China is facing increasing marine microplastic pollution. Despite the fact that the South China Sea is the largest marine area in China, the ecological danger and present state of microplastic contamination in this region have not been systematically and comprehensively investigated. This study analyzed the abundance, distribution, and characteristics of microplastics in different environmental media and biological samples from the Xisha Islands in the South China Sea, and then the ecological risk assessment of microplastic pollution in this area was conducted. The findings indicated that the quantities of sediments, soil, water, fish, and birds were 41.56 ± 19.12 items/kg, 92.94 ± 111.05 items/kg, 2.89 ± 1.92 items/L, 2.57 ± 2.12 items/ind, and 1.702 ± 1.50 items/ind, respectively. By evaluating the pollution load index (PLI), polymer hazard index (PHI), and potential ecological risk index (PERI), the PLI of the Xisha Islands in the South China Sea as a whole indicated that the hazard level was slightly polluted, the PHI was at a high-risk level, and the PERI samples were at no risk, except for the soil and seawater, which were at a medium-risk level.

Eld's deer (Rucervus eldii) is a rare and globally endangered tropical Southeast Asian deer species. There is no research on pathogens in Eld's deer in Hainan, China. This study aimed to understand the virus diversity and novel viruses in Eld's deer, and provided important epidemiological baseline information for conservation of this endangered species. 33 nasal swabs, 33 anal swabs, and 9 wound (bitten by ticks) swabs were collected from 33 wild Eld's deer in a nature reserve in Hainan, which constituted into 5 pools. Based on next-generation sequencing (NGS) and macrogenomic analysis, there were differences in the 5 pools of viral reads, while the overall viral reads were closely related to mammals. The novel papillomavirus (PsPV-HMU-1) and Circular Rep-encoding (replication-associated protein encoding) single-stranded DNA (CRESS DNA) virus (PsaCV-HMU-1) were identified in Eld's deer, with amino acid homology of the less than 77.20% of the L1 and less than 45.43% of the rep, respectively. PsPV-HMU-1 and PsaCV-HMU-1 are relatively independent on their phylogenetic trees, and with the overall prevalence of 24.24% (8/33) and 3.03% (1/33) in Eld's deer, respectively. Our results expanded the viral genomic information and host range, and implied that it is necessary for continued epidemiological surveillance in order to understand pathogenicity and the potential for cross-species transmission of viruses in wild Eld's deer.