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In this study, the accumulation rate of plastic litter was investigated by sampling quadrats placed on the North Island of Qilianyu, and the composition was analyzed and identified to determine its source. The results showed that the annual average accumulation rate of plastic litter on North Island was 0.64 ± 0.32 pieces·m -2 ·month -1 , with a mass accumulation rate of 11.30 ± 7.73 g·m -2 ·month -1 . The accumulation rate of plastic litter was mainly influenced by wind speed and direction, with higher accumulation rates occurring during the southwest monsoon season and tropical cyclones. ATR-FTIR analysis indicated that polyethylene (44 %) and polypropylene (41 %) were the most abundant types of polymers. This study reveals the current status of plastic litter pollution in green turtle nesting grounds on North Island in Qilianyu, which can be used as a reference for management strategies that mitigate plastic litter pollution., Competing Interests: Declaration of competing interest The authors declare no conflicts of interests., (Copyright © 2024. Published by Elsevier Ltd.)

Trace element pollution is a potential threat to the reproduction of sea turtles. Hainan Island was previously the most important nesting ground of green sea turtles in China before they disappeared approximately 36 years ago. The Chinese government has encouraged restoration work on historical nesting grounds, and it is necessary to evaluate the status of these sites before conducting habitat restoration. This study analyzed the concentrations of seven trace elements in the surface sediments of 13 historical nesting grounds in Hainan. The average concentrations were 19.47 (Cr), 4.67 (Ni), 6.99 (Cu), 0.08 (Cd), 16.68 (Pb), 0.02 (Hg), and 5.27 (As) mg/kg, which were lower than the first-grade limit values of the GB (18668-2002) national standard in China. The concentrations were close to the background value, except for the relatively high Cd value. The potential ecological risk was ranked as Cd > Hg > As > Cu > Pb > Cr. The spatial distribution of trace element contamination in Hainan was uneven, with high potential ecological risk levels of Cd and Hg contamination in Longwan'gang, Shimeiwan, Yazhou Qu, and Fushicun. Marine mariculture, wastewater discharge, and fishing boats are the main sources of trace element contamination in Hainan. We recommend strengthening the control of Hg and Cd contamination sources, monitoring trace elements in relevant/interest areas, and the environmental protection department should curb local residents from directly discharging mariculture wastewater and domestic sewage into the sea., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Chemical pollutants present a substantial threat to the survival of the green turtle (Chelonia mydas). In this study, the concentrations of 12 trace elements (TEs) in seawater, sediments, and green turtle forage and eggshells from the Xisha Islands in the South China Sea, along with their patterns of transfer and accumulation, were identified. The results revealed that the median TE concentrations in seawater and sediments were lower than the first-grade limit values of the national standard in China, indicating a low ecological risk. The concentrations (μg·g -1 ) of TEs in forage ranged from 0.05-0.69, 3.43-14.4, 157-2391, 27.9-124, 2.05-9.39, 0.30-9.78, 2.01-80.50, 0.18-5.76, 0.06-0.98, 2.00-18.4, 0.02-0.24, and 0.01-0.09 for Cr, Mn, Sr, Fe, Ni, Cu, Zn, Se, Cd, As, Pb, and Hg, respectively. Seawater, sediments, turtle forage, and eggshells exhibited different TE profiles, which were driven by Hg, Sr, Cr, and Pb in seawater and sediments; Fe and Ni in sediments; Cd and As in forage; and Zn, Se, and Cu in eggshells. The contents of Cu, Zn, and Se increased slightly with trophic level, indicating that they were transferred through dietary pathways. Although Cd and As appeared to bioaccumulate in green turtle forage, it was not transferred to their eggshells, which may be related to the excretion and metabolism process in the mother's body. Thus, eggshells may be a poor bioindicator for the exposure of female green turtles to these toxic elements., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Microplastics, new persistent pollutants, have recently attracted considerable attention. When present in beach sediments, microplastics may adversely affect the nesting and hatching of sea turtles on beaches. In this study, we investigate microplastic pollution at Qilianyu (northeastern Xisha Islands), the largest known nesting ground for green sea turtles ( Chelonia mydas ) in China. We found that the average abundance of microplastics in the beach surface sediments was 338.44 ± 315.69 thousand pieces·m -3 or 1,353.78 ± 853.68 pieces·m -2 , with foam and fragments as the main microplastic type identified. The microplastic particles were categorised as small and were predominantly within the 0.05-1 mm size category. Most microplastic particles were white (71.31%). Polystyrene and polyethylene were found to be the most common forms of plastic present. Microplastic pollution was not only observed on the beach surface but also at the bottom of nests approximately 60 cm may be harmful to the incubation of sea turtle eggs. We suggest removing plastic litter, especially small pieces of plastic, on beaches to reduce the threat of microplastic pollution to marine life, including sea turtles. Furthermore, the foam used in aquaculture should be recovered and replaced before it becomes fragmented due to age. In addition, regional cooperation between stakeholders in the South China Sea should be strengthened to collectively promote the reduction and cleanup of marine litter., Competing Interests: The authors declare that they have no competing interests., (© 2022 Zhang et al.)

In China, Hainan Island is a priority area for turtle conservation because of its biodiversity. Over the years, errors in turtle taxonomy and distribution have been made in the scientific literature, perpetuating into relevant laws and government documents and affecting conservation and management. In the present article, we describe the species of nonmarine turtles on Hainan Island, China, based on literature, museum specimens, and field surveys during the past 27 yrs. Historically, 23 nonmarine turtle species were recorded on Hainan Island. Among them, 9 species should be removed due to errors: 5 species are not naturally distributed on Hainan Island (Manouria impressa, Sacalia bealei, Cuora flavomarginata, Mauremys nigricans, and Mauremys reevesii), 3 are invalid hybrids (Ocadia philippeni, Sacalia pseudocellata, and Cuora serrata), and 1 is a synonym of another species (Mauremys megalocephala is a synonym of M. reevesii). In addition, of the 3 new species recorded from Hainan Island (Sacalia insulensis, Pelodiscus variegatus, and Pelodiscus parviformis), S. insulensis replaces Sacalia quadriocellata, P. variegatus is valid, and P. parviformis is likely an error. Therefore, there should be 12 nonmarine turtle species naturally found on Hainan Island: Platysternon megacephalum, Cuora galbinifrons, Cuora mouhotii, Cuora trifasciata, Geoemyda spengleri, Mauremys mutica, Mauremys sinensis, S. insulensis, Palea steindachneri, Pelochelys cantorii, Pelodiscus sinensis, and P. variegatus. Clarifying the presence and distribution of nonmarine turtle species will provide a reference for future research and practical guidance for conservation management on this turtle-rich island. [ABSTRACT FROM AUTHOR]

The herpetofauna of the Indomalayan bioregion of Asia suffers from severe habitat loss, unsustainable harvesting, and lack of research and conservation. Here, we investigated the range‐wide phylogeography of the endangered "eyed" turtles (genus Sacalia, including the Beale's Eyed Turtle S. bealei and the Four‐eyed Turtle S. quadriocellata) and discovered a natural interspecific hybrid turtle population in China. Based on phylogeny of the mitochondrial Cytochrome b gene of 101 samples in this study and public data, three major clades and six subclades were identified: S. bealei (SBE) in eastern‐southern China, east S. quadriocellata in South China (northern east [SQUen] and southern east [SQUes] subclades), and west S. quadriocellata mainly in Vietnam (northern west [SQUwn], central west [SQUwc], and southern west [SQUws] subclades). We sequenced 16 nuclear DNA loci of 87 samples from SBE, SQUen, SQUes, and SQUwn subclades. Population genetic clustering analysis suggested a structure similar to the mitochondrial phylogeny, where most samples were classified into four genetic clusters corresponding to the four mtDNA subclades. However, a proportion of samples carrying SQUen mtDNA haplotypes formed an additional distinct cluster SHY. Those samples are found in the contact zone of the two species bearing mosaic and intermediate morphological characteristics. We detected an admixed ancestry in SHY from SBE and SQUen that conformed to an intrapopulation breeding scenario for at least hundreds of generations after the initial hybrid event, leading to a conclusion that SHY is a distinct and near‐panmictic population derived from natural interspecific hybridization. In addition, SQUes (Hainan Island endemic) is of special concern due to significant isolation and low genetic diversity. We suggest that seven evolutionarily significant units should be recognized to facilitate appropriate conservation actions. These findings also highlight the urgent need for further herpetological research and conservation in this region. [ABSTRACT FROM AUTHOR]