Sea Turtles Research Articles

Inter-island nesting dynamics and clutch survival of green turtles Chelonia mydas within a marine protected area in the Bijagós Archipelago, West Africa

Understanding spatial heterogeneity in reproductive success among at-risk populations facing localised threats is key for conservation. Sea turtle populations often concentrate at one nesting site, diverting conservation efforts from adjacent smaller rookeries. Poilão Island, Bijagós Archipelago, Guinea-Bissau, is a notable rookery for green turtles Chelonia mydas within the João Vieira-Poilão Marine National Park, surrounded by three islands (Cavalos, Meio and João Vieira), with lower nesting activity. Poilão’s nesting suitability may decrease due to turtle population growth and sea level rise, exacerbating already high nest density. As the potential usage of secondary sites may arise, we assessed green turtle clutch survival and related threats in Poilão and its neighbouring islands. High nest density on Poilão leads to high clutch destruction by later turtles, resulting in surplus eggs on the beach surface and consequently low clutch predation (4.0%, n = 69, 2000). Here, the overall mean hatching success estimated was 67.9 ± 36.7% (n = 631, 2015–2022), contrasting with a significantly lower value on Meio in 2019 (11.9 ± 23.6%, n = 21), where clutch predation was high (83.7%, n = 98). Moderate to high clutch predation was also observed on Cavalos (36.0%, n = 64) and João Vieira (76.0%, n = 175). Cavalos and Meio likely face higher clutch flooding compared to Poilão. These findings, alongside observations of turtle exchanges between islands, may suggest a source-sink dynamic, where low reproductive output sink habitats (neighbouring islands) are utilized by migrants from Poilão (source), which currently offers the best conditions for clutch survival.

USE OF VISCOELASTIC COAGULATION TESTING IN MEGACHIROPTERA (PTEROPUS HYPOMELANUS AND PTEROPUS VAMPYRUS) REVEALS HIGH VARIABILITY IN CLOT KINETICS.

Megachiroptera is a mammalian suborder that includes old world fruit bats. Common clinical problems among captive Megachiroptera, such as liver disease (e.g., iron storage disease), kidney disease (e.g., protein-losing nephropathy), and heart disease (e.g., dilated cardiomyopathy), carry elevated risk for hemostatic derangements. The assessment of viscoelastic coagulation assays, however, has not yet been reported in bats. The main objective of the study was to describe viscoelastography data using the Viscoelastic Coagulation Monitor (VCM) Vet in captive large flying foxes (Pteropus vampyrus) (n = 20) and variable flying foxes (Pteropus hypomelanus) (n = 10). Additional objectives were to compare viscoelastic and clotting parameters (1) between healthy P. vampyrus and P. hypomelanus bats and (2) between untreated bats and those treated with meloxicam or aspirin, and (3) to examine relationships between activated partial thromboplastin time (aPTT) and potentially homologous viscoelastic parameters clotting time (CT) and clot formation time (CFT). The results showed marked variability among clinically normal bats. The intrinsic pathway, as measured by aPTT, had prolonged times compared with most terrestrial mammals, but similar times to birds, marine mammals, and sea turtles. A search of P. vampyrus genome found stop codons present in two exons of the factor XI gene; alterations in factor XI expression would be expected to alter intrinsic coagulation. Because of the high variability, no statistically significant findings were noted in the secondary objectives. Correlation between aPTT and CT or CFT was not strong (rs = 0.406 or 0.192, respectively). The results from this study suggest that clot kinetics vary widely among Megachiroptera when using the VCM Vet with untreated blood. A prolonged intrinsic coagulation pathway, as has been found in other megachiropteran species, and activation of the extrinsic coagulation pathway during venipuncture may be responsible for the inconsistent results.

Predictive modelling reveals Australian continental risk hotspots for marine debris interactions with key threatened species.

Anthropogenic debris is a global threat that impacts threatened species through various lethal and sub-lethal consequences, as well as overall ecosystem health. This study used a database of over 24,000 beach surveys of marine debris collated by the Australian Marine Debris Initiative from 2012 to 2021, with two key objectives: (1) identify variables that most influence the occurrence of debris hotspots on a continental scale and (2) use these findings to identify likely hotspots of interaction between threatened species and marine debris. The number of particles found in each beach survey was modelled alongside fifteen biological, social, and physical spatial variables including land use, physical oceanography, population, rainfall, distance to waste facilities, ports, and mangroves to identify the significant drivers of debris deposition. The model of best fit for predicting debris particle abundance was calculated using a generalized additive model. Overall, debris was more abundant at sites near catchments with high annual rainfall (mm), intensive land use (km2), and that were nearer to ports (km) and mangroves (km). These results support previous studies which state that mangroves are a significant sink for marine debris, and that large ports and urbanized catchments are significant sources for marine debris. We illustrate the applicability of these models by quantifying significant overlap between debris hotspots and the distributions for four internationally listed threatened species that exhibit debris interactions; green turtle (26,868 km2), dugong (16,164 km2), Australian sea lion (2903 km2) and Flesh-footed Shearwater (2413 km2). This equates to less than 1% (Flesh-footed Shearwater, Australian sea lion), over 2% (green sea turtle) and over 5% (dugong) of their habitat being identified as areas of high risk for marine debris interactions. The results of this study hold practical value, informing decision-making processes, managing debris pollution at continental scales, as well as identifying gaps in species monitoring.

Beyond Lab Walls: Strategies for Empowering Postgraduates to Create Positive Social Change through Sea Turtle Conservation

Beyond Lab Walls: Strategies for Empowering Postgraduates to Create Positive Social Change through Sea Turtle Conservation

Detection of Shoreline Changes With Automated Water Extraction Index (AWEI) In Galur District, Kulon Progo Regency

Abstract Monitoring shoreline change is one of the efforts in the management and protection of the coastal environment. Through digital image processing as the utilization of shoreline extraction index can be used as a reference in measuring the rate of shoreline change. Galur District is one of the sub-districts in Kulon Progo Regency that experiences the highest abrasion process, the worst abrasion that has occurred in recent years is located at Trisik Beach where abrasion threatens the existence of stalls, turtle conservation sites and also coastal vegetation that grows along the beach. The purpose of this study is to determine changes in the coastline starting in 2013, 2018, and 2023 and also to analyze numerically through DSAS the rate of change in the coastline both the influence of abrasion and accretion processes in Galur District. The method used in this research is Quantitative Descriptive assisted by Landsat 8 image transformation using Automated Water Extraction Index (AWEI) and measuring the rate of shoreline change using DSAS based on EPR and NSM values. The results of this study show that Banaran Village has the highest shoreline retreat changes where in 2013 - 2018 the shoreline retreat reached 70 meters and in 2018 - 2023 the coastal retreat reached -75.7 meters, while for the rate of change in Karang Sewu Village in 2013 - 2018 the shoreline retreat reached -33.2 meters and in 2018 - 2023 showed the highest abrasion of -33.5 meters.

Impacts of pelagic longline fisheries on sea turtles in the Santos Basin, Brazil

Strand monitoring is valuable for identifying human-caused threats to sea turtles but has limitations in fully understanding their overall impact. To address this gap, we conducted a survey to examine sea turtle interactions with longline fisheries, focusing on the types of hooks used for different target fish species. The study aimed to determine the prevalence of sea turtles entangled with hooks in these fisheries and to investigate seasonal and spatial variations in strandings. From August 2015 to December 2020, regular surveys were carried out along 2,013 km, on the South and Southeast coasts of Brazil to monitor sea turtle strandings. Data were collected on the presence and types of hooks, as well as the developmental stages of the affected turtles. The study analyzed spatial and seasonal variations and conducted necropsies to determine causes of death and assess internal damage from fishing gear. A total of 4,631 stranded sea turtles were documented: Caretta caretta, n=3,678, w/hooks=96; Lepidochelys olivacea, n=753, w/hooks=20, and Dermochelys coriacea, n=200, w/hooks= 01. Four types of hooks were identified, with a predominance of “J” hooks typically used in the region to capture dolphinfish, Coryphaena hippurus (72/122 hooks). The most affected developmental stages were large juveniles of C. caretta and L. olivacea. The distribution of hooks differed among the states; “J” hooks targeting C. hippurus on the continental shelf were predominantly found in São Paulo state. In contrast, circular hooks for swordfish (Xiphias gladius) and tuna hooks for tuna (Thunnus spp.), used in offshore fisheries, were more common in southern states. The abundance of “J”, hooks increased during the spring months, aligning with the C. hippurus fishing season. “J” hooks were primarily found in the esophagus of stranded turtles (88/122), indicating that their size and shape facilitate ingestion. Necropsies revealed that 43.1% of deaths (50/116) were due to intestinal lesions caused by hooks, fishing lines, and/or cables. Despite the small relative frequency of individuals found with hooks (117/4631), pelagic longline fisheries, especially those targeting C. hippurus, are a serious threat to sea turtle populations and, therefore, require specific monitoring and mitigating measures. Furthermore, the number of affected individuals may be underestimated since stranding does not represent total mortality at sea.

Sharing Session Pengelolaan Biota Laut Dalam Rangka Penyelamatan Penyu Di Daerah Pesisir Pantai Lowita Di Desa Wiring Tasi Kecamatan Suppa Kabupaten Pinrang

This community service activity takes the form of a sharing session with the aim of finding a model for managing marine biota in the context of saving sea turtles. This activity was carried out at Lowita Beach in Wiring Tasi Village, Suppa District, Pinrang Regency and was attended by the community, turtle conservation observers as well as academics. The implementation time is November 4-5 2023. Based on the results of the activities that have been described, the conclusions from community service activities, socialization of the development of the ecotourism concept in improving community welfare are as follows: providing positive benefits for the community, educating, and sharing knowledge for mutual progress. . The target of this activity is for coastal communities to support economic growth by preserving the environment, with the hope that ecotourism can increase tourist visits in the area which can contribute to improving the welfare of the community. MSMEs can grow and develop, contribute more to the community, and create new jobs.

Deep vs shallow: GPS tags reveal a dichotomy in movement patterns of loggerhead turtles foraging in a coastal bay

BackgroundIndividual variation in movement strategies of foraging loggerhead turtles have been documented on the scale of tens to hundreds of kilometers within single ocean basins. Use of different strategies among individuals may reflect variations in resources, predation pressure or competition. It is less common for individual turtles to use different foraging strategies on the scale of kilometers within a single coastal bay. We used GPS tags capable of back-filling fine-scale locations to document movement patterns of loggerhead turtles in a coastal bay in Northwest Florida, U.S.A.MethodsIridium-linked GPS tags were deployed on loggerhead turtles at a neritic foraging site in Northwest Florida. After filtering telemetry data, point locations were transformed to movement lines and then merged with the original point file to define travel paths and assess travel speed. Home ranges were determined using kernel density function. Diurnal behavioral shifts were examined by examining turtle movements compared to solar time.ResultsOf the 11 turtles tagged, three tracked turtles remained in deep (~ 6 m) water for almost the entire tracking period, while all other turtles undertook movements from deep water locations, located along edges and channels, to shallow (~ 1–2 m) shoals at regular intervals and primarily at night. Three individuals made short-term movements into the Gulf of Mexico when water temperatures dropped, and movement speeds in the Gulf were greater than those in the bay. Turtles exhibited a novel behavior we termed drifting.ConclusionsThis study highlighted the value provided to fine-scale movement studies for species such as sea turtles that surface infrequently by the ability of these GPS tags to store and re-upload data. Future use of these tags at other loggerhead foraging sites, and concurrent with diving and foraging data, would provide a powerful tool to better understand fine-scale movement patterns of sea turtles.

Loggerhead Sea Turtles as Hosts of Diverse Bacterial and Fungal Communities

Research on microbial communities associated with wild animals provides a valuable reservoir of knowledge that could be used for enhancing their rehabilitation and conservation. The loggerhead sea turtle (Caretta caretta) is a globally distributed species with its Mediterranean population categorized as least concern according to the IUCN Red List of Threatened Species as a result of robust conservation efforts. In our study, we aimed to further understand their biology in relation to their associated microorganisms. We investigated epi- and endozoic bacterial and endozoic fungal communities of cloaca, oral mucosa, carapace biofilm. Samples obtained from 18 juvenile, subadult, and adult turtles as well as 8 respective enclosures, over a 3-year period, were analysed by amplicon sequencing of 16S rRNA gene and ITS2 region of nuclear ribosomal gene. Our results reveal a trend of decreasing diversity of distal gut bacterial communities with the age of turtles. Notably, Tenacibaculum species show higher relative abundance in juveniles than in adults. Differential abundances of taxa identified as Tenacibaculum, Moraxellaceae, Cardiobacteriaceae, and Campylobacter were observed in both cloacal and oral samples in addition to having distinct microbial compositions with Halioglobus taxa present only in oral samples. Fungal communities in loggerheads’ cloaca were diverse and varied significantly among individuals, differing from those of tank water. Our findings expand the known microbial diversity repertoire of loggerhead turtles, highlighting interesting taxa specific to individual body sites. This study provides a comprehensive view of the loggerhead sea turtle bacterial microbiota and marks the first report of distal gut fungal communities that contributes to establishing a baseline understanding of loggerhead sea turtle holobiont.

Long‐term (29‐year) spatiotemporal patterns of sea turtle deaths in the southern Gulf of Mexico

Abstract Sea turtles are key imperilled species that interact with numerous threats in their critical in‐water and inland habitats, which they occupy along their complex life cycle. Therefore, analysing these interactions is essential for adapting ongoing conservation and management actions. The long‐term recording of stranded sea turtle individuals and the potential causes of death in their breeding habitats is crucial for defining and adapting conservation actions. Twenty‐nine years of sea turtle stranding and mortality data (1992–2019) at nesting beaches in Campeche, Mexico, were analysed to describe their spatiotemporal patterns per species and possible causes of death. The most impacted species was the hawksbill turtle, followed by green and Kemp's ridley individuals. The most frequent probable causes of death in this region were bycatch, seismic surveys, vehicle strikes and slaughter at nesting beaches. Both immature and breeding individuals were stranded, mostly the former, and the most frequent months were in the summer (June–August). This study establishes a historic reference baseline for the spatiotemporal mortality patterns of imperilled sea turtle species in the southeastern Gulf of Mexico. It shows their interactions with anthropogenic activities and the circumstances jeopardizing their population recovery. It also points out management and conservation actions to implement to improve their long‐term viability in the context of the operationalization of their key attributes and interactions with their seascapes.

Enhancing Sea Turtle Conservation Efforts through Collaboration Approach: Case Study of ORI MA FALA Program, Ternate

Enhancing Sea Turtle Conservation Efforts through Collaboration Approach: Case Study of ORI MA FALA Program, Ternate

Ethnobiological methods enhance our capacity to document potential climate sentinels: a loggerhead sea turtle (Caretta caretta) case study

The accelerated pace of climate-driven shifts is surpassing the temporal scope of conventional field research, potentially leading to a disconnect between ecosystem changes and scientific data collection. Climate change is producing rapid transformations within dynamic marine ecosystems, with a pronounced effect on high trophic-level species such as loggerhead sea turtles (Caretta caretta). We present a new model for data collection using ethnobiological methods, emphasizing how local community members can contribute to expanding scientific knowledge via context-informed observations, to document species occurrences beyond their anticipated habitats during climatic anomalies. In rapidly changing conditions, local expert knowledge can complement conventional scientific methods, providing high-quality data with extensive coverage—especially for elusive species—and yielding insight into potential emerging phenomena that may otherwise go unnoticed. Conventional methods for predicting distribution shifts in rare species are vulnerable to spatial biases, favoring predictions based on the most probable habitats. We present the case study of a live sea turtle sighting by a local expert in Monterey Bay, California, USA, identified post hoc as a loggerhead, to illustrate methods which can be transferred and applied to other rare and highly migratory marine species such as marine mammals, sharks, and seabirds. This emerging framework incorporates diverse knowledge sources and methodologies in monitoring climate-driven ecological shifts, enriching conservation strategies, enhancing our understanding of complex ecosystems, and contributing to robust evidentiary standards for rare species observations.

Husbandry Techniques of Lepidochlys olivacea at Raksa Bintana Sea Turtle Conservation, Indonesia

Currently, the threat to sea turtle conservation is still quite high both by natural and anthropogenic (human) factors. Therefore, we try to make efforts in sea turtle conservation, through transferring sea turtle eggs to a semi-natural nest. Subsequently, the rearing of hatchlings that successfully hatched from semi-natural nests. Based on these factors, it is important for us to know how to preserve Lepidochlys olivacea and to analyze the physical and chemical parameters of hatchling rearing. The method of rearing the sea turtles after hatching at the research site has 3 stages, namely moving the newly hatched baby turtles from semi-natural nests to the rearing tanks, 30-day rearing actions in the holding tanks (feeding, changing water, and checking water quality) and releasing the sea turtles to their natural environment, namely the open sea. From the data that has been taken for 30 days, the average temperature results were found to be 26-28oC, for salinity data of 22-25 ppm and for DO data of 7.7-7.9. The measured DO data is still under the range of PP 22 of 2021 Appendix VIII concerning the Implementation of Environmental Protection and Management.

TURTLE CONSERVATION AND EDUCATION CENTER (TCEC) AS A DIGITAL PROMOTION STRATEGY TO INCREASING THE NUMBER OF TOURIST VISITS AND SUSTAINABILITY

Promotional strategies play a pivotal role in enhancing the attractiveness of tourist destinations. This research endeavors to explore the promotional tactics utilized by the Turtle Conservation And Education Center (TCEC) to amplify tourist footfall, scrutinize its marketing blend, and evaluate the repercussions of these promotional endeavors. Employing three methodologies for data collection, namely interviews, observations, and documentation, the study conducts qualitative data analysis using descriptive approaches. The results will elucidate the promotional maneuvers implemented to augment tourist visits via the Marketing Mix (7Ps) adopted by TCEC. These maneuvers encompass social media engagement, partnerships with travel agencies, development of tailored tour packages, participation in tourism expos, and educational ventures. These endeavors aspire to widen the visibility of TCEC among tourists. The impact of these promotional campaigns is manifested in the surge of annual tourist arrivals. In 2019, around 41,563 visitors were recorded, a figure that substantially dwindled to 5,795 in 2020 due to the adverse repercussions of the Covid-19 pandemic on Bali's tourism, particularly at TCEC. Nonetheless, there was a marginal upturn to 7,187 tourist visits in 2021, escalating further to 10,872 by 2022. This notable upsurge underscores the efficacy of TCEC's marketing team in their promotional endeavors, accentuating the center's conservation initiatives, amenities, and available activities. TCEC remains proactive in its promotional stratagems, persistently disseminating information to visitors regarding its conservation initiatives and offerings.

TURTLE CONSERVATION AND EDUCATION CENTER (TCEC) AS A DIGITAL PROMOTION STRATEGY TO INCREASING THE NUMBER OF TOURIST VISITS AND SUSTAINABILITY

Promotional strategies play a pivotal role in enhancing the attractiveness of tourist destinations. This research endeavors to explore the promotional tactics utilized by the Turtle Conservation And Education Center (TCEC) to amplify tourist footfall, scrutinize its marketing blend, and evaluate the repercussions of these promotional endeavors. Employing three methodologies for data collection, namely interviews, observations, and documentation, the study conducts qualitative data analysis using descriptive approaches. The results will elucidate the promotional maneuvers implemented to augment tourist visits via the Marketing Mix (7Ps) adopted by TCEC. These maneuvers encompass social media engagement, partnerships with travel agencies, development of tailored tour packages, participation in tourism expos, and educational ventures. These endeavors aspire to widen the visibility of TCEC among tourists. The impact of these promotional campaigns is manifested in the surge of annual tourist arrivals. In 2019, around 41,563 visitors were recorded, a figure that substantially dwindled to 5,795 in 2020 due to the adverse repercussions of the Covid-19 pandemic on Bali's tourism, particularly at TCEC. Nonetheless, there was a marginal upturn to 7,187 tourist visits in 2021, escalating further to 10,872 by 2022. This notable upsurge underscores the efficacy of TCEC's marketing team in their promotional endeavors, accentuating the center's conservation initiatives, amenities, and available activities. TCEC remains proactive in its promotional stratagems, persistently disseminating information to visitors regarding its conservation initiatives and offerings.

Status and impacts to sea turtles in Vietnam

Sea turtles face a great danger of extinction because of human impacts, and the number of turtle occurrence is decreasing. By interviewing fishermen, coastal residents and authorities combined with field surveys in some places where turtles regularly lay eggs, such as Con Dao and Ninh Thuan, the results show that 05 species of sea turtles were found in Vietnam: The Green (Chelonia mydas), Hawksbill (Eretmochelys imbricata), Olive Ridley (Lepidochelys olivacea), Loggerhead (Caretta caretta) and Leatherback (Dermochelys coriacea). Among them, Green turtles are the most abundant and distributed in all surveyed localities; Hawksbill and Olive Ridley were smaller in number; and Loggerhead and Leatherback were the two species with the least number. Only 03 species remaining to breed on the beaches: Green, Olive Ridley, and Leatherback. The Hawksbill turtles used to lay eggs in the past but have been no longer recorded. Con Dao is a home for the largest number of breeding Green turtles. The reasons for the decline of turtles in Vietnam were the collection of eggs and nesting turtles, fisheries bycatch, development of coastal infrastructure and waste pollution, habitat degradation, and illegal trade in sea turtle products.

Simulating drifting fish aggregating device trajectories to identify potential interactions with endangered sea turtles.

Purse-seine fishers using drifting fish aggregating devices (dFADs), mainly built with bamboo, plastic buoys, and plastic netting, to aggregate and catch tropical tuna, deploy 46,000-65,000 dFADs per year in the Pacific Ocean. Some of the major concerns associated with this widespread fishing device are potential entanglement of sea turtles and other marine fauna in dFAD netting; marine debris and pollution; and potential ecological damage via stranding on coral reefs, beaches, and other essential habitats for marine fauna. To assess and quantify the potential connectivity (number of dFADs deployed in an area and arriving in another area) between dFAD deployment areas and important oceanic or coastal habitat of critically endangered leatherback (Dermochelys coriacea) and hawksbill (Eretmochelys imbricata) sea turtles in the Pacific Ocean, we conducted passive-drift Lagrangian experiments with simulated dFAD drift profiles and compared them with known important sea turtle areas. Up to 60% of dFADs from equatorial areas were arriving in essential sea turtle habitats. Connectivity was less when only areas where dFADs are currently deployed were used. Our simulations identified potential regions of dFAD interactions with migration and feeding habitats of the east Pacific leatherback turtle in the tropical southeastern Pacific Ocean; coastal habitats of leatherback and hawksbill in the western Pacific (e.g., archipelagic zones of Indonesia, Papua New Guinea, and Solomon Islands); and foraging habitat of leatherback in a large equatorial area south of Hawaii. Additional research is needed to estimate entanglements of sea turtles with dFADs at sea and to quantify the likely changes in connectivity and distribution of dFADs under new management measures, such as use of alternative nonentangling dFAD designs that biodegrade, or changes in deployment strategies, such as shifting locations.

Mixed stock analysis identifies natal origins of green turtles at foraging grounds in southeastern Australia

IntroductionIdentifying critical habitats for marine turtles and connectivity between genetic stocks and the foraging grounds they use is a conservation priority worldwide. Green turtles (Chelonia mydas) are impacted by a wide range of anthropogenic threats that can vary by geographic region and the ontogenetic stage of the individual. In Australia, the strengthening of the East Australian Current due to climate change is increasing ocean temperatures, particularly in southern New South Wales (NSW), which is having large-scale impacts on the distribution and abundance of marine resources. Green turtles are frequently observed in temperate southern NSW waters, but our knowledge of their habitat use, migration patterns and the impact of threatening processes is limited.MethodsTo assess the origins of green turtles from foraging grounds in southeastern Australia, samples were obtained from green turtles of all size classes (post-hatchlings to adults) that had stranded along an ~870 km expanse of the NSW coast and Lord Howe Island between 1997 and 2021. Mitochondrial DNA control region sequences for 283 individuals were compared to 25 potential source genetic stocks in the Indo-Pacific using mixed-stock analysis.ResultsA total of 26 haplotypes were identified in NSW, of which 14 had been previously observed at a rookery, eight had been identified previously, but not at a rookery (i.e. orphan haplotypes), and four were previously undescribed. Mixed-stock analysis revealed that NSW waters support multiple genetic stocks but are dominated by those of the southern Great Barrier Reef and New Caledonia genetic stocks. A small proportion of green turtles originated from more distant stocks in the Indo-Pacific region.DiscussionUnderstanding the connectivity between green turtle rookeries and foraging grounds provides an opportunity to assess the impact of anthropogenic threats to turtle stocks, and in turn, prioritize management actions for the conservation of green turtles across regional, national and international jurisdictions.

Nesting crawls and associated behaviors of turtles in the genus <i>Batagur</i> along the Chambal River, India

The pattern of nesting crawls and related behaviors can play a very important role in the survival of the eggs aswell as the emerging hatchlings. Studies on marine turtles suggest that nest location can increase exposure to predation,cause thermal stress and dehydration, and consume valuable stored energy in emerged hatchlings, all of which decreasethe likelihood of survival. Red-crowned Roofed Turtles (Batagur kachuga) and Three-striped Roofed Turtles (Batagurdhongoka) are listed as critically endangered on the IUCN Red List. We surveyed a 30-km stretch of sandbank along theChambal River during Batagur nesting seasons in February to early April 2017–2019 and encountered a total of 640nests along eight sand banks. Nesting crawls of B. dhongoka from the water’s edge to successful nesting sites were significantlylonger than those of B. kachuga. We observed only one type of nesting crawl pattern for B. kachuga, whereas fourtypes of such crawls were recorded for B. dhongoka. Moreover, nest shapes differed significantly between the two species.

Marine Turtle Identification, Sightings, and Nesting Area Mapping in Batanes Province, the Philippines

The Batanes archipelago – a province designated by the Philippine government as a protected area – possesses abundant marine resources and diverse ecosystems that serve as optimal habitats for marine turtles to forage, reproduce, and nest. Ivatans, the native inhabitants of Batanes who are also indigenous peoples, possess knowledge of the existence of marine turtles in their coastal waters; however, published reports are still unavailable. This study provides significant data on species identification, observations, and the distribution of nesting areas across the province. This study presents novel findings, revealing that green sea turtles Chelonia mydas and hawksbill turtle Eretmochelys imbricata thrive in the coastal waters of Batanes. A household survey using a semi-structured questionnaire (n = 90), 48 key informant interviews, and site monitoring were utilized as data collection methods and examined using descriptive data analysis. We randomly selected respondents from the household surveys from each municipality and pre-identified key informants based on their roles in each municipality (e.g. government officials, fisherfolk leaders). Likewise, 45% of the respondents claimed that they usually encounter marine turtles a few times a week, specifically during their fishing operations. The mapped nesting sites showed a wide range across the province; three were already established by the Provincial Environment and Natural Resources Office. The data gathered, and findings of this study serve as a basis for local resource managers – particularly in implementing initiatives for sustainable management, conservation, and protection of marine turtle biodiversity in Batanes. Before developing conservation and management strategies, involving the community in decision-making is crucial to address potential concerns – significantly when a specific ethnic group such as the Ivatans on Batanes Island – is affected.