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- Foraging ecology of the critically endangered hawksbill sea turtle in the Gulf of GuineaPublication . Vieira, Sara; Ferreira-Airaud, Betânia; Baptista, Vânia; Tiwari, Manjula; Castilho, Rita; Teodosio, MariaUnderstanding the ecological roles of critically endangered species is essential for effective conservation planning. This study investigates the foraging ecology and nutritional condition of the hawksbill sea turtle (Eretmochelys imbricata) in São Tomé Island, a key foraging ground in the Gulf of Guinea. We integrated stable isotope analyses of epidermal tissues with RNA/DNA ratios to assess habitat use, trophic position, and physiological status across life stages. Thirty hawksbill turtles (juveniles and adults) were sampled during in-water surveys conducted between 2021 and 2022 using minimally invasive techniques. Prey samples were also collected for isotopic baselines. Carbon (δ13C) and nitrogen (δ15N) values revealed significant ontogenetic shifts, with adults occupying broader isotopic niches. While sponges remained the dominant food source at both stages, adults exhibited greater dietary diversity, including red algae and tunicates. Juveniles showed higher spatial and temporal fidelity, suggesting stronger residency patterns. Estimated trophic positions ranged from 2.57 to 2.79, consistent with secondary consumers. RNA/DNA ratios indicated higher metabolic activity in juveniles and males, while lower values in females likely reflect reproductive metabolic suppression. These findings represent the first integrative assessment of hawksbill turtle foraging and nutritional condition in the region. The study provides critical baseline data on one of the most genetically isolated and endangered hawksbill populations worldwide. This approach enhances understanding of their ecological function and supports the development of targeted conservation actions that account for life-stage–specific needs, contributing to adaptive management and long-term recovery of this critically endangered population.
- Microplastic distribution and risk assessment in soil environment across Asian regionsPublication . Rehman, Zia Ur; Song, Jing; Wang, Chunhui; Nunes, Luís; Kazmi, Syed Shabi Ul Hassan; Azeem, Muhammad; Fu, Linxuan; Zhang, Yu; Li, GangPlastic pollution has emerged as a growing global environmental problem in recent years. As a major region for plastic production and consumption, Asia is at the forefront of this challenge. Although multiple studies have focused on microplastic (MP) pollution in aquatic systems in the region, understanding of their distribution characteristics and ecological impacts in terrestrial ecosystems remains limited, particularly at an intercontinental scale. In addition, standardized ecological risk assessment methods and predictive frameworks for soil microplastics (MPs) remain lacking. This study investigated the spatiotemporal distribution of MP pollution in Asian countries, focusing on the differences between various regions in terms of quantity density, morphological characteristics (shape, size, and color), and land-use types. By integrating data from 128 studies published between 2018 and 2025, totaling 3370 sampling points, a comprehensive database was constructed to reveal the MP distribution patterns and potential risks. The analysis found significant spatial heterogeneity in Asian regions, with higher concentrations found in South Eastern Asia (8227.55 items/kg), Eastern Asia (3122.73 items/kg), and Southern Asia (2407.07 items/kg). The highest quantity densities of MPs were found in industrial and urban soils (4995.2 and 4359.6 items/kg), followed by agricultural soils (2812.8 items/kg), shedding light on the influence of intensive human activities and plastic inputs. In terms of morphological characteristics, fragments, fibers, and films shaped MPs predominated in most soils, with white, transparent, and black particles being the most common. Moreover, the analysis suggested possible vertical migration and gradual accumulation of MPs within soil profiles. Based on spatial distribution and morphological characteristics, this study evaluated the ecological risk using pollution load index and potential ecological risk index suggesting that certain regions may exhibit comparatively higher reported risk levels under the present assessment framework, particularly in Viet Nam, Indonesia, India, Iran, Bangladesh, and China, based on the currently available dataset. Lastly, machine learning models were applied for preliminary classification of soil MP ecological risk levels, with the random forest model showing the highest accuracy (99.5%), followed by GBDT (98.6%) and KNN (88.4%). This study provides spatial evidence for risk-oriented and predictive assessment of soil MP pollution across Asia and offers data support for future management and policy interventions.