Plastisphere characterization and ecological implications of plastic pollution in Northeast Tiger and Leopard...

The plastisphere, as a microbial niche on plastics, exacerbates ecological risks to biodiversity in critical habitats like the Northeast Tiger and Leopard National Park, a sanctuary for endangered Amur tigers (Panthera tigris altaica) and leopards (Panthera pardus orientalis). However, existing research has paid limited attention to the characteristics of the plastisphere within protected areas and its potential threats. Focusing on water sources frequently utilized by sika deer (Cervus nippon), a keystone prey species, this study characterizes plastisphere bacterial across plastic types (PET, PP, PE) and uses (pesticide bags, plastic bags, fishing nets) via 16S rRNA sequencing. Results revealed: (1) Plastisphere bacterial diversity significantly exceeds surrounding water, driven by stochastic assembly; (2) Functional taxa mediating carbon/nitrogen cycling (e.g. Leptolyngbya, Novosphingobium, Methylobacterium) are enriched on plastics, surpassing water/soil abundances; (3) The bacterial communities on PET and pesticide bags exhibited significantly greater enrichment in functional pathways associated with pathogens and antibiotic resistance genes (ARGs), indicating a higher ecological risk; (4) Source tracking identifies plastisphere and soil as the dominant contributors to sika deer gut microbiota, indicating direct microbial exchange. These interactions elevate infection risks for sika deer and apex predators, threatening food chain integrity. Our findings highlight the urgent need to incorporate plastic pollution control into conservation strategies for endangered species, particularly in ecologically sensitive regions, which has significant implications for the future development and management of national park systems. This study provides novel scientific insights into plastisphere-driven ecological threats and advocates for sustainable habitat management to mitigate cascading impacts on biodiversity.