aims to describe the population structure of the green turtle in southwestern Cuba through traditional analytical approaches and allocation methods. The collections were made between 1998 and 2007 on five beaches in the Cuban southwest. Seven microsatellite loci from 149 individuals were amplified and genetic variability parameters were calculated. The population structure was inferred through the use of Wright's F, Analysis of Molecular Variance (AMOVA), and population assignment algorithms based on Bayesian analysis (STRUCTURE) and factorization of sparse non-negative matrices (implemented in R). Most of the loci were not in Hardy-Weinberg equilibrium, and several presented linkage disequilibrium. The AMOVA and differentiation statistics suggest the presence of structure at the geographical level analyzed. The highest value of ΔK and the lowest value of cross-entropy were reached for K = 2, a result that suggests that in southwestern Cuba there is the contribution of two ancestral populations of Chelonia mydas. Relative migration estimates indicate active genetic exchange between nesting colonies in southwestern Cuba. [ABSTRACT FROM AUTHOR]

Previous genetic studies have demonstrated that natal homing shapes the stock structure of marine turtle nesting populations. However, widespread sharing of common haplotypes based on short segments of the mitochondrial control region often limits resolution of the demographic connectivity of populations. Recent studies employing longer control region sequences to resolve haplotype sharing have focused on regional assessments of genetic structure and phylogeography. Here we synthesize available control region sequences for loggerhead turtles from the Mediterranean Sea, Atlantic, and western Indian Ocean basins. These data represent six of the nine globally significant regional management units (RMUs) for the species and include novel sequence data from Brazil, Cape Verde, South Africa and Oman. Genetic tests of differentiation among 42 rookeries represented by short sequences (380 bp haplotypes from 3,486 samples) and 40 rookeries represented by long sequences (∼800 bp haplotypes from 3,434 samples) supported the distinction of the six RMUs analyzed as well as recognition of at least 18 demographically independent management units (MUs) with respect to female natal homing. A total of 59 haplotypes were resolved. These haplotypes belonged to two highly divergent global lineages, with haplogroup I represented primarily by CC-A1, CC-A4, and CC-A11 variants and haplogroup II represented by CC-A2 and derived variants. Geographic distribution patterns of haplogroup II haplotypes and the nested position of CC-A11.6 from Oman among the Atlantic haplotypes invoke recent colonization of the Indian Ocean from the Atlantic for both global lineages. The haplotypes we confirmed for western Indian Ocean RMUs allow reinterpretation of previous mixed stock analysis and further suggest that contemporary migratory connectivity between the Indian and Atlantic Oceans occurs on a broader scale than previously hypothesized. This study represents a valuable model for conducting comprehensive international cooperative data management and research in marine ecology. [ABSTRACT FROM AUTHOR]

Management of the critically endangered hawksbill turtle in the Wider Caribbean (WC) has been hampered by knowledge gaps regarding stock structure. We carried out a comprehensive stock structure re-assessment of 11 WC hawksbill rookeries using longer mtDNA sequences, larger sample sizes (N = 647), and additional rookeries compared to previous surveys. Additional variation detected by 740bp sequences between populations allowed us to differentiate populations such as Barbados-Windward and Guadeloupe (Fst = 0.683, P < 0.05) that appeared genetically indistinguishable based on shorter 380bp sequences. POWSIM analysis showed that longer sequences improved power to detect population structure and that when N < 30, increasing the variation detected was as effective in increasing power as increasing sample size. Geographic patterns of genetic variation suggest a model of periodic long-distance colonization coupled with region-wide dispersal and subsequent secondary contact within the WC. Mismatch analysis results for individual clades suggest a general population expansion in the WC following a historic bottleneck about 100 000–300 000 years ago. We estimated an effective female population size (Nef) of 6000–9000 for the WC, similar to the current estimated numbers of breeding females, highlighting the importance of these regional rookeries to maintaining genetic diversity in hawksbills. Our results provide a basis for standardizing future work to 740bp sequence reads and establish a more complete baseline for determining stock boundaries in this migratory marine species. Finally, our findings illustrate the value of maintaining an archive of specimens for re-analysis as new markers become available. [ABSTRACT FROM PUBLISHER]

Resistance to different antibiotics was found in 26 of the 30 strains analyzed, more than 70% of the strains analyzed were resistant to carbenicillin and ampicillin and a significant correlation was found between the resistance to both antibiotics. Plasmids were found in 80% of the strains analyzed, and 11 different plasmid profiles were observed. The most common profile obtained had only a 21.2-kbp plasmid, a significant correlation was found between the presence of this plasmid and resistance to carbenicillin, although some exceptions could be detected. Plasmids were cured from a cephalothin resistant strain and reintroduced into the plasmid-free cell and into Escherichia coli DH5α, both strains gained resistance to this antibiotic. [Copyright &y& Elsevier]

Provides information on a study which observed the bacterial uptake by the nauplii of the brine shrimp, Artemia franciscana. In-depth look at two groups of nauplii; Function of the nauplii; Evaluation of the antibiotic residue left in the nauplii after rinsing; Methodology used to conduct the study; Results of the study.

Olive ridleys ( Lepidochelys olivacea) are the most numerous sea turtle species worldwide and also locally along the Pacific coast of Mexico. Published data on their distribution and nesting abundance along the coast of Nayarit and northern Jalisco, Mexico are, however, scarce. Here we describe the current extent of conservation activities and the history of efforts to protect sea turtles along this 394-km stretch of coastline. We found that 110 km (of the total of 394 km) are monitored by 18 sea turtle conservation programs, which in 2015 accounted for 43.2% of the total shoreline. Olive ridley sea turtle nesting was encountered on all monitored beaches. Our use of hatchery-protected nests as a measure of nesting levels is undoubtedly an underestimate of overall nesting in the region; however, it nevertheless provides a baseline of current nesting intensity in sites under conservation. Bahía de Banderas presented the highest nesting levels in the study area with 46.4% (3742 ± 904; mean ± SD) of the total protected nests (8073 ± 547) while only representing 14.2% (15.4 ± 3.8 km) of the total area monitored (109.6 ± 4.5 km). The results provided here represent a valuable baseline upon which future research and assessments can be built when analyzing the sea turtle conservation progress in the region. [ABSTRACT FROM AUTHOR]

Sea turtles and their nests face multiple threats on nesting beaches. Techniques have been developed to mitigate threats, these include relocating nests to fenced-off hatcheries or polystyrene boxes. The alteration of the nest's natural environment may have direct effects on hatchling phenotype and locomotor performance. To test the effects of these two incubation conditions on proxies for hatchling fitness, we analysed locomotor performance (time to crawl 3 m and righting response) and phenotypic measures (weight and carapace length and width) of olive ridley sea turtle (Lepidochelys olivacea) hatchlings. We found that mean temperature was higher in hatcheries (30.5°C) than in polystyrene boxes (29.9°C) and that hatchlings incubated in polystyrene boxes had smaller straight carapace length (39.2 mm ± 2.0) and were significantly slower in crawl speed (CS) (0.0107 m s-1 ± 0.005) than those from hatcheries (SCL = 40.7 mm ± 1.3; CS = 0.018 m s-1 ± 0.005). [ABSTRACT FROM AUTHOR]

The nesting colony of green sea turtles (Chelonia mydas) at Guanahacabibes Peninsula Biosphere Reserve and National Park is one of the largest in the Cuban archipelago; however, little information about its nesting ecology is available. Temporal and spatial variation in nesting and reproductive success as well as morphometric characteristics of gravid females were used to ecologically characterize this colony. Nine beaches of the Southernmost coast of Guanahacabibes Peninsula were monitored for 14 years (1998-2012) to determine green turtle nesting activity, from May to September (peak nesting season in this area). Beach dimensions were measured to determine nest density using the length and the area. Afterward the beaches were divided in two categories, index and secondary. Females were measured and tagged to compare new tagged females (823) with returning tagged females (140). Remigration interval was also determined. Temporal variation was identified as the annual number of nesting emergences and oviposits per female, with apparent peaks in reproductive activity on a biennial cycle in the first six years followed by periods of annual increase in nest number (2003-2008) and periods of decreasing number of nests (2010-2012). We also found intra-seasonal variation with the highest nesting activity in July, particularly in the second half of the month. The peak emergence time was 22:00-02:00hr. In terms of spatial variation, smaller beaches had the highest nest density and nesting was more frequent 6-9m from the high tide line, where hatchling production was maximized although hatchling success was high on average, above 80%. Morphometric analysis of females was made and newly tagged turtles were smaller on average than remigrants. Our results are only a first attempt at characterizing Guanahacabibes' populations but have great value for establishing conservation priorities within the context of national management plans, and for efficient monitoring and protection of nesting beaches. [ABSTRACT FROM AUTHOR]

Abstract: The hawksbill turtle is a critically endangered species that has been extensively exploited for centuries. Príncipe Island off western Africa harbours one of the species'' major nesting populations in the eastern Atlantic, as well as hosting year-round foraging aggregations of juveniles, subadults and adult males. To gain insight into the population''s genetic structure and relationships with regional stocks, we analysed mitochondrial DNA (mtDNA) sequences of nesting females (N=9), foraging adult females (N=11), adult males (N=32), subadults (N=15) and juveniles (N=80). The nesting population was found to be fixed for a single haplotype (EATL), which had been previously reported in both western and eastern Atlantic hawksbill foraging sites but had no known rookery source prior to this study. Thus it is now possible to confirm the westward transoceanic movement by hawksbills originating from Príncipe Island. Our analyses demonstrated that the Príncipe Island nesting colony is genetically distinct from breeding populations in the western Atlantic and is phylogenetically linked with Indo-Pacific hawksbill clades, suggesting that Príncipe Island was most likely colonised by migrants from the Indian Ocean via the Cape of Good Hope in southern Africa. Mixed stock analyses revealed that the eastern Atlantic appears to be the primary foraging area for Príncipe hawksbills (75%) while most of the foraging juveniles in Príncipe waters originate from the Príncipe rookery (84%). Furthermore, the presence of Caribbean haplotypes at low frequencies (<5%) suggests that eastward transatlantic movements by juveniles to distant foraging and developmental habitats also take place. Depleted hawksbill populations in the eastern Atlantic combined with the low genetic variability and high genetic distinctiveness found in the Príncipe nesting and foraging aggregations with respect to the western Atlantic, underscore the high degree of isolation and vulnerability of this eastern Atlantic stock. These characteristics are highly relevant for the development of effective conservation programmes and highlight the urgent need to consolidate international cooperation across regional boundaries. [Copyright &y& Elsevier]

Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a "conservation priorities portfolio" system using categories of paired risk and threats scores for all RMUs (n=58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the world's 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and prioritysetting for widespread, long-lived taxa. [ABSTRACT FROM AUTHOR]

Background: Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques - including site-based monitoring, genetic analyses, mark-recapture studies and telemetry - can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges. Methodology/Principal Findings: To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine- to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally. Conclusions/Significance: The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework - including maps and supporting metadata - will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Marine turtle hatchling survival depends not only on suitable incubation temperatures allowing for viable embryo development but also adequate locomotor capacity to avoid predation while crawling from the beach to the sea and when swimming into the open ocean. To investigate the effects of temperature on swimming performance of olive ridley (Lepidochelys olivacea) hatchlings, we incubated eggs at different constant temperatures (24–34 °C) using a split-clutch approach. Swimming performance of hatchlings was tested and video-recorded for 24 h in static water under a day/night cycle (experiment 1) and for 30 min in continuously flowing water in the dark (experiment 2). Data from experiment 1 were evaluated visually to estimate the time of swimming activity. For experiment 2, we used software to calculate movement parameters from which hatchling performance was estimated. In both experiments, intermediate incubation temperatures (28–30 °C) were optimal not only for hatchling success and morphological dimensions but also for swimming performance, with 30 °C being the most favorable. Performance from hatchlings diminished with higher and lower temperatures, especially at the coldest range (26–27 °C). Phenotypic plasticity was observed from low and high incubation temperatures, with higher variation in performance among hatchlings from eggs incubated at 26–27 °C and 32–33 °C than for those incubated at 28–30 °C. Our results consistently showed that incubation temperature exerts the greatest influence on swimming performance and that maternal origin (clutch) has a significant effect on individual hatchling morphology. Given that the olive ridley year-round breeding leads to variable nest incubation temperatures in hot summers and cooler winter months, our results highlight the need for careful temperature management to produce hatchlings with optimal swimming capacities and, hence, highest survival probabilities. Unlabelled Image • We used incubation temperatures spanning natural range (24–34 °C) for olive ridleys. • Intermediate temperatures produced hatchlings with best swimming performance. • Intermediate temperatures also produced heaviest and largest hatchlings. • Lowest swimming performance found from lowest and highest incubation temperatures. • Swimming performance was independent of hatchling size. [ABSTRACT FROM AUTHOR]