Hawksbill Turtles Eretmochelys Imbricata Research Articles

Intra-species variability in migratory movement of hawksbill turtles in the southwest Indian Ocean

Implementing effective conservation measures to manage migratory populations is challenging, especially in a relatively inaccessible dynamic environment such as the ocean. With limited financial and human resources, efforts must be intelligently prioritized to achieve conservation success and reduce uncertainties of conservation efforts. The southwest Indian Ocean (SWIO) hosts some of the world’s most important breeding grounds for the Critically Endangered hawksbill turtle Eretmochelys imbricata. However, knowledge gaps remain about the movement patterns of this species. Between 2007 and 2022, we deployed 17 satellite tags onto hawksbill turtles from scattered locations in the SWIO: 16 nesting females—Granitic Islands, Seychelles (n = 9); north Madagascar (n = 5); Moheli, Comoros (n = 1); Juan de Nova, Terres australes et antarctiques françaises (n = 1)—and 1 female bycaught in fisheries (east Madagascar). We found strong variability in migratory movements amongst individuals, particularly in terms of distance and movement persistence. Detailed analysis of movement persistence reveals that these individuals behave differently in neritic and oceanic habitats, with a lower movement persistence in neritic habitats. We identified a total of 12 foraging areas scattered throughout the SWIO, both in coastal and open-sea neritic habitats. These results reinforce the need to consider the importance of neritic habitats, for both migration and foraging, in conservation policies. The quantification of the degree of migratory variability is particularly important to developing conservation plans and strategies at both the national and international level, including the delineation of regional management units (RMUs) in the Indian Ocean.

Hawksbill and green turtle niche overlap in a marine protected area, US Virgin Islands

Studying how species interact with their environment and other co-occurring species are 2 main aspects of ecology. For marine turtles, ocean currents drive migratory routes and may determine the location of surrounding foraging grounds. As a result, circumglobal species like the hawksbill turtle Eretmochelys imbricata and green turtle Chelonia mydas adapt to diverse foraging habitats and employ varied feeding strategies. Dietary specializations may reduce competition for available food and space resources between co-occurring hawksbill and green turtles in US Virgin Island shallow reef habitats. This study analyzed isotopic data from immature hawksbill (n = 49; range: 18.7-49.8 cm straight carapace length [SCL]) and green turtles (n = 225; range: 24.1-69.4 cm SCL) to examine foraging niche. We used nitrogen stable isotope (δ15N) values as an indicator of trophic positioning and carbon stable isotope (δ13C) values as a habitat variable. Turtles were hand-captured across an 8 yr period (2012-2019), which facilitated the distinction of isotopic patterns in both the environment and among individual turtles. Understanding variations in habitat, community dynamics, and dietary consumption allowed us to utilize a 5 point framework to translate isotopic space to foraging niche. We found that the site’s relatively stable environmental conditions allow for isotopic overlap between hawksbill and green turtles despite the specialized feeding strategies each species employs. We also underscore the need to evaluate species-specific tissue turnover estimates as evidenced by the influence of tropical storms on recaptured turtle isotopic signatures. These findings inform our understanding of resource use for these imperiled species at our study site and are useful for future global isotopic comparisons.

Plesiochorus irwinorum n. sp. (Trematoda: Gorgoderidae) from the urinary bladder of the hawksbill turtle, Eretmochelys imbricata (Testudines: Cheloniidae), off the east coast of Australia

Plesiochorus Looss, 1901 is a genus of Gorgoderidae infecting the urinary bladders of marine turtles globally. Currently, just two morphologically similar species are recognised, Plesiochorus cymbiformis (Rudolphi, 1819) Looss, 1901 and Plesiochorus elongatus Pigulevsky, 1953, which have been distinguished by molecular data and subtle morphological differences. Here we describe a new species, Plesiochorus irwinorumn. sp., infecting hawksbill turtles (Eretmochelys imbricata (L.)), which is primarily distinguished from the other two species of Plesiochorus on the basis of ITS2, cox1 and 28S sequence data. Morphometric data for specimens examined during this study overlap between P. cymbiformis and P. irwinorumn. sp. for every measured feature, rendering them functionally cryptic. However, principal components analysis clearly distinguishes the two species. Additionally, we report new specimens of P. cymbiformis, and provide new sequence data for specimens from Australian loggerhead (Caretta caretta (L.)) and hawksbill turtles. There is little understanding of the host-specificity or geographical distribution of the three species of Plesiochorus, and it remains possible that some of the previously reported sequences have been attributed to the wrong species.

Trends in abundance and reproductive success of the hawksbill turtle nesting population at Buck Island Reef National Monument, St. Croix, US Virgin Islands

Index nesting sites for the Critically Endangered hawksbill turtle Eretmochelys imbricata are essential for assessing population trends and demographics, and informing conservation strategies. Using 29 yr (1988-2017) of saturation tagging data from a protected Caribbean index site, we assessed annual trends in abundance and reproductive success for the hawksbill nesting population at Buck Island Reef National Monument (BIRNM), St. Croix, US Virgin Islands. Approximately 43 ± 21 (mean ± SD) females and 154 ± 60 nests were encountered each year during nocturnal patrols. Remigration interval and inter-nesting period averaged 3.2 ± 1.6 yr and 17.4 ± 7.1 d, respectively. After a significant recovery since 1988, female abundance stabilized during 2007-2017 (p < 0.01, R2 = 0.82), whereas nest abundance declined (p < 0.01, R2 = 0.71) and neophyte recruitment exhibited a decreasing trend. There was no trend in annual mean hatch success (69.4 ± 26.6%), emergence success (63.0 ± 29.1%), and hatchling production (89.2 ± 45.0 individuals clutch-1) during the study period; but clutch size (p < 0.01, R2 = 0.65; 142.8 ± 28.9 eggs clutch-1) and female curved carapace length (p < 0.01, R2 = 0.56; 88.4 ± 4.7 cm) significantly decreased. The BIRNM population has stabilized, but declines in body size and nest abundance highlight the need for evaluating demographics to diagnose the factor(s) driving changes in abundance and productivity. Our study provides a foundation for evaluating Caribbean hawksbill demographics, while contributing a valuable assessment of clutch size and in situ nest success for the species.

Novel Use of Anchialine Ponds by Hawksbill Turtles in The Bahamas

We present 4 observations of hawksbill turtles Eretmochelys imbricata found in anchialine ponds on 3 islands in The Bahamas. These ponds had no surface connection to the ocean, but they were connected by subterranean conduits that, in at least one instance, extended over 1.5 km in length. It is possible that the turtles were placed in these ponds by humans; however, it appears more likely that they accessed these habitats via the subterranean conduits suggesting that anchialine ponds may function as either novel habitat or a potential ecological trap.

Past Biodiversity: Japanese Historical Monographs Document the Epibiotic Barnacles and Cold-Stunning Event of the Hawksbill Turtle Eretmochelys imbricata

The historical monographs called “Honzou Gaku” present the first record of cold-stunning of a hawksbill turtle Eretmochelys imbricata (Linnaeus, 1766) in the Echigo region of Japan during the Edo period (1600–1868), and the barnacles attached to the turtle were identified as Platylepas hexastylos (Fabricius, 1798). Analysis of this finding adds substantial knowledge to our understanding of the life history of the hawksbill turtles along the coast of Japan. As reported in this study, literature on the historical heritage of other animals or plants can also provide information about their past biodiversity.

Beach profiling and ghost crab densities on a hawksbill turtle nesting beach in the Seychelles

Increasing beach sediment loss from erosion and high levels of crab Ocypode spp. predation are threatening turtle nests and nesting habitat. The 900 m long beach on Cousine Island, Seychelles, supports a nesting population of approximately 70–130 hawksbill turtle Eretmochelys imbricata nests each season. Seasonal and storm-related erosion and accretion cycles on Cousine Island have the potential of destroying 50% or more of all turtle egg clutches on the island in a single nesting season. Observed crab predation rates had reached 90–100% in preferred nesting beach zones in previous years. This has resulted in intensive management measures to minimise turtle egg and nest losses. We investigated the distribution and population density of ghost crabs and the morphology of the beach across the different beach area zones and across the turtle-nesting season during 2014–2015. Crab burrow numbers varied between beach zone areas and across the season and were highest on the backshore. Crab density correlated negatively with available beach area, and we found that crab density increased in the presence of turtle nests. When examining beach dynamics, we found them to be cyclical and found the nesting beach prone to higher levels of erosion than accretion with significant changes in beach width throughout the season. The mean vertical beach elevation drop on Cousine Island was higher than what hawksbill turtles have been reported to prefer. We suggest the continuation of beach elevation monitoring and management to use the beach morphology data to assist with hawksbill turtle nest translocations to minimise nest losses and maximise hatchling recruitment success.

GENETIC AND MORPHOLOGIC CHARACTERIZATION OF DIASCHISTORCHIS PANDUS (DIGENEA: PRONOCEPHALIDAE) TREMATODES EXTRACTED FROM HAWKSBILL TURTLES, ERETMOCHELYS IMBRICATA (TESTUDINES: CHELONIIDAE), IN GRENADA, WEST INDIES.

The hawksbill turtle Eretmochelys imbricata is a critically endangered species with a worldwide distribution. Limited information is available about the naturally occurring intestinal parasites of this species and what impact these parasites may have on the health of the hawksbill turtle. Diaschistorchis pandus was identified postmortem in 5 hawksbill turtles from Grenada, West Indies, using morphologic characterization. Sanger sequencing was performed for conserved ribosomal regions (5.8S, ITS2, 28S) and the mitochondrial cytochrome c oxidase subunit 1 gene (COI). Phylogenetic analysis of the 28S rRNA gene sequence data shows D. pandus clustering with other trematodes in the family Pronocephalidae, corroborating morphological classification. No genetic sequences have been previously reported for this trematode species, which has limited the collection of objective epidemiological data about this parasite of marine turtles.

Detection of high heteroplasmy in complete loggerhead and hawksbill sea turtles mitochondrial genomes using RNAseq

Sea turtle populations around the world face rapid decline due to the effect of anthropogenic and environmental factors. Among the affected populations are those of hawksbill turtles (Eretmochelys imbricata) and loggerhead turtles (Caretta caretta), which is why a greater effort is currently being made in their monitoring and tracing. The intragenic degree of heteroplasmic mutations, commonly associated with diseases of variable symptoms, has not been analyzed in these species. In this study, heteroplasmy in the complete mitogenome (mtDNA) of three loggerhead turtles and one hawksbill turtle was identified from data obtained by RNAseq. Individuals Cc3, Ei1, Cc1 and Cc2 presented 0.3, 1.7, 1.8 and 7.1% of heteroplasmic mutations in all their mtDNA, respectively. The protein-coding genes that presented the highest percentage of heteroplasmy were ND4 and ND5 in individual Cc2 with 16 and 38.6%, respectively. Of the tRNA genes, only tRNATyr was heteroplasmic in the four individuals with 5.63% (Cc1), 25.35% (Ei1 and Cc2) and 49.3% (Cc3). In this study, we identified the critical sites of heteroplasmy in each individual and the genetic variability of their mitogenomes. The data obtained represents the baseline for future projects that evaluate the population status of these species.

Youth wildlife preferences and species-based conservation priorities in a low-income biodiversity hotspot region

SummaryPublic preferences for wildlife protection can dictate the success or failure of conservation interventions. However, little research has focused on wildlife preferences among youth or how youth prioritize species-based conservation. We conducted a study of youth between 7 and 20 years old (n = 128) at five local schools situated near critical hawksbill turtle (Eretmochelys imbricata) nesting beaches in El Salvador to determine their wildlife preferences and how they prioritize species for conservation based on five attributes: endemism; use for hunting and fishing; rapid decline in population size; presence around their home; and ecological significance. These Salvadoran youth showed preferences for native over non-native species and tended to rank rapid population decline as the most important attribute for prioritizing wildlife for protection, followed by use for hunting and fishing. Participants in local environmental education activities placed greater importance on species in rapid decline than non-participants, who considered endemism as most important. Overall, these findings reveal how environmental education may successfully promote increased prioritization of imperilled species among youth. Economic payments for conserving hawksbill turtles may link the two top reasons that Salvadoran youth provided for protecting species by compensating for the reduced hunting required to facilitate population stabilization.

Creation of a peptide database of corneous beta-proteins of marine turtles for the identification of tortoiseshell: archaeological combs as case study.

Tortoiseshell is a proteinaceous material derived from the scutes of marine turtles, and was shaped into an abundance of objects, especially luxurious items, at its peak in the seventeenth and eighteenth century. It has continued to be used even after the advent of plastics and remains one of the main causes of illegal poaching of marine turtles, in particular the hawksbill turtle Eretmochelys imbricata. Tortoiseshell is made of structural proteins, of which the most abundant are known as β-keratins, or ‘corneous beta-proteins' (CBPs), a family of short proteins containing a central structure in β-sheets. There are, however, few CBP sequences of marine turtles in protein databases. The scutes of the five main species of marine turtles (Chelonia mydas, Caretta caretta, Eretmochelys imbricata, Lepidochelys olivacea and Lepidochelys kempii) were analysed by proteomics, using nano-liquid chromatography-Orbitrap-mass spectrometry to generate peptidic markers for species identification. A total of 187 marker sequences were identified, the large majority of them obtained from automated de novo sequencing. The sequences were classified into peptides A to F: A to D at the N-terminus and central region that forms the β-pleated sheets, E1–4 for a variable region of glycine-repeats region and F at the C-terminus. The markers were tested against a set of combs discovered in various archaeological sites of modern period in France, successfully identifying hawksbill turtle and highlighting patterns of degradation in archaeological tortoiseshell.

Later Nesting by Hawksbill Turtle following Sea Surface Warming

We studied the nesting behavior of the Hawksbill Turtle (Eretmochelys imbricata) along the northeastern coast of Brazil, specifically in southern Rio Grande do Norte. We compare the peak of nesting activity for several seasons from 2006 to 2016. The raw data consist of daily records of the presence of hawksbill turtle on a beach (N = 3,717). In the statistical analysis, we construct a cumulative sum of data and perform a logistic fitting. Furthermore, we use the derivative of the fitting to find the peak of nesting season. We observed a drift in the oviposition peak of the Hawksbill Turtle. In addition, the peak of maximal sea surface temperature in the nesting area followed a similar drift. The results suggest that the Hawksbill Turtle population has been responding to warming environmental changes.

Effects of nest management methods on hatching success and predation rates of hawksbill turtles on Cousine Island, Seychelles

Sea turtle populations have declined globally and are of conservation concern. We investigated the effects of nest management methods on hatching success and egg/hatchling predation rates of hawksbill turtles Eretmochelys imbricata on Cousine Island, Seychelles. We determined the effectiveness of two different crab-barrier methods (netted and fenced) on hatching success and predation rates. We examined the relative influence of nest-site cover (full sun, partial sun or full shade) and location (zones of high risk or low risk of predation) on hatching success and predation rates. We also examined temperature disparity between netted and control nests to estimate potential effects on sex ratios and measured typical beach-substrate temperatures in the different nesting habitats. We compared data from 40 netted, 40 fenced and 40 control nests during the 2014/2015 breeding season. Overall, hawksbill turtle hatching success was not significantly affected by treatment or cover; however, netted nests and nests incubating in full sun had the highest mean hatching success. Predation rate was generally low but variable, and the rates differed significantly between the three treatments. Nest temperatures differed significantly between the netted and control nests, with netting used to protect nests having a substantial cooling effect. Hatchling sex ratios for natural nests were skewed towards females and those for netted nests skewed towards males. With climate change and increasing ambient temperatures imminent, a better understanding of how the spatial distribution of nests and variations in environmental factors influence hawksbill turtle hatching success and the levels of predation on eggs and hatchlings will assist future conservation measures.

Nesting ecology and hatching success of the hawksbill turtle (2004–2014) on Cousine Island, Seychelles

Populations of the Critically Endangered hawksbill turtle Eretmochelys imbricata in the Seychelles showed significant declines in the past. They have since recovered and nesting numbers are increasing because of increased protection and management intervention. Data on their nesting ecology on Cousine Island were collected and analysed for the breeding seasons from 2004/2005 to 2013/2014 with the aim of improving management methods. The findings indicate that the number of nesting individuals increased during the study period (from x̅ = 34.3 nesters between 2004 and 2009, to x̅ = 55.4 nesters between 2010 and 2014); however, the clutch frequency was relatively low compared with other study areas. Night-time nesting increased, most likely because of increased disturbances across the study period. Clutch sizes decreased significantly across the nesting season, and there was a significant drop in hatching success in clutch sizes exceeding 200 eggs. The predation rate and infertility rate each showed an increasing trend over time. Nests incubating in full sun showed the highest mean hatching success rate and had the shortest mean incubation duration. The present study provides insight into the species’ nesting ecology on Cousine Island and will better inform management decisions aimed at increasing hatching success and minimising threats such as beach erosion and predation.

Exceptionally high natal homing precision in hawksbill sea turtles to insular rookeries of the Caribbean

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 620:155-171 (2019) - DOI: https://doi.org/10.3354/meps12957 Exceptionally high natal homing precision in hawksbill sea turtles to insular rookeries of the Caribbean Kathryn E. Levasseur1,2,*, Seth P. Stapleton2,3, Mykl Clovis Fuller4, Joseph M. Quattro1 1Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA 2Jumby Bay Hawksbill Project, Jumby Bay, PO Box 243, St. John’s, Antigua, West Indies 3Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, St. Paul, MN 55108, USA 4Antigua Sea Turtle Conservation Project, Environmental Awareness Group, Long Street, St. John’s, Antigua, West Indies *Corresponding author: kathryn.levasseur@gmail.com ABSTRACT: Marine turtles migrate back to their natal region during reproduction, but the precision of this homing behavior and how the precision varies among populations and across biogeographic regions are unclear. We hypothesize that marine turtles nesting on insular landmasses navigate to their rookeries with greater precision than those nesting on continuous coastlines. We analyzed new mitochondrial and microsatellite marker data from hawksbill turtles Eretmochelys imbricata at nesting sites across Antigua and Barbuda, West Indies, to assess the scale of natal homing in the highly insular Leeward Islands. We then used published data from 15 western Atlantic rookeries to examine regional patterns of rookery structure. Mitochondrial control region data showed weak to no partitioning among nesting sites within Antigua and strong partitioning between Antigua and Barbuda, suggesting natal homing at a scale of 50 km. Microsatellite data showed weak to no partitioning between sites, indicating male-mediated gene flow. Regionally, we found stronger population structuring among rookeries of insular landmasses than among those of larger landmasses with continuous coastlines, despite shorter average rookery separation for the former. We also found a positive relationship between a rookery’s isolation index (a metric incorporating distances from larger landmasses) and its genetic divergence from proximate rookeries. These findings support our hypothesis, and we caution that insular rookeries that host marine turtles with extreme homing behavior have limited ability to colonize new nesting habitat. The unprecedented rates of development and increasing instability of present-day nesting habitat might therefore pose a greater and increasing threat to insular rookeries. KEY WORDS: Philopatry · Endangered species · Management units · Eretmochelys imbricata · Mitochondrial DNA · Microsatellites Full text in pdf format Supplementary material PreviousNextCite this article as: Levasseur KE, Stapleton SP, Fuller MC, Quattro JM (2019) Exceptionally high natal homing precision in hawksbill sea turtles to insular rookeries of the Caribbean. Mar Ecol Prog Ser 620:155-171. https://doi.org/10.3354/meps12957 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 620. Online publication date: June 18, 2019 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2019 Inter-Research.

Insights into identifying habitat hot spots and migratory corridors of green turtles in the South China region

Abstract Sea turtles are globally endangered, and face daily anthropogenic threats, such as direct take, by‐catch, and habitat degradation. Current research efforts on sea turtles in the South China region mainly focus on captivity and husbandry, haematology and blood chemistry, and nesting ecology. Published information on the marine habitat use of wild populations is limited. This situation therefore creates a pressing need for scientific research on free‐ranging sea turtles as a foundation for habitat management and species protection in South China. In this study, habitat use and oceanic movement of nesting, and by‐catch or stranded green turtles, were determined by satellite tracking combined with home‐range analysis. Coupled with previous findings, the foraging grounds of several sea turtle species (green turtle Chelonia mydas, hawksbill turtle Eretmochelys imbricata and loggerhead Caretta caretta) were mainly distributed along the coasts of Hainan Island Province and Guangdong Province, mainland China, as well as Taiwan and the Philippines, and the outlying islands in the South China Sea and East China Sea. Habitat hot spots and migratory corridors of green turtles, in particular nesting turtles in South China, were identified. Coastal waters near Wanning City of Hainan Island, the eastern Leizhou Peninsula, Iriomote‐jima and Ishigaki‐shima of the Ryukyu Islands of Japan, and Dao Bach Long Vi of Vietnam serve as foraging grounds for nesting green turtles from different origins in South China. Moreover, the Paracel (Xisha) and the Pratas (Dongsha) Islands in the South China Sea, Huidong Gangkou, and its vicinity in mainland China, and Liouciou Island and Penghu Island of Taiwan contain both nesting sites and foraging grounds for green turtles. The sites that are associated with migratory corridors, in particular Hainan Island, eastern Leizhou Peninsula, and Liouciou Island, which currently lack conservation plans for sea turtles, should be given higher priority for habitat and species protection.

Identification of marine key areas across the Caribbean to ensure the conservation of the critically endangered hawksbill turtle

Acquisition of data on animal movement when developing management strategies is a common challenge in species conservation, especially when dealing with a critically endangered species as the hawksbill turtle Eretmochelys imbricata. To reach the objective of the 2008 national action plan for Martinique Island (French West Indies), the present paper examines horizontal and vertical movements in juveniles (n = 3) and adults life stages (11 females and 2 males) of 16 hawksbill turtles. Our results reveal the strong site fidelity of individuals to their foraging grounds (mean male foraging home range: 89.3 ± 20.2 km2, mean female foraging home range: 336 ± 284.7 km2, mean juvenile foraging home range: 157.3 ± 71.2 km2) and to the females' inter-nesting areas (mean home range: 284.2 ± 523.7 km2). A spatial foraging overlap occurred between juveniles and males as they shared 41% of their 95% kernel foraging habitat. The turtles performed mainly long and shallow dives within the first 20 m deep around Martinique Island, occupying shallow waters close to shore. The migratory routes of the adult females revealed regional connectivity between the Caribbean islands, crossing 31 exclusive economic zones and international waters, and featuring distinct foraging grounds. This finding reinforces the significance of a cooperative network at the Caribbean scale to ensure the efficient conservation of this critically endangered species.

Informing research priorities for immature sea turtles through expert elicitation

Although sea turtles have received substantial focus worldwide, research on the immature life stages is still relatively limited. The latter is of particular importance, given that a large proportion of sea turtle populations comprises immature individuals. We set out to identify knowledge gaps and identify the main barriers hindering research in this field. We analyzed the perceptions of sea turtle experts through an online survey which gathered their opinions on the current state of affairs on immature sea turtle research, including species and regions in need of further study, priority research questions, and barriers that have interfered with the advancement of research. Our gap analysis indicates that studies on immature leatherback Dermochelys coriacea and hawksbill Eretmochelys imbricata turtles are lacking, as are studies on all species based in the Indian, South Pacific, and South Atlantic Oceans. Experts also perceived that studies in population ecology, namely on survivorship and demography, and habitat use/behavior, are needed to advance the state of knowledge on immature sea turtles. Our survey findings indicate the need for more interdisciplinary research, collaborative efforts (e.g. data-sharing, joint field activities), and improved communication among researchers, funding bodies, stakeholders, and decision-makers.

Spatiotemporal preferences in nesting of the hawksbill turtle (Eretmochelys imbricata) in Melaka, Malaysia

Nesting of hawksbill turtles (Eretmochelys imbricata) was monitored in 2013 and 2014 at 20 nesting beaches along the shores of Melaka, Peninsular Malaysia. Total nest numbers found were 481 and 463 in 2013 and 2014, respectively. The mean clutch size in 2013 of 123.5 ± 32.3 (SD) was similar to that in 2014 (118.5 ± 39.7). The distributions of nests were not uniform among the 20 beaches, and a large number of nests were found in Padang Kemunting, Kem Terendak, and Pulau Upeh, where the beaches were not always long. The nest sites indicated that the hawksbill turtle preferred to build its nest within the woody vegetation zone. The preferred vegetation species was Scaevola taccada. The temporal nesting pattern was year-round in both years, but the peak nesting season was between May and August, in the south-west monsoon season, possibly due to the gentle winds during this period. The turtles tended to nest between 22:01 and 24:00 h. This study provides basic information about hawksbill turtle nesting and insights into their spatial and temporal nesting preferences, which will contribute towards the conservation of this endangered species.

Histopathological findings in lungs of hawksbill turtles collected on the coasts of the states of Espírito Santo and Rio de Janeiro, Brazil

ABSTRACT The present work aimed to report the histopathological findings verified in lungs of hawksbill turtles (Eretmochelys imbricata) retrieved from the coasts of the states of Espírito Santo and Rio de Janeiro, Brazil. Between the years 2010 and 2014, 29 E. imbricata individuals were found stranded on the coasts, already dead or dying during treatment. Lung samples of all specimens were collected during necropsies, fixed in 10% neutral buffered formalin, subjected to routine histological processing and classified histomorphologically. The findings revealed that 37.93% of the specimens presented lung lesions. Of these, 90.91% were rescued alive and 9.09% were found dead; 63.63% were females and 36.37% were males. The mean weight was 5.44 Kg and the mean length 39 cm, characterizing young individuals. The animals originated from São Francisco de Itabapoana - RJ, Aracruz - ES, São Mateus - ES, Guarapari - ES, Linhares - ES, Itapemirim - ES, and Anchieta - ES. Macroscopic analysis revealed presence of foam, hyperemia, nodules in the parenchyma, cyst and caseous material. Microscopic examination evidenced heterophilic bronchopneumonia, parasitic granulomatous pneumonia caused by spirorchiids, bacterial granulomatous pneumonia, fungal granulomatous pneumonia, and congestion. It was concluded that juvenile specimens of Eretmochelys imbricata, females and males, originated from the states of Espírito Santo and Rio de Janeiro and found stranded both alive or dead, have significant lung lesions, mainly inflammatory ones, associated or not with infectious agents.