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Future climate change scenarios project that the increase in surface temperatures will affect ocean temperatures, inducing shifts in marine biodiversity. Sea turtles are species that are particularly vulnerable to the effects of climate change because temperature is a factor that influences embryonic development. We collected clutches of olive ridley turtles from a mass‐nesting beach in the Mexican Pacific, which were incubated in ex situ conditions. When the hatchlings emerged, we measured the body condition index—which evaluates the weight‐length relationship—and swim thrust, both were considered traits associated with fitness, termed "fitness proxies," and evaluated the effects of incubation temperature, maternal effects, and paternity on these fitness proxies. The body condition index was correlated positively and significantly with the arribada month and temperature during the last third of the incubation period but showed an inverse relationship with the maternal effect. While swim thrust was positively correlated with the maternal effect and the arribada month, there was an inverse relationship with incubation temperature during the first third of the period. Paternity, whether single or multiple, did not have a significant effect on either fitness proxies; however, it may have effects on the average fitness of a population of hatchlings. These results underscore the need to expand research on the sublethal effects of high incubation temperatures on the adaptation and survival of sea turtles, particularly in scenarios of rapid climate change. Research highlights: The body condition index was positively and significantly correlated with the temperature during the last third of the incubation period, while the swim thrust showed an inverse correlation with incubation temperature during the first third.Mother's carapace area showed a significant effect on the body condition index and swim thrust of olive ridley hatchlings, but multiple paternity within the clutches did not have a significant effect on either fitness proxies. [ABSTRACT FROM AUTHOR]

Turtles have been prominent subjects of sexual size dimorphism (SSD) analyses due to their compact taxonomy, mating systems, and habitat diversity. In prior studies, marine turtles were grouped with fully aquatic non‐marine turtles (NMATs). This is interesting because it is well‐established that the marine environment imposes a distinct selective milieu on body form of vagile vertebrates, driven by convergent adaptations for energy‐efficient propulsion and drag reduction. We generated a comprehensive database of adult marine turtle body sizes (38,569 observations across all species), which we then used to evaluate the magnitude of SSD in marine turtles and how it compares to SSD in NMAT. We find that marine turtles are only minimally sexually size dimorphic, whereas NMAT typically exhibit female‐biased SSD. We argue that the reason for this difference is the sustained long‐distance swimming that characterizes marine turtle ecology, which entails significant energetic costs incurred by both sexes. Hence, the ability of either sex to allocate proportionately more to growth than the other is likely constrained, meaning that sexual differences in growth and resultant body size are not possible. Consequently, grouping marine turtles with NMAT dilutes the statistical signature of different kinds of selection on SSD and should be avoided in future studies. [ABSTRACT FROM AUTHOR]

Chelonid alphaherpesvirus 5 (ChHV5) has been consistently associated with fibropapillomatosis (FP), a neoplastic disease that affects sea turtles globally. The DNA of ChHV5 has been detected in cutaneous and noncutaneous tissues (e.g., lung) of green sea turtles Chelonia mydas with (FP+) and without (FP−) clinical signs of FP, indicating a persistent ChHV5 infection. Previously published and custom primer pairs were used to amplify the fragments of ChHV5 unique long (UL) partial genes (UL30 and UL18) through end‐point PCR from cutaneous tumors (n = 31), nontumored skin (n = 49), and lungs (n = 26) from FP+ (n = 31) and FP− (n = 18) green sea turtles. The DNA of ChHV5 was detected in cutaneous tumors (80.6%, 25/31), nontumored skin (74.2%, 23/31 FP+; 27.8%, 5/18 FP−), and lung samples (91.7%, 11/12 FP+; 100%, 14/14 FP−). The high occurrence of ChHV5 observed in lung samples from FP− individuals was unexpected (14/14), providing the first evidence of ChHV5 DNA presence in lungs of individuals without FP. Our results also revealed high ChHV5 occurrence among the tested cohort (93.9%, 46/49) and suggested that a large proportion (83.4%, 15/18) of FP− green sea turtles had subclinical ChHV5 infections. Hence, our findings support the hypothesis that ChHV5 requires one or more possibly environmental or immune‐related co‐factors to induce FP. [ABSTRACT FROM AUTHOR]

For many species, climate oscillations drove cycles of population contraction during cool glacial periods followed by expansion during interglacials. Some groups, however, show evidence of uniform and synchronous expansion, while others display differences in the timing and extent of demographic change. We compared demographic histories inferred from genetic data across marine turtle species to identify responses to postglacial warming shared across taxa and to examine drivers of past demographic change at the global scale. Using coalescent simulations and approximate Bayesian computation (ABC), we estimated demographic parameters, including the likelihood of past population expansion, from a mitochondrial data set encompassing 23 previously identified lineages from all seven marine turtle species. For lineages with a high posterior probability of expansion, we conducted a hierarchical ABC analysis to estimate the proportion of lineages expanding synchronously and the timing of synchronous expansion. We used Bayesian model averaging to identify variables associated with expansion and genetic diversity. Approximately 60% of extant marine turtle lineages showed evidence of expansion, with the rest mainly exhibiting patterns of genetic diversity most consistent with population stability. For lineages showing expansion, there was a strong signal of synchronous expansion after the Last Glacial Maximum. Expansion and genetic diversity were best explained by ocean basin and the degree of endemism for a given lineage. Geographic differences in sensitivity to climate change have implications for prioritizing conservation actions in marine turtles as well as for identifying areas of past demographic stability and potential resilience to future climate change for broadly distributed taxa. [ABSTRACT FROM AUTHOR]

Abstract: A new stem cheloniid turtle, Cabindachelys landanensis, gen. et sp. nov., is represented by a nearly complete skull and partial hyoid collected in lower Paleocene shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda, Angola. A partial chelonioid carapace previously reported from this locality is referred here to C. landanensis. Cabindachelys landanensis possesses clear synapomorphies of Pan‐Cheloniidae, including a rod‐like rostrum basisphenoidale, V‐shaped basisphenoid crest, and secondary palate, but also retains a reduced foramen palatinum posterius, unlike most other pan‐cheloniids. Phylogenetic analysis suggests that C. landanensis forms a weakly‐supported clade with Erquelinnesia gosseleti, Euclastes acutirostris, Euclastes wielandi and Terlinguachelys fischbecki, although a close relationship between the protostegid T. fischbecki and these durophagous pan‐cheloniids is unlikely. The Paleocene–Eocene strata near Landana have produced a number of turtle fossils, including the holotype specimen of the pleurodire Taphrosphys congolensis. A turtle humerus collected c. 1 m above the holotype skull of C. landanensis differs from humeri of chelonioids and Taphrosphys, indicating that a third turtle taxon is present at Landana. Cheloniid fossil material is rare in the Landana assemblage, in comparison with the abundant remains of Taphrosphys congolensis found throughout the stratigraphic section. This disparity implies that C. landanensis preferred open marine habitats, whereas Taphrosphys congolensis spent more time in nearshore environments. The appearance of new durophagous species such as C. landanensis in the early Paleocene reflects the rapid radiation of pan‐cheloniids as they diversified into open niches following the K–Pg extinction. [ABSTRACT FROM AUTHOR]

Seasonal movements and core habitat areas of immature Kemp's ridley sea turtles ( Lepidochelys kempii) in the northern Gulf of Mexico were tracked via satellite telemetry. Tagged turtles were incidentally captured by recreational fishermen and rehabilitated at the Institute for Marine Mammal Studies in Gulfport, Mississippi., The average size of the core habitat areas (50% KDE (kernel density estimation)) was 1660.2 km2 ± 3438.2 SD. Turtles displayed strong intra- and inter-annual site fidelity to the Mississippi Sound during the spring, summer, and autumn months. During the winter months, most turtles, probably influenced by water temperatures, migrated to nearshore waters of Louisiana on either side of the Mississippi River Delta. However, other migration strategies were also observed., Overall, these data indicate that the Mississippi Sound is an important developmental habitat for this critically endangered species. In addition, their wintering grounds in Louisiana are utilized by adult Kemp's ridleys and other sea turtle species as foraging grounds and migratory corridors. The high use of these areas by sea turtle populations increases the potential for negative impacts from anthropogenic disturbances (e.g. shrimp trawling, oil production, hypoxia) that occur there., Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This study is a quantitative evaluation of historic nesting levels of the Kemp's ridley sea turtle (Lepidochelys kempii) in 1947 based on (1) the Herrera film of a 1947 arribada, (2) Hildebrand's 1947 report regarding the 1947 arribada shown in the Herrera film, (3) historic documentation regarding the Herrera film, and (4) current nesting characteristics related to arribada size relative to total nests for a season. Using this information in a quantitative approach, we estimate a total of approximately 26 916 nests during the 1947 arribada recorded by Herrera. Based on current nesting trends, we also predict that this would equate to approximately 121 517 total nests for the 1947 season (range of 82 514–209 953), which would represent approximately 48 607 nesting females (range of 33 006–83 981). This suggests that during and prior to the 1947 nesting season a relatively robust population of Kemp's ridleys existed, which could support arribadas consisting of at least 26 916 females. The results of the current study indicate that from 1947 through 1985 (the lowest point in the decline of Kemp's ridley nesting) the Kemp's ridley population underwent a 99.4% decline (range of 99.2–99.7%) from an estimated 121 517 nests per season in 1947 to 702 nests per season in 1985. Although the Kemp's ridley population has been recovering since the 1985 season, it has deviated from its exponential recovery rate and has declined in recent years. The current levels of nesting (12 053 nests in 2014) are still relatively low at 9.9% (range of 5.7–14.6%) of the total estimated nests that occurred in 1947. It is currently not clear whether this population will recover to historic levels considering recent nesting trends and due to a variety of threats that may hinder its recovery. [ABSTRACT FROM AUTHOR]

Aim Hurricanes bring wind and rainfall that can have dramatic effects on coastal ecosystems, which provide important nesting locations for some migratory species. We investigated the frequency with which hurricanes impact spatially and biologically distinct sea turtle nesting populations to understand whether the reproductive biology of sea turtles can buffer population-level impacts of these disturbances. Location North-western Atlantic and north-eastern Pacific Oceans. Methods Historical hurricane paths from 1970 to 2007 were combined into a spatial layer of seasonal storm frequency, which we used to quantify the frequency of impacts on sea turtle nesting sites. This was done by comparing spatio-temporal patterns of hurricane frequency among nesting sites used by different species and spatially/biologically distinct populations ('regional management units'). Results Hurricanes affected 97% of sea turtle nesting beaches ( n = 2444) over four decades, and the seasonal incidence of these storms overlapped substantially with sea turtle nesting and egg incubation periods. The spatial distribution of storms, in relation to the distribution of species and regional management units, determined relative exposure to large storm events. Green ( Chelonia mydas), hawksbill ( Eretmochelys imbricata) and leatherback ( Dermochelys coriacea) turtle nesting beaches experienced relatively frequent storms; loggerhead ( Caretta caretta) and Kemp's ridley ( Lepidochelys kempii) turtle nesting beaches experienced relatively fewer storms; and olive ridley turtle ( Lepidochelys olivacea) nesting sites were least affected. Main conclusions Extreme weather events are common features of coastal environments and may impact sea turtles by altering nesting habitat quality (through sand erosion and accretion) and lowering within-season reproductive success by drowning incubating embryos or eroding nests. The unique reproductive attributes of sea turtles (i.e. individual females reproduce at 2-5-year intervals, and when reproducing lay 2-7 clutches of c. 100 large eggs at c. 2-week intervals) may be uniquely suited to exploiting highly disturbed nesting habitats. The impacts of hurricanes on sea turtle populations may be limited because even in severe storm seasons only a proportion of adult females are reproducing, and only those eggs incubating at the time of storm impact will be directly affected. Understanding whether the frequency of large storms influences long-term population dynamics will aid in the development of effective local and regional management plans for sea turtle recovery efforts. [ABSTRACT FROM AUTHOR]

Fisheries observers have documented interactions between sea turtles in the family Cheloniidae and the Atlantic sea scallop fishery. Sea turtle injuries resulting from interactions with scallop dredges are being mitigated through shifts in fishing effort and modifications to fishing gear. The standard New Bedford dredge can trap objects and crush them as they pass between the dredge frame and sea floor, so a modified turtle excluder dredge has been designed to reduce the likelihood of a turtle's passing under the frame when the dredge fishes on the seafloor. The key elements of the modified design are a forward cutting bar (which results in a sloping rather than a vertical face), a reduced number of bale support bars (just the center and outer bales), extension of the outer bale bars before tapering to the gooseneck (hauling point), and a reduction in the sources of entrapment between the depressor plate and the cutting bar via reduced spacing of struts. We evaluated the ability of the modified dredge to cause live sea turtles to pass over it by using loggerhead sea turtle carcasses as a proxy. The carcasses were placed on the seafloor in the path of a towed dredge equipped with video cameras. Nine interactions between carcasses and the modified dredge were documented on video recordings. In each of the interactions, the carcass hit the dredge and passed over the dredge frame with little or no physical damage to the recovered carcasses. These carcass studies suggest that the turtle excluder dredge reduces sea turtle injuries associated with interactions between sea turtles and scallop dredges fishing on the seafloor. [ABSTRACT FROM AUTHOR]

Although the Atlantic waters of North America support hundreds of thousands of loggerhead sea turtles ( Caretta caretta), remarkably little is known regarding their migratory ecology and habitat use. We integrate satellite tracking with remotely sensed oceanographic data to uncover two different migratory strategies used by loggerhead turtles at the northern part of their range. Most turtles travelled from the nesting beach to forage at higher latitudes in summer, before migrating south to wintering grounds in the autumn. Others moved south after nesting to forage for up to 514 days and did not make an autumn migration. Both groups utilized warm waters at the very edge of the Gulf Stream during winter: for southerly turtles obviating seasonal migration, and for northerly turtles minimizing the distance, time and energy required to reach northern areas for subsequent foraging seasons, avoiding lethally cold winter temperatures in inshore waters at the same latitude, and reducing energy costs that would be incurred within the fast-flowing Gulf Stream. Females made long resting dives of up to 7 h 24 min, effectively hibernating during the colder months. Offshore federal waters of the USA constitute a more important habitat for both foraging and wintering turtles than previously appreciated. These areas are potential hotspots for interaction with fisheries and proposed US military training activities and should receive special monitoring efforts to fully assess the extent of overlap. [ABSTRACT FROM AUTHOR]

A new, unusually well-preserved juvenile specimen of Ctenochelys stenoporus from the Niobrara Formation is described. The skull has come apart at its sutures and all bones of the braincase and ear region are preserved three-dimensionally. This allows a detailed reconstruction of the important brain structures of a basal juvenile cheloniid turtle. It is compared with adult Ctenochelys specimens, and the major ontogenetic changes in the skull and postcranial skeleton are described. Furthermore, the specimen is compared with other fossil and extant cheloniids with well-known braincases and the differences between basal and advanced cheloniids turtles are specified. [ABSTRACT FROM AUTHOR]

A declining population of the freshwater turtle Mauremys rivulata (Chelonia, Geoemydidae) living in a human-impacted area along the Strymon River, just upstream from Kerkini Lake (Prefecture of Serres, northern Greece), was investigated by capture–recapture and radio-tracking. Fyke nets placed along the river and in ponds lying on the riparian lowland gave about 2000 catches in 6 years, permitting us to assess major inter-habitat movements during ontogenesis and throughout the seasons. Annual intensive radio-tracking of 15 females and 10 males gave finer details of movement patterns between different river-wetland habitats. Younger specimens, including yearlings, inhabited the ponds almost exclusively, whereas the adult population shifted seasonally from the ponds during the mating season to a marsh area lying on the opposite side of the river for aestivation and overwintering. The river served mainly as a corridor for transit between the two habitats. Moreover, longitudinal movements along the river were observed, particularly in the males, which probably allow dispersal and gene flow between subpopulations living in the area. One major threat to the viability of M. rivulata in the study area is the diversion of water for irrigation during the summer, drying up the Strymon completely, which reduces the water level in the ponds. Livestock crossing the area for grazing and watering in the ponds is also of impact, as turtles in the ponds are trampled on and nests are disturbed. [ABSTRACT FROM AUTHOR]

The olive ridley is the most abundant seaturtle species in the world but little is known of the demography of this species. We used skeletochronological data on humerus diameter growth changes to estimate the age of North Pacific olive ridley seaturtles caught incidentally by pelagic longline fisheries operating near Hawaii and from dead turtles washed ashore on the main Hawaiian Islands. Two age estimation methods [ranking, correction factor (CF)] were used and yielded age estimates ranging from 5 to 38 and 7 to 24 years, respectively. Rank age-estimates are highly correlated ( r = 0.93) with straight carapace length (SCL), CF age estimates are not ( r = 0.62). We consider the CF age-estimates as biologically more plausible because of the disassociation of age and size. Using the CF age-estimates, we then estimate the median age at sexual maturity to be around 13 years old (mean carapace size c. 60 cm SCL) and found that somatic growth was negligible by 15 years of age. The expected age-specific growth rate function derived using numerical differentiation suggests at least one juvenile growth spurt at about 10–12 years of age when maximum age-specific growth rates, c. 5 cm SCL year−1, are apparent. [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]

Aim To examine the exploitation, recovery and current status of green turtles ( Chelonia mydas) nesting at Ascension Island. Location Ascension Island (UK) (7°57′ S, 14°22′ W), South Atlantic Ocean. Methods We analysed records of the harvest of green turtles nesting at Ascension Island between 1822 and 1935, illustrating the decline in numbers over this period. Using a deterministic age-class structured model we predict the initial number of breeding females present in the population prior to the recorded harvest and compare this to our estimate of the current population based upon our recent annual surveys (1999–2004). Results Prior to 1822 we estimate the nesting population of green turtles to have been at least 19,000–22,000 individuals in order for the population to have survived the level of harvest recorded. From recent data (1999–2004), we estimate the current breeding population of green turtles at this site to be 11,000–15,000 females. Our results illustrate a dramatic recovery of the population, which is still increasing exponentially and shows no evidence of slowing, suggesting it has not reached 50% of its carrying capacity. Main conclusions We estimate that, since the 1970s, the Ascension Island population of green turtles has increased by 285% and question the recent listing of this species as endangered by the IUCN (World Conservation Union), in particular in the Atlantic Ocean, where 75% of the populations assessed by the IUCN are increasing. Indeed, we estimate the global population of this species to be in excess of 2.2 million individuals. We suggest that the IUCN's global listing process detracts attention from those populations that are truly threatened with extinction and should not, in its present form, be applied to globally distributed long-lived species such as marine turtles. [ABSTRACT FROM AUTHOR]

Sixty-nine tortoises, turtles and terrapins representing 28 species of the order Chelonia, class Reptilia were evaluated by endoscopy for renal disease. Under general anaesthesia, coelomic and/or extracoelomic endoscopic evaluations and biopsies of the kidney(s) were undertaken. Endoscopic approaches required a 2 to 4 mm skin incision in the prefemoral fossa, and minimal blunt dissection through the subcutaneous tissues. For the coelomic approach the coelomic aponeurosis of the transverse and oblique abdominal muscles was penetrated so that the cranioventral kidney(s) could be examined and biopsied. The extracoelomic approach required the endoscope to be advanced in a caudodorsal direction, between the coelomic aponeurosis and the broad iliacus muscle, so that the dorsolateral kidney(s) could be examined and biopsied. Both techniques were safe and effective for obtaining renal biopsies for histological examination and microbiological culture. Several renal pathologies were identified including glomerulonephrosis, tubulonephrosis, interstitial nephritis, uric acid accumulation, tubulonephritis, glomerulonephritis, renal oedema, glomerulosclerosis, nephrosclerosis, soft tissue mineralisation, and pyelonephritis. Several infectious conditions were identified, including a predominance of Gram-negative bacterial infections, two cases of hexamitiosis, and one case of mycobacteriosis. [ABSTRACT FROM AUTHOR]

A total of 16 chelonid herpesviruses that were isolated between 1992 and 1998 were compared with one another on the basis of serology and restriction enzyme digestion patterns of viral DNA. The viruses stem from tortoises of three different species in four different European countries and the United States of America. The majority of the isolates were similar to one another. One isolate, however, differed strongly from all others both serologically and in the restriction cleavage pattern of its DNA, showing that there are at least two different sero- and genotypes of herpesviruses that infect tortoises. [ABSTRACT FROM AUTHOR]

Reports on a study in which the frequency of Salmonella shedding in feces of captive chelonians in France was estimated. Percentage of Salmonella in household chelonians and in animals at a rescue center; Low rate of infection in animals from zoological gardens.

The hawksbill turtle ( Eretmochelys imbricata), listed since 1996 by the IUCN as Critically Endangered and by the Convention on International Trade in Endangered Species (CITES) as an Appendix I species, has been the subject of attention and controversy during the past 10 years due to the efforts of some nations to re-open banned international trade. The most recent debate has centred on whether it is appropriate for Cuba to harvest hawksbills from shared foraging aggregations within her national waters. In this issue of Molecular Ecology, Bowen et al. have used molecular genetic data to show that such harvests are likely to have deleterious effects on the health of hawksbill populations throughout the Caribbean. [ABSTRACT FROM AUTHOR]